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RELATED APPLICATIONS [0001] This application is a continuation of PCT Patent Application Serial No. PCT/CN2010/072399, filed May 3, 2010, which claims priority to Chinese Patent Application Serial No. 200910107196.3, filed May 1, 2009 and Chinese Patent Application Serial No. 200910107195.9, filed May 1, 2009, the disclosures of which are incorporated herein by reference. TECHNICAL FIELD [0002] The present application relates to a pressure reducing gas storage device, an air-jet system and a motor vehicle. BACKGROUND [0003] In order to avoid severe environmental pollution and directly utilize the wind resistance airflow encountered by a motor vehicle during while running, U.S. Pat. No. 7,641,005 B2 issued to the applicant of the present application provides an engine comprising left and right wind-powered pneumatic engines arranged symmetrically. Each of the left and right wind-powered pneumatic engines comprises an impeller chamber as well as impeller and vanes arranged therein. Compressed air is used in the engine as main power, and external wind resistance are received for use as auxiliary power, thereby driving the impellers and vanes to operate to generate power output. The power drives the motor vehicle after it is shifted via a central main power output gearbox. [0004] The above invention firstly proposed a wind-powered pneumatic engine which utilizes high pressure air as the main power and directly utilizes the wind resistance airflow as the auxiliary power, and a motor vehicle in which the need of converting wind resistance airflows into electrical power and the need of a complex mechanic-electric energy conversion system are eliminated, and the structure thereof is simplified. Therefore, a new way to save energy and find a substitute for fuel is provided. [0005] In order to further optimize the performance of the wind-powered pneumatic engine and improve the operating efficiency of the wind-powered pneumatic engine and the motor vehicle, based on the aforementioned application, another U.S. patent application Ser. No. 12/377,513 (WO 2008/022556) filed by the applicant provides a combined wind-powered pneumatic engine. This engine comprises left and right wind resistance engines operating independently and a plurality of first compressed air engines arranged around the left and right wind resistance engines. The left and right wind resistance engines comprise a second impeller and the first compressed air engines comprise a first impeller. The power outputted by the left wind resistance engines and its peripheral first compressed air engines, as well as the power outputted by the right wind resistance engine and its peripheral first compressed air engines, is outputted as main power through a left power output shaft, a right power output shaft, a reversing wheel and gear. [0006] However, the above mentioned wind-powered pneumatic engine and motor vehicle using compressed air as the source of main power are still a new technology. Therefore, there remains a need of further perfection and improvement to the structure of the wind-powered pneumatic engine and the motor vehicle employing the wind-powered pneumatic engine as discussed above. So is particularly in view of power performance. SUMMARY OF THE INVENTION [0007] The object of the present application is to provide a pressure reducing gas storage device, an air jet system and a motor vehicle which are capable of continuously stable working. [0008] In accordance with an aspect of the present application, a pressure reducing gas storage device comprises a gas storage tank and a heat exchanger. The gas storage tank comprises an inlet for receiving compressed air and an outlet for outputting air. The heat exchanger is used to heat the air in the air input into the gas storage tank. [0009] The pressure reducing gas storage device further comprises a pressure reducing valve. The compressed air enters the gas storage tank after its pressure is reduced by the pressure reducing valve. The heat exchanger comprises a first heat exchange unit filled with a first medium. The first medium exchanges heat with the air in the gas storage tank so as to heat the air. The pressure reducing gas storage device further comprises a cooler and a first circulating pump. The first heat exchange unit, the cooler and the first circulating pump form an inner circulating cooling system. The first medium circulates within the first heat exchange unit and the cooler. The cooler exchanges heat with ambient air. The first heat exchange unit has a first temperature regulation chamber which surrounds the gas storage tank. The first medium is filled between the first temperature regulation chamber and the gas storage tank. The two ends of the cooler are connected to the temperature regulation chamber. [0010] The heat exchanger further comprises a second heat exchange unit. The inlet, the first heat exchange unit, the second heat exchange unit and the outlet are arranged in turn. The second heat exchange unit has a second temperature regulation chamber, a second medium and a heater. The second temperature regulation chamber surrounds the gas storage tank. The second medium is filled between the second temperature regulation chamber and the gas storage tank. The heater is provided on the second temperature regulation chamber and heats the second medium. The second medium exchanges heat with the air in the gas storage tank. The second temperature regulation chamber is connected to a radiator and the second medium circulates within the second temperature regulation chamber and the radiator. The radiator exchanges heat with ambient air. [0011] A motor vehicle refrigeration system comprises a gas storage tank, a pressure reducing valve, a heat exchanger, a cooler and a first circulating pump. The gas storage tank receives compressed air the pressure of which is reduced by a pressure reducing valve. The first heat exchange unit, the cooler and the first circulating pump form an inner circulating cooling system. The first medium circulates within the first heat exchange unit and the cooler. The cooler exchanges heat with ambient air. [0012] A compressed air engine comprises a housing, an impeller body arranged in the housing and an air-jet system. The output of the air-jet nozzle is used to eject compressed air onto the impeller body within the housing. [0013] The pressure reducing valve comprises a housing, a valve core located within the housing, an regulation block and an elastic body. The valve core is sealingly and slidably fitted with the housing. The housing has a housing cavity axially running therethrough and an airway radially running therethrough. The housing cavity is connected to an air intake pipeline by which the housing cavity is connected to the gas storage tank. The valve core has a sealing end and a regulation end and the elastic body is arranged between the regulation block and the regulation end of the valve core. The regulation block is fixed with the housing and the valve core has a first position and a second position. In the first position, the sealing end blocks the air intake pipeline to disconnect the air intake pipeline with the gas storage tank; and in the second position, the sealing end is apart from the air intake pipeline to connect the air intake pipeline with the gas storage tank. [0014] The pressure reducing valve comprises a first control valve and a second valve. The first control valve comprises a first valve seat having a cavity, a first valve plug, a second elastic body, a first gas pipeline, a second gas pipeline, a third pipeline and a fourth pipeline. The first valve plug is arranged in the cavity and divides the cavity into a first chamber and a second chamber. The first valve plug is sealingly and slidably fitted with the first valve seat. The second elastic body is arranged in the second chamber and supports the first valve plug. The second gas pipeline connected to the first gas pipeline is connected to the second chamber. The third gas pipeline connects the first chamber with the second chamber. Both of the fourth gas pipeline and the first gas pipeline are connected with the first chamber. The cross-sectional area of the second gas pipeline is less than that of the third gas pipeline. The second control valve connected to the third gas pipeline controls the gas flow in the third gas pipeline. The first valve plug has a first position and a second position along the sliding direction. At the first position the first valve plug blocks the first gas pipeline to disconnect the first gas pipeline and the first chamber, and at the second position the first valve plug departs from the first gas pipeline to connect the first gas pipeline with the first chamber. [0015] An air-jet system comprises a compressed air tank for storing compressed air, a distributor for transporting compressed air to the compressed air engine, and a pressure reducing gas storage device. The output of the compressed air tank is connected to an inlet of the pressure reducing gas storage device via a pipeline and the outlet of the pressure reducing gas storage device is connected to the distributor. [0016] A motor vehicle comprises wheels, a drive train, a compressed air engine and an air-jet system. The air jet system, the compressed air engine, the drive train and the wheels are power connected in turn. [0017] The present application has the following technical effects. When the applicant of this application tested a motor vehicle using a compressed air engine, he found that the power of the motor vehicle is usually insufficient after running a long time. In this case, the applicant had to stop testing and check each part of the motor vehicle, but he failed to find the malfunction until he once found that the air-jet nozzle was condensed and frozen so that it cannot normally eject gas. Based on an analysis of the above situation, the applicant further found that the pressure reducing valve is also easy to be frozen. As for this case, the phenomenon of being frozen is eliminated by providing a heat exchanger to heat the air input in the gas storage tank. In addition, by providing a cooler, the temperature of ambient air is reduced and energy is saved. By providing a heater, not only the working stability of compressed air is further improved, but also the heating of the motor vehicle is achieved. BRIEF DESCRIPTION OF THE DRAWINGS [0018] FIG. 1 is a schematic structural view showing the connection of a compressed air tank, an air-jet system and a compressed air engine of a motor vehicle. [0019] FIG. 2 is a schematic structural view showing the air pressure regulator of the motor vehicle at a close configuration. [0020] FIG. 3 is a schematic structural view showing the air pressure regulator of the motor vehicle at an open configuration. [0021] FIG. 4 is a sectional view along the line A-A in FIG. 3 . [0022] FIG. 5 is a schematic structural view of the motor vehicle (only two wheels are illustrated). [0023] FIG. 6 is a top schematic view of the motor vehicle. [0024] FIG. 7 is a top schematic view showing a wind resistance engine and a compressed air engine assembled together. [0025] FIG. 8 is a front schematic view showing the wind resistance engine and the compressed air engine assembled together. [0026] FIG. 9 is a front schematic view of a compressed air engine of the motor vehicle. [0027] FIG. 10 is a top schematic view of the compressed air engine of the motor vehicle. [0028] FIG. 11 and FIG. 12 are schematic diagrams respectively illustrating a wind resistance engine and a compressed air engine connected in parallel and in series. [0029] FIG. 13 is a schematic structural view of a nozzle. [0030] FIG. 14 is a top view of a motor vehicle according to a second embodiment. [0031] FIG. 15 is a top view of a motor vehicle according to a third embodiment. [0032] FIG. 16 is a top view of a motor vehicle according to a fourth embodiment. [0033] FIG. 17 is a schematic structural view showing a flow regulating valve being closed according to the fifth embodiment. [0034] FIG. 18 is a schematic structural view showing a flow reducing valve being opened according to the fifth embodiment. [0035] FIG. 19 is a schematic structural view illustrating a connection relationship among a flow reducing valve, a compressed air tank, a distributor and a transmission mechanism according to the fifth embodiment. [0036] FIG. 20 is a top view of a motor vehicle utilizing another kind of wind resistance engine. [0037] FIGS. 21-23 are front sectional view, side sectional view and top view of the wind resistance engine in FIG. 20 . DETAILED DESCRIPTION [0038] As shown in FIG. 1 to FIG. 8 , a motor vehicle according to this embodiment comprises an air-jet system, a compressed air engine 4 , wind resistance engines 3 , 3 ′, a drive train 11 and wheels 123 . The air-jet system has an air-jet nozzle 60 and the compressed air engine 4 has a primary power output shaft 120 . The air-jet nozzle 60 of the air-jet system ejects gas to the compressed air engine 4 . The compressed air engine 4 compresses gas and then expands gas so that the primary power output shaft 120 of the compressed air engine 4 is driven to rotate, which drives the wheels 123 to rotate via the drive train 11 . The drive train 11 may comprise a gearbox 112 , a universal transmission device 113 connected to the gearbox 112 , and a drive axle 114 connected to the universal transmission device 113 . A first clutch 56 is provided between the primary power output shaft 120 of the compressed air engine 4 and the drive train 11 . The drive axle 114 is connected to the wheels 123 . [0039] As shown in FIG. 1 to FIG. 4 , the air-jet system comprises a compressed air tank 20 for storing compressed air, a pressure reducing gas storage device, a distributor 30 and the air-jet nozzle 60 . The output of the compressed air tank 20 is connected to an inlet of the pressure reducing gas storage device via a pipeline 3 . The outlet of the pressure reducing gas storage device is connected to the air-jet nozzle 60 via the distributor 30 . The distributor 30 is used to distribute the gas outputted by the pressure reducing gas storage device into multiple routes of gas, each of which is ejected by a corresponding air-jet nozzle 60 . The pressure reducing gas storage device comprises a gas storage tank and a heat exchanger. The gas storage tank comprises a first air chamber 2 having a first inlet 21 and a first outlet 22 . The first inlet 21 is used to input air and the first outlet 22 is used to output air. The two ends of the pipeline 3 are connected to the compressed air tank 20 and the first inlet 21 of the first air chamber 2 , respectively. There may be provided one or more pipelines 3 . The cross section area of the pipeline 3 is less than that of the compressed air tank 20 and less than that of the first air chamber 2 . The heat exchanger comprises a first heat exchange unit 40 arranged on the first air chamber 2 . The first heat exchange unit 40 comprises a first temperature regulation chamber 41 surrounding the first air chamber 2 and a first medium 42 filled between the first temperature regulation chamber 41 and the first air chamber 2 . The first medium 42 may be liquid (for example, water) or gas or other heat exchangeable mediums. The temperature of the first medium 42 is higher than that of the gas within the first air chamber 2 so that the compressed air in the compressed air tank 20 is released into the first air chamber 2 via the pipeline 3 and then exchanges heat with the first medium 42 . The heated air is output from the first outlet 22 of the first air chamber 2 . The first air chamber 2 may be made of a material having good heat conduction property so as to facilitate the heat exchange of the air in the first air chamber 2 with the first medium 42 . The first temperature regulation chamber 41 may be made of a material which is thermal insulation or has poor heat conduction property so that the heat is difficult to be dissipated into the ambient air. [0040] The first heat exchange unit 40 is connected to a cooler 5 . Each of the two ends of the cooler 5 is connected to the first temperature regulation chamber 41 to form a refrigeration cycle loop. The cooler 5 is provided with a first circulating pump 51 and a first circulating pump switch 52 for controlling the switch of the first circulating pump 51 . The temperature of the first medium 42 in the first temperature regulation chamber 41 decreases after the first medium 42 exchanges heat with the air in the first air chamber 2 . The first medium 42 of which the temperature is decreased circulates in the cooler 5 and the first temperature regulation chamber 41 . A refrigeration air-conditioning circulates the ambient air to exchange heat with the cooler 5 so that the ambient air is cooled to achieve refrigeration effect. [0041] The air output from the compressed air tank 20 is ejected via the air-jet nozzle 60 after it is heated by the first heat exchange unit 40 of the pressure reducing gas storage device so that condensation or even freeze will not be occurred at the air-jet nozzle 60 due to lower temperature. Meanwhile, the effect of decreasing the temperature of ambient air is achieved by connecting the first heat exchange unit 40 to the refrigeration air-conditioning and using the first medium 42 whose temperature has been decreased as circulating medium. Therefore, energy is saved. [0042] As shown in FIG. 2 to FIG. 4 , the air-jet system may further comprise an air pressure regulator 6 for maintaining the air pressure in the first air chamber 2 at a predetermined value. The air pressure regulator 6 comprises a housing 610 , a valve core 620 , an elastic body 630 , a locking block 640 and a regulating block 650 . The housing 610 is mounted at the first inlet 21 of the first air chamber 2 via a fastener 14 . The housing 610 is partly located within the first air chamber 2 and partly extends out of the first air chamber 2 . The housing 610 has a housing cavity 611 axially running therethrough and an airway 612 radially running therethrough. The housing cavity 611 is in communication with an air intake pipe 613 which is in communication with the pipeline 3 . The airway 612 is in communication with the first air chamber 2 . The valve core 620 is located within the housing cavity 611 and sealingly and slidably fitted with the housing. Two ends of the valve core 620 in the axial direction of the housing 610 are a sealing end 621 and a regulation end 622 . The sealing end 621 may seal the airway 612 and the air intake pipe 613 . The elastic body 630 may be capable of deforming expansively along the axial direction of the housing 610 . Two ends of the elastic body 630 bear against the regulation end 622 of the valve core 620 and the regulating block 650 , respectively. The regulating block 650 is thread connected to the housing 610 , and the locking block 640 is thread connected to the housing 610 and presses the regulating block 650 against the elastic body 630 . The regulating block 650 and the locking block 640 have axially running through first and second lead holes 651 , 641 , respectively. The first and second lead holes 651 , 641 communicate with each other to guide gas into the housing cavity 611 and onto the regulation end 622 of the valve core 620 . The diameter of the first lead hole 651 is less than that of the second lead hole 641 . The sealing end 621 of the valve core is in the form of truncated cone, and an elastic sealing ring 623 is fixed on the contour surface of the sealing end 621 . An elastic sealing ring 623 is also fixed on the contour surface of the regulation end of the valve core. On the section perpendicular to the axis of the housing 610 , the cross section area of the sealing end 621 of the valve core is less than that of the regulation end 622 . The pressure applied on the sealing end 621 includes the air pressure of the air input from the pipeline 3 , and the pressure applied on the regulation end 622 includes the air pressure of the air in the first air chamber 2 and the elastic force of the elastic body 630 . The elastic body is for example a spring, or other components capable of deforming expansively along the axis direction of the housing 610 . [0043] The working principle of the air pressure regulator is described below. When the air pressure of the gas input via the pipeline 3 is stable, a pressure reducing passage 614 is formed between the valve core 620 and the housing 610 so that the gas in the pipeline 3 can enter the first air chamber 2 through the pressure reducing passage 614 and the airway 612 . When the air pressure of the gas input via the pipeline 3 is higher than a predetermined value, the air pressure of the input gas pushes the valve core 620 to move toward the side of the regulation end 622 , and thereby the volume of the pressure reducing passage 614 increases and the air pressure in the first air chamber 2 decreases. When the air pressure of the gas input via the pipeline 3 is lower than the predetermined value, the force applied to the regulation end 622 is larger than that applied to the sealing end 621 so that the valve core moves toward the side of the sealing end 621 , and thereby the volume of the pressure reducing passage 614 decreases and the air pressure in the first air chamber 2 increases. When the air pressure of the gas input via the pipeline 3 changes, the valve core moves linearly according to the variation of the forces applied to the sealing end 621 and the regulation end 622 so as to stabilize the air pressure in the first air chamber 2 at a predetermined air pressure. When the air pressure regulator is turned off, the sealing end 621 blocks the airway 612 and the air intake pipe 613 and the gas in the pipeline 3 cannot enter the first air chamber 2 . The air pressure of the gas outputted by the pressure reducing gas storage device can be stabilized at a predetermined air pressure by providing the air pressure regulator. [0044] The prestressing force of the elastic body 630 may be adjusted by screwing or unscrewing the regulation block 640 so that the initially set air pressure of the air pressure regulator may be changed. [0045] The pressure reducing gas storage device may further comprise a second air chamber 7 and a second heat exchange unit 8 . In the direction of airflow, the first air chamber 2 is in front of the second air chamber 7 . The second air chamber 7 has a second inlet 71 and a second outlet 72 . The second inlet 71 is connected to the first outlet 22 of the first air chamber 2 . The second heat exchange unit 8 comprises a second temperature regulation chamber 81 surrounding the second air chamber 7 , a second medium 82 such as liquid or gas filled between the second temperature regulation chamber 81 and the second air chamber 7 , and a heater 83 for heating the second medium 82 . The heater 83 is for example, a solar energy heater, electrical heater, microwave heater or other heaters capable of heating a medium. There can be provided one or more heaters and there also can be provided one or more kinds of heaters. The second temperature regulation chamber 81 is connected to a radiator 9 of a heating air-conditioning to form a heating cycle loop. The radiator 9 is provided with a second circulating pump 901 and a second circulating pump switch 902 for controlling the switch of the second circulating pump 901 . The heated second medium 82 circulates within the second temperature regulation chamber 81 and the radiator 9 . The heating air-conditioning circulates ambient air to exchange heat with the radiator 9 so that the temperature of ambient air increases to achieve the effect of heating. The air may be further heated by the second heat exchange unit 8 after being heated by the first heat exchange unit 40 , so that it is more difficult to condense or even freeze the air-jet nozzle of the air-jet system. The second inlet 71 of the second air chamber 7 may also be provided with a pressure reducing valve 6 . [0046] In addition, the first temperature regulation chamber 41 and the second temperature regulation chamber 81 are connected via a pipeline to form a cycle loop. This cycle loop is provided with a third circulating pump 903 and a third circulating pump switch 904 for controlling the switch of the third circulating pump 903 . [0047] The heat exchanger may only comprise a first heat exchange unit which heats air in an air storage tank by means of heat exchange. There can be provided one or more first heat exchange units. The heat exchanger may also only comprise a second heat exchange unit having a heater. There can be provided one or more second heat exchange units. The heat exchanger may also comprise both of the first and second heat exchange units. When the first heat exchange unit is used, not only air may be heated, but also the cooled first medium may be used as medium to reduce the temperature in the motor vehicle. When the second heat exchange unit is used, the heated second medium may be used as medium to increase the temperature in the motor vehicle. [0048] As shown in FIG. 6 to FIG. 8 , there are provided two wind resistance engines arranged symmetrically, namely, a first wind resistance engine 3 and a second wind resistance engine 3 ′. The first wind resistance engine comprises a first casing 117 , a first impeller chamber 43 enclosed by the first casing 117 , a plurality of first impellers 44 and a first impeller shaft 45 . Each of the first impellers 44 is fixed on the first impeller shaft 45 and located within the first impeller chamber 43 . The first casing 117 is provided with a first air intake 1 for receiving front resistance fluid during the running of the motor vehicle. The first air intake 1 has an external opening and an inner opening. The caliber of the external opening is larger than that of the inner opening. The first air intake 1 communicates with the first impeller chamber 43 . The resistance fluid is directed into the first impeller chamber 43 via the first air intake 1 to drive the first impellers 44 and the first impeller shaft 45 to rotate. Auxiliary power is output via the first impeller shaft 45 . The second wind resistance engine 3 ′ comprises a second casing 117 ′, a second impeller chamber 43 ′, a second impeller 44 ′, a second impeller shaft 45 ′ and a second air intake 1 ′ for receiving resistance fluid. The first impeller chamber 43 and the second impeller chamber 43 ′ are arranged independently and do not communicate with each other. The first impeller shaft 45 is parallel with the second impeller shaft 45 ′ and rotates in an opposite direction to the second impeller shaft 45 ′. A first transfer gear 46 is fixed on the first impeller shaft 45 and a second transfer gear 118 is fixed on the second impeller shaft 45 ′. The motor vehicle further comprises a first reversing device, a second reversing device and an auxiliary power output shaft. The first reversing device comprises a reversing gear 119 and a transmission belt 47 and the second reversing device comprises a first drive conical gear 49 and a second drive conical gear 50 . The first drive conical gear 49 engages with the second drive conical gear 50 and the axis of the first drive conical gear 49 is perpendicular to that of the second drive conical gear 50 . The reversing gear 119 engages with the first transfer gear 46 and the axis of the reversing gear 119 is parallel with that of the first transfer gear 46 . The transmission belt 47 is wound around the first drive conical gear 49 , the second transfer gear 118 and the reversing gear 119 which are arranged triangularly. The first drive conical gear 49 is fixed on an auxiliary power output shaft 130 . The power outputted by the first impeller shaft 45 and the second impeller shaft 45 ′ is switched onto the auxiliary power output shaft 130 via the first reversing device, and the power outputted by the auxiliary power output shaft 130 is switched to the drive train 11 of the motor vehicle via the second reversing device. There may be two, one or more than two wind resistance engines. A plurality of impellers fixed on the impeller shafts are mounted in the impeller chamber of the wind resistance engine and the impellers and impeller shafts are driven to rotate by the resistance fluid. [0049] After the power outputted by the impeller shafts of the wind resistance engine is reversed via the reversing device, it may directly drive the drive train of the motor vehicle, as shown in FIG. 11 , and it may also be connected in series with the primary power output shaft of the compressed air engine to drive the drive train of the motor vehicle, as shown in FIG. 12 . [0050] As shown in FIG. 6 to FIG. 8 , The compressed air engine 4 is arranged to be independent of the first and second wind resistance engines 3 , 3 ′ and located at the back of the first and second wind resistance engines 3 , 3 ′. The compressed air engine 4 has the primary power output shaft 120 and the second transfer gear 50 is fixed at the end of the primary power output shaft 120 . With the first and second drive conical gears 49 , 50 which are vertically engaged with each other, the power, which is outputted by the first and second wind resistance engines 3 , 3 ′, is reversed vertically and outputted to the primary power output shaft 120 of the compressed air engine. [0051] The motor vehicle is provided with a first clutch 160 via which the power outputted by the first and second wind resistance engines 3 , 3 ′ is output to the auxiliary power output shaft 130 , as shown in FIG. 8 . During the starting stage of the motor vehicle, the wind resistance engine does not output power and the first clutch 160 disengages so that the auxiliary power output shaft 130 would not be rotated with the primary power output shaft 120 , thus reducing the starting load of the motor vehicle. During the normal running of the motor vehicle, the first clutch 160 engages, the power outputted by the auxiliary power output shaft 130 and that outputted by the primary power output shaft 120 together drive the drive train 11 of the motor vehicle. The first clutch 160 may be for example a prior art one-way clutch, overrunning clutch, etc, and of course may also be other clutches having disengaging and engaging states. [0052] As shown in FIG. 6 to FIG. 10 , the compressed air engine 4 further comprises a housing and a round impeller body 74 located within the housing 70 . The housing comprises an annular side casing 72 , an upper cover plate 73 and a lower cover plate 73 ′. The upper cover plate 73 and lower cover plate 73 ′ are respectively fixed at the upper and lower openings of the annular side casing 72 so that the annular side casing 72 , the upper cover plate 73 and lower cover plate 73 ′ form a closed impeller body chamber 68 . The impeller body 74 is located within the impeller body chamber 68 and the central portion of the impeller body 74 is fitted on the primary power output shaft 120 . By notching on the circumference surface of the impeller body 74 which joints with the inner surface of the side casing 72 , a set of working chambers 69 are formed and distributed evenly around the axis of the primary power output shaft 120 . On the section perpendicular to the axis of the primary power output shaft 120 , the working chamber 69 takes a form of a triangle formed by three curves connected end to end. There may be one or more sets of working chambers 69 . The working chambers may be a thorough-slot structure axially running through on the impeller body. The inner surfaces of the upper cover plate, the lower cover plate and the side casing close the working chamber. The working chambers may also be of a non-thorough-slot structure provided in the middle of the circumference surface of the impeller body and the inner surface of the side casing closes the working chambers. Of course, the working chamber may also be closed by the inner surfaces of the upper cover plate and the lower cover plate, or by the inner surfaces of the lower cover plate and the side casing. That is to say, the working chambers are closed by the inner surface of the casing. [0053] The inner surface of the side casing 72 is also provided with a plurality of ejecting inlets 67 and a plurality of ejecting outlets 64 . The ejecting inlets 67 and ejecting outlets 64 are arranged alternately. An annular first-order silencer chamber 63 is also provided within the side casing 72 . A plurality of first-order exhaust ports 65 are provided on the external surface of the side casing 72 , and each of the ejecting outlets 64 has a corresponding first-order exhaust port 65 . The ejecting outlets 64 communicate with the first-order exhaust ports 65 via the first-order silencer chamber 63 . The ejecting inlets 67 communicates with none of the ejecting outlets 64 , the first-order exhaust port 65 and the first-order silencer chamber 63 . The ejecting outlets 64 and their corresponding first-order exhaust port 65 are spaced at an angle on the circumference centered on the axis of the primary power output shaft 120 . An air-jet nozzle seat 71 is fixed on the position corresponding to each of the ejecting inlets 67 on the side casing 72 . Each air-jet nozzle seat 71 is fixed with two air-jet nozzles 60 . Each of the air-jet nozzles 60 extends into the corresponding ejecting inlet 67 and is connected to a gas ejecting pipe 54 , and the axes of the two air-jet nozzles 60 on each of the ejecting inlets 67 form an acute angle. The compressed air in the compressed air tank 20 is transferred into the working chambers 69 via the gas ejecting pipe 54 and the air-jet nozzle 60 . For each working chamber 69 , the air ejected by the air-jet nozzle 60 drives the impeller body 74 to rotate and is compressed to be temporarily stored in the working chambers 69 . When moving to the ejecting outlets 64 , the temporarily stored gas in the working chamber 69 expands and jets out from the ejecting outlets 64 at a high speed. The reaction force formed when the gas is ejected again drives the impeller body 74 to rotate. When the impeller body 74 rotates, the primary power output shaft 120 is driven to rotate, which further drives the drive train 11 of the motor vehicle. [0054] For each working chamber 69 , it takes a period of time from receiving the gas ejected by the air-jet nozzle 60 to ejecting the gas from the ejecting outlets 64 . During the period of time, the gas is compressed and temporarily stored in the working chamber 69 so that the reaction force formed when the gas is ejected is larger and thus more power can be provided for the motor vehicle. Since the working chamber 69 is closed by the inner surface of the housing, it facilitates the compression and temporary storage of the compressed gas. In addition, in order to prevent the compressed gas from being condensed when being input to the compressed air engine, the air-jet nozzle seat 71 may be provided with a first heater 77 for heating the air-jet nozzle 60 . The first heater 77 may be an electrically heated wire which is embedded in the air-jet nozzle seat 71 . As shown in FIG. 13 , the air-jet nozzle 60 comprises an air-jet nozzle body 617 having an axially running through cavity 618 . The air-jet nozzle body 617 is provided with a second heater 615 . The second heater 615 is an electrically heated wire which is wounded around the air-jet nozzle body 617 . The air-jet nozzle body is also provided with a heat insulation layer 616 . The second heater 615 is located between the heat insulation layer 616 and the air-jet nozzle body 617 . The first and second heaters may be selected from a group consisting of an electrical heater, a microwave heater and a solar energy heater. [0055] The motor vehicle further comprises a first electromotor 53 which is power connected with the primary power output shaft 120 of the compressed air engine 4 via a belt transmission mechanism 51 . The belt transmission mechanism 51 comprises a pulley 511 and a belt 512 wounded around the pulley 511 . [0056] As shown in FIG. 6 to FIG. 8 , the motor vehicle further comprises a compressed air reuse system for communicating the first-order exhaust ports 65 of the compressed air engine with the impeller chambers 43 , 43 ′ of the wind resistance engines. The compressed air reuse system comprises a first-order exhaust pipe 57 , a second-order silencer chamber 59 and a second-order exhaust pipe 58 . The inlets of the first-order exhaust pipe 57 communicate with the first-order exhaust ports 65 , respectively, and the outlets of the first-order exhaust pipe 57 are gathered to the second-order silencer chamber 59 . The second-order silencer chamber 59 communicates with the inlets of the second-order exhaust pipe 58 . The outlets of the second-order exhaust pipe 58 communicate with both of the first impeller chamber 43 and the second impeller chamber 43 ′. The gas ejected at a high speed from the ejecting outlets 64 of the compressed air engine passes through the first-order silencer chamber 63 and the first-order exhaust port 65 in turn, then enters the first-order exhaust pipe 57 and after being silenced by the second-order silencer chamber 59 , finally enters the first and second impeller chambers 43 , 43 ′ to drive the first and second impellers to rotate so as to reuse the compressed air. Accordingly, energy can be saved effectively and the driving force of the motor vehicle can be further improved. [0057] FIG. 14 illustrates a second embodiment of the motor vehicle, which differs from the first embodiment mainly in that the first and second wind resistance engines 3 , 3 ′ are of horizontal type mounting and the first and second impeller shafts 45 , 45 ′ are mounted horizontally and perpendicular to the primary power output shaft 120 . In the first embodiment, the first and second wind resistance engines 3 , 3 ′ are of vertical type mounting and the first and second impeller shafts 45 , 45 ′ are mounted vertically, as shown in FIG. 8 . As for the second embodiment, although the power outputted by the first and second impeller shafts of the first and second wind resistance engines is converted to be coaxially output after being firstly reversed, it cannot be directly transferred to the drive train since the rotation direction of the coaxial output is perpendicular to that required by the drive train. It is necessary to use a second reversing device to convert the power outputted by the first and second wind resistance engines to the rotation direction which is identical to the rotation direction of the drive train. [0058] FIG. 15 illustrates a third embodiment of the motor vehicle, which differs from the first embodiment mainly in that a second clutch 111 is provided between the auxiliary power output shaft 130 commonly used by both of the first and second wind resistance engines 3 , 3 ′ and the primary power output shaft 120 of the compressed air engine 4 . The power connection or disconnection of the wind resistance engines and the wind resistance engine may be performed by the second clutch 111 . The wind resistance engines according to this embodiment are of horizontal type mounting. [0059] As shown in FIG. 16 to FIG. 19 , a pressure reducing valve 40 is arranged between the distributor 30 and the compressed air tank 20 of the motor vehicle. The pressure reducing valve 40 comprises a first control valve 300 and a second control valve 400 . The first control valve 300 comprises a first valve seat 301 , a first valve plug 302 and an elastic body 303 . The first valve seat 301 has a cavity 304 . The first valve plug 302 is arranged in the cavity 304 and is slidably and sealingly fitted with the first valve seat 301 . The first valve plug 302 is located in the cavity 304 and divides the cavity 304 into a first chamber 305 and a second chamber 306 . The first control valve 300 further comprises a first gas pipeline 307 , a second gas pipeline 308 , a third gas pipeline 309 and a fourth gas pipeline 310 . The first gas pipeline 307 is used to receive the compressed air input from the compressed air tank 20 . The second gas pipeline 308 communicates at one end with the first gas pipeline 307 , and at the other end with the second chamber 306 . The third gas pipeline 309 communicates at one end with the second chamber 306 , and at the other end with the first chamber 305 . The first chamber 305 is connected to the distributor 30 via the fourth gas pipeline 310 . The first gas pipeline 307 has a diameter greater than that of the second gas pipeline 308 and that of the third gas pipeline 309 , and the second gas pipeline 308 has a diameter less than that of the third gas pipeline 309 . The first valve plug 302 has a close position and an open position with respect to the first valve seat 301 . When the first valve plug 302 is at the close position, it blocks the junction between the first gas pipeline 307 and the first chamber 305 , so that the first gas pipeline 307 is disconnected from the first chamber 305 ; and when the first valve plug 302 is at the open position, it is apart from the junction between the first gas pipeline 307 and the first chamber 305 so that the first gas pipeline 307 communicates with the first chamber 305 . [0060] The first valve plug 302 comprises a columnar main body 311 and a closing portion 312 with a less diameter than that of the main body 311 and having a needle-shaped head. The main body 311 is slidably fitted with the first valve seat 301 . The periphery surface of the main body 311 is surrounded by a first elastic sealing ring 316 , through which the main body 311 is sealingly fitted with the first valve seat 301 . The main body 311 has an axially running through inner chamber 317 in which the closing portion 312 extending into the chamber 305 is disposed and linearly movable with respect to the main body 311 . The elastic body 303 comprises a first elastic body 313 and a second elastic body 314 . The first elastic body 313 is disposed in the inner chamber 317 , with its two ends bearing against the closing portion 312 and a positioning block 315 , respectively. The second elastic body 314 is disposed in the second chamber 306 and is fixed at one end to the bottom 301 a of the first valve seat 301 and at another end to the positioning block 315 . The positioning block 315 is fixed through thread fitting to the bottom of the inner chamber 317 . A second elastic sealing ring 318 is fixed onto the top surface of the main body 311 . [0061] The second control valve 400 is disposed on the third gas pipeline 309 for controlling the gas flux in the third gas pipeline 309 . The control on gas flux may comprise controlling changes between flow and non-flow as well as between large flow and small flow. The second control valve 400 comprises a second valve seat 401 and a second valve plug 402 . The second valve plug 402 comprises a second main body 404 and a conical body 405 located at the front end of the second main body 404 . The second valve seat 401 is provided with a gas passage 406 having a gas inlet 407 and a gas outlet 408 , both of which are connected with the third gas pipeline 309 . A control cavity 410 which is cone-shaped corresponding to the cone body is provided within the gas passage 406 . The second main body 404 is thread fitted with the control cavity 410 so that a second gap 403 between the second main body 403 and the control cavity 410 can be adjusted through the thread, thereby a gas flux in the third gas pipeline 309 is controlled. It can be understood for the persons in the art that the second control valve 400 may be implemented by other conventional airflow control means. The second valve plug 402 is connected to the output port of a transmission mechanism 500 , and the input port of the transmission mechanism 500 is coupled with a control switch of a motor vehicle. The transmission mechanism 500 comprises a second transmission mechanism 502 and a power connected first transmission mechanism 501 connecting the control switch with the second transmission mechanism 502 . The second transmission mechanism 502 , such as a belt transmission mechanism, comprises a driving pulley 503 and a driven pulley 504 having a less diameter than that of the driving pulley 503 . A belt 505 is wound around the driving pulley 503 and the driven pulley 504 . The first transmission mechanism 501 moves according to an operation of the control switch to drive the driving pulley 503 to rotate, which further drives the driven pulley 504 to rotate by means of the belt 505 . The driven pulley 504 drives the second valve plug 402 to rotate, rendering the second valve plug 402 screwed or unscrewed with respect to the second valve seat 401 . In other words, the regulation of the flux of the third gas pipeline is carried out by changing size of the second gap 403 between the first valve plug and the first valve seat. When the second gap 403 becomes zero, the second control valve 400 is closed, and the third gas pipeline 309 is disconnected. [0062] When the compressed air does not enter the pressure reducing valve, the head of the closing portion 312 blocks the junction between the first gas pipeline 307 and the first chamber 305 under the elastic force of the first and second elastic body 313 , 314 . At this moment, there is a gap between the second sealing ring 318 and the top 301 b of the first valve seat 301 (or the second sealing ring 318 has reached the top 301 b ). When the compressed air enters the pressure reducing valve, the compressed air aerates into the chamber 306 through the first gas pipeline 307 and the second gas pipeline 308 . During aeration, if the control switch 7 is not turned on, the pressure of the second chamber 306 continues driving the first valve plug 302 to move toward the top 301 b , allowing the head of the closing portion to block up the junction (a peripheral surface 320 of the closing portion 312 clings to the inner wall 321 of the first gas pipeline 307 ) stably, until the second sealing ring 318 bears against the top 301 b (or the second sealing ring 318 presses against the top 301 b after being elastically deformed). When the control switch 7 is turned on, the second valve plug 402 is unscrewed, allowing the third gas pipeline 309 to be unblocked, and gas in the second chamber 306 flows to the first chamber 305 through the third gas pipeline 309 , rendering a reduction of the pressure in the second chamber 306 . The pressure of the compressed air forces the closing portion 312 of the first valve plug 302 to leave the junction, allowing the compressed air to enter the distributor 30 through the first chamber 305 and the fourth gas pipeline 310 . While the compressed air is entering the fourth gas pipeline 310 through the first chamber 305 , the whole first valve plug 302 moves toward the bottom 301 a of the first valve seat 301 . When forces applied to the first valve plug 302 become equilibrium, the main body 311 and the closing portion 312 stay still with respect to each other. A first gap 319 for passage of the compressed air is then formed between the periphery surface 320 of the closing portion and the inner wall 321 of the first gas pipeline. While the compressed air tank stops supplying gas, the closing portion of the first valve plug blocks the junction between the first gas pipeline and the first chamber again under forces applied by the first and second elastic body, with the closing portion clinging to the inner wall of the first gas pipeline. [0063] The flux and pressure of gas in the third gas pipeline may be regulated through operation of the second control valve, which makes the closing portion move up or down and leads to change of the first gap between the inner wall of the first gas pipeline and the periphery surface of the closing portion, thereby regulating the flux and pressure of gas in the fourth gas pipeline. [0064] The first, second and third elastic bodies may be for example a spring, or an elastic sleeve, clips, or other components capable of deforming expansively or elastically along the sliding direction of the first valve plug. [0065] With such a pressure reducing valve, compressed air in the compressed air tank is output to the distributor after the air pressure is regulated. The second elastic body 313 acts as a buffer effectively reducing a rigid strike force between the first valve plug 302 and the first valve seat 301 , and meanwhile improving the air tightness provided by the closing portion 312 to the first gas pipeline 307 . Since the second gas pipeline 308 has a cross section area less than that of the third gas pipeline 309 , control on the whole gas path of the control valve 300 can be achieved, and meanwhile a flux can be amplified so as to improve precision of control. [0066] When two distributors are provided, two pressure reducing valves are provided corresponding to the two distributors and controlled by the same control switch. In this situation, as shown in FIG. 19 , the second transmission mechanism comprises two driven pulleys separately driving the second valve plugs of the two pressure reducing valves. In other examples, more than two pressure reducing valves in series may be provided in order to achieve multistage control of the compressed air input to the gas distributor. [0067] In addition, as shown in FIG. 16 , the pressure reducing valve may be arranged wholly in heat exchange medium 600 which exchanges heat with the gas in the pressure reducing valve so that the gas is output via a distributor after being heated. The heat exchange medium 600 is used as the circulating medium of a cooler 700 of the refrigeration air-conditioning, and is cooled after being exchanged heat with the gas in the pressure reducing valve. The cooled heat exchange medium circulates in the cooler 5 so that the temperature of ambient air is reduced. The heat exchange medium may be for example antiseptic, un-volatile coolant with good cooling effect. [0068] FIGS. 20-23 illustrate another embodiment of the wind resistance engine of the motor vehicle. The wind resistance engine 3 comprises a casing 801 , an impeller chamber 802 enclosed by the casing 801 , an auxiliary power output shaft 130 and a plurality of sets of impellers 804 . Each set of impellers 804 at least comprises a plurality of impellers each of which is fixed on the auxiliary power output shaft 130 and the impellers are staggered. The impeller chamber 802 has an air intake 805 for receiving front resistance fluid generated when the motor vehicle is running. The air intake 805 is a trumpet-type inlet with a bigger external opening and a smaller internal opening. Each set of impellers 804 are located in the air intake 805 and the diameters thereof decrease in turn toward the interior of the air intake. The auxiliary power output shaft 130 is coaxial with the primary power output shaft 120 of the compressed air engine 4 . A second clutch 111 is provided between the primary power output shaft 120 and the auxiliary power output shaft 130 . In addition, the impeller chamber has one first exhaust port 806 and two second exhaust ports 807 arranged symmetrically. The first exhaust port 806 is located at the side of the casing 801 and at the back of the impellers 804 . The air intake 805 is coaxial with the auxiliary power output shaft 130 . The axis of the first exhaust port 806 forms an angle with that of the auxiliary power output shaft 130 . The second exhaust ports 807 are located at the ends of the casing 801 and at the back of the impellers 804 . The axis of the second exhaust port 807 forms an angle with that of the auxiliary power output shaft 130 . The structure of the compressed air engine is to the same as that described previously. [0069] In the starting stage, the second clutch 111 disengages and the primary power output shaft 120 disconnects from the auxiliary power output shaft 130 . The compressed air engine 4 directly drives the drive train of the motor vehicle and does not need to drive the impellers of the wind resistance engine 3 to rotate so that the starting load is effectively reduced. When the motor vehicle is in motion, the third clutch engages and the primary power output shaft 120 is power connected to the auxiliary power output shaft 130 . Each set of impellers is driven by external wind resistance airflow that the motor vehicle encounters to rotate, and the impellers drive the auxiliary power output shaft 130 to rotate. The power of the auxiliary power output shaft 130 is transferred to the drive train of the motor vehicle via the primary power output shaft 120 . [0070] Since the primary power output shaft 120 is coaxial with the auxiliary power output shaft 130 , it is not necessary to reverse the power of the auxiliary power output shaft to output so that the structure is simplified, the power drive line is shortened and energy is saved. Since a plurality of sets of impellers 804 are used, the resistance fluid in front of the motor vehicle may be utilized more effectively. [0071] A compressed air supply system comprises a compressed air tank, a pressure reducing valve, a heat exchanger and an output pipeline. The output of the compressed air tank is connected to the pressure reducing valve via the pipeline. The working gas, outputted by the pressure reducing valve where the gas pressure is reduced, enters the output pipeline. The heat exchanger which is used to heat the pressure reducing valve comprises a container filled with coolant, and the pressure reducing valve is arranged in the coolant. The compressed air supply system further comprises a cooler and a first circulating pump. The container, the cooler and the first circulating pump communicate with each other and use the coolant as medium to form a circulating cooling system. The system exchanges heat with ambient air through the cooler. The heat exchanger comprises a heater for heating the output pipeline. The compressed air supply system further comprises a radiator and a second circulating pump. The heater, the cooler and the second circulating pump communicate with each other to form a circulating radiation system. The system exchanges heat with ambient air through the radiator. A compressed air motor vehicle refrigeration system comprises a compressed air tank, a pressure reducing valve and a container filled with coolant. The working gas outputted by the pressure reducing valve where the pressure is reduced enters the output pipeline. The pressure reducing valve is arranged in the coolant. The container, the cooler and the first circulating pump communicate with each other and use the coolant as medium to form a circulating cooling system. The system exchanges heat with ambient air through the cooler. The pressure reducing valve may be the one as shown in FIGS. 2-4 , FIG. 17 and FIG. 18 . [0072] Although the above description makes explanation in detail for the present application in reference to preferred embodiments, the practice of the present application should not be construed to be limited to these descriptions. A person skilled in the art can make various simple deductions or replacements without departing from the spirit and concept of the present application, which should be construed to fall into the scope of the appended claims of the present application.

A pressure reducing gas storage device, an air-jet system and a motor vehicle are disclosed herein, wherein the pressure reducing gas storage device comprises a gas storage tank including an inlet for receiving compressed air and an outlet for outputting air and a heat exchanger for heating the air in the air input into the gas storage tank. By providing a heat exchanger to heat the air input in the gas storage tank, the phenomenon of being frozen is eliminated and the pressure reducing gas storage device is able to work continuously and stably.

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of Ser. No. 14/849,497, entitled “CARDIOPULMONARY RESUSCITATION DEVICE,” to Brent F. Morgan, filed Sep. 9, 2015, the subject matter of which is incorporated herein by reference. BACKGROUND OF THE INVENTION Field of the Invention This invention relates generally to an artificial resuscitation device. Description of the Related Art Cardiopulmonary resuscitation (CPR) is an emergency procedure that involves the compression and decompression of the thoracic cavity in response to pressure applied to the sternum. CPR is typically performed in many different emergency situations, such as when a person is experiencing circulatory arrest (i.e. cardiac arrest) and respiratory arrest (e.g. drowning). It is known that most people who receive CPR outside of a hospital do not survive. For example, recent statistics indicate that only about 8% of people who receive CPR outside of a hospital survive. Conversely, about 88% of those who receive CPR at a hospital do survive. One reason people do not survive when receiving CPR outside of a hospital is that the CPR is not performed correctly. In some instances, the pressure applied during compression is not applied evenly. The applied pressure often will not compress the entire thoracic cavity to get adequate pumping started. Instead, the applied pressure is applied as a sharp force to the sternum. The sternum must also be compressed/decompressed at an optimal distance and rate. The chances of a successful resuscitation are greatly reduced if the chest is compressed too deeply or in too shallow a manner. Further, in an emergency situation, people would greatly benefit from a device that is simple to use and quickly guides them through the steps necessary to successfully perform CPR. Hence, it would be desirable to provide an alternative to conventional manual CPR techniques that particularly non-medical personnel can perform properly so as to increase the likelihood of surviving. BRIEF SUMMARY OF THE INVENTION The present invention is directed to a cardiopulmonary resuscitation device which aids in the performance of CPR. The novel features of the invention are set forth with particularity in the appended claims. The invention will be best understood from the following description when read in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS It should be noted that like reference characters are used throughout the several views of the drawings. FIG. 1 is a perspective view of a cardiopulmonary resuscitation device. FIG. 2 is side view of the cardiopulmonary resuscitation device of FIG. 1 . FIG. 3 is an opposed side view of the cardiopulmonary resuscitation device of FIG. 1 . FIG. 4 is perspective view of the inside of the cardiopulmonary resuscitation device of FIG. 1 showing a circuit board, which carries control circuitry, and a distance sensor apparatus in communication therewith. FIG. 5 is a block diagram of one embodiment of the cardiopulmonary resuscitation device of FIG. 1 showing the control circuitry and distance sensor of FIG. 4 . FIG. 6 a is a side view of one embodiment of the control circuitry and circuit board of FIGS. 4 and 5 . FIG. 6 b is a circuit diagram of a first portion of the control circuitry of FIGS. 4, 5, and 6 a , wherein the first portion includes a microcontroller and display screen. FIG. 6 c is a circuit diagram of a second portion of the control circuitry of FIGS. 4, 5 , and 6 a , wherein the second portion includes a first converter and first biasing circuit, which provide a first reference potential. FIG. 6 d is a circuit diagram of a third portion of the control circuitry of FIGS. 4, 5, and 6 a , wherein the second portion includes a second converter and second biasing circuit, which provide a second reference potential. FIG. 7 is a perspective view of the circuit board and control circuitry of FIG. 4 . FIG. 8 is an opposed perspective view of the circuit board and control circuitry of FIG. 4 . FIG. 9 is a perspective view of the distance sensor apparatus of FIG. 4 . FIG. 10 is an opposed perspective view of the distance sensor apparatus of FIG. 4 . FIG. 11 is a front view of the cardiopulmonary resuscitation device of FIG. 1 being operated by a user when performing CPR on a patient. FIG. 12 a is a side view of the cardiopulmonary resuscitation device in a direction shown in FIG. 11 . FIG. 12 b is a partial view of the cardiopulmonary resuscitation device in a region shown in FIG. 11 . FIG. 13 a is a side view of the cardiopulmonary resuscitation device in the direction shown in FIG. 11 . FIG. 13 b is a partial view of the cardiopulmonary resuscitation device in the region shown in FIG. 11 . FIG. 14 a is a perspective view of a cardiopulmonary resuscitation device suitable for use for infants, according to another embodiment. FIG. 14 b is a cutaway view of the cardiopulmonary resuscitation device of FIG. 14 a in the compression phase of CPR. FIG. 14 c is a cutaway view of the cardiopulmonary resuscitation device of FIG. 14 a in the decompression phase of CPR. DETAILED DESCRIPTION OF THE INVENTION FIG. 1 is a perspective view of a cardiopulmonary resuscitation device 100 . FIG. 2 is side view of the cardiopulmonary resuscitation device 100 of FIG. 1 , and FIG. 3 is an opposed side view of the cardiopulmonary resuscitation device 100 of FIG. 1 . In this embodiment, the cardiopulmonary resuscitation device 100 includes a cover 102 and case 106 , which are coupled together in a repeatably removeable manner. In this embodiment, the case 102 includes a gripping portion 107 , which facilitates the ability to hold the cardiopulmonary resuscitation device 100 with hands. As shown in FIG. 2 , the cardiopulmonary resuscitation device 100 has is shaped to have opposed lengthened sides 154 and 155 , and opposed shortened sides 156 and 157 . A length axis 103 and width axis 105 are shown in FIG. 2 for reference purposes only. The length axis extends between the shortened sides 156 and 157 , and the width axis extends between the opposed lengthened sides 154 and 155 . It should be noted that a lengthened side is longer than the shortened side, and a shortened side is shorter than the lengthened side. The lengthened sides 154 and 155 can have many different lengths. In some embodiments, the lengthened sides 154 and 155 are less than about eighteen inches. In some embodiments, the lengthened sides 154 and 155 are between about eight inches and eighteen inches. In general, the lengthened sides 154 and 155 are chosen to have lengths that match the chest width of a typical human. The cover 102 and case 106 can include many different types of material, such as plastic. In some embodiments, the cardiopulmonary resuscitation device 100 includes a backing of resilient material, such as foam. The backing of resilient material can be positioned at many different locations, such as on the cover 102 and/or case 106 . In this embodiment, the cardiopulmonary resuscitation device 100 includes an extension portion 109 , wherein the extension portion 109 includes portions of the cover 102 and case 106 . In particular, the extension portion 109 includes a cover extension portion 104 , wherein the cover extension portion 104 is included with the cover 102 . Further, the extension portion 109 includes a case extension portion 108 , wherein the case extension portion 108 is included with the case 106 . The extension portion 109 provides the cardiopulmonary resuscitation device 100 with an L-shape. The extension portion 109 extends in a direction substantially away from the length axis 103 . The extension portion 109 extends in the same substantial direction as the width axis 105 . In this embodiment, the extension portion 109 extends from proximate to the intersection of the lengthened side 155 and the shortened side 157 . It should be noted, however, that the extension portion 109 can extend from other portions, such as the intersection of the lengthened side 154 and the shortened side 157 . In this embodiment, and as shown in FIGS. 1 and 2 , the cardiopulmonary resuscitation device 100 includes a display screen 116 , which extends through the cover 102 . Display screen 116 will be discussed in more detail below with FIGS. 5, 6, 7 and 8 . The display screen 116 is carried by a circuit board 110 ( FIGS. 4, 6, 7, and 8 ). The display screen 116 is for displaying information regarding the operation of the cardiopulmonary resuscitation device 100 . In this embodiment, and as shown in FIGS. 1 and 2 , the cardiopulmonary resuscitation device 100 includes a pressure switch 142 , which is disposed inside the case 106 . The pressure switch 142 will be discussed in more detail below with FIGS. 5 and 8 . The pressure switch 142 can be of many different types, such as a force sensing resistor. The resistance of the force sensing resistor changes in response to an applied force. In this embodiment, and as shown in FIGS. 1 and 2 , the cardiopulmonary resuscitation device 100 includes a luminaire 144 , which extends through the cover 102 . The luminaire 144 is useful to provide the user of the cardiopulmonary resuscitation device 100 with a visual indication that the sternum is being compressed and decompressed the desired distance. The luminaire 144 will be discussed in more detail below with FIGS. 5 and 8 . In some embodiments, the cardiopulmonary resuscitation device 100 includes a luminaire 143 , which extends through the cover 102 . The luminaire 143 can provide the visual indication that the sternum is being compressed and decompressed the desired distance. In some embodiments, the luminaire 144 indicates when the device is on or off, and the luminaire 143 provide the visual indication that the sternum is being compressed and decompressed the desired distance. In this embodiment, and as shown in FIG. 3 , the cardiopulmonary resuscitation device 100 includes a distance sensor apparatus 160 , which extends through the case 106 . The distance sensor apparatus 160 will be discussed in more detail below with FIGS. 4, 5, 9, and 10 . The distance sensor apparatus 160 includes a receive sensor 166 and transmit sensor 167 , which extend through the case 106 . In particular, the receive and transmit sensors 166 and 167 extend through the case extension portion 108 . The receive and transmit sensors 166 and 167 can extend through the case 106 in many different ways. In this embodiment, the receive and transmit sensors 166 and 167 extend through corresponding openings of the case 106 . In general, the receive and transmit sensors 166 and 167 extend through at least one opening of the case 106 . It should be noted that the opening(s) through which the receive and transmit sensors 166 and 167 are opposed to the opening through which the display screen 116 extends ( FIGS. 1 and 2 ). In this way, the display screen 116 and distance sensor apparatus 160 face opposed directions. FIG. 4 is perspective view of the inside of the cardiopulmonary resuscitation device 100 of FIG. 1 with the cover 102 removed from the case 106 . In this embodiment, the cardiopulmonary resuscitation device 100 includes the circuit board 110 , which is carried by the case 106 . The circuit board 110 carries the control circuitry 112 , which controls the operation of the cardiopulmonary resuscitation device 100 . It should be noted that the display screen 116 is positioned on the opposite side of the circuit board 110 in FIG. 4 , as is shown in FIGS. 7 and 8 . The devices included with the control circuitry 112 will be discussed in more detail below. In this embodiment, the control circuitry 112 includes a microcontroller 114 , which controls the operation of the cardiopulmonary resuscitation device 100 . The control circuitry 112 includes a sound device 117 , which is operatively coupled to the microcontroller 114 . As will be discussed in more detail below, the sound device 117 provides a sound indication in response to receiving a sound signal S Sound ( FIG. 5 ) from the microcontroller 114 . In this embodiment, the sound indication corresponds to an audible sound. The audible sound is within a frequency range of human hearing. The microcontroller 114 provides the sound signal S Sound in response to movement of the cardiopulmonary resuscitation device 100 . The sound signal S Sound is useful to provide the user of the cardiopulmonary resuscitation device 100 with an audible indication that the sternum is being compressed and decompressed the desired distance. In an embodiment, the signal S Sound will also indicate that the desired distance was not reached. This might happen if the compression/decompression was done in either too shallow a manner or was done too deeply. In this case, the signal S Sound can be used to generate a different sound altogether to indicate an improper action. Thus, the person performing CPR is provided auditory feedback as to whether the CPR is being done correctly or incorrectly. It should be noted that, in some embodiments, the luminaire 144 operates in response to receiving the sound signal S Sound . This feature is useful so that the luminaire 144 operates when the sound device 117 operates. The luminaire 144 is provided power so it is capable of operating when the pressure switch 142 has an activated condition, as will be discussed in more detail below. The cardiopulmonary resuscitation device 100 includes a battery 118 , which is carried by the case 106 and positioned proximate to the circuit board 110 . The battery 118 provides power to the control circuitry 112 through a battery cable 119 , as will be discussed below with FIG. 7 . As mentioned above, the cardiopulmonary resuscitation device 100 includes the distance sensor apparatus 160 . The distance sensor apparatus 160 is carried by the case 106 , as shown in FIG. 4 . In particular, the distance sensor apparatus 160 is carried by the case extension portion 108 . The distance sensor apparatus 160 is positioned between the case extension portion 108 and the cover extension portion 104 . The distance sensor apparatus 160 is connected to the control circuitry 112 through a sensor cable 146 , as will be discussed below with FIGS. 9 and 10 . FIG. 5 is a block diagram of one embodiment of the cardiopulmonary resuscitation device 100 of FIG. 1 . As mentioned above, the cardiopulmonary resuscitation device 100 includes the sound device 117 operatively coupled to the microcontroller 114 . The sound device 117 provides the sound indication in response to receiving the sound signal S Sound from the microcontroller 114 . The microcontroller 114 provides the sound signal S Sound to the sound device 117 in response to movement of the cardiopulmonary resuscitation device 100 , as will be discussed in more detail below. In this embodiment, the cardiopulmonary resuscitation device 100 includes the luminaire 143 operatively coupled to the microcontroller 114 . The luminaire 143 provides the visual indication in response to receiving the light signal S Light from the microcontroller 114 . The microcontroller 114 provides the light signal S Light to the luminaire 143 in response to movement of the cardiopulmonary resuscitation device 100 , as will be discussed in more detail below. It should be noted that, in some embodiments, the light signal S Light is provided by the sound device 117 so that the sound indication and visual indication are provided a substantially the same time. In this embodiment, the display screen 116 is operatively coupled to the microcontroller 114 through a display channel 111 so that a display signal S Display flows therebetween. The display signal S Display includes information it is desired to display on display screen 116 , as will be discussed in more detail below. As mentioned above, the cardiopulmonary resuscitation device 100 includes the pressure switch 142 . In this embodiment, the pressure switch 142 is connected directly to the circuit board 110 , and the battery cable connector 140 is connected to the battery cable 119 ( FIG. 4 ) in a repeatably removeable manner. The battery 118 ( FIG. 4 ) provides a power signal S Power to the battery cable connector 140 through the battery cable 119 . In this embodiment, the cardiopulmonary resuscitation device 100 includes biasing circuits 122 and 132 operatively coupled to the pressure switch 142 . The pressure switch 142 is repeatably moveable between activated and deactivated conditions. In the activated condition, the pressure switch 142 allows the power signal S Power to flow to the biasing circuits 122 and 132 . In the deactivated condition, the pressure switch 142 does not allow the power signal S Power to flow to the biasing circuits 122 and 132 . In some embodiments, the pressure switch 142 moves from the deactivated condition to the activated condition in response to a force applied to the cardiopulmonary resuscitation device 100 . In this embodiment, the cardiopulmonary resuscitation device 100 remains in the activated condition for a predetermined amount of time. In this embodiment, the biasing circuit 122 is in communication with a converter 120 , wherein the converter 120 is in communication with the display screen 116 . The biasing circuit 122 and converter 120 provide a potential difference V 2 to the display screen 116 when the pressure switch 142 is in the activated condition. The biasing circuit 122 and converter 120 do not provide the potential difference V 2 to the display screen 116 when the pressure switch 142 is in the deactivated condition. In this way, the display screen 116 , biasing circuit 122 and converter 120 are operatively coupled to the pressure switch 142 . Further, the biasing circuit 132 is in communication with a converter 130 , wherein the converter 130 is in communication with the microcontroller 114 . The biasing circuit 132 and converter 130 provide a potential difference V 1 to the microcontroller 114 when the pressure switch 142 is in the activated condition. The biasing circuit 132 and converter 130 do not provide the potential difference V 1 to the microcontroller 114 when the pressure switch 142 is in the deactivated condition. In this way, the microcontroller 114 , biasing circuit 132 and converter 130 are operatively coupled to the pressure switch 142 . The cardiopulmonary resuscitation device 100 includes the distance sensor apparatus 160 , which is connected to the control circuitry 112 through the sensor cable 146 . As will be discussed in more detail below, a sensor signal S Sensor flows between the distance sensor apparatus 160 and control circuitry 112 . In particular, the sensor signal S Sensor flows between the distance sensor apparatus 160 and microcontroller 114 . The sensor signal S Sensor is provided in response to movement of the cardiopulmonary resuscitation device 100 . The sensor signal S Sensor includes information corresponding to a distance that the cardiopulmonary resuscitation device 100 has moved. In this embodiment, the sensor cable 146 is connected to sensor cable connectors 147 and 148 at opposed ends, wherein the sensor cable connector 147 is connected to the distance sensor apparatus 160 in a repeatably removeable manner. The control circuitry 112 includes a sensor cable connector 141 carried by the circuit board 110 ( FIG. 6 a ). The sensor cable connector 148 is connected to the sensor cable connector 141 in a repeatably removeable manner. The control circuitry 112 is in communication with the distance sensor apparatus 160 so the sensor signal S Sensor can flow therebetween. In particular, the microcontroller 114 is in communication with the distance sensor apparatus 160 through the sensor cable 146 and sensor cable connectors 147 , 148 , and 141 . The microcontroller 114 is in communication with the distance sensor apparatus 160 so the sensor signal S Sensor can flow therebetween. In this way, the control circuitry 112 is in communication with the distance sensor apparatus 160 . FIG. 6 a is a side view of one embodiment of the control circuitry 112 carried by the circuit board 110 ( FIG. 4 ). The circuit board 110 can be of many different types of circuit boards. In this embodiment, the circuit board 110 is a printed circuit board. As will be discussed in more detail below with the circuit diagrams of FIGS. 6 b , 6 c , and 6 d , the control circuitry 112 includes a plurality of electrical components. The electrical components include conductive pins and/or terminals that extend through openings of the circuit board 110 , and are soldered thereto. The pins and terminals are connected together so that the electrical components operate as a circuit. The electrical components of the control circuitry 112 can be of many different types. For example, the electrical components of the control circuitry 112 include a resistor. The resistor can be of many different types, such as a through-hole and surface mounted resistor. The electrical components of the control circuitry 112 include a capacitor. The capacitor can be of many different types, such as an electrolytic capacitor. Electrolytic capacitors are provided by many different companies, such as Nichicon, which provides the UWT1E100MCL1GB and UWT1E220MCL1GB aluminum electrolytic capacitors. The electrical components of the control circuitry 112 includes an inductor. The inductor can be of many different types, such as a wire wound inductor. Wire wound inductors are provided by many different companies, such as ABRACON Corporation, which provides the AISC-1210HS wire wound inductor. Taiyo Yuden provides the CB2518T331K wire wound inductor. The electrical components of the control circuitry 112 include a diode. The diode can be of many different types, such as a Schottky barrier rectifier. VISHAY Intertechnology provides the SS1P3L and SS1P4L surface mounted Schottky barrier rectifiers. The electrical components of the control circuitry 112 include a connector, such as connectors 140 and 141 . The connector can be of many different types of connectors, such as a PCB header. PCB headers are provided by many different companies, such as MOLEX, which provides the 35312 Series of pitch headers. FIG. 6 b is a circuit diagram of a first portion of the control circuitry 112 of FIGS. 4 and 6 a . In this embodiment, the control circuitry includes the microcontroller 114 . The microcontroller 114 can be of many different types of microcontrollers. In this embodiment, the microcontroller 114 is a TEXAS INSTRUMENTS MSP430G2 Mixed Signal Microcontroller. A pin 10 of the microcontroller 114 is connected to the reference potential V 1 through a resistor 150 a . A pin 1 of the microcontroller 114 is connected to the reference potential V 1 , and a pin 14 of the microcontroller 114 is connected to the current return 145 . Pins 1 and 14 of the microcontroller 114 are in communication with each other through a capacitor 152 a . A pin 3 of the microcontroller 114 is connected to a first pin of the sensor cable connector 141 through a resistor 150 e . It should be noted that the sensor signal S Sensor flows through the resistor 150 a between the first terminal of the sensor cable connector 141 and pin 3 of the microcontroller 114 . Second and third pins of the sensor cable connector 141 are connected to the reference potential V 2 and current return 145 , respectively. A pin 4 of the microcontroller 114 is connected to a control terminal of a transistor 115 . The transistor 115 can be of many different types. In this embodiment, the transistor 115 is an NPN transistor, which is provided by NXP as model number PDTD123Y. A first terminal of the transistor 115 is connected to the current return 145 . The control circuitry 112 includes the sound device 117 . The sound device 117 can be of many different types. In this embodiment, the sound device 117 is a magnetic buzzer, which is provided by KOBITONE Audio Company as part number 254-EMB105-RO. The sound device 117 includes a first pin connected to the reference potential V 2 , and a second pin connected to a second terminal of the transistor 115 . In this embodiment, the control circuitry 112 includes the luminaire 143 . The luminaire 143 can be of many different types, such as a light emitting diode. The control circuit 112 includes the display screen 116 . The display screen 116 can be of many different types. In this embodiment, the display screen 116 is a NHD-0116AZ-FL-YBW liquid crystal display screen, which is provided by Newhaven Display International. The second pin of the sound device 117 is connected to a negative pin of the display screen. The control circuit 112 includes a resistor 150 d , which is connected between the reference potential V 2 and a positive pin of the display screen 116 . Pins 6 , 7 , 8 , and 9 of the microcontroller 114 are connected to pins 11 , 12 , 13 , and 14 , respectively, of the display screen 116 . It should be noted that the connection between the pins 6 , 7 , 8 , and 9 of the microcontroller 114 and the pins 11 , 12 , 13 , and 14 of the display screen 114 form the display channel 111 ( FIG. 5 ) through which the display signal S Display flows. As will be discussed in more detail below, the display signal S Display can include many different types of information, such as distance and/or rate information. The control circuitry 112 includes a resistor 150 c with a first terminal connected to the current return 145 , and a second terminal connected to a pin 3 of the display screen 116 . The second terminal of the resistor 150 c is connected to a first pin of a resistor 150 b . A second pin of the resistor 150 b is connected to the reference potential V 2 . Pins 1 and 5 of the display screen are connected to the current return 145 and to a first terminal of a capacitor 152 b . A second terminal of the capacitor 152 b is connected to the reference potential V 2 , and to a pin 2 of the display screen 116 . As discussed above with FIG. 5 , the reference potential V 1 of FIG. 6 b is provided by the converter 120 and biasing circuit 122 . Further, the reference potential V 2 of FIG. 6 b is provided by the converter 130 and biasing circuit 132 . One embodiment of a circuit that provides the reference potential V 1 is shown in FIG. 6 c , and one embodiment of a circuit that provides the reference potential V 2 is shown in FIG. 6 d. FIG. 6 c is a circuit diagram of a second portion of the control circuitry 112 of FIGS. 4 and 6 a , wherein the second portion includes the converter 120 and biasing circuit 122 . The converter 120 can be of many different types. In this embodiment, the converter 120 is an asynchronous DC-DC buck converter manufactured by BCD Semiconductor Manufacturing Limited as model number AP3211. In this embodiment, the control circuitry 112 includes the battery cable connector 140 . A first terminal of the battery cable connector 140 is connected to a first terminal of the pressure switch 142 , and a second terminal of the battery cable connector 140 is connected to the current return 145 . The pressure switch 142 is shown in FIGS. 1, 2, 5 and 8 . In this embodiment, the biasing circuit 122 includes a capacitor 125 a with a first terminal connected to the second terminal of the pressure switch 142 , and a second terminal connected to the current return 145 . The biasing circuit 122 includes an inductor 128 a with a first terminal connected to the first terminal of the capacitor 125 a , and a second terminal connected to a first terminal of a capacitor 125 b . A second terminal of the capacitor 125 b is connected to the current return 145 . In this embodiment, the biasing circuit 122 includes a resistor 126 a with a first terminal connected to the first terminal of the capacitor 125 b and a second terminal connected to a first terminal of a resistor 126 b . A second terminal of the resister 126 b is connected to the current return 145 . The biasing circuit 122 includes a capacitor 125 c with a first terminal connected to the first terminal of the resistor 126 a and a second terminal connected to the current return 145 . The converter 120 includes a pin 4 connected to the first terminal of the capacitor 125 c , and a GND terminal connected to the current return 145 . In this embodiment, the biasing circuit 122 includes a capacitor 125 d with first and second terminals connected to pin 1 and 6 of the converter 120 , respectively. The biasing circuit 122 includes a diode 129 with first and second terminals connected to the pin 6 of the converter 120 and the current return 145 , respectively. The biasing circuit 122 includes an inductor 128 b with a first terminal connected to the pin 6 of the converter 120 , and a second terminal connected to a first terminal of a resistor 126 c . The second terminal of the resistor 126 c is connected to a pin 3 of the converter 120 , and to a first terminal of a resistor 126 d . A second terminal of the resistor 126 d is connected to the current return 145 . The biasing circuit 122 includes a capacitor 125 e with a first terminal connected to the second terminal of the inductor 128 b , and a second terminal connected to the current return 145 . It should be noted that the second portion of the control circuitry 112 of FIG. 6 c provides the reference potential V 1 at the first terminal of the capacitor 125 e. FIG. 6 d is a circuit diagram of a third portion of the control circuitry 112 of FIGS. 4 and 6 a , wherein the third portion includes the converter 130 and biasing circuit 132 . The converter 130 can be of many different types. In this embodiment, the converter 130 is an asynchronous DC-DC buck converter manufactured by BCD Semiconductor Manufacturing Limited as model number AP3211. In this embodiment, the biasing circuit 132 includes a capacitor 135 a with a first terminal connected to the second terminal of the pressure switch 142 , and a second terminal connected to the current return 145 . The first terminal of the capacitor 135 a is connected to a pin 4 of the converter 130 . A GND pin of the converter 130 is connected to the current return 145 . In this embodiment, the biasing circuit 132 includes a capacitor 135 b with first and second terminals connected to pin 1 and 6 of the converter 130 , respectively. The biasing circuit 132 includes a diode 139 with first and second terminals connected to the pin 6 of the converter 130 and the current return 145 , respectively. The biasing circuit 132 includes an inductor 138 with a first terminal connected to the pin 6 of the converter 130 , and a second terminal connected to a first terminal of a resistor 136 a . A second terminal of the resistor 136 a is connected to a pin 3 of the converter 130 , and to a first terminal of a resistor 136 b . A second terminal of the resistor 136 b is connected to the current return 145 . The biasing circuit 132 includes a capacitor 135 c with a first terminal connected to the second terminal of the inductor 138 , and a second terminal connected to the current return 145 . It should be noted that the third portion of the control circuitry 112 of FIG. 6 d provides the reference potential V 2 at the first terminal of the capacitor 135 c. FIG. 7 is a perspective view of the circuit board 110 and control circuitry 112 of FIG. 4 , and FIG. 8 is an opposed perspective view of the circuit board and control circuitry 112 of FIG. 4 . As mentioned above, the circuit board 110 carries the control circuitry 112 and display screen 116 . The control circuitry 112 is connected to the display screen 116 , and controls the operation of the display screen 116 . In this embodiment, the control circuitry 112 is connected to the battery 118 through the battery cable 119 ( FIG. 4 ). In this embodiment, a battery cable connector 113 is connected to the battery cable 119 , wherein the battery cable connector 113 is repeatably moveable between connected and disconnected conditions with the battery cable connector 140 . The battery cable connector 140 is discussed in more detail above with FIGS. 5, 6 a , and 6 c . The battery 118 ( FIG. 4 ) provides the power signal S Power ( FIGS. 5, 6 c , and 6 d ) to the battery cable connector 140 ( FIGS. 5, 6 a , 6 b , and 6 c ) through the battery cable 119 and battery cable connector 113 . As mentioned above, the distance sensor apparatus 160 ( FIG. 4 ) is connected to the control circuitry 112 through the sensor cable 146 . The distance sensor apparatus 160 can be connected to the control circuitry 112 in many different ways. In this embodiment, a sensor cable connector 148 is connected to the sensor cable 146 , wherein the sensor cable connector 148 is repeatably moveable between connected and disconnected conditions with the sensor cable connector 141 ( FIGS. 5, 6 a , and 6 b ). The sensor signal S Sensor flows between the distance sensor apparatus 160 and the control circuitry 112 when the sensor cable connector 148 is connected to the sensor cable connector 141 . In particular, the sensor signal S Sensor flows between the distance sensor apparatus 160 and microcontroller 114 through the sensor cable 146 , and sensor cable connectors 141 and 148 . The sensor signal S Sensor flows between the sensor cable connector 141 and the microcontroller 114 , as shown in FIG. 6 b. In this embodiment, the control circuitry 112 includes the pressure switch 142 ( FIGS. 1, 2, 5, 8 ). As discussed in more detail above, with FIG. 5 , the pressure switch 142 turns the cardiopulmonary resuscitation device 100 to the activated condition in response to a force applied thereto. In the on and off positions, the display screen 116 is in an on and off condition, respectively. Further, in the on and off positions, the control circuitry 112 is in an on and off condition, respectively. In this embodiment, the control circuitry includes the luminaire 144 ( FIG. 8 ). The luminaire 144 can be of many different types of lights, such as a light emitting diode. Light emitting diodes are provided by many different manufacturers, such as CREE and Philips. Visual Communications Company (VCC) provides the VAOL-3GWY4 Superbright LED lamp. The luminaire 144 can provide many different colors of illumination, such as white, red, green, and blue, among others. It should be noted that a lens can be positioned proximate to the luminaire 144 . The lens can be of many different types, such as a Fresnel lens. The lens is useful to focus the light provided by the luminaire 144 . The lens is also useful to hold the luminaire 144 to the cardiopulmonary resuscitation device 100 . As will be discussed in more detail below, the luminaire 144 is useful to provide the user of the cardiopulmonary resuscitation device 100 with a visual indication that the sternum is being compressed and decompressed the desired distance. FIG. 9 is a perspective view of a distance sensor apparatus 160 of FIG. 4 , and FIG. 10 is an opposed perspective view of the distance sensor apparatus 160 of FIG. 3 . The distance sensor apparatus 160 can be of many different types. In this embodiment, the distance sensor apparatus 160 is an ultrasonic distance sensor. There are many different ultrasonic distance sensors that can be used, such as the PING ultrasonic distance sensor, which is provided by PARALAX as model number 28015. In this embodiment, the distance sensor apparatus 160 includes a circuit board 164 , which carries distance sensor circuitry 162 ( FIG. 10 ). The transmit and receive sensors 166 and 167 are carried by the circuit board 164 and operatively coupled to the distance sensor circuitry 162 . As mentioned above, the distance sensor apparatus 160 is connected to the sensor cable 146 . The distance sensor apparatus 160 can be connected to the sensor cable 146 in many different ways. In this embodiment, the distance sensor apparatus 160 includes a sensor cable connector 168 , which is carried by the circuit board 164 and connected to the distance sensor circuitry 162 . As mentioned above with FIG. 5 , the sensor cable connector 147 is connected to the sensor cable 146 . The sensor cable connector 147 is repeatably moveable between connected and disconnected conditions with the sensor cable connector 168 . The sensor signal S Sensor is allowed to flow through the sensor cable 146 when the sensor cable connector 147 is connected to the sensor cable 146 . As mentioned above, one reason people do not survive when receiving CPR outside of a hospital is because the CPR is not performed correctly. The operation of the cardiopulmonary resuscitation device 100 will now be discussed to illustrate how it facilitates the correct performance of CPR. FIG. 11 is a front view of the cardiopulmonary resuscitation device 100 being operated by a user when performing CPR on a patient 170 , wherein the patient is supported by a support surface 171 (e.g., a floor or ground). It should be noted that the pressure switch 142 turns the cardiopulmonary resuscitation device 100 to the activated condition in response to the user applying the force thereto. The luminaire 144 moves from the deactivated condition to the activated condition in response to the user applying the force thereto. In particular, the force is applied to the cover 102 . Further, it should be noted that transmit and receive sensors 166 and 167 are shown in phantom in FIG. 11 . In this embodiment, the cardiopulmonary resuscitation device 100 is positioned on the chest 172 of the patient 170 . In particular, the cardiopulmonary resuscitation device 100 is positioned on the chest 172 of the patient 170 so the case 106 extends across a sternum 174 of the patient 170 . It should be noted that the chest 172 is typically resilient, so it moves back into shape after being compressed. In this way, chest 172 forms a resilient surface. In this embodiment, the cardiopulmonary resuscitation device 100 is positioned on the chest 172 of the patient 170 so that in use, as shown in FIGS. 11, 12 a and 13 a , the extension portion 109 extends beyond the body of the patient away from the chest 172 . In particular, the cardiopulmonary resuscitation device 100 is positioned on the chest 172 of the patient 170 so the extension portion 109 extends away from the sternum 174 . The extension portion 109 extends away from the sternum 174 and over a shoulder 173 of the patient 170 . The extension portion 109 extends over the shoulder 173 so that the distance sensor apparatus 160 faces the support surface 171 . In particular, the extension portion 109 extends over the shoulder 173 so that the transmit sensor 166 and receive sensor 167 face the support surface 171 . The extension portion 109 extends away from the chest 172 so the distance sensor apparatus 160 is held away from the chest 172 . FIG. 12 a is a side view of the cardiopulmonary resuscitation device 100 in a direction 176 of FIG. 11 , and FIG. 12 b is a partial view of the cardiopulmonary resuscitation device 100 in a region 177 of FIG. 11 . The cardiopulmonary resuscitation device 100 is shown positioned on the chest 172 in FIG. 12 a in the same orientation shown in FIG. 11 . It should be noted that the shortened side 157 is shown when looking in the direction 176 . Further, it should be noted that the transmit and receive sensors 166 and 167 are shown in phantom in FIG. 12 a . As will be discussed in more detail below, the transmit and receive sensors provide an ultrasonic pulse S Ultrasonic and echo pulse S Echo , respectively. As will be discussed in more detail below, it is desirable to move the chest 172 between uncompressed and compressed positions in a repeatable manner. The uncompressed position is denoted as Position 1 , and the compressed position is denoted as Position 2 . Hence, it is desirable to move the chest 172 between the Positions 1 and 2 in a repeatable manner. The distance between Positions 1 and 2 is denoted as a distance D 1 . Further, the distance between the Position 1 and the support surface 171 is denoted as a distance D 2 . In FIG. 12 b , the position of the cardiopulmonary resuscitation device 100 is displayed by the display screen 116 . For simplicity and illustrative purposes, the position of the cardiopulmonary resuscitation device 100 at Position 1 is displayed as “0 cm” by the display screen 116 . As will be discussed in more detail below, the display screen will display a distance value corresponding to distance D 1 when the cardiopulmonary resuscitation device 100 at Position 2 . It should be noted that at Position 1 , the luminaire 143 does not provide light, and the sound device 117 does not provide the sound indication. It should also be noted that the distance value is provided to the display screen 116 with the display signal S Display . In this embodiment, the display screen 116 displays information corresponding to the rate in which the chest 172 is moving between the compressed and uncompressed positions. The information corresponding to the rate in which the chest 172 is being compressed and uncompressed is displayed in units of counts per minute (cpm). It should be noted that information corresponding to the rate is provided to the display screen 116 with the display signal S Display . In FIG. 12 b , the counts per minute is being displayed as “0 cpm” for simplicity and illustrative purposes. Hence, information corresponding to “0 cpm” is provided to the display screen 116 with the display signal S Display . In operation, and as shown in FIG. 12 a , a force 178 is applied to the cardiopulmonary resuscitation device 100 and, in response, the cardiopulmonary resuscitation device 100 moves from the deactivated condition to the activated condition. In some embodiments, the cardiopulmonary resuscitation device 100 remains in the activated condition for a predetermined amount of time in response to the force 178 being applied thereto. The force 178 is applied to the cardiopulmonary resuscitation device 100 so that the chest 172 moves from the uncompressed position at Position 1 to the compressed position at Position 2 in response. In particular, the force 178 is applied to the cover 102 and case 106 . The force 178 is typically applied using the hands (not shown) of the user of the cardiopulmonary resuscitation device 100 . It should be noted that the force 178 is applied more evenly across the chest 172 and sternum 174 because the cardiopulmonary resuscitation device 100 is positioned as shown in FIG. 11 . Recent medical studies show that applying the force 178 across the chest 172 and sternum 174 increases the likelihood that the patient 170 will survive. In particular, the force 178 is distributed along the length axis 103 ( FIG. 2 ). It is believed that distributing the force 178 along the length axis 103 increases the likelihood that the patient 170 will survive. FIG. 13 a is a side view of the cardiopulmonary resuscitation device 100 in the direction 176 of FIG. 11 , and FIG. 13 b is a partial view of the cardiopulmonary resuscitation device 100 in the region 177 of FIG. 11 . The cardiopulmonary resuscitation device 100 is shown positioned on the chest 172 in FIG. 13 a in the same orientation shown in FIG. 11 . It should be noted that the shortened side 157 is shown when looking in the direction 176 . Further, it should be noted that the transmit and receive sensors 166 and 167 are shown in phantom in FIG. 13 a. In operation, the distance sensor apparatus 160 provides the ultrasonic pulse S Ultrasonic towards the support surface 171 with the transmit sensor 166 , and the distance sensor apparatus 160 receives the echo pulse S Echo with the receive sensor 167 in response. It should be noted that the echo pulse S Echo corresponds to the ultrasonic pulse S Ultrasonic being reflected by the support surface 171 . The distance sensor apparatus 160 provides the ultrasonic pulse S Ultrasonic and receives the echo pulse S Echo in response to the cardiopulmonary resuscitation device 100 being moved between Positions 1 and 2 . The sensor signal S Sensor is provided to the microcontroller 114 by the distance sensor apparatus 160 in response to the ultrasonic pulse S Ultrasonic being transmitted. The sensor signal S Sensor is terminated in response to the echo pulse S Echo being received by the receive sensor 167 . The width of the echo pulse S Echo corresponds to the distance D 2 the ultrasonic pulse traveled. Information corresponding to the width of the echo pulse S Echo is provided to the control circuitry 112 with the sensor signal S Sensor . In particular, information corresponding to the width of the echo pulse S Echo is provided to the microcontroller 114 with the sensor signal S Sensor ( FIGS. 5, 6 b , and 7 ). The microcontroller 114 determines the distance D 1 by determining the width of the echo pulse S Echo . Information corresponding to the distance D 1 is provided to the display screen 116 by the microcontroller 114 through the display channel 111 ( FIGS. 5 and 6 b ). It should be noted that information corresponding to the distance D 1 is provided to the display screen 116 with the display signal S Display . As shown in FIG. 13 a , the cardiopulmonary resuscitation device 100 has moved from the Position 1 to Position 2 , which corresponds to a movement of the distance D 1 . Hence, the display screen 116 displays a distance value corresponding to distance D 1 . In FIG. 13 b , the distance value is chosen to be “5 cm” because recent medical studies show that this is the optimum compression distance for CPR. Information corresponding to “5 cm” is provided to the display screen 116 in the display signal S Display . It should be noted that the distance value can have many other values that depend on the distance D 1 between Positions 1 and 2 . The display screen 116 will display the distance that the cardiopulmonary resuscitation device 100 has moved during CPR so that the user will know how far the chest 172 has been compressed. It is believed that the distance value of about 5 centimeters is desired to increase the likelihood that the patient 170 will survive CPR. It should be noted that at Position 2 , the luminaire 143 does provide light, and the sound device 117 does provide sound the sound indication. In this way, the cardiopulmonary resuscitation device 100 provides a visual and audio indication that the chest 172 has been compressed a desired amount. Further, the cardiopulmonary resuscitation device 100 does not provide the visual and audio indication if the chest 172 has not been compressed the desired amount. In response to the visual and audio indication, the user removes the force 178 so that the chest 172 moves from Position 2 to Position 1 . The movement of the chest 172 from Position 2 to Position 1 is indicated by a force 179 . It should be noted that the force 179 can be from the resiliency of the chest 172 . It should be noted that the display screen 116 displays distance values between Position 1 and Position 2 while the cardiopulmonary resuscitation device 100 is moving therebetween. Hence, in the example above, the display screen 116 will display “2.5 cm” when the cardiopulmonary resuscitation device 100 is halfway between Positions 1 and 2 . In this way, the display screen 116 displays an intermediate distance value. It should be noted that information corresponding to the intermediate distance values is provided to the display screen 116 with the display signal S Display . As mentioned above, the display screen 116 displays information corresponding to the rate in which the chest 172 is being compressed and uncompressed. In FIG. 13 b , the counts per minute is being displayed as “100 cpm” for simplicity and illustrative purposes. Recent medical studies show that the rate value of about 100 cpm is desired to increase the likelihood that the patient 170 will survive CPR. In this way, the cardiopulmonary resuscitation device 100 provides the user with information corresponding to the rate of compressions. It should be noted that information corresponding to “100 cpm” is provided to the display screen 116 with the display signal S Display . Hence, the invention provides a cardiopulmonary resuscitation device which facilitates the ability of the user to correctly perform CPR on a patient. The cardiopulmonary resuscitation device provides a visual indication that CPR is being performed at a desired rate of compressions and decompressions. Further, the cardiopulmonary resuscitation device provides visual and audio indications that the chest of the patient has been compressed by a desired amount. The cardiopulmonary resuscitation device is also shaped so that the force applied to the chest of the patient is applied more evenly, so that the entirety of the thoracic cavity is compressed and not just one sharp point. These features of the cardiopulmonary resuscitation device allow the user to increase the likelihood that the patient will survive CPR. FIG. 14 a is a perspective view of a cardiopulmonary resuscitation device 200 , according to another embodiment. The cardiopulmonary resuscitation device 200 is similar in many respects to the cardiopulmonary resuscitation device 100 except that it is designed for use on infants. As illustrated, the cardiopulmonary resuscitation device 200 includes a case 206 that is smaller in size than the case 106 since it is to be used on a small-sized person. A protection layer 204 , constructed of a high-density foam material or the like, is disposed on a bottom surface of the case 206 so that compressions are gentler. Legs 210 support the case 206 and permit the case 206 to be lowered onto the chest of the infant 240 . The legs 210 support the case 206 and permit the case 206 to be positioned on the chest of the small person or infant 240 , the case 206 extending across the chest and upper arms of the infant 240 so each leg 210 of the pair of legs supports the case 206 and extends generally exterior of an arm of the infant 240 . Each of the legs 210 may further include feet 208 on respective distal ends. The legs 210 can include a plurality of notches 212 each of which is set apart a predetermined distance. The legs 210 are prevented from being lowered by detents 215 . In operation, the detents 215 can be released by pulling tabs 218 which allow the case 206 to freely side down until it touches the chest of the infant 240 . When the case 206 reaches the proper position, the tabs 218 can be released to again lock the detents 215 . FIG. 14 b is a cutaway view of the cardiopulmonary resuscitation device 200 in the compression phase. In the compression phase, the device 200 compresses the chest and sternum of the infant 240 . In operation, compression can occur by pressing down on finger pads 220 . The pressing motion causes the case 206 , to push against the chest and sternum of the infant, distributing the pressing force substantially evenly along the length axis of the case 206 and across the chest and sternum of the infant 240 . Decompression is facilitated by springs 202 that urge the case 206 back upwardly when pressure against the finger pads 220 is momentarily released. FIG. 14 c is a cutaway view of the cardiopulmonary resuscitation device 200 in the decompression phase. Although other embodiments of the cardiopulmonary resuscitation device utilize an ultrasonic distance sensor, the cardiopulmonary resuscitation device 200 need not use an ultrasonic distance sensor. Instead, a limit switch can be used to determine whether the case 206 has been moved a proper distance. In an embodiment, the springs 202 are only able to compress about 3 mm. Once the distance traveled is reached, the springs 202 concurrently hit a hard stop and a limit switch 250 . Once the limit switch is activated, it can activate the luminaire 143 and cause the sound device 117 to emit an audible sound, as described previously with respect to other embodiments. Furthermore, the data from the limit switch can be used by a microcontroller or equivalent to measure and then display the number of compressions per minute on the display screen 116 . The embodiments of the invention described herein are exemplary and numerous modifications, variations and rearrangements can be readily envisioned to achieve substantially equivalent results, all of which are intended to be embraced within the spirit and scope of the invention as defined in the appended claims.

A cardiopulmonary resuscitation device includes a case having an extension portion extending therefrom. In operation, the user places the case across the chest of a person being given CPR, and presses the case into the person's chest, applying uniform force in according to a rhythm guided by audible and/or visual feedback. The cardiopulmonary resuscitation device includes a control circuit having a display screen, and a distance sensor apparatus operatively coupled to the control circuit. In another embodiment, the cardiopulmonary resuscitation device is structured for use on an infant-sized human. In this embodiment, the device includes a pair of legs extending through the case, the support structure permitting the case to be positioned on the chest of an infant-sized human; wherein the case is useable to perform cardiopulmonary resuscitation on the infant-sized human by repeated press-release movements using a finger pad disposed on the case.

BACKGROUND OF THE INVENTION The invention relates generally to heart-monitoring systems and more particularly to the improved suppression of pacemaker artifacts appearing in ECG signals. In the art of heart-monitoring, thoracic electrical potentials of the patient are sensed to provide an input signal to amplifying means which amplify and process the signal for application to various utilization devices including recorders, CRT displays, heart-rate indicating means, and the like. In the particular instance of heart-rate monitoring, the heart-rate indicator is normally responsive only to sensed signals which correspond in frequency and amplitude substantially with the QRS complex or the R wave of a natural heart beat appearing in the ECG. However, in the event the patient is receiving artificial stimulation as by a heart pacemaker, the sensed electrical signals resulting directly from the pacer may additionally introduce artifact signals having amplitudes and/or frequencies which may be inaccurately identified as a naturally occurring heart rhythm and, in the worst case, may provide an indication of continuing heart activity when, in fact, heart activity has ceased and the patient is technically dead. This erroneous determination that a pacer signal artifact constitutes a normal QRS complex may be made not only by heart-rate indicating means, but also by other analytical means including human observers. For this reason, it is important to suppress pacer signal artifacts which might otherwise be misinterpreted as a functioning of the heart. The pacer signal artifact normally comprises a stimulation pulse portion, or "spike", representative of the discharge of capacitively-stored electrical energy into the patient's heart and generally also a recharge waveform portion or "tail" attending the recharge of the pacer's energy-storing capacitor. The prior art has provided various circuit means for suppressing the "spike" portion of the pacer signal artifact, usually by preventing transmission of the sensed signal to the utilization circuitry for the duration of the pacer discharge pulse. Such circuits have, however, generally been relatively complex and/or subject to drift and/or muscle noise or artifact. Recently, means have been provided for also suppressing the pacer recharge waveform or "tail", as described in greater detail in U.S. application Ser. No. 760,487 for PACEMAKER ARTIFACT SUPPRESSION IN CORONARY MONITORING BY Marchese et al., filed Jan. 19, 1977, now U.S. Pat. No. 4,105,023 and which is incorporated herein by reference to the extent consistent herewith. Briefly, the "tail" suppression circuitry of the aforementioned application utilizes a differentiating circuit to recognize the occurrence of a pacer pulse and to control the timing of an interval associated with pacer recognition circuitry such that immediately following the end of the "spike" portion of a recognized pacer signal artifact, the pacer "tail" portion is sampled and the amplitude of the sample is utilized for generating a "tail" suppression signal of opposite polarity to the "tail" portion of the pacer signal artifact. The "tail" suppression signal is arithmetically added with the ECG signal containing the pacer signal artifact such that the pacer "tail" portion thereof is reduced in amplitude and substantially cancelled, thereby avoiding the possibility of its actuating rate-indicating circuitry or the like. Regarding the prior technique and circuitry for suppressing the "tail" portion of the pacer signal artifact as disclosed in the aforementioned U.S. patent application, it will be appreciated that generation of the "tail" suppression signal required an amplitude measurement to be made of the "tail" immediately following termination of the "spike" portion of the pacer signal artifact. In order to accomplish this, it was first necessary to determine that a high frequency signal in the sensed ECG was indeed a pacer artifact signal and subsequently to accurately identify the brief interval during which the amplitude of the "tail" is to be sampled. The circuitry employed for such technique tends to be complex. Accordingly, it is a principal object of the present invention to provide an improved means for the suppression of pacer signal artifact in a heart-monitoring system. Included in this object is the provision of means for preventing false actuation of heart-rate indicating means by any portion of a heart pacer signal artifact. It is a further object of the present invention to provide improved means for suppressing the recharge waveform portion of a pacer signal artifact appearing in a sensed ECG signal. Included in this object is the provision of relatively simple, reliable and low-cost means for the suppression of the recharge waveform portion of a signal artifact. It is a still further object of the present invention to provide improved pacer signal artifact suppression means with minimal response to muscle artifact. It is an even further object of the present invention to provide improved means for the suppression of the discharge pulse portion of a pacer signal artifact. These and other objects will be in part obvious and in part pointed out in greater detail hereinafter. SUMMARY OF THE INVENTION One aspect of the invention recognizes that the electrical recharge of a pacer is equal and opposite to its heart-stimulating electrical discharge. By measuring the latter and knowing approximately the time-constant of the former, it is possible to generate an approximate recharge suppression signal. In accordance with the principles of the invention, there is provided, in a heart-monitoring system for receiving a sensed ECG signal from a patient and including means for suppressing the pacer discharge pulse portion and the recharge waveform portion of a heart pacer signal artifact possibly appearing in the sensed ECG signal, improved signal suppression means comprising means responsive to the pacer discharge pulse portion of a pacer signal artifact in the sensed ECG signal for providing a measure of the electrical discharge of the respective discharge pulse portion, said measure of discharge being representative of the electrical recharge of the recharge waveform portion of the respective pacer signal artifact; means responsive to said measure of electrical discharge for generating a recharge waveform suppression signal of opposite polarity to the recharge waveform portion of the pacer signal artifact; and means for arithmetically summing the recharge waveform suppression signal with the recharge waveform portion of the pacer signal artifact, the magnitude and time constant of the recharge waveform suppression signal being scaled to reduce and/or substantially cancel the recharge waveform portion of the pacer signal artifact. In a preferred embodiment, the means for obtaining a measure of the pacer electrical discharge comprises integrating a signal proportional to the voltage of the discharge pulse portion of a pacer signal artifact utilizing an operational amplifier having an input and an output, the sensed ECG signal being connected to the amplifier input, and energy-storing means connected in a local feedback loop between the output and the input of the operational amplifier at least for the interval during which a pacer discharge pulse portion exists for integrating the sensed ECG signal applied to the operational amplifier input, the integral of the ECG signal over the interval of pacer discharge pulse portion existence being a measure of the pacer electrical discharge of the respective pacer discharge pulse portion. Further, the recharge waveform suppression signal generating means comprises means for utilizing the energy stored by the storing means during the integration to generate a suppression current of decreasing magnitude substantially immediately following the discharge pulse portion of the pacer signal artifact, the initial magnitude and the rate of decay of the suppression current being determined by a resistance-capacitance circuit to which the stored energy is applied, the suppression current being extended to the operational amplifier input and being of the opposite polarity to the current of the recharge waveform signal portion of the sensed ECG signal applied to the operational amplifier input thereby to have a mutually cancelling effect. The capacitance of the aforementioned resistance-capacitance circuit may also comprise part of the feedback loop so as to provide the energy-storing or integrating means. The aforementioned feedback loop including the energy-storing means is normally disconnected from significant feedback relationship with the operational amplifier and is selectively controllable for connection into significant feedback relationship therewith, the feed-back arrangement including controllable, normally-open switch means in series with the energy-storing means and being responsive to the output of the operational amplifier exceeding a predetermined amplitude level for connecting the feedback arrangement in significant feedback relationship with the operational amplifier. A second feedback loop is normally operatively connected between the output and input respectively of the operational amplifier for providing negative feedback to the operational amplifier input to limit the amplitude of the signal appearing at the output thereof to values normally less than the predetermined amplitude level required for response of the switch means. The second feedback loop includes rate-limiting means and second integrating means, the former serving to effectively disconnect the loop when a predetermined rate-of-amplitude change of the sensed ECG signal is exceeded to allow the operational amplifier output signal to exceed the predetermined amplitude level required for response to the switch means and the latter being utilized to minimize or eliminate DC offset in the operational amplifier's output signal. The normally-open switch means may comprise a pair of oppositely-poled, parallel-connected, complementary transistors connected between the output of the operational amplifier and the energy-storing means. A resistor of relatively large ohmic value connected in parallel with the transistor switches serves to minimize the appearance of noise in the signal from the operational amplifier when both transistors are non-conducting and the first or local feedback loop is essentially opened. According to a further aspect of the invention, improved suppression and/or rejection of the pacer pulse portion, as well as the brief initial portion of the "tail", is provided by gated follow and hold circuitry which passes or blocks passage of a tentative output signal appearing at a selected point in the aforementioned feedback loop. Preferably, the tentative output signal is obtained at the output of the rate-limiting means, which output may be undesirable during rate-limiting. Signal level detection means respond to the signal at the output of the operational amplifier exceeding a predetermined threshold occurring only during rate-limiting to control the follow and hold means such that it blocks passage of the tentative output signal during that interval. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic representation of the heart-monitoring system of the invention operatively connected to a patient having an implanted heart pacer; FIG. 2 depicts the output circuit of the heart pacer including the impedance of the patient; FIG. 3 represents the sensed thoracic voltage waveform of a patient having a pacemaker and includes sensed pacer stimulation pulses and PQRST complexes of the heart; FIG. 4 is an enlarged partial view of FIG. 3 showing a sensed pacer signal artifact in greater detail; FIG. 5 is a schematic diagram of the ECG amplifier including the pacer signal artifact suppression circuitry of the heart-monitoring system of FIG. 1; and FIGS. 6a-6g comprise a waveform ladder diagram showing the time and amplitude relationships of various waveforms throughout the ECG amplifier of FIG. 5. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, there is illustrated a heart-monitoring system 10 comprised of an ECG amplifier 11, a heart-rate meter 12, and display 14 which may be a CRT and/or a permanent recorder. The monitoring system 10 and more specifically the ECG amplifier 11, is electrically connected to a patient 15 via a plurality of conductors 16 connected with respective electrodes 17 in contact with, and appropriately positioned on, the skin of the patient. FIG. 1, being merely diagrammatic, does not necessarily represent optimum positioning of electrodes 17. Patient 15 is illustrated as having an implanted pacer 18 connected in operative heart-stimulating relation with his heart 19. Typically the output circuitry of pacer 18, as illustrated in FIG. 2, includes a capacitor, C, connected through a resistor, R, to a source of voltage, +E, and connected at its other end to a heart electrode 21 which is operatively disposed within or adjacent to heart 19. Another electrode 22 of the pacer 18 is also operatively connected to the heart 19 and serves as a circuit reference or current return path. The patient 15 represents an impedance R p between the electrodes 22 and 21. Capacitor C charges through the circuit comprising patient impedance R p , capacitor C and resistor R. A switching transistor 20 having a grounded emitter and having its collector connected to resistance R and capacitor C is switched into conduction for discharging the energy stored in capacitor C into the heart 19 to provide stimulation in a known manner. FIG. 4 represents the waveform of the voltage e h appearing at electrode 21 of pacer 18 in FIG. 2 during and following the generation of a pacer discharge or stimulation pulse ("spike") DP. Capacitor C is assumed to be charged to voltage +E prior to the occurrence at time t o , of a control signal of duration T w on the base of transistor 20. The control signal (not shown) controls the time during which energy is discharged to the heart 19 and typically may be about 0.5-3 msec., with 2 msec. being selected for the purposes of illustration herein. At t 0 transistor 20 conducts, immediately dropping the voltage at electrode 21 by the magnitude E. The capacitor C then begins to discharge through the heart with a time constant T d which is the product of capacitor C and the patient impedance R p . At the end of 2 msec. (i.e. t 2 ), normally prior to complete discharge of capacitor C, transistor 20 is turned off and the capacitor C begins to recharge with the time constant T c being equal to (R + R p ) C, where R is known and generally many times larger than R p . It will be noted in FIG. 4 that when the discharge pulse DP terminates at t 2 (2 msec.), the voltage on pacer electrode 21 moves positively beyond the normal zero reference level and experiences an overshoot voltage e 4 which is determined by the relationship e 4 = (e 3 R p )/(R + R p ), where e 3 is the magnitude of voltage decay during discharge of capacitor C. Typically, the magnitude of voltage E may be 6 volts, R p might be about 500 ohms, R may be about 25 kilohms, e 3 may be several volts, and the magnitude of the overshoot e 4 may be about 1/40 of that, or in the range of 25-150 MV. The recharge time constant T c may be 200-300 msec. such that capacitor C is not substantially fully recharged for possibly 500 msec. or more. Accordingly, it will be appreciated that the pacer recharge waveform RW, or so-called pacer "tail", may have a magnitude greater than 100 MV at the heart for many 10's of milliseconds and even more than 100 msec. Important to the invention, as will later become evident, is the fact that the electrical recharge of capacitor C is equal and opposite to its electrical discharge. The charge (or discharge) is proportional to the integral of the voltage with time, assuming a constant capacitance. Thus, in FIG. 4, the integral of the spike (SV DP ) provides a measure of the discharge and the integral of the tail (SV RW ) provides a measure of the recharge, the two being equal and opposite at the end of their respective pacer signal portions. Although the magnitude of the pacer discharge pulse DP and the recharge waveform RW are substantially attenuated when sensed by electrodes 17 at the skin of patient 15, the electrical signals attendant normal heart functioning and represented by the PQRST complex of FIG. 3 are similarly attenuated such that the pacer discharge pulse DP is normally many times larger than any part of the PQRST complex and the recharge waveform RW may have an initial magnitude comparable to or greater than the R-wave portion of the complex. Furthermore, the general frequency characteristics of the recharge waveform RW are comparable to those exhibited by a normal QRS complex. For these reasons, the pacer discharge pulse DP and/or the recharge waveform RW may jointly or separately appear as normal QRS complexes to the R-wave detection circuitry of heart-rate meter 12, as well as to someone monitoring the display 14. Referring briefly to FIG. 3, the displayed waveform illustrates the signal sensed by electrode 17 at the skin of patient 15 and provided as an input signal to amplifier 11 of the monitoring system 10. The left-most perturbation in the signal is designated PSA for Pacer Signal Artifact and includes the discharge pulse portion DP and the recharge waveform portion RW of a pacer pulse. This particular PSA was not successful in achieving capture of the heart. The next-rightward perturbation shows a pacer signal artifact PSA which was successful in achieving capture of the heart, thus resulting in the stimulated generation of the Q (not seen) RST complex by the heart within about 100 msec. after the pacer pulse. Next rightward, there is illustrated a complete, natural PQRST complex of the heart, without a PSA signal inasmuch as pacer 18 is of the demand type. Finally, there is a repetition of a pacer signal artifact PSA which is unsuccessful in achieving capture of the heart. The heart rate meter 12 possesses magnitude and frequency discriminating circuitry of a generally known type for recognizing the R-wave in the ECG signal and recording or indicating such as evidence of a heart beat. However, that circuitry of meter 12 may also respond to the discharge pulse DP and/or the recharge waveform RW of the pacer signal artifact PSA to additionally register a heart beat, when, in fact, no heart beat may be present. Accordingly, circuitry associated with amplifier 11 is operative to suppress not only the discharge pulse DP but also the recharge waveform RW in accordance with the invention to prevent their falsely actuating the rate meter 12. It will be appreciated that while the pacer signal artifact suppression circuitry to be hereinafter described is preferably associated with amplifier 11, at least a portion of it might be "packaged" as part of the rate meter 12. In the illustrated embodiment, the circuitry for suppressing the pacer signal artifact is provided in the ECG amplifier 11, shown in greater detail in FIG. 5. Most of the circuitry of amplifier 11 is isolated, as represented by the dotted line 23 in FIG. 5, to prevent the flow of dangerous currents between the patient and the remaining circuitry such as rate meter 12 and/or display unit 14. A floating power supply 24 provides the requisite operating potentials for the isolated section of amplifier 11 and includes a floating reference potential (illustrated as ), +V (i.e. +15 volts), and -V (i.e. +15 volts). The +and -V power supply potentials are extended to the various differential amplifiers and related circuitry of ECG amplifier 11 by conductors omitted from the illustration. The leads 16 from the patient comprise inputs to the differential preamplifier A 0 which develops and initially amplifies the basic ECG input signal to amplifier 11. Amplifier A 0 may typically have a gain of about fifteen (15) and further has a one kHz bandwidth for attenuating high frequency noise. The preamplified signal appearing at the output of amplifier A 0 is extended through input resistor 25 to input junction 26 which is connected to the inverting input of an operational amplifier A 1 . The input signal to amplifier A 1 from the patient via preamplifier A 0 and resistor 25 is illustrated in FIG. 6A and includes a T-wave at the end of a PQRST complex and a pacer signal artifact. It will be appreciated that the duration of the T-wave is many, many times that of the spike portion of the pacer artifact. The non-inverting input to operational amplifier A 1 is normally connected to a reference potential such that the amplifier inverts the input signal illustrated in FIG. 6A. The inverting amplifier A 1 is provided with a general feedback loop designated by arrow 27 for providing degenerative or negative feedback to the input thereof and a local, negative feedback loop also connected to the input thereof and designated by the arrow 28. The feedback loops, as represented by arrows 27 and 28, generally operate in a complementary nature to one another with the general feedback loop 27 providing significant feedback in the presence of normal ECG signals except during the early interval of a pacer signal artifact, and the feedback loop 28 providing significant feedback essentially only during the interval in which loop 27 does not provide significant feedback. The term "significant" as applied to feedback loops 27 and 28 herein is used to distinguish operation of those feedback loops in their conventional feedback mode from that mode approximating an open loop condition in which little or no feedback is provided. In addition to the normal ECG signal input from amplifier A 0 and the complementary inputs from feedback loops 27 and 28, the amplifier A 1 also receives at junction 26 an input comprising a recharge waveform suppression signal developed over the path designated by arrow 29. In fact, the recharge waveform suppression signal path represented by arrow 29 operates in time-succession with the provision of negative feedback via the feedback loop represented by arrow 28, both having an energy-storing capacitor 30 in common therewith for the purpose to be hereinafter explained. The output of amplifier A 1 is extended via line 31 to a rate limiter 32, the output of which is extended to the non-inverting input of an amplifier A 2 . The general negative feedback loop (represented by arrow 27) for amplifier A 1 is completed by extending the signal appearing at the output of amplifier A 2 through a low frequency rejection circuit or integrator 33 and thence through resistor 34 to the junction 26 at the input of amplifier A 1 . The rate limiter 32 serves a dual function, that of partially suppressing the discharge pulse portion of a pacer signal artifact and possibly the more important function of essentially opening the feedback loop 27 throughout the interval of the pacer discharge pulse portion and continuing for a like interval thereafter. The rate limiter 32 is of conventional design and includes a four-diode bridge having a resistor 36 connected from the positive supply of voltage to the common anodes of two legs of the bridge and a resistor 37 connected from the negative supply of voltage to the common cathodes of the other two legs of the bridge. Conductor 31 is connected to apply the output of amplifier A 1 to one cathode-anode junction of bridge 35, the other cathode-anode junction thereof being connected to one side of a capacitor 38 which has its other side connected to the reference potential. The values of resistors 36 and 37 are identical and form complementary current sources to the bridge 35 and ultimately to capacitor 38. The magnitude of current supply to the capacitor 38 is controlled by the amplitude of the signal appearing on 31 up to a maximum current determined by the values of the resistors 36 and 37. In the present embodiment, the values of resistors 36 and 37 (91k ohm) and the value of capacitor 38 (10M fd ) are selected such that the maximum rate at which the voltage on capacitor 38 may vary is limited to some predetermined value. In the present instance, that value is 1 volt per second referred to the input of amplifier 11 (i.e. about 15 volts per second at capacitor 38). The voltage on capacitor 38 is thus able to accurately follow the voltage excursions on line 31 for signal slew rates which are less than the predetermined rate limit, but is limited by the predetermined rate-limit value for signal excursion rates which exceed that limit. The rate-limit value is selected to pass those signals appearing on line 31 having frequency characteristics commensurate with either the normal PQRST complex of an ECG signal or the myoelectric artifacts commonly referred to as muscle noise, and to rate-limit for higher signal slew rates which are characteristic of the discharge pulse portion of a pacer signal artifact. By not rate-limiting for muscle noise, the circuitry is prevented from generating an undesired recharge waveform suppression signal. The maximum amplitude of voltage excursion appearing on capacitor 38 is limited during overload (i.e. to one-half volt) by a pair of oppositely-poled diodes 39 in parallel therewith. The output from rate-limiter 32 during the occurrence of a pacer signal artifact is illustrated in FIG. 6D wherein it is observed that throughout the duration of the discharge pulse portion of the signal (i.e. t 0 -t 2 ), the rate-limiter output increases at a constant, rate-limited slope and following conclusion of the discharge pulse portion the rate-limited output drops at its maximum rate, that rate having the same magnitude of slope as the increasing rate but in the opposite or negative direction and continuing for a like interval (i.e. t 2 -t 4 ). The low-frequency rejection circuit 33 is an integrator comprised of operational amplifier A 3 with the output of amplifier A 2 extended to the non-inverting input thereof. The gains of amplifiers A 1 and A 2 and the value of resistor 34 are such that the gain around the loop 27 is unity, and the inclusion of the integrator 33 makes that gain unity plus the integral of the signal (i.e. 1 +∫A 2 output). In other words, the loop gain increases from unit (1) as the frequency of the signal applied to the input of operational amplifier A 3 in integrator 33 decreases. As this signal decreases in frequency, or, in fact, attains a DC offset value, that DC value serves to increase the value of the integral. Inasmuch as the feedback in loop 27 is of a degenerative nature, an increase in the value of the integrator gain increases the loop gain such that any DC offset which might otherwise bias the output of amplifier A 1 and/or amplifier A 2 ) is now removed. During rate-limiting when loop 27 is open, integrator 33 serves to hold the offset correction previously determined. If rate-limiter 32 were not present in the feedback loop 27, that loop would continuously provide negative feedback and low-frequency rejection to the amplifier A 1 such that the output therefrom would be a stable, inverted replica of the small amplitude input signal provided by preamplifier A 0 , as illustrated in FIG. 6B. However, the presence of rate-limiter 32 serves to, in essence, open the feedback loop 27 during the interval of rate-limiting caused by the spike portion of a pacer signal artifact. Although during this interval there may be some degree of negative feedback via loop 27 to the amplifier A 1 due to the ramping signal on capacitor 38, such feedback is not significant for the purpose of stabilizing the circuit and thus, the output of amplifier A 1 responds as illustrated in FIG. 6C. Instead of the unity gain under closed-loop conditions, as represented by the output appearing in FIG. 6B, the apparent gain of amplifier A 1 is now increased due to the removal of the negative feedback component at the input of amplifier A 1 . During operation with significant negative feedback being provided by a closed loop 27, the normal signal voltage excursion at the output of amplifier A 1 might typically be a small fraction of a volt. However, when this significant negative feedback is removed by the operation of a pacer spike on the rate-limiter 32, the signal at the output of amplifier A 1 will be substantially larger during the pacer spike portion. Further, the initial 1-2 milliseconds of the recharge waveform will be similarly amplified until rate-limiting ceases. A voltage-level detector 40 connected to the output of amplifier A 1 responds to the increased magnitude of voltage appearing at the output of amplifier A 1 during the occurrence of the pacer discharge pulse portion for controlling the local feedback loop 28 and for also controlling the gate of a FET switch 41 associated with a follow-and-hold circuit 42 connected to the output of amplifier A 2 . The voltage-level detector 40 is comprised of the emitter-base junctions of a pair of complementary (npn-pnp) transistors 43 and 44 respectively. The emitters of transistors 43 and 44 are connected in common to the output of amplifier A 1 and their bases are connected in common to one side of capacitor 30. The other side of capacitor 30 is connected to the input junction 26. A resistor 45 of high ohmic value (i.e. 4.7M) is connected in parallel across the emitter-base junctions of transistors 43 and 44. During normal operation, the local feedback loop 28 is comprised only of the very high resistive path through resistor 45 and the capacitor 30 such that no significant feedback is provided. In effect, that loop might be considered as open, with the large resistance 45 being present essentially only to slightly reduce open-loop gain and thereby minimize the generation and occurrence of noise through the amplifier A 1 . During this time, the negative feedback provided by loop 27 is such that the voltage appearing at the output of amplifier A 1 is less than that (± Th in FIGS. 6B and 6C) required to forwardly bias the emitter-base junction of either transistor 43 or 44 such that they, in effect, comprise an open switch in the local feedback loop 28. However, with the occurrence of the leading edge of the pacer discharge pulse portion, slew rate limiter 32 operates to effectively disconnect feedback loop 27 and the voltage level at the output of amplifier A 1 increases greatly (either positively or negatively depending on the pacer polarity) to exceed either +Th or -Th and one or the other of the transistors 43 and 44 is forward-biased to provide a conductive path between the output of the amplifier A 1 and the capacitor 30, thereby effectively closing local feedback loop 28 and providing significant negative feedback to the input of amplifier A 1 . It will be appreciated that because level detector 40 comprises a complementary pair of transistors, it is capable of responding to pacer signal artifacts of either polarity. Throughout the duration of the discharge pulse portion of the pacer signal, the output of amplifier A 1 is fed back to its input through capacitor 30 in the manner of an integrator. Capacitor 30 serves to integrate the discharge pulse portion of the pacer signal, which integration is representative of and provides a measure of the charge delivered by the pacer for stimulating the patient's heart, as earlier discussed. The polarity of the charge developed on capacitor 30 is determined by the polarity of the discharge pulse portion of the pacer signal. During this charging of capacitor 30, the closed loop 28 serves to control the output of amplifier A 1 as seen in FIG. 6C. At the completion of the discharge pulse portion of the pacer signal, the feedback loop 27 continues to be open for a brief period of time (i.e. t 2 -t 4 ) and the voltage at the output of amplifier A 1 is, accordingly, of relatively large magnitude but now of the opposite polarity represented by the recharge waveform. At this time (i.e. t 2 ), that one of transistors 43, 44 which had been conducting is turned off and the other transistor is turned on to control the follow-and-hold circuit 42 as will be hereinafter described and also to control amplifier A 1 while capacitor 38 is recovering. Although this conduction by the formerly non-conducting one of the transistors 43, 44 results in some depletion of the charge accumulated on capacitor 30, such depletion is relatively slight inasmuch as the magnitude of the signal at the output of amplifier A 1 during the recharge waveform may be significantly less than that of the discharge pulse portion and further, both transistors 43, 44 become non-conducting quickly when rate-limiter 32 no longer operates to open loop 27 at time t 4 which may be about 2 milliseconds after the completion of the discharge pulse portion at t 2 . Furthermore, the circuit element values may be prescaled to take this drop into consideration. When transistors 43, 44 cease conduction, the feedback loop 28 will return to the near open-loop condition through resistor 45. However, now the capacitor 30, which has been charged proportionally to the charge delivered to the heart during the pacer spike portion, will begin to slowly discharge through the serial path represented by arrow 29 which includes the junction 26 at the input of amplifier A 1 and resistors 46 and 47 connected in series between the other end of capacitor 30 and the reference potential. The RC time constant of resistors 46, 47 and capacitor 30 is selected to generally correspond with the recharge time constant T C associated with the particular pacer and the patient. For instance, if recharge time constant T C is about 200 milliseconds, the time constant of resistors 46 and 47 and capacitor 30 should similarly be about 200 milliseconds. Resistor 47 is preferably variable to facilitate adjustment of the magnitude and the time constant of the signal waveform in discharge path 29 to substantially correspond with that of the recharge waveform generated by a particular pacer 18 and appearing at junction 26. Inasmuch as the resistance R of one type of pacer may differ somewhat from that of another pacer, it is desirable to provide this feature of adjustability for scaling the magnitude and time constant of the tail suppression signal. Further, although the magnitude and decay constant of the tail suppression signal may not match exactly (oppositely) a particular pacer tail, it will reduce the resultant signal to an acceptable level, in most instances. Inasmuch as junction 26 is connected to the inverting input amplifier A 1 , the polarity of the charge stored on capacitor 30 during the feedback interval attending the discharge pulse portion of the pacer artifact is such that the signal current through capacitor 30 along discharge path 29 and appearing at junction 26 as represented by the waveform of FIG. 6E, is opposite in polarity to the recharge waveform then appearing at junction 26. Accordingly, because the current of the signal provided at junction 26 by the discharging capacitor 30 is opposite in polarity and comparable in both magnitude and decay time constant to the recharge waveform, the magnitude of such recharge waveform following summation with the recharge waveform suppression signal is considerably reduced and, in essence, suppressed at the input to amplifier A 1 and, accordingly, through rate-limiter 32 and amplifier A 2 to the output thereof. A pair of parallel-connected, oppositely-poled diodes 48 are connected in parallel with capacitor 30 to speed the recovery of capacitor 30 from overload. Further, a normally-open switch 49 is connected in parallel with capacitor 30. While open, switch 49 has essentially no effect on the operation of the circuitry as hereinbefore described. However, when switch 49 is closed, as by manual actuation, capacitor 30 is essentially removed from both local feedback loop 28 and discharge path 29 with the resultant effect that the recharge waveform appearing at junction 26 is not suppressed and will appear at the output of amplifier A 2 for the purposes of analysis (i.e. polarity display), etc. Referring to the follow-and-hold circuit 42, the output of amplifier A 2 is connected to the source electrode of FET 41, the drain electrode of which is connected in common with one end of resistor 50 and one end of capacitor 51. Resistor 50 extends serially to a low-pass filter 52, the output of which extends to a gain control amplifier 53 which, in turn, controls a light-emitting diode (not shown) associated with optical coupling element 54. Optical coupling element 54 serves to isolate the aforementioned circuitry from the heart-rate meter 12 and the display apparatus 14 to which its output is either directly or indirectly connected. The capacitor 51 extends between the drain electrode of FET 41 and the reference potential for tracking and storing the potential appearing on the drain electrode. A self-restoring drive or biasing network 95 comprised of switching diode 55, zero-biasing resistor 56, diode-biasing resistors 57 and 58 and coupling capacitor 59 is connected to the gate electrode of FET 41 for maintaining the FET in a normally-conducting mode and responding to a negative pulse coupled thereto through capacitor 59 for temporarily switching the FET into non-conduction. The resistor 57 is driven by the output of amplifier A 2 so that diode 55 is biased more positively than the source of FET 41. With FET 41 normally biased into conduction, the signal appearing at the output of A 2 is extended through the follow-and-hold circuitry 42 and subsequently through optical coupler 54 to display 14 and/or heart-rate meter 12. However, it will be appreciated that in the interval during which rate-limiting occurs (i.e. t 0 -t 4 ), the rate-limited voltage appearing on capacitor 38 and illustrated as a triangular stump in FIG. 6D may, itself, be capable of stimulating an erroneous response by the heart-rate meter 12. This situation arises because although the slope of the rate-limited signal must be low enough to effectively open the feedback loop 27, it must not be so low as to suppress validly occurring QRS waveforms. Therefore, the output of amplifier A 2 is disconnected from the follow-and-hold capacitor 51 and resistor 50 for the interval during which the rate-limited triangular stump appearing in FIG. 6D exists. This is accomplished by reverse-biasing the gate electrode on FET 41, as illustrated by the control voltage waveform in FIG. 6F. The relatively negative or reverse-biased control voltage applied to the gate of FET 41 is determined by the level detector 40 which operates through transistor 60 to generate a negative pulse or step which, in turn, is coupled through capacitor 59 to the self-restoring bias circuit 95 associated with the gate of FET 41. The collector of transistor 43 is connected to the cathode of an isolating diode 61 having its anode connected to a junction 62. Similarly, the collector of transistor 44 is connected through a transistorized inverter, generally represented by arrow 63, to the junction 62. The base of transistor 60 is connected through current-limiting base resistor 64 to the junction 62. The quiescent potential at junction 62 is +V which biases transistor 60 into non-conduction. The collector of transistor 60 is connected to the reference potential and a capacitor 71 is connected between the collector and the junction between resistors 65 and 66. An optical coupling unit 70 has its primary side (i.e. an LED, not shown) connected in the emitter circuit of transistor 60 in series with a current-limiting resistor 68 and resistor 65. When either of transistors 43, 44 of level detector 40 begins conducting with the occurrence of a pacer discharge pulse, the voltage at junction 62 drops, resulting in turn-on of transistor 60 and a resultant drop in the potential at its emitter. The capacitor 59 is connected at one end to the emitter of transistor 60 and, accordingly, serves to AC couple the resulting negative spike or step to the self-restoring drive circuit 95 to thereby bias FET 41 into non-conduction. Following the drop in voltage on the emitter of transistor 60, the capacitor 59 will begin to recharge with a time constant determined essentially by resistor 57 and its own capacitance until such time as forward-bias returns to the gate of FET 41 and it resumes conduction. This interval may be about 8-10 milliseconds which is normally longer than the rate-limited interval represented by the triangular stump in FIG. 6D. The capacitor 71 is provided to insure that transistor 60 does not briefly return to non-conduction in the brief interval between turn-off of one of transistors 43, 44 and the turn-on of the other. Were transistor 60 to briefly return to non-conduction, there would appear a positive voltage step at its emitter which would be coupled through capacitor 59 to briefly return FET 41 to conduction and thereby pass the peak-value of the rate-limited signal through circuit 42. Instead, the RC time constant established by resistor 65 and capacitor 71 is such that the transistor 60 does not return to non-conduction during the brief interval of switching of the transistors in level detector 40. When the response of rate-limiter 32 to a pacer signal artifact has been completed and both transistors 43, 44 of level detector 40 return to non-conduction, the transistor 60 similarly returns to non-conduction resulting in the generation of a positive step which is AC coupled through capacitor 59 to return FET 41 to its normally conducting condition. The result of disconnecting FET switch 41 during the rate-limiting interval is illustrated in FIG. 6G wherein the voltage appearing on capacitor 51 at the moment switch 41 becomes non-conducting is only slightly greater than the base line value and, accordingly, remains as such throughout the interval of non-conduction of the FET switch. Thus, the follow-and-hold circuit 42 removes the rate-limited stump from the pacer signal artifact, and the recharge waveform suppression circuit including capacitor 30 serves to suppress the appearance of the following recharge waveform such that substantially only the PQRST complex is presented to optical coupler 54. The low-pass filter 52 serves to remove any remaining switching transients and sets the upper limit to the bandwidth of amplifier 11. The optical coupler 70 associated with switch 60 serves to generate a trigger signal each time transistor 60 begins conduction in response to detector 40 detecting the presence of a pacer signal artifact. This trigger signal is extended via line 72 to the trigger input of a one-shot multivibrator 73 for generating a pacer tag signal of possibly ten milliseconds duration for extension via line 74 to an input of summer 75. The other input to summer 75 is obtained, via line 76, from the non-isolated output of optical coupler 54 on which appears the sensed ECG signal having the pacer discharge pulse portion and the recharge waveform portion of a pacer signal artifact suppressed. The pacer tag appearing on line 74 is summed with the signal appearing on line 76 to provide an output signal on line 77 which comprises any PQRST complex as well as a pacer tag to indicate the occurrence and timing of a pacer signal artifact. The signal on line 77 is extended to the display 14. If it is desired that display 14 present only the signal appearing on line 76, whether with or without the pacer artifact signal suppressed, the pacer tag may be deleted from the display by opening normally-closed switch 69 connected in series between resistor 68 and transistor 60. This positioning of switch 69 allows the "stump" of FIG. 6D to appear as an indication of the pacer pulse polarity. Switch 69 might instead be connected to gate the one-shot 73 directly, thereby permitting the "stump" to also be suppressed on line 76. Switches 49 and 69 might be ganged. It will be appreciated that instead of the embodiment illustrated in FIG. 5, it would be possible to extend the input from the patient and the input of the general feedback represented by loop 27 to a non-inverting input of amplifier A 1 and to further replace the non-inverting integrator 33 with an inverting integrator and to additionally provide a further gain controlling (resistive) feedback loop extending from the output of amplifier A 2 to the inverting input of amplifier A 1 . The gain of the closed loop may be easily controlled by the resistance in the separate feedback path, but in either embodiment, the effect is substantially the same. The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

In cardiac signal processing apparatus, there is provided improved means for suppressing pacer signal artifacts, including both the discharge pulse and the recharge waveform (tail) of such artifact. Rate-limiting circuitry is used to substantially suppress the discharge pulse. However additional circuitry responsive to the detection of a pacer pulse is operative to obtain a measure of the electrical discharge of the discharge portion of the respective pacer pulse and to use such measure to generate a tail suppression signal which, when added to the original signal, substantially cancels the original pacer tail. A feed-back loop is opened by the rate-limiter when a pacer pulse occurs and in turn permits a large signal to be imposed on a threshold-level-type pacer pulse detector for connecting the large signal (pacer pulse) to a capacitor during the discharge portion of the pacer pulse. The capacitor begins to discharge shortly after the pacer pulse's discharge portion with a polarity and time constant selected to substantially cancel (when summed) the pacer tail.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to the molding of optical glass lenses and, more particularly, to the manufacture of preform elements having a controlled peripheral edge wall geometry for use in the molding of optical glass lenses. 2. Brief Description of the Prior Art Various methods and apparatus for the compression molding of glass optical elements are known in the prior art. With these methods and apparatus, optical element preforms sometimes referred to as gobs are compression molded at high temperatures to form glass lens elements. The basic process and apparatus for molding glass optical elements is taught in a series of patents assigned to Eastman Kodak Company. Such patents are U.S. Pat. No. 3,833,347 to Angle et al, U.S. Pat. No. 4,139,677 to Blair et al, and U.S. Pat. No. 4,168,961 to Blair. These patents disclose a variety of suitable materials for construction of mold inserts used to form the optical surfaces in the molded optical glass elements. Those suitable materials for the construction of the mold inserts included glasslike or vitreous carbon, silicon carbide, silicon nitride, and a mixture of silicon carbide and carbon. In the practice of the process described in such patents, a glass preform or gob is inserted into a mold cavity with the molds being formed out of one of the above mentioned materials. The molds reside within a chamber in which is maintained a non-oxidizing atmosphere during the molding process. The preform is then heat softened by increasing the temperature of the mold to thereby bring the preform up to about 100° C. above the Glass Transition Temperature (T g ) for the particular type of glass from which the preform had been made. Pressure is then applied by the mold to force the preform to conform to the shape of the mold. The mold and preform are then allowed to cool below the transition temperature of the glass. The pressure from the mold is then relieved. The temperature is lowered further and the finished molded lens is removed. Because the molding of glass optical elements is done by compression rather than injection (as is utilized in plastic molding) a precursor metered amount of glass, generally referred to as a preform, is required. There are two fundamental shapes of preforms required which generally parallel the two fundamental finished lens shapes. For negative lenses, plano-plano preforms usually will be sufficient. These can be fabricated in high volume relatively inexpensively by grinding and polishing. For positive lenses, a ball (sphere) or ball-like lump of glass is needed. The basic constant when molding positive or negative lenses is that the molds must touch the softened glass at the center first and then press out to the edges to avoid wrinkles and voids in the finished lens element. Plano-plano preforms for use in optical glass molding operations have been manufactured by pressing the molten glass gob to create a generally round disk. The problem with pressing molten glass to form a plano-plano preform has been that the generally circular disk is not truly circular because the peripheral edge wall was allowed to free form during pressing. Further, the peripheral edge wall of the disk has been generally rounded in cross section perpendicular to the cylindrical axis of the disk. Irregular peripheral edge wall geometry of the preform can result in difficulties in the insertion of the preform into the molding apparatus. These difficulties can lead to the preform being misaligned in the apparatus resulting in a non-usable molded lens element. U.S. Pat. No. 3,293,017 and U.S. Pat. No. 3,271,126, both to Jenkins, teach a method and apparatus for forming small, thin and relatively uniform glass wafers or disks apparently for use in capacitors. The wafers are formed by dripping molten glass from an orifice in single drops or gobs onto a mold supported by a piston rod. The mold is then pneumatically driven to extend the piston rod such that the mold rises to press the drip of molten glass against a fixed plunger. A wire brush is employed to sweep the form to glass disks from the mold into a shoot. Although plano-plano preforms can be made relatively inexpensively by grinding and polishing, the cost could be significantly reduced by pressing molten preforms to form disks having two opposing planar surfaces and a substantially cylindrical peripheral edge wall perpendicular to the two opposing planar surfaces. Forming glass preforms by pressing molten glass gobs to achieve a preform element having the desired peripheral edge wall geometry is heretofore unknown. SUMMARY OF THE INVENTION It is, therefor, an object of the present invention to provide a method and apparatus for pressing molten glass gobs to form plano-plano preforms with controlled peripheral edge wall geometry. It is a further object of the present invention to provide a method for manufacturing plano-plano preforms for subsequent use in manufacturing molded optical glass elements wherein the preforms do not have to be ground and polished. Still another object of the present invention is to provide a method and apparatus for manufacturing glass preforms having a shape which approximates the final shape of the finished glass element molded therefrom. Briefly stated, these and numerous other features, objects and advantages of the present invention will become readily apparent upon a reading of the detailed description, claims and drawings set forth herein. These features, objects and advantages are accomplished by dripping gobs of molten glass of predetermined weight and volume onto a rotary table plate. The rotary table plate rotates the molten gob to a position under a pressing head which includes a seamless cylindrical sleeve with a plunger capable of reciprocating movement therein. The inside diameter of the sleeve is preferably the maximum diameter of what will ultimately be the finished lens. The pressing head is driven down against the top surface of rotary table. The plunger is set at a predetermined height within the sleeve to thereby set the thickness of the preform. In such manner, the sleeve simultaneously surrounds the gob as the plunger presses the gob to yield a plano-plano preform. Alternatively, the seamless cylindrical sleeve can descend first to achieve peripheral containment of the molten glass gob with the plunger then being actuated through operation of a cam to the correct thickness as it packs the glass gob into the temporary cavity formed on the rotary table within the sleeve. The variation in the volume of glass produced by the dropping mechanism is used to define the size and tolerances of the pressing head pieces so that no flashing occurs on the corners of the parts thus produced. After the molten gob is pressed to form the preform, the pressing head is raised from the table and the plunger is further actuated to eject the preform from the sleeve. The preform then falls back to the rotary table where it is rotated to another position for removal therefrom. In this manner, preforms, particularly piano-plano preforms, can be made without any grinding or polishing and without a free formed peripheral edge wall. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic of an apparatus for producing gobs of molten glass of predetermined weight and volume. FIG. 2 is a top plan view of a rotary table apparatus which can be used in conjunction with the apparatus depicted in FIG. 1 to catch the gobs produced thereby. FIG. 3 is a partial sectional view taken along line 3--3 of FIG. 2. FIG. 4 is a perspective view of an alternative embodiment rotary table for catching gobs of molten glass produced by the apparatus of FIG. 1. FIG. 5 is a side elevational/partial sectional view of the pressing head of the present invention positioned over the rotary table. FIG. 6 is a side elevational/partial sectional view showing the pressing head of the present invention positioned over a glass gob on the rotary table. FIG. 7 is a side elevational/partial sectional view showing the pressing head of the present invention with the sleeve thereof lowered to meet the table and surround a glass gob. FIG. 8 is a side elevational/partial sectional view showing the plunger of the pressing head of the present invention in a depressed position thereby pressing the glass gob into a plano-plano preform. FIG. 9 is a side elevational/partial sectional view wherein the pressing head of the present invention has been raised from the rotary table with the preform still held within the sleeve. FIG. 10 is a side elevational/partial sectional view wherein the piston within the pressing head of the present invention has been depressed within the cylinder to eject the preform. FIG. 11 is a side elevation of an alternative embodiment of the present invention with an alternative embodiment pressing head shown in cross section. FIG. 12 is a side elevational/partial sectional view of an alternative embodiment of the present invention. FIG. 13 is a perspective view of a plano-plano preform as produced by the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Turning first to FIG. 1 there is shown a schematic of an apparatus for producing gobs of molten glass. That apparatus includes a reservoir crucible 10 which holds a supply of molten glass 12. Reservoir crucible 10 is provided with an outlet stem 14 which feeds molten glass from the reservoir crucible 10 to a working crucible 16. The working crucible 16 has a discharge nozzle 18 extending from the bottom thereof. The discharge nozzle 18 includes an frusto conical tip 20. The discharge nozzle 18 with its tip 20 are fabricated with a precise geometry in order to assist in defining a flow rate of molten glass therefrom. The working crucible 16 is supported on one end of a balance system including a beam 22 spanning a fulcrum 24. At the opposite end of beam 22 is a counterweight 26. As the weight of the working crucible 16 decreases, additional molten glass from the reservoir crucible 10 is delivered in a controlled manner to the working crucible 16. A servo feedback system 28 receives a signal from a sensor 30 sensing the position of counterweight 26. In such manner, as the working crucible 16 is depleted of molten glass, the servo feedback system 28, through sensor 30, detects the low mass of molten glass in the working crucible 16 and thereby produces a signal that regulates heat radiated from heater 32 positioned proximate to outlet stem 14. This temperature regulation of outlet stem 14 of the reservoir crucible 10 acts to meter the flow of molten glass 12 from the reservoir crucible 10 thereby replenishing molten glass to the working crucible 16. In this manner, the pressure head within working crucible 16 and, more particularly, at tip 20, is held relatively constant. Thus, the flow rate of molten glass through discharge nozzle 18 and tip 20 can be controlled to be substantially uniform over an extended period of time. This ensures that gob size is repeatable and, therefore, substantially uniform. For purposes of uniformity, it is beneficial to provide a supplemental heating device in close proximity to the discharge nozzle 18 and tip 20. For example, a flow rate of the order of one gram per second may be used to obtain a gob mass of approximately 1.5 grams. The working crucible 16 may be equipped with a stirring mechanism 34 in order to avoid the formation and entrainment of bubbles in the molten glass within working crucible 16. Gobs are typically referred to as small gobs or large gobs. Usually, large gobs weigh one (1) gram and above. To make small gobs, the temperature controls on the tip 20 are set so that the molten glass drips to form drops or gobs of an appropriate and repeatable size. To make a large gob the tip geometry and the orifice size are adjusted or formed such that the molten glass flows rather than drips out of the orifice of the tip 20 and into one of a plurality of catching tools 36 located on a rotary table 38 (see FIGS. 2 and 3). The rotary table 38 is indexed to turn at a rate consistent with the flow rate of molten glass gobs dripping from tip 20 established for a given preform type (i.e., glass type and size). The individual catching tools 36 are cammed up or raised by a suitable lifting means to a position proximate to tip 20 for an appropriate dwell time to meter the proper size molten glass gob from tip 20 through the application of heat to discharge nozzle 18 and tip 20 by means of an external heater element (not shown). The catching tool 36 is then lowered sufficiently to pull off a separating tail without benefit of shears while the tail is still in the heating zone of tip 20. An additional heater (not shown) may be employed to ensure that the glass gob located on the catching tool 36 and its tail remain hot. In such manner, the tail heals into the surface of the molten glass gob while the gob and the tail are both hot and produces only a minimal mark, or no mark at all on the surface of the glass gob as the gob is cooled. It is beneficial to preheat the catching tool 36 immediately prior to the delivery of a glass gob thereto from tip 20. Preheating the catching tools 36 help keep the glass gob from cooling down too quickly to minimize chill wrinkle and helps maintain the glass at a temperature above its softening point while the tail heals into the surface of the gob. The temperature of the catching tool should be elevated to at least 200° C. and preferably should be heated to a temperature in the range of from about 400° C. to about 750° C. A graphite catching tool 38 is preferred because graphite does not interact chemically with glass. However, since graphite burns at 500° C., a graphite catching tool should not be heated to above about 400° C. Materials other than graphite can be used for the manufacture of catching tools 36 so that such catching tools 36 can withstand higher temperatures. For example, catching tools manufactured from ceramic such as aluminosilicate can be used allowing such catching tools 36 to be heated to temperatures up to and exceeding 750° C. The above-described method for the formation of gobs is particularly useful when forming large gobs where a tail is likely to form thereby creating a need to ensure that the tail is reintegrated with the gob with minimal surface defamation of the gob. The preferred method and apparatus for the formation of large gobs discussed briefly above is taught in greater detail in U.S. Pat. No. 5709,723 which is hereby incorporated herein by reference. For the formation of small molten glass gobs, the method and apparatus taught in U.S. Pat. Nos. 3,271,126 and 3,293,017, both to Jenkins is preferred. To make a small gob, the thermal controls on the tip 20 are set so that the appropriate size drop is created and repetitively reproduced in the manner described in the above-referenced Jenkins patents. These gobs are dropped and caught on a rotary table plate 40 (see FIG. 4) which does not include the individual catching tools 36 employed with rotary table 38 of FIG. 2. In the embodiment of FIG. 3, the support surface 39 of rotary table plate 40 serves as the lower mold surface for making plano-plano preforms, surface 39 is planar. The molten glass gobs are dropped and caught on the rotary table plate 40 with the rotation of rotary table plate 40 being sequenced under tip 20. The rotary table plate 40 is indexed at a turn rate consistent with the drop rate established for a given gob to be formed into a particular preform. The rotary table plate 40 rotates each individual gob 41 to a position under a pressing head 42 (see FIGS. 6). Rotational movement of the rotary table plate 40 is halted for the actuation of the pressing head 42 when the newly dropped gob 41 of glass in indexed to move to the location under the pressing head 42, the sleeve or cylinder 44 of the pressing head 42 descends first to achieve peripheral containment of the glass gob 41 (see FIG. 7). A plunger or cylinder 46 of pressing head 42 is then actuated through a camming device or other means (not shown) to descend within sleeve 44 to a predetermined height above rotary table plate 40 (see FIG. 8). In this manner, the glass gob 41 is pressed to generally take the shape of the cavity formed between the planar mold surface 48 of plunger 46 and rotary table plate 40 within sleeve 44 to thereby become a preform 49. The variation and the volume of each glass gob 41 produced by the dropping mechanism described above is used to define the size and tolerances of the pressing head 42 so that no flashing occurs on the comer of sleeve 44 and plunger 46. After start up of both the gob formation apparatus and the pressing head 42, thermal equilibrium of the tools is quickly achieved and chill wrinkle of the glass gobs 41 is minimized. If chill wrinkle becomes a problem for a particular size of glass gob 41 or a particular type of glass used to form the gob 41, auxiliary heating of the pressing head 42 can be used. After the glass gob 41 has been pressed to generate a preform 49, the pressing head 42 is raised from table plate 40 with the preform 49 usually remaining within sleeve 44 (see FIG. 9). Plunger 46 is then further actuated to eject the finished preform 49 from sleeve 44 (see FIG. 10). The finished preform 49 is then free to continue on its cooling ride around rotary table 40 until it reaches an appropriate position for removal therefrom. An alternative preferred embodiment pressing head 100 is depicted in FIG. 11. This pressing head 100 includes a sleeve 102 in which resides a plunger or piston 104 having a planar face 106. There is a compression spring 108 about the shaft 110 of piston 104 which is maintained in compression by means of clip 112 attached to shaft 110. Spring 108 thereby biases piston 104 to reside in a fully retracted position within sleeve 102. The distance from the planar surface 106 when piston 104 is in such fully retracted position to the annular bottom surface 114 of sleeve 102 is equal to the desired thickness of the preform to be pressed therewith. Sleeve 102 includes a flange 116 extending radially therefrom. Mounted to flange 116 is a spacer ring 118. There is a clamp 120 which encircles flange 116 and spacer ring 118. Attached to clamp 120 is arm 122 which supports pressing head 100. Arm 120 extends from a piston rod 124 driven by pneumatic cylinder 126. Pneumatic cylinder 126 is mounted to frame 128 which also supports rotary table 40. Projecting from frame 128 is post 130. Affixed to the top of post 130 is cantilevered member 132 which extends such that the distal end of cantilevered member 132 resides directly above the top of shaft 110. In the operation of the pressing head 100, once the rotary table 40 has moved a gob into position, pneumatic cylinder 126 is actuated to drive pressing head 100 down against the top surface of rotary table 40. In such manner, the lower end of sleeve 102 simultaneously surrounds the gob as planar surface 106 presses the gob to yield a plano-plano preform. Pneumatic cylinder 126 then raises the pressing head 100 with the preform usually remaining within the pressing head 100. Pneumatic cylinder 126 raises the pressing head 100 further such that the top of shaft 110 is engaged by cantilevered member 132 thereby overcoming the bias of spring 108 and causing piston 104 move downwardly within sleeve 102. This downward movement of piston 104 ejects the preform from sleeve 102. The geometry for a particular tip 20 of discharge nozzle 18 depends on a number of factors including the type of glass, the gob size, and the type of preform being made (ball, plano-plano, or large gob). For example, if a dense flint glass such as Hoya FDS-3 is being used to form large gob-type preforms over four (4) grams, it would be necessary that tip 20 would flow the molten glass therefrom at a greater distance without separation because of the depth of the mold cavity needed to accommodate the large preform. Usually, a frustro-conical type tip works best. On the other hand, if a ball preform is being made with a weight of about three hundred forty (340) milligrams from a high temperature crown glass such as Hoya TaC-4, the tip 20 would be designed so that a single drop of glass would form on the end of the tip 20 substantially equal to three hundred forty (340) milligrams before dropping into the catcher. The amount of glass that forms the preform is determined by the outside diameter of the tip 20, the material of the tip 20 is made from (100% Pt or Pt/Au), and the drop rate. With familiar glass types, tip size and geometry are based on previous experience. With particular types of glass not previously used in such a process, the data must be derived empirically through trial and error. Looking next at FIG. 13, there is shown in schematic form another alternative embodiment of the present invention wherein the rotary table 54 (shown in cross section) is provided with a plurality of cylindrical recesses 56 in the surface thereof. The rotation of rotary table 54 is indexed such that each cylindrical recess 56 catches an individual gob 52 falling from tip 20. A pressing head 58 then moves downwardly to engage the top surface of the rotary table 54 thereby pressing down on the gob 52 and forcing it to conform to the shape of the cylindrical recess 56. In this manner, pressing head 58 does not need a sleeve such as that used in conjunction with the embodiment shown in FIGS. 1-11. Instead, cylindrical wall 60 of each cylindrical recess 56 serves to provide peripheral containment of gob 52 as it is pressed to thereby yield the controlled edge geometry of the preform 62. This alternative embodiment may be preferable to use in conjunction with a method for making large gobs. After partial cooling, the preforms can be removed from cylindrical recesses 56 by means of a vacuum pick-up (not shown). By using the process of the present invention to make preforms, preforms 49 are manufactured without grinding or polishing and yet have a controlled peripheral edge wall geometry which joins the two optical surfaces. Thus, a piano-plano preform 49 (see FIG. 13) is made that includes a first generally planar surface 64, a second generally planar surface 66, and a generally cylindrical peripheral edge wall 58 which is perpendicular to the first and second planar surfaces 64, 66. Although the present invention is described herein as being particularly useful in making plano-plano preforms, it should be recognized by those skilled in the art that the present invention can also be used to make preforms with shapes other than plano-plano. For example, it may be desirable to make preforms where one or both sides are convex. To accomplish this the rotary tables 38, 40 may be equipped with recesses which include a generally concave lower molding surface onto which the glass gobs 41 are dropped. In addition, the pressing surface of plunger 46 could be made to be generally concave in shape. From the foregoing, it will be seen this invention is one well adapted to obtain all of the ends and objects hereinabove set forth together with other advantages which are apparent and which are inherent to the invention. It will be understood that certain features and subcombinations are of utility and may be employed with reference to other features and subcombinations. This is contemplated by and is within the scope of the claims. As many possible embodiments may be made of the present invention without departing from the scope thereof, it is to be understood that all matter herein set forth and shown in the accompanying drawings is to be interpreted as illustrative and not in the limiting sense.

Optical glass preforms for use in subsequent molding processes for the production of lenses are produced which have a controlled peripheral edge wall geometry. Gobs of molten glass of predetermined weight and volume are dripped onto a lower mold surface. A pressing head including a sleeve and a plunger are lowered such that the sleeve surrounds the gob. The plunger is then depressed such that the upper mold surface of the plunger resides in a predetermined elevation above the lower mold surface thereby forcing the gob to conform to the cavity created within the sleeve and between the upper and lower mold surfaces. In such manner the sleeve serves as a form or exterior boundary for the resultant preform such that a preform is produced which requires no grinding or polishing prior to its use in subsequent molding operations.

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a diaphragm-type miniaturized oxygen electrode, more particularly, to a miniaturized oxygen electrode useful for many applications including a measurement of the dissolved oxygen concentration of a solution, to an electrolyte composition suitable for forming the sensing site of the miniaturized oxygen electrode, and to a process of mass-producing miniaturized oxygen electrodes having a uniform quality. An oxygen electrode is very useful for measuring the dissolved oxygen concentration in many fields. For example, oxygen electrodes are used in the field of water control, the BOD (Biochemical Oxygen Demand) in water is measured, and in the fermentation and brewing field, the dissolved oxygen concentration of a fermentation tank or fermenter is measured, to ensure an efficient fermentation of alcohol, etc. An oxygen electrode can be combined with an enzyme to form a biosensor or an enzyme electrode to be used for measuring the concentration of sugar, vitamins, etc. For example, an oxygen electrode can be combined with glucose oxidase to measure the concentration of glucose or grape sugar. This utilizes a phenomenon in which glucose is oxidized by the dissolved oxygen with the aid of a catalytic action of glucose oxidase to form gluconolactone, with a resulting reduction of the dissolved oxygen amount diffusing into an oxygen electrode. In addition to the measurement of the dissolved oxygen concentration of a solution, an oxygen electrode can be advantageously used for controlling the oxygen concentration of a gas phase For example, a reduction of the ambient oxygen concentration to below 18% causes a dangerous oxygen deficiency, and in medical-care equipment, such as oxygen inhalation and gas anesthetization, the oxygen concentration of a gas used must be strictly controlled. The oxygen electrode is thus very advantageously used in many fields, including environmental instrumentation, the fermentation industry, clinical care, and industrial hygiene. Description of the Related Art The conventional oxygen electrode typically has a structure as shown in FIG. 1, wherein a vessel or container 118 made of glass, plastics, stainless steel, or the like has an open end (lower end) covered and sealed with an oxygen gas-permeable membrane 107 made of silicone resin, fluororesin or the like, and an aqueous solution 119 of potassium chloride (KCl), sodium hydroxide (NaOH), etc., is filled in the vessel 118, in which an anode 104 made of silver (Ag), lead (Pb), etc., and a cathode 105 made of platinum (Pt), gold (Au), etc., are arranged. The conventional oxygen electrode has a complicated structure, and therefore, it is difficult not only to miniaturize but also to mass-produce same. The present inventors and others have proposed a new type of miniaturized oxygen electrode that can be produced by utilizing a semiconductor production process including a photolithography and an anisotropic etching, as disclosed in Japanese Unexamined Patent Publication (Kokai) No. 63-238,548 and U.S. Pat. No. 4,975,175. The proposed oxygen electrode has a structure as shown in FIGS. 2 and 3, in which FIG. 2(b) shows an unfinished structure in which an oxygen gas-permeable membrane is not yet formed. This structure is produced by the following sequence. Two grooves 202 to be filled with an electrolyte-containing material are formed on a silicon wafer 201 by an anisotropic etching and the wafer surface is then covered by an SiO 2 insulating layer 203 to form an electrically insulating substrate. Then, two component electrodes, i.e., an anode 204 and a cathode 205, are formed on the insulating layer 203. The anode 204 has one end 204A for external electrical connection and the other end of two branches extending into the grooves 202. The cathode 205 has one end 205A for external electrical connection and the other end extending to the top surface of a plateau retained between the grooves 202. An electrolyte-containing material 206 is filled in the grooves 202, and the filled electrolyte-containing material 206 is in contact with the anode 204 within the grooves 202 and with the cathode 205 on the plateau. The upper surface of the filled electrolyte-containing material 206 is then covered with an oxygen gas-permeable membrane 207. Nevertheless, the step of filling the grooves 202 with the electrolyte-containing material 206 and the step of covering the filled electrolyte-containing material 206 with the oxygen gas-permeable membrane 207 are difficult to carry out in a semiconductor process, and therefore, are manually carried out chip by chip after the wafer 201 on which miniaturized oxygen electrodes have been formed is cut into chips forming respective oxygen electrodes. The manual operation is a serious obstacle to the realizing of a mass-production, and further, involves too much fluctuation in operation to obtain miniaturized oxygen electrodes having a stable or uniform performance. Therefore, it has been desired to provide a structure of a miniaturized oxygen electrode and a production process thereof in which the filling of an electrolyte-containing material and the forming of an oxygen gas-permeable membrane can be carried out collectively or generally and uniformly, on a wafer as a whole, before the wafer is cut into chips. The step of filling an electrolyte-containing material has the following problems. The present inventors studied gels containing an aqueous solution of potassium chloride and polyelectrolytes and found that, because many of these are not photosensitive, the photolithography used in the semiconductor process cannot be actually applied to the filling of an electrolyte-containing material. The electrolyte-containing material must be a liquid having a fluidity when it is filled in a groove, and the filled material must form a dense film after being dried. Also, whether or not the filled material contains water significantly affects the quality of an oxygen gas-permeable membrane applied on the filled material, and therefore, upon application for an oxygen gas-permeable membrane, the electrolyte-containing material is preferably dried. The water required for the measurement of the oxygen concentration is supplied as a water vapor through the gas-permeable membrane just before the measurement starts. The electrolyte-containing material need not contain water during the production of an oxygen electrode. Screen printing is a preferred method of filling an electrolyte-containing material collectively in a number of miniaturized oxygen electrodes on a wafer. This screen printing generally uses an emulsion mask and a metal mask to define a printed pattern. An emulsion mask is prepared by applying a photosensitive resin in the form of an emulsion on a mesh of a stainless steel, etc. to provide a printing pattern. Some resins have a transparency which advantageously facilitates the fine alignment required when producing a miniaturized oxygen electrode because a wafer covered by a resin mask is visible through the resin. The emulsion mask, however, is very weak against water, as can be understood from the fact that the developing treatment of an emulsion is carried out by using water, and the printing of a water-containing substance is difficult. On the other hand, the metal mask is prepared by forming holes in a plate of a stainless steel, etc., and therefore, is strong against water. The metal mask, however, is disadvantageous for the fine alignment, because it does not have a transparency. Moreover, the metal mask occasionally provides a printing quality lower than that obtained by the emulsion mask, when using some kinds of printing inks. The present inventors proposed a process in which an electrolyte-containing gel is applied by screen printing, i.e. calcium alginate gel, polyacrylamide gel, and agarose gel are printed, as disclosed in Japanese Unexamined Patent Publication (Kokai) No. 1-56,902. This process uses a metal mask to print an aqueous gel and cannot be advantageously used in the production of a miniaturized oxygen electrode, for the reasons mentioned above. Moreover, a strong film cannot be obtained because an oxygen gas-permeable membrane is formed on a wet gel. Potassium chloride is generally used as the electrolyte of an oxygen electrode. Although potassium chloride is a superior electrolyte, it is not suitable for use in a miniaturized oxygen electrode because it has a drawback in that it is only soluble in water and that a filled aqueous solution becomes a white brittle powder when dried. The present inventors also proposed a polyelectrolyte, as disclosed in Japanese Unexamined Patent Publication (Kokai) No. 2-240,556. Although this has a good film forming property, the proposed polyelectrolyte is also soluble only in water, and is difficult to treat because it has a high polymerization degree and exhibits a high viscosity even as a dilute solution. The step of forming an oxygen gas-permeable membrane has the following problems. The gas-permeable membrane is made of silicone resin, fluororesin, or other electrically insulating material. The gas-permeable membrane is therefore formed not to cover the whole surface of a wafer but to have a pattern such that the component electrode ends or "pads" 204A and 205 for external electrical connection are exposed. The gas-permeable membrane is formed selectively in the predetermined wafer region other than the pad region to be exposed either by applying a resin only to the predetermined region or by first forming the gas-permeable membrane on the whole surface of a wafer and then removing the gas-permeable membrane in the pad region to be exposed. A screen printing of a liquid resin is known as the former method, i.e., the selective application of a resin. This method has an advantage in that a single printing operation simultaneously effects both the application and the patterning of a resin, but the silicone resin used for forming a gas-permeable membrane is progressively cured by the water in the ambient air, and therefore, the viscosity of the resin varies during printing to cause a nonuniform printing, and in the worst case, a clogging of a printing stencil. A lift-off process using a photoresist is known as the latter method, i.e., the formation and selective removal of a gas-permeable membrane. This process has an advantage in that the semiconductor process is advantageously applied and a complicated pattern can be easily obtained. This method, however, when applied in the production of a miniaturized oxygen electrode, provides a completely cured gas-permeable membrane having a high strength such that the membrane is difficult to peel or exfoliate selectively at the portion to be exposed, even by using an ultrasonic treatment. Thus, the lift-off process cannot be practically used in the production of a miniaturized oxygen electrode. U.S. Pat. No. 4,062,750 to J. F. Butler discloses a thin film type electrochemical electrode formed on a silicon substrate, having a feature in that an electroconductive layer extends through the silicon substrate thickness so that a signal from a sensor disposed on one side of the substrate is taken out from the other side of the substrate. As this electrode does not have the pad portion of the present inventive electrode, a gas-permeable membrane may cover the whole surface and a patterning of the membrane for exposing the pad portion is not required This electrode, however, requires a complicated production process, causing a problem in the practical application. The filling of an electrolyte is carried out by vacuum deposition, and although sodium chloride and potassium chloride can be vacuum deposited, many of the inorganic salts used as a buffering agent are deteriorated by dehydration and condensation when exposed to the heat associated with vacuum deposition. Therefore, even when a buffered electrolyte is obtained, the resulting pH will significantly deviate from an expected value and the obtained electrolyte composition must be very restricted, and thus this is not an optimum process. Moreover, problem arises when a single vacuum deposition apparatus is used for both depositing electrolytes and for depositing electrode metals, and therefore, individual deposition apparatuses must be provided for the respective depositions. M. J. Madou et al. proposed a micro-electrochemical sensor, as disclosed in U.S. Pat. No. 4,874,500 and in AIChE SYMPOSIUM SERIES, No. 267, vol. 85, pp. 7-13 (1989). This sensor also has a feature in that an electroconductive layer extends through the silicon substrate thickness and a signal from a sensor disposed on one side of the substrate is taken out from the other side of the substrate, and therefore, has the same drawback as that of J. F. Butler. An electrolyte is filled in such a manner that an alcoholic solution of poly(hydroxyethylmathacrylate), etc. is painted on, the solvent is evaporated, an electrolyte solution is introduced to form a gel, and then dried. The conventional problem is apparently eliminated, because an electrolyte is introduced after a polymer is applied, but a crystal grows when a potassium chloride solution is evaporated. When the amount of potassium chloride is small, the grown crystal is enclosed with the polymer, but when the amount is large, a number of large crystals appear, which may not be supported by the polymer. On the other hand, the amount of an electrolyte must be as large as possible, because the service life of an oxygen electrode is affected by the electrolyte amount contained therein. Thus, the restricted amount of electrolyte reduces the service life of an oxygen electrode. SUMMARY OF THE INVENTION The object of the present invention is to provide a miniaturized oxygen electrode which can be mass-produced at a high efficiency by collectively and uniformly processing a substrate as a whole, a production process thereof, and an electrolyte composition able to be advantageously used therefor. To achieve the above object according to the first aspect of the present invention, there is provided an electrolyte composition for screen printing, comprising: an organic solvent; an inorganic salt in the form of a fine powder able to pass through a screen printing mesh, the salt powder being dispersed in the organic solvent; and polyvinyl pyrrolidone dissolved in the organic solvent. The electrolyte composition is screen-printed to form an electrolyte-containing material on a substrate. The inorganic salt is preferably selected from potassium chloride and sodium chloride. The inorganic salt used as an electrolyte must be in the form of a fine powder which can pass through the screen printing mesh, for example, in the form of a fine particle having a diameter not larger than 50 μm. The organic solvent used in the present invention is preferably an alcohol such as butanol, pentanol, or hexanol. The present inventive electrolyte composition is prepared by dispersing an inorganic salt such as potassium chloride, which is a superior electrolyte, in the form of a fine particle adapted for screen printing, in a high molecule polymer dissolved in an organic solvent. The present invention uses polyvinyl pyrrolidone as the high molecule polymer. An inorganic salt such as potassium chloride in the form of a fine particle may be prepared either by pulverizing a solid material or by pouring an aqueous solution containing an inorganic salt in saturation or in a high concentration near saturation into an organic solvent such as alcohol and acetone, which can be mixed with water in any proportion, to precipitate fine particles. Either method provides a powder of fine particles having a uniform size. The present inventive electrolyte composition may further comprise a buffering agent, to ensure a constant pH (hydrogen ion concentration) of the electrolyte. The buffering agent is a salt exhibiting a buffering effect, such as phosphate, acetate, borate, citrate, phthalate, tetraborate, glycine salt, and tris(hydroxymethyl)aminomethane salt, and is used in the form of a fine powder like the potassium chloride powder. According to the second aspect of the present invention, there is also provided a miniaturized oxygen electrode comprising: an electrically insulating substrate; an electrolyte-containing material disposed on the substrate; a set of component electrodes in contact with the electrolyte-containing material and disposed on the substrate; and an oxygen gas-permeable membrane covering the electrolyte-containing material; the electrolyte-containing material being formed by screen-printing on the substrate the electrolyte composition according to the first aspect of the present invention. According to the third aspect of the present invention, there is provided a process of producing a miniaturized oxygen electrode, comprising the steps of: preparing an electrically insulating substrate; forming an electrolyte-containing material on the substrate; and forming on the substrate a set of component electrodes in contact with the electrolyte-containing material; forming an oxygen gas-permeable membrane covering the electrolyte-containing material; the forming of the electrolyte-containing material being carried out by screen-printing on the substrate the electrolyte composition according to the first aspect of the present invention. According to the second and third aspects of the present invention, a fine powder of an inorganic salt, polyvinyl pyrrolidone, and an organic solvent are blended to form an electrolyte composition in the form of a paste, which is then applied to a substrate at predetermined portions collectively by screen printing. The printed electrolyte composition, when dried, forms a dense film such that an oxygen gas-permeable membrane can be properly formed thereon. According to the fourth aspect of the present invention, there is provided a miniaturized oxygen electrode comprising: an electrically insulating substrate; an electrolyte-containing material disposed on the substrate; a set of component electrodes disposed on the substrate, each having an end in contact with the electrolyte-containing material and an end for external electrical connection; and an oxygen gas-permeable membrane covering the substrate in a portion containing the electrolyte-containing material; the oxygen gas-permeable membrane being removed from the substrate in a region containing the end for external electrical connection, by removing a removable cover film interposed between the substrate and the oxygen gas-permeable membrane. According to the fifth aspect of the present invention, there is provided a process for producing a miniaturized oxygen electrode, comprising the steps of: preparing an electrically insulating substrate; forming an electrolyte-containing material on the substrate; forming on the substrate a set of component electrodes each having an end in contact with the electrolyte-containing material and an end for external electrical connection; and forming a removable cover film on the substrate in a region to be exposed in the following removing step, the region containing the component electrode end for external electrical connection; forming an oxygen gas-permeable membrane covering the substrate surface including the region of the removable cover film; and removing the oxygen gas-permeable membrane by peeling the removable cover film away from the substrate surface, to expose the to-be-exposed region of the substrate and thereby shape the oxygen gas-permeable membrane to a predetermined pattern. The process according to the fifth aspect of the present invention preferably comprises the steps of: screen-printing a thermosetting resin onto the to-be-exposed region of the substrate; heating the resin to cure the resin to form a resin film as the removable cover film; forming the oxygen gas-permeable membrane covering the substrate surface including the region of the resin film; peeling the resin film to expose the to-be-exposed region, and thereby shape the oxygen gas-permeable membrane to a predetermined pattern. According to the fourth and the fifth aspects of the present invention, an oxygen gas-permeable membrane is formed selectively or patterned to cover the necessary region of the substrate surface by first covering a region of substrate to be exposed with a removable cover film, applying a resin for forming an oxygen gas-permeable membrane onto the whole surface of the substrate by spin coating, and then peeling or exfoliating the removable cover film to thereby remove the oxygen gas-permeable membrane together with the cover film in the region of substrate to be exposed. The present invention uses, as the material of the removable cover film, a thermosetting resin, a solution of polyvinylchloride in an organic solvent, or other resins. Such resins are applied to the predetermined region of a substrate by screen printing, and then cured by heating or drying to form a removable cover film. The electrically insulating substrate, on which the present inventive miniaturized oxygen electrode is formed, may be an electrically insulating substrate having a flatness and a smoothness sufficient for forming a miniaturized oxygen electrode by using the semiconductor process. A silicon wafer is most advantageously used as the insulating substrate, from the viewpoint of the application of the production process of silicon semiconductors currently most generally used. The present invention may be directly applied to miniaturized oxygen electrodes formed on insulating substrates other than the silicon wafer. Namely, a miniaturized oxygen electrode is produced by using a flat substrate of an electrically insulating substance such as glass, quartz and plastics, in such a manner that a component electrode pattern is formed on the substrate, an electrolyte-containing material is filled in the oxygen sensing site by screen printing an electrolyte composition of the present invention, and then an oxygen gas-permeable membrane is selectively formed or patterned by the steps including forming a removable cover film by screen-printing a thermosetting resin, etc., on the pad portion, i.e., the region of the substrate including the component electrode end for external electrical connection. It will be easily understood that, even in this case, the present invention also provides an advantage in that a number of miniaturized oxygen electrodes are formed collectively at one time on the whole region of an integral substrate. According to the present invention, the screen-printed electrolyte composition contains a fine powder of an inorganic salt or an electrolyte not dissolved but dispersed in an organic solvent, and therefore, the inorganic salt, even when dried, does not form a brittle crystal but remains a fine powder, and this enables an electrolyte-containing material in the form of a dense solid material to be formed. The thus obtained electrolyte-containing material is essentially composed of the inorganic salt and polyvinyl pyrrolidone. Upon operating a miniaturized oxygen electrode, water is introduced into the electrolyte-containing material. Both the inorganic salt and polyvinyl pyrrolidone are water-soluble and completely dissolved in the introduced water, and thus the present inventive electrolyte-containing material satisfies the requirement for a miniaturized oxygen electrode that it remains in a solid state during the formation of an oxygen gas-permeable membrane and forms an aqueous solution when the miniaturized oxygen electrode is operated. Potassium chloride and sodium chloride are superior electrolytes and can be advantageously used as the inorganic salt according to the present invention, to obtain the best performance of a miniaturized oxygen electrode. The addition of a salt having a pH buffering effect, such as phosphate, to the present inventive electrolyte composition ensures that the electrolyte has a constant pH. As the electrochemical reaction in the oxygen electrode depends on the pH value, the constant pH improves the stability of the oxygen electrode performance. The miniaturized oxygen electrode according to the present invention is produced by filling an electrolyte composition containing an inorganic salt as an electrolyte in the form of a fine powder, collectively in all of the predetermined portions of a substrate, by screen printing, to thereby ensure a uniform filling operation and a high productivity. The process of producing a miniaturized oxygen electrode according to the present invention fills an electrolyte composition containing an inorganic salt as an electrolyte in the form of a fine powder, collectively in all of the predetermined portions of a substrate by screen printing, and thereby ensures a uniform filling operation and mass-production of a miniaturized oxygen electrode even when the filled portion has a complicated shape. The present inventive production process can also advantageously cope with any increase in the number of filling portions associated with an enlargement of the substrate size. The miniaturized oxygen electrode according to the present invention ensures a high productivity even when the oxygen gas-permeable membrane and the exposed portion have a complicated shape, because the oxygen gas-permeable membrane is patterned (or selectively formed) by removing a cover film formed in a predetermined shape. The oxygen gas-permeable membrane is applied collectively on the entire substrate surface by spin-coating, and thereby a high productivity is ensured and an oxygen gas-permeable membrane having a uniform thickness over the entire substrate surface is formed. The miniaturized oxygen electrode according to the present invention can be produced at a high productivity by effectively forming an oxygen gas-permeable membrane having a uniform thickness over the entire substrate surface, i.e., by first covering a substrate region to be exposed with a removable cover film, forming an oxygen gas-permeable membrane collectively on the entire substrate surface, and then peeling or exfoliating the removable cover film to selectively form or pattern the oxygen gas-permeable membrane. The process according to the present invention can easily cope with a complicated pattern of oxygen gas-permeable membrane and with any increase in the number of portions to be exposed, because an oxygen gas-permeable membrane is patterned through the steps of: applying a thermosetting resin of a resin dissolved in an organic solvent to the to-be-exposed portions by screen printing; curing the applied resin by heating or drying to form a removable cover film; and then peeling or exfoliating the removable cover film. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows the essential arrangement of a conventional oxygen electrode, in Section view; FIGS. 2(a) through (c) show a miniaturized oxygen electrode in plan view (a, b) and sectional view (c); FIGS. 3(a) through (n) show a process sequence according the present invention, in sectional and plan views; FIG. 4 is a graph showing a typical response of a miniaturized oxygen electrode according to the present invention, in terms of the relationship between the time elapsed from the addition of Na 2 SO 3 and the output current; FIG. 5 is a graph showing the linear calibration curve of a oxygen electrode according to the present invention, in terms of the relationship between the dissolved oxygen content and the output current; FIGS. 6(a) through (f) show a process sequence according to the present invention, in sectional and plan views; FIGS. 7(a) through (1) show a process sequence the present invention, in sectional and plan views; FIGS. 8(a) through (c) show a three-pole miniaturized oxygen electrode; FIGS. 9(a) through (e) show a process sequence for producing a three-pole miniaturized oxygen electrode, according to the present invention, in sectional and plan views; FIG. 10 shows a miniaturized oxygen electrode mounted on an adapter, for use in a fermenter, in sectional view; and FIG. 11 shows an arrangement of a device for measuring the oxygen concentration in which a miniaturized oxygen electrode according to the present invention is applied. DESCRIPTION OF THE PREFERRED EMBODIMENTS Example 1 Referring to FIG. 3, a process sequence for producing a miniaturized oxygen electrode according to the present invention by using a silicon wafer will be described below. Although the sequence is described for the case in which a miniaturized oxygen electrode is formed on a 2-inch silicon wafer, for simplicity, essentially the same process sequence can be also used for a larger wafer. The Figures depict the wafer in which the corresponding process step is completed. Step 1: Cleaning Wafer A 2-inch silicon wafer 301 (400 μm thick, (100) plane) was thoroughly cleaned with a mixed solution of hydrogen peroxide and ammonia and with a concentrated nitric acid. Step 2: Forming SiO 2 Layer (FIG. 3(a)) The wafer 301 was wet-thermally oxidized at 1000° C. for 200 min to form a 0.8 μm thick SiO 2 layer 312 on both sides of the wafer. The SiO 2 layer 312 is to be patterned in the following step 4 and used as a mask when anisotropically etching the silicon wafer in the following step 5. Step 3: Forming Resist Pattern (FIG. 3(b)) A negative-type photoresist (Tokyo Ohka Kogyo Co., Ltd., OMR-83, viscosity 60 cP) was applied on the entire upper surface of the wafer, prebaked at 80° C. for 30 min. and was subjected to a photolithography treatment to form a resist pattern 313. The resist pattern 313 covers the upper surface of the wafer 301 except for a region 302A at which grooves 302 (FIG. 3(d)) for receiving an electrolyte-containing material are to be formed in the following step 5. The resist pattern 313 serves as a mask upon etching the SiO 2 layer 312 in the following step 4. The same photoresist was applied on the lower surface of the wafer 301, which was then baked at 150° C. for 30 min. Step 4: Etching SiO 2 Layer (FIG. 3(c) The wafer 301 was immersed in en etchant for SiO 2 (50%HF/1ml+NH 4 F/6 ml) to partially remove the SiO 2 layer 312 in the portion 302A not covered with the photoresist 313. The wafer 301 was then immersed in a mixed solution of connected sulfuric acid and hydrogen peroxide, to remove the photoresist 313. Step 5: Anisotropically Etching Silicon Wafer (FIG. 3(d)) The wafer 301 was immersed in an etchant for silicon (35% KOH) at 80° C. to anisotropically etch the silicon wafer 301 by using the SiO 2 layer as a mask, and thereby forming two 300 μm deep grooves 302 for receiving an electrolyte-containing material. After the anisotropic etching was finished, the wafer 301 was cleaned with pure water. Step 6: Removing SiO 2 Layer (FIG. 3(e)) Subsequent to the water cleaning, the SiO 2 layer 312 was removed by the same operation as that performed in Step 4. Step 7: Forming SiO 2 Layer (FIG. 3(f)) The same operations as performed in Steps 1 and 2 were carried out to effect a thermal oxidation of the wafer 301, and thereby form a 0.8 μm thick SiO 2 layer 303 on the entirety of both sides of the wafer 301. The thus-formed SiO 2 layer 303 functions as an insulating layer of a miniaturized oxygen electrode or the final product. Step 8: Forming Thin Layers of Chromium and Silver (FIGS. 3(g1), 3(g2)) A 400 Å thick chromium thin layer 314 and a 4000 Å thick silver thin layer 315 overlying on the chromium layer 314, were formed on the entire upper surface of the wafer 301 by vacuum deposition. The silver thin layer 315 is an electroconductive layer composing the substantial portion of component electrodes (anode and cathode) and the chromium thin layer 314 is a ground layer for ensuring an adhesion of the silver thin layer 315 to the SiO 2 insulating layer 303 formed on the wafer 301. Step 9: Forming Photoresist Pattern (FIGS. 3(h1), 3(h2)) This step provides a photoresist pattern 316 to be used as a mask in the following Steps 10 and 11, in which the silver thin layer 315 and the chromium thin layer 314 are etched to thereby effect a patterning of component electrodes (anode and cathode) of a miniaturized oxygen electrode. A positive-type photoresist (Tokyo Ohka Kogyo Co., Ltd., OFPR-800, viscosity 20 cP or OFPR-5000, viscosity 50 cP) was dropped on the wafer 301 to uniformly cover the wafer 301. The photoresist is preferably dropped in an amount such that it spreads just to the wafer circumferential edge. The wafer 301 was prebaked at 80° C. for 30 min. The wafer 301 was pattern-aligned with a glass mask by a mask aligner, exposed to light, and developed to form a photoresist pattern 316. The exposure and development cycle was repeated to ensure a complete exposure of the positive-type photoresist layer, which is too thick to complete the exposure over the thickness at one time. Step 10: Etching Thin Layers of Silver and Chromium (FIGS. 3(i1) and 3(i2)) The wafer 301 was immersed in an etchant for silver (NH 3 water/1 ml+H 2 O 2 /1 ml+water/20 ml) to remove a bare portion of the silver layer, and thereby form the substantial portion of component electrodes. The wafer was then immersed in an etchant for chromium (NaOH/0.5 g+K 3 Fe(CN) 6 /1 g+water/4 ml) to remove a bare portion of the chromium layer 314. Step 11: Forming Photoresist Pattern (FIG. 3(j1) and 3(j2) This step provides a photoresist pattern 317 for defining the oxygen sensing site of a miniaturized oxygen electrode. A layer 317 of a negative-type photoresist (Tokyo Ohka Kogyo Co., Ltd., OMR-83, viscosity 60 cP) was formed on the wafer 301 to cover the wafer surface in the portion other than a region 309 of the oxygen sensing site (two grooves and a flat plateau therebetween) and a pad region 311, at which the pad portions 304A and 305A of component electrodes 304 and 305 are to be formed. This is performed by applying the photoresist to the wafer surface, prebaking the wafer at 80° C. for 30 min, and exposing to light and developing the photoresist layer. Thereafter, the photoresist layer was postbaked at 150° C. for 30 min. Step 12: Screen-Printing Electrolyte Composition (FIGS. 3(k1), 3(k2) and 3(k3)) An electrolyte composition was screen-printed at the oxygen sensing site 309 (two grooves and a flat plateau therebetween) defined by the photoresist 317, to form an electrolyte-containing material 306. The preparation of the electrolyte used will be described later. Step 13: Forming Pad Region Cover Film (FIGS. 3(l1) and 3(l2)) A thermosetting release coating (Fujikura Kasei Co. XB-801) was screen-printed at the pad region 311 at a thickness of 100 μm and cured by heating at 150° C. for 10 min. to form a removable cover film 308. Step 14: Forming Oxygen Gas-Permeable Membrane (FIGS. 3(m1) and 3(m2)) An oxygen gas-permeable membrane 307 having a double-layered structure was formed on the wafer 301 to entirely cover the upper surface of the wafer 301. The lower layer of the membrane 307 was first formed by applying a negative-type photoresist (Tokyo Ohka Kogyo Co., Ltd., OMR-83, viscosity 100 cP) to the wafer 301 by spin coating, prebaking at 80° C. for 30 min., exposing the entire wafer surface to light and developing, and postbaking at 150° C. for 30 min. The upper layer of the membrane 307 was then formed by applying a silicone resin (Toray-Dow Corning Silicone Co. SE9176) to the wafer 301 by spin coating and curing the coated resin by heating at 70° C. for 30 min. in an oven moistened by water contained in a Petri dish or a beaker placed in the oven. Step 15: Exposing Pads (FIGS. 3(n1) and 3(n2) The cover film 308 formed on the pad region 311 was peeled with a pincette to selectively remove the oxygen gas-permeable membrane in that region, and thereby expose the pads 304A and 305A of a miniaturized oxygen electrode. Step 16: Separating Miniaturized Oxygen Electrodes A number of miniaturized oxygen electrodes were collectively formed on the wafer 301 at one time by the preceding Steps 1 through 15 and were cut into chips by a dicing saw. The shown example provides forty chips of miniaturized oxygen electrodes at one time. Example 2 Miniaturized oxygen electrodes were produced by the same process sequence as that of Example 1, except that Step 13 of forming a pad region cover film was modified as follows: Step 13': Forming Pad Region Cover Film (Modified) Polyvinylchloride resin dissolved in tetrahydrofuran was screen-printed at the pad region 311 at a thickness of 50 μm and cured by heating at 70° C. to form a cover film 308. The electrolyte composition according to the present invention used in Step 12 of Examples 1 and 2 was prepared in the following manner. Preparation Procedure 1: Providing Fine Powder of Inorganic Salt Fine particles of potassium chloride or sodium chloride were formed by either of the following procedures (a) and (b): (a) A solid material of potassium chloride or sodium chloride was pulverized to fine particles having a diameter of 10 μm or less by a pulverizer (Fritsch Co. Type P-5). (b) A saturated aqueous solution of potassium chloride or sodium chloride was prepared. The solution was poured into an organic solvent such as ethanol, propanol, or acetone of an amount of ten times the solution, through a Teflon ball filter (Iuchiseieido Co., pore diameter 10 μm). The organic solvent was thoroughly agitated by a stirrer during the pouring. This provided a precipitation of fine particles of inorganic salt, which was collected by a glass filter, washed two or three times with a fresh organic solvent of the same kind, and dried to obtain fine particles having a diameter of 10 μm or less. Preparation Procedure 2: Blending Electrolyte Composition The above-obtained fine particles of inorganic salt, polyvinyl pyrrolidone, and an organic solvent were blended to form an electrolyte composition in the form of a paste. The following is an example of the thus-blended composition. ______________________________________Electrolyte Composition: Case 1______________________________________Potassium chloride fine particle 0.25 gPolyvinyl pyrrolidone 1 gPentanol 5 g______________________________________ The blending may be carried out in a manner such that the electrolyte composition contains 30 to 70% of a solid part and the remainder of an organic solvent, the solid part containing 50 to 90% of an inorganic salt. The following is an example of the thus-blended composition. ______________________________________Electrolyte Composition: Case 2______________________________________Potassium chloride fine particle 4 gPolyvinyl pyrrolidone 1 gPentanol 5 g______________________________________ According to preferred embodiment of the present invention, an electrolyte composition further comprises a salt having a pH-buffering effect. Although a phosphate was added in the following case, the buffering agent used in the present invention may be selected from the group consisting of phosphates, acetates, borates, citrates, phthalates, tetraborates, glycine salts, and tris(hydroxymethyl)aminomethane salts. An electrolyte composition with an addition of a phosphate as a buffering agent may be prepared in the following manner, for example. Preparation Procedure 1: Providing Fine Powder of Inorganic Salt Fine particles of potassium chloride or sodium chloride were formed by either of the following procedures (a) and (b): (a) 74.55 g of potassium chloride and 8.71 g of dipotassium hydrogen phosphate were weighed and pulverized to particles having a diameter of 10 μm or less by a pulverizer (Fritsch Co., Type P-5). (b) 74.55 g of potassium chloride and 8.71 g of dipotassium hydrogen phosphate were weighed and dissolved in 230 ml of water. The aqueous solution was poured into an amount of ethanol ten times the amount of the solution, through a Teflon ball filter (Iuchiseieido Co., pore diameter 10 μm). The ethanol was thoroughly agitated by a stirrer during the pouring. This resulted in a precipitation of fine particles of inorganic salt, which was then collected by a glass filter, washed with a fresh ethanol two or three times, and dried to obtain fine particles having a diameter of 10 μm or less. The fine particles of potassium chloride or sodium chloride and the fine particles of phosphate or a buffering agent may be separately prepared. For example, when a concentrated aqueous solution of potassium chloride or sodium chloride is formed, an aqueous solution of potassium dihydrogen phosphate and sodium dihydrogen phosphate (4:6 in molar ratio) can be separately formed. Both solutions are preferably in a saturation state, which provides a greater amount of fine particles, i.e., a high efficiency. Note that the weighed phosphates must be completely dissolved in water, because the proportion of the dissolved phosphates significantly affects the pH value. The thus-prepared aqueous solutions are poured into an organic solvent such as ethanol, in the same manner as described above, respectively, and the precipitated fine particles are collected. Preparation Procedure 2: Blending Electrolyte Composition The above-obtained fine particles of inorganic salts, polyvinyl pyrrolidone, and an organic solvent were blended to form an electrolyte composition in the form of a paste. The followings are examples of the thus-blended compositions. ______________________________________Electrolyte Composition: Case 3______________________________________Mixture of fine particles of 0.25 gpotassium chloride and phosphatePolyvinyl pyrrolidone 1 gPentanol 5 g______________________________________Electrolyte Composition: Case 4 (fineparticles of buffering agent separately formed)______________________________________Potassium chloride fine particle 3.5 gPhosphate fine particle 0.5 gPolyvinyl pyrrolidone 1 gPentanol 5 g______________________________________ The performance of the miniaturized oxygen electrode produced in Examples 1 and 2 was tested by measuring the dissolved oxygen concentration of a 10 mM buffered phosphoric acid solution having a pH value of 7.0 at an applied voltage of 0.6 V and a temperature of 25° C. FIG. 4 shows a response curve observed when sodium sulfite is added to a solution saturated with 100% oxygen, to instantaneously reduce the oxygen concentration to zero. The response time was 40 seconds, which corresponded to the variation of the dissolved oxygen concentration. FIG. 5 shows a calibration curve obtained in this case, from which it is seen that a good linearity is ensured over the entire range of the dissolved oxygen concentration of from 0 ppm through 8 ppm, i.e., the saturation concentration. Example 3 Referring to FIG. 6, a process sequence for producing a miniaturized oxygen electrode according to the present invention by using an electrically insulating flat substrate other than a silicon wafer will be described. Step 1: Forming Component Electrode Pattern (FIG. 6(a)) A 60 mm square, 1.6 mm thick, cleaned electrically insulating flat substrate 401 was prepared. The insulating substrate 401 may be made of glass, quartz, ceramics, plastics or other electrically insulating substances. A component electrode pattern consisting of an anode 404 and a cathode 405 was formed on the insulating substrate 401 by either of the following procedures (a) and (b): (a) A silver thin layer is formed by vacuum deposition and is etched to form a predetermined electrode pattern, in the same manner as used in preceding Examples 1 and 2. (b) An electroconductive paste (Fujikura Kasei Co., D-1230 modified) is screen-printed on the substrate. The component electrodes 404 and 405 have ends for external electrical connections or pads 404A and 405A, respectively. An auxiliary pad 420 provided between the pads 404A and 405A can be used for a miniaturized oxygen electrode having a three-pole structure, for example. Step 2: Screen-Printing Electrolyte Composition (FIG. 6(b)) The same electrolyte composition as used in Example 1 was screen-printed to fill a region 409 of the oxygen sensing site, and thereby form an electrolyte-containing material 406. Step 3: Forming Pad Region Cover Film (FIG. 6(c)) A thermosetting release coating (Fujikura Kasei Co., XB-801) was screen-printed at a pad region 411 containing the pads 404A and 405A and the auxiliary pad 420, to form a cover film 408 covering the pad region 411. Step 4: Forming Oxygen Gas-Permeable Membrane (FIG. 6(d)) An oxygen gas-permeable membrane 407 having a double-layered structure was formed on the substrate 401 to entirely cover the upper surface of the substrate 401. The lower and the upper layers of the membrane 407 were formed by applying a negative-type photoresist (Tokyo Ohka Kogyo Co., Ltd., OMR-83, viscosity 100 cP) and a silicone resin (Toray-Dow Corning Silicone Co., SE9176) by spin coating, respectively, and then curing the applied layers. Step 5: Exposing Pad Region (FIG. 6(e)) The cover film 408 formed on the pad region 411 was peeled with a pincette to selectively remove the oxygen gas-permeable membrane 407 in that portion, and thereby expose the pads 404A and 405A of a miniaturized oxygen electrode. The auxiliary pad 420 was simultaneously exposed. Step 6: Separating Miniaturized Oxygen Electrodes (FIG. 6(f)) A plurality of miniaturized oxygen electrodes were collectively formed on the electrically insulating substrate 401 at one time by the preceding Steps 1 to 6, and were cut into chips by a dicing saw. The shown example provided seven chips of miniaturized oxygen electrodes 418 from a single substrate, simultaneously. Although the preceding Examples formed the component electrodes of silver, the component electrodes may be formed of gold instead of silver, or a cathode and an anode may be formed of gold and silver, respectively. For example, the component electrodes can be formed of gold instead of silver by a partial modification of the process steps of Example 1, as follows. Example 4 Steps 8 and 10 of Example 1 were modified in the following manner. In Step 8 (FIGS. 3(g1) and 3(g2)), the same operation was performed as in Example 1, except that a gold thin layer 315 (4000 Å thick) was vacuum deposited instead of the silver thin layer 315 (4000 Å thick). The subsequent Step 9 (FIGS. 3(h1) and 3(h2)) was performed in the same manner as in Example 1. In Step 10 (FIGS. 3(i1) and 3(i2)), the same operation was performed as that in Example 1, except that the wafer 301 was immersed in an etchant for gold (KI/4 g +I 2 /1 g+water/40 ml) instead of the etchant for silver. These modifications provided a miniaturized oxygen electrode having a component electrode formed of gold. A miniaturized oxygen electrode having a gold cathode and a silver anode may be produced in the following manner. Example 5 Referring to FIG. 7, a process sequence for producing a miniaturized oxygen electrode having a gold cathode and a silver anode according to the present invention by using a glass substrate will be described. Step 1: Cleaning Substrate (FIG. 7(a)) A 60 mm square, 1.6 mm thick glass substrate 511 was thoroughly washed with a detergent (for example, Furuuchi Kagaku Co., Semico Clean 56) and acetone. Step 2: Forming Thin Layers of Chromium, Gold and Silver (FIG. 7(b)) A chromium thin layer (400 Å thick, for example), a gold thin layer (4000 Å, for example) and a silver thin layer 512 (4000 Å thick, for example) were formed on the substrate 511, in that order, by a vacuum deposition. The chlomium thin layer ensures a good adhesion between the glass substrate 511 and component electrodes of gold and silver. Step 3: Forming Photoresist Pattern (FIG. 7(c)) A positive-type photoresist (for example, Tokyo Ohka Kogyo Co., Ltd., OFPR-800, 20 cP or OFPR-5000, 50 cP) was applied on the silver thin layer 512 and prebaked at 80° C. for 30 min. The thus-formed photoresist layer was exposed to light and developed to form a photoresist pattern 513 corresponding to all component electrodes. Step 4: Etching Gold and Silver Thin Layers (FIG. 7(d)) The substrate 511 was immersed in an etchant for silver (for example, 29%NH 4 OH/1 ml+31%H 2 O 2 /1 ml+water/20 ml) to pattern the silver thin layer 512. The substrate 511 was then immersed in an etchant for gold (for example, KI/4 g+I 2 /1 g+water/40 ml) to pattern the gold thin layer. This exposed the chromium thin layer 514 in the portion not covered with the photoresist layer. Step 5: Re-Patterning Photoresist Pattern (FIG. 7(e)) The positive-type photoresist layer 513 was exposed to light and developed again so that the photoresist pattern 513 remained only in the portion at which an anode is to be formed, and the other portion of the photoresist pattern 513 was removed to expose the silver thin layer 512. Step 6: Patterning Component Electrodes (FIG. 7(f)) The substrate 511 was immersed in an etchant for silver to remove the silver thin layer exposed in the preceding Step 5, and thereby expose the underlying gold thin layer, with the result that the gold cathode 504, including part of the extended card edge portion (or pad) 503, and part of a floating card edge portion (or pad), were exposed. The substrate was then immersed in an etchant for chromium (for example, NaOH/0.5 g+K 3 Fe(CN) 6 /1 g+water/4 ml) to remove an open portion of the chromium thin layer 514. The substrate was immersed in acetone to entirely remove the photoresist pattern 513, and thereby expose the silver anode 505 including part of the extended card edge portion (or pad) 503. This completed the formation of the entire arrangement of component electrodes including the gold cathode 504 and the silver anode 505. Step 7: Forming Photoresist Pattern (FIG. 7(g)) A negative-type photoresist (for example, Tokyo Ohka Kogyo Co., Ltd., OMR-83, 60 cP) was applied to the entire upper surface of the substrate 511 by spin coating and prebaked at 70°-80° C. for 30 min. After an exposure to light and development, the photoresist was postbaked at 150° C. for 30 min. to form a photoresist pattern 516, which covered the substrate surface except for an oxygen sensing site of the silver anode 505, part of the gold cathode 504, and the card edge portion (or pad) 503. Step 8: Screen-Printing Electrolyte Composition (FIG. 7(h)) An electrolyte composition of the present invention was screen-printed on the oxygen sensing site 515 defined by the photoresist pattern 516, to form an electrolyte-containing material 517. Step 9: Forming Pad Region Cover Film (FIG. 7(i)) A thermosetting release coating (Fujikura Kasei Co., XB-801) was screen-printed on the pad region (or card edge portion) 503 at a thickness of 100 μm, and then cured by heating at 150° C. for 10 min. to form a cover film 508. Step 10: Forming Oxygen Gas-Permeable Membrane (FIG. 7(j) A oxygen gas-permeable membrane 507 having a double-layered structure was formed on the glass substrate 511 to entirely cover the substrate upper surface. The lower layer of the membrane 507 was first formed by spin-coating a negative-type phtoresist (Tokyo Ohka Kogyo Co., Ltd., OMR-83, viscosity 100 cP), prebaking at 80° C. for 30 min., exposing the entire substrate surface to light, and postbaking at 150° C. for 30 min. The upper layer was then formed by spin-coating a silicone resin (Toray-Dow Corning Silicone Co., SE9176) and curing by heating at 70° C. for 30 min. in an oven moistened with the water contained in a Petri dish or a beaker placed in the oven. Step 11: Exposing Pads (FIG. 7(k)) The cover film 508 formed in the pad region 503 was peeled off with a pincette to selectively remove the oxygen gas-permeable membrane 507 in that portion, and thereby expose the pads (or card edges) 504A and 505A of a miniaturized oxygen electrode. The selective removal of the oxygen gas-permeable membrane 507 was effected in such a way that, when the cover film 508 was peeled off, the oxygen gas-permeable membrane 507 was cut by the edge of the cover film 508 between the membrane portion positioned on the cover film 508 and the other membrane portion away from the cover film 508. The portion of oxygen gas-permeable membrane remaining on the glass substrate strongly adhered to the substrate and was not exfoliated by the later treatments, including a water vapor treatment describe later. The oxygen gas-permeable membrane also ensures a high reliability such that it does not fracture when attached to a catheter and used in a medical care, or when used for monitoring the oxygen concentration in a fermenter subjected to a sterilization at a temperature of 120° C. and a differential pressure of 1.2 atm. for about 15 min. Step 12: Separating Miniaturized Oxygen Electrodes (FIG. 7(l)) A plurality of miniaturized oxygen electrodes were collectively formed on the glass substrate 511 at one time and were cut into chips by a dicing saw. The shown example provides seven miniaturized oxygen electrodes from a single substrate at one time. The oxygen gas-permeable membrane strongly adhered to the substrate and did not exfoliate during a cutting thereof along a scribe line, and further, did not exhibit a lowered reliability when subjected to a reliability test. The miniaturized oxygen electrode according to the present invention can be applied to any clark type device for electrochemically detecting oxygen, including Galvani type, and three-pole type oxygen electrodes. FIGS. 8(a), (b) and (c) show an example of the three-pole type miniaturized oxygen electrode, wherein FIG. 8(b) shows an unfinished structure in which an oxygen gas-permeable membrane is not yet formed. A working electrode 702, a counter electrode 703 and a reference electrode 704 are formed on a silicon wafer 701 (see FIG. 8(b)) and an oxygen gas-permeable membrane 705 covers the surface except for pads 702A, 703A and 704A of the respective electrodes. FIG. 8(c) shows an I-I section of an oxygen sensing site, in which an electrolyte composition 715 is filled in grooves formed in the silicon wafer to form a electrolyte-containing material. Example 6 A three-pole type miniaturized oxygen electrode according to the present invention and having a basic structure as shown in FIGS. 8(a) to (c) was produced according to the present invention in the following sequence. Step 1: Forming Grooves for Receiving Electrolyte-Containing Material (FIG. 9(a1) and 9(a2)) In the same sequence as carried out in Steps 1 through 7 of Example 1, grooves 706 for receiving an electrolyte-containing material and an SiO 2 insulating layer 707 were formed on both sides of a silicon wafer 701. Step 2: Forming Component Electrode Pattern (FIGS. 9(b1) and 9(b2)) In the same sequence as carried out in Steps 2 through 6 of Example 5, a working electrode 702 and a counter electrode 703, both of gold, and a reference electrode 704 of silver were formed. Step 3: Forming Photoresist Pattern (FIGS. 9(c1) and 9(c2)) By the same operation as carried out in Step 11 of Example 1, a photoresist pattern 711 was formed to cover the substrate surface except for a region 712 of the oxygen sensing site and a pad region 713. Step 4: Screen-Printing Electrolyte Composition (FIGS. 9(d1) and 9(d2)) By the same operation carried out in Step 12 of Example 1, an electrolyte composition 715 was screen-printed on the oxygen sensing site 712. Step 5: Forming Pad Region Cover Film (not shown) By the same operation as carried out in Step 13 of Example 1, a removable cover film was formed. Step 6: Forming Oxygen Gas-Permeable Membrane (not shown) By the same operation as carried out in Step 14 of Example 1, an oxygen gas-permeable membrane was formed. Step 7: Exposing Pads (FIGS. 9(e1) and 9(e2)) By the same operation as carried out in Step 15 of Example 1, pads 702A, 703A and 704A were exposed. Step 8: Separating Miniaturized Oxygen Electrodes (not shown) By the same operation as carried out in Step 16 of Example 1, a number of miniaturized oxygen electrode formed on the silicon wafer were cut into chips. In Examples 1 through 6, miniaturized oxygen electrodes were produced at a yield of 98% or more and exhibited a good response characteristic, i.e., an output fluctuation of less than ±3% when measured in water saturated with oxygen. The produced miniaturized oxygen electrode is preserved in the dried condition and can be made operative when supplied with water through the oxygen gas-permeable membrane by water vapor sterilization (for example, at 121° C. and 2.2 atm.), immersion in water, exposure to a saturated water vapor, etc. When an miniaturized oxygen electrode is used for a fermenter, the above-mentioned preparation or water supply may be conveniently effected together with sterilization of the culture medium. As shown in FIG. 10, a miniaturized oxygen electrode 801 of the present invention is conveniently attached to a special adaptor 802 designed for a fermenter (proposed by the present inventors and others in Japanese Patent Application No. 1-231,708). The external electrical connection of a miniaturized oxygen electrode is usually carried out by inserting the card edge portion (or pad portion) 503 to a card edge connector (for example, Fujitsu Ltd., Type 760). FIG. 11 shows an arrangement of an oxygen concentration measuring device in which a miniaturized oxygen electrode of the present invention is used. An oxygen concentration measuring device 810 is composed of a miniaturized oxygen electrode 819 of the present invention and a controller 820. The controller 820 is composed of a voltage supply unit 821 for generating a voltage to be supplied to the oxygen electrode 819, a current-to-voltage converter unit 822 for converting an output current from the oxygen electrode 819 to a voltage, a calibration unit 823 for calibrating an output voltage from the converter unit 822 at the oxygen concentrations of 0% and 100%, and a display unit 824. The device 810 measures the dissolved oxygen concentration in many kinds of solutions and the oxygen concentration of gas phases. As herein described, the present invention provides a miniaturized oxygen electrode which can be mass-produced at a high efficiency by collectively and uniformly processing a substrate as a whole by using the semiconductor process, a production process thereof, and an electrolyte composition able to be advantageously used therefor.

An electrolyte composition for screen printing, comprising: an organic solvent; an inorganic salt in the form of a fine powder able to pass through a screen printing mesh, the salt powder being dispersed in the organic solvent; and polyvinyl pyrrolidone dissolved in the organic solvent A miniaturized oxygen electrode having an oxygen sensing site filled with the electrolyte composition. A process for producing a miniaturized oxygen electrode, including a step of patterning or selectively removing an oxygen gas-permeable membrane at a pad region by removing or peeling off an underlying cover film formed thereunder.

TECHNICAL FIELD [0001] The present disclosure relates to a content processing and delivery system and, more specifically, to a system for processing different types of content for different types of user devices with different delivery networks using different business rules. BACKGROUND [0002] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art. [0003] Satellite television has become increasingly popular due to the wide variety of content and the quality of content available. A satellite television system typically includes a set top box that is used to receive the satellite signals and decode the satellite signals for use on a television. The set top box typically has a memory associated therewith. The memory may include a digital video recorder or the like as well as the operating code for the set top box. [0004] Satellite television systems typically broadcast content to a number of users simultaneously in a system. Satellite television systems also offer subscription or pay-per-view access to broadcast content. Access is provided using signals broadcast over the satellite. Once access is provided the user can access the particular content. The broadcasting of a large selection of channels and pay-per-view programs uses a considerable amount of satellite resources. [0005] Content providers are increasingly trying to determine additional ways to provide content to users. Some content may be desired by a small number of customers. In such a case using valuable satellite resources at peak viewing times may not be cost effective. Less popular content may be broadcast by satellite at less popular viewing times, or may be available for downloading on demand via a broadband connection. Such content may be received and stored by a digital video recorder for later viewing. SUMMARY [0006] The present disclosure provides a system that is capable of supporting many types of devices and various types of processing to accommodate the various types of devices. [0007] In one aspect of the disclosure, a method includes providing a first set of business rules for a first content including a first target, providing a second set of business rules for a second content including a second target, providing the first target and the second target to a work flow system, from a work flow system and obtaining first content and first business rule identification and second content with a second business rule identification. The method further includes associating the first content with the first business rules, associating the second content with the second business rules, processing the first content to form first processed content in response to the first business rules, storing the first processed content in a content repository, processing the second content to form second processed content in response to the second business rules and storing the second processed content in a content repository. [0008] In a further aspect of the disclosure, a system includes a content management system having a first set of business rules for a first content including a first target and a second set of business rules for a second content including a second target. The system also includes a workflow system in communication with the content management system receiving the first target and the second target. The work flow system obtains first content with a first business rule identification and second content with a second business rule identification. The content management system associates the first content with the first set of business rules and associates the second content with the second set of business rules. A processing system processes the first content to form first processed content in response to the first business rules and processing the second content to form second processed content in response to the second business rules. A content repository stores the first processed content and the second processed content. [0009] Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. DRAWINGS [0010] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. [0011] FIG. 1 is a schematic illustration of a communication system according to the disclosure. [0012] FIG. 2 a is a detailed block diagrammatic view of the content processing system of FIG. 1 . [0013] FIG. 2 b is a detailed block diagrammatic view of an alternative the content processing system of FIG. 1 for web based devices. [0014] FIG. 3 is a detailed block diagrammatic view of the fixed user device of FIG. 1 . [0015] FIGS. 4 a and 4 b are representational views of packets formed according to the present disclosure. [0016] FIG. 5 is a flowchart illustrating a method for publishing and purging content. [0017] FIG. 6 is a state diagram for publishing and purging content. [0018] FIG. 7 is a flowchart illustrating a first method for operating the present disclosure. [0019] FIG. 8 is a flowchart illustrating a second method for operating the present disclosure. DETAILED DESCRIPTION [0020] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. For purposes of clarity, the same reference numbers will be used in the drawings to identify similar elements. As used herein, the term module refers to an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A or B or C), using a non-exclusive logical OR. It should be understood that steps within a method may be executed in different order without altering the principles of the present disclosure. [0021] The following system is described with respect to a satellite system and a broadband system. The broadband distribution system may be implemented in a cable or telephone-type system. An optical fiber may also be used in the broadband system. Wireless distribution may also be used in the broadband distribution system. [0022] While the following disclosure is made with respect to example DIRECTV® broadcast services and systems, it should be understood that many other delivery systems are readily applicable to disclosed systems and methods. Such systems include other wireless distribution systems, wired or cable distribution systems, cable television distribution systems, Ultra High Frequency (UHF)/Very High Frequency (VHF) radio frequency systems or other terrestrial broadcast systems (e.g., Multi-channel Multi-point Distribution System (MMDS), Local Multi-point Distribution System (LMDS), etc.), Internet-based distribution systems, cellular distribution systems, power-line broadcast systems, any point-to-point and/or multicast Internet Protocol (IP) delivery network, and fiber optic networks. Further, the different functions collectively allocated among a head end (HE), integrated receiver/decoders (IRDs) and a content delivery network (CDN) as described below can be reallocated as desired without departing from the intended scope of the present patent. [0023] Further, while the following disclosure is made with respect to the delivery of video (e.g., television (TV), movies, music videos, etc.), it should be understood that the systems and methods disclosed herein could also be used for delivery of any media content type, for example, audio, music, data files, web pages, etc. Additionally, throughout this disclosure reference is made to data, information, programs, movies, assets, video data, etc., however, it will be readily apparent to persons of ordinary skill in the art that these terms are substantially equivalent in reference to the example systems and/or methods disclosed herein. As used herein, the term title will be used to refer to, for example, a movie itself and not the name of the movie. [0024] Referring now to FIG. 1 , a communication system 100 includes a content processing system 102 that is used as a processing and transmission source, a plurality of content providers, one of which is shown at reference numeral 104 and a first satellite 106 . A second satellite 108 may also be incorporated into the system. The satellites 106 , 108 may be used to communicate different types of information or different portions of various contents from the content processing system 102 . The system 100 also includes a plurality of fixed user devices 110 such as integrated receiver/decoders (IRDs). Wireless communications are exchanged between the content processing system 102 and the fixed user devices 110 through one or more of the satellites 106 , 108 . The wireless communications may take place at any suitable frequency, such as, for example, Ka band and/or Ku-band frequencies. [0025] A mobile user device 112 may also be incorporated into the system. The mobile user device 112 may include, but is not limited to, a cell phone 114 , a personal digital assistant 116 , a portable media player 118 , a laptop computer 120 , or a vehicle-based device 122 . It should be noted that several mobile devices 112 and several fixed user devices 110 may be used in the communication system 100 . The mobile devices 112 may each have a separate antenna generally represented by antenna 124 . The mobile devices may be web-based devices using WiFi, WiMax, cellular broadband or wireless broadband systems. [0026] In addition to communication via the satellites 106 , 108 , various types of information such as security information, encryption-decryption information, content, or content portions may be communicated terrestrially. Various communication means such as a communication network 132 include, but are not limited to, the public switched telephone network (PSTN), a terrestrial wireless system, a broadband system, stratospheric platform, an optical fiber, or the like may be used to terrestrially communicate with the fixed user device 110 or the mobile user device 112 . To illustrate the terrestrial wireless capability an antenna 134 is illustrated for wireless terrestrial communication to the mobile user device 112 . [0027] Information or content provided to content processing system 102 from the media source 104 may be transmitted, for example, via an uplink antenna 138 to the satellite(s) 106 , 108 , one or more of which may be a geosynchronous or geo-stationary satellite, that, in turn, rebroadcast the information over broad geographical areas on the earth that include the user devices 110 , 112 . The satellites may have inter-satellite links 107 that allow the satellites to communicate signals therebetween. Among other things, the example content processing system 102 of FIG. 1 provides program material or content to the user devices 110 , 112 and coordinates with the user devices 110 , 112 to offer subscribers pay-per-view (PPV) program services and broadband services, including billing and associated decryption of video programs. Non-PPV (e.g. free or subscription) programming may also be received. To receive the information rebroadcast by satellites 106 , 108 , each for user device 110 is communicatively coupled to a receiver or downlink antenna 140 . [0028] Lists of available content may also be communicated by way of the communication network 132 or the satellites 106 , 108 . The lists may also be made available at a web server. The lists and content may be communicated separately through different means or through the same means. [0029] Security of assets broadcast via the satellites 106 , 108 may be established by applying encryption and decryption to assets or content during content processing and/or during broadcast (i.e., broadcast encryption). For example, an asset can be encrypted based upon a control word (CW) known to the content processing system 102 and known to the user devices 110 , 112 authorized to view and/or playback the asset. In the illustrated example communication system 100 , for each asset the content processing system 102 generates a control word packet (CWP) that includes, among other things, a time stamp, authorization requirements and an input value and then determines the control word (CW) for the asset by computing a cryptographic hash of the contents of the CWP. The CWP is also broadcast to the user devices 110 , 112 via the satellites 106 , 108 . The user devices authorized to view and/or playback the broadcast encrypted asset will be able to correctly determine the CW by computing a cryptographic hash of the contents of the received CWP. If the user device 110 is not authorized, the IRD 110 will not be able to determine the correct CW that enables decryption of the received broadcast encrypted asset. The CW may be changed periodically (e.g., every 30 seconds) by generating and broadcasting a new CWP. In an example, a new CWP is generated by updating the timestamp included in each CWP. Alternatively, a CWP could directly convey a CW either in encrypted or unencrypted form. Other examples of coordinated encryption and decryption abound, including for example, public/private key encryption and decryption. [0030] Referring now to FIG. 2 a , the content processing system 102 of FIG. 1 is illustrated in further detail. The content provider 104 may include various types of content providers, including those that provide content by way of a satellite 200 , DVD 202 , via a network as a file in 204 , by way of tapes and other means. The content provider 104 may also provide a content description and other metadata 208 to the system. An input server 212 may receive the various content and associated metadata and convert the format in a format conversion system 214 . A house format asset storage server 216 may be used to store the content asset in a house format. Still image files, trailers, and other information may also be stored in the house format asset storage server. A workflow management system 220 is used to control the format conversion system 214 and the server 212 . Also, the workflow management system 220 is coupled to the house format asset storage server 216 and performs ingest control. The house format asset storage server 216 provides still images to a content management system 221 and house format file, video and audio files to the video transport processing system 223 . [0031] The VTPS 223 may encode the packets containing the content. The encoder may encode the data into various transport formats such as DIRECTV® proprietary formats, or industry standard formats. The encoded data is then packetized into a stream of data packets by a packetizer 270 that also attaches a header to each data packet to facilitate identification of the contents of the data packet such as, for example, a sequence number that identifies each data packet's location within the stream of data packets (i.e., a bitstream). The header also includes a program identifier (PID) (e.g., a service channel identifier (SCID)) that identifies the program to which the data packet belongs. [0032] The stream of data packets (i.e., a bitstream) is then broadcast encrypted by, for example, the well-known Advanced Encryption Standard (AES) or the well-known Data Encryption Standard (DES). In an example, only the payload portion of the data packets are encrypted thereby allowing a user device 110 to filter, route and/or sort received broadcast encrypted data packets without having to first decrypt the encrypted data packets. [0033] The content management system 221 generally controls the overall movement and distribution of contents through the content processing system 102 . [0034] A licensing and contract information 222 and ads from ad sales 224 may be provided to the content management system 221 . That is, licensing information, tier assignments, pricing and availability may be provided to the content management system. Asset information, file names and durations may be exchanged between the content management system 221 and the workflow management system 220 . The asset information, such as file names and durations, may be determined at the server 212 that is coupled to the workflow management system 220 . [0035] The Content Management System (CMS) 221 in combination with the SPS ( 230 ) is used to provide the requested channel, program associated data (PAD), channel information and program information packets (PIPs). The CMS 221 may schedule content processing for a plurality of received assets based on a desired program lineup to be offered by the communication system 100 . For example, a live TV program for which a high demand for reruns might be expected could be assigned a high priority for content processing. [0036] A schedule PAD server (SPS) 230 may be coupled to the CMS and is used to generate a broadband video PAD that is communicated to a conditional access system for broadband video 232 . The conditional access system for broadband video 232 may be used to generate control words and control word packet in pairs and provide those to the video transport processing system 223 . [0037] In the illustrated example of FIG. 2 a , users of the user devices 110 (of FIG. 1 ) are charged for subscription services and/or asset downloads (e.g., PPV TV) and, thus, the content processing system 102 includes a billing system 234 to track and/or bill subscribers for services provided by the system 100 . For example, the billing system 234 records that a user has been authorized to download a movie and once the movie has been successfully downloaded the user is billed for the movie. Alternatively, the user may not be billed unless the movie has been viewed. [0038] A billing system 234 receives pricing and availability information from the content management system 221 . A conditional access system 236 receives callback information from the communication network 132 . The conditional access system may be used to generate authorizations, pay-per-view billing data, and callback data from the billing system 234 . Remote record requests may also be provided from the conditional access transaction system 238 . A conditional access system BCC 240 may be used to generate a conditional access packet from the information from the conditional access system 236 . [0039] The billing system 234 may generate purchase data that is provided to the enterprise integration (EI) block 242 . The enterprise integration block 242 may generate remote record requests to the conditional access transaction system 238 . Remote record requests may be generated through a web interface such as DIRECTV.com® in block 244 . Various ordering information, such as ordering broadband video, pay-per-view, and various services may be received at the web interface 244 . Various trailers may also be accessed by the users through the web interface 244 provided from the house format asset storage server 216 . Enterprise integration block 242 may also receive guide information and metadata from the content management system 221 . [0040] Titles, description and various categories from the content management system 221 may be provided to the advanced program guide system 248 . The program guide system 248 may be coupled to a satellite broadcasting system such as a broadcast transport processing system 250 that broadcasts content to the users through the satellite 106 , 108 . [0041] The program guide data generated by the program guide system 248 may include information that is used to generate a display of guide information to the user, wherein the program guide may be a grid guide and informs the user of particular programs that are broadcast on, particular channels at particular times. The program guide may be a list of content available through a communication means. A program guide may also include information that a user device uses to assemble programming for display to a user. For example, the program guide may be used to tune to a channel on which a particular program is offered. The program guide may also contain information for tuning, demodulating, demultiplexing, decrypting, depacketizing, or decoding selected programs. [0042] Content files may also be provided from the content management system 221 to the content distribution system 260 . [0043] Referring back to the video transport processing system 223 , the video transport processing system 223 includes a transport packaging system 270 . The transport processing system 270 creates pre-packetized unencrypted files. An encryption module 272 receives the output of the transport processing system and encrypts the packets. Fully packaged and encrypted files may also be stored in the content repository 274 . Encryption may take place in the data portion of a packet and not the header portion. [0044] One or more content delivery networks 280 may be used to provide content files such as encrypted or unencrypted and packetized files to the communication network 132 for distribution to the user devices 110 , 112 . The content distribution system 260 may make requests for delivery of the various content files and assets through the communication network 132 . The content distribution system 260 also generates satellite requests and broadcasts various content and assets through the broadcast transport processing system 250 . Some content delivery networks may be dedicated to a certain type of service or communication means. As will be described in FIG. 2 b , one content delivery network may be dedicated to web service. Others may be dedicated to mobile phone service. Still others may be dedicated to other types of communication. [0045] The communication network 132 may be a web-based system such as the Internet 122 which is a multiple-point-to-multiple-point communication network. However, persons of ordinary skill in the art will appreciate that point-to-point communications may also be provided through the communication network 132 . For example, downloads of a particular content file from a content delivery network may be communicated to a particular user device. Such file transfers and/or file transfer protocols are widely recognized as point-to-point communications or point-to-point communication signals and/or create point-to-point communication paths, even if transported via a multi-point-to-multi-point communication network such as the Internet. It will be further recognized that the communication network 132 may be used to implement any variety of broadcast system where a broadcast transmitter may transmit any variety of data or data packets to any number of or a variety of clients or receivers simultaneously. Moreover, the communication network 132 may be used to simultaneously provide broadcast and point-to-point communications and/or point-to-point communication signals from a number of broadcast transmitters or content delivery networks 280 . [0046] The content delivery network 280 may be implemented using a variety of techniques or devices. For instance, a plurality of Linux-based servers with fiber optic connections may be used. Each of the content delivery networks 280 may include servers that are connected to the Internet or the communication network 132 . This allows the user devices to download information or content (example, a movie) from the content delivery network 280 . The content delivery network 280 may act as a cache for the information provided from the content repository 274 . A particular user device may be directed to a particular content delivery network 280 depending on the specific content to be retrieved. An Internet uniform resource locator (URL) may be assigned to a movie or other content. Further, should one of the delivery networks 280 have heavy traffic, the content delivery network may be changed to provide faster service. In the interest of clarity and ease of understanding, throughout this disclosure reference will be made to delivering, downloading, transferring and/or receiving information, video, data, etc. by way of the content delivery network 280 . However, persons of ordinary skill in the art will readily appreciate that information is actually delivered, downloaded, transferred, or received by one of the Internet-based servers in or associated with the content delivery network 280 . [0047] It should be appreciated that the content delivery network 280 may be operated by an external vendor. That is, the operator of the content delivery network 280 may not be the same as the operator of the remaining portions of the content processing system 102 . To download files from the content delivery network 280 , user devices 110 , 112 may implement an Internet protocol stack with a defined application layer and possibly a download application provided by a content delivery network provider. In the illustrated example, file transfers are implemented using standard Internet protocols (file transfer protocol FTP), hyper text transfer protocol (HTTP), etc. Each file received by the user device may be checked for completeness and integrity and if a file is not intact, missing, and/or damaged portions of the files may be delivered or downloaded again. Alternatively, the entire file may be purged from the IRD and delivered or downloaded again. [0048] The broadcast transport processing system 250 may provide various functions, including packetizing, multiplexing and modulating, and uplink frequency conversion. RF amplification may also be provided in the broadcast transport processing system 250 . [0049] Wireless delivery via the satellites 106 , 108 may simultaneously include both files (e.g., movies, pre-recorded TV shows, games, software updates, asset files, etc.) and/or live content, data, programs and/or information. Wireless delivery via the satellites 106 , 108 offers the opportunity to deliver, for example, a number of titles (e.g., movies, pre-recorded TV shows, etc.) to virtually any number of customers with a single broadcast. However, because of the limited channel capacity of the satellites 106 , 108 , the number of titles (i.e., assets) that can be provided during a particular time period is restricted. [0050] In contrast, Internet-based delivery via the CDN 280 can support a large number of titles, each of which may have a narrower target audience. Further, Internet-based delivery is point-to-point (e.g., from an Internet-based content server to a user device 110 , 112 ) thereby allowing each user of the user device 110 , 112 to individually select titles. Allocation of a title to satellite and/or Internet-based delivery or content depends upon a target audience size and may be adjusted over time. For instance, a title having high demand (i.e., large initial audience) may initially be broadcast via the satellites 106 , 108 , then, over time, the title may be made available for download via the CDN 280 when the size of the target audience or the demand for the title is smaller. A title may simultaneously be broadcast via the satellites 106 , 108 and be made available for download from the CDN 280 via the communication network 132 . [0051] In the example communication system 100 , each asset (e.g., program, title, content, game, TV program, etc.) is pre-packetized and, optionally, pre-encrypted and then stored as a data file (i.e., an asset file). Subsequently, the asset file may be broadcast via the satellites 106 , 108 and/or sent to the CDN 280 for download via the CDN 280 (i.e., Internet-based delivery). In particular, if the data file is broadcast via the satellites 106 , 108 , the data file forms at least one payload of a resultant satellite signal. Likewise, if the data file is available for download via the CDN 280 , the data file forms at least one payload of a resultant Internet signal. [0052] It will be readily apparent to persons of ordinary skill in the art that even though at least one payload of a resultant signal includes the data file regardless of broadcast technique (e.g., satellite or Internet), how the file is physically transmitted may differ. In particular, transmission of data via a transmission medium (e.g., satellite, Internet, etc.) comprises operations that are: (a) transmission medium independent and b) transmission medium dependent. For example, transmission protocols (e.g., transmission control protocol/Internet protocol (TCP/IP), user datagram protocol (UDP), encapsulation, etc.) and/or modulation techniques (e.g., quadrature amplitude modulation (QAM), forward error correction (FEC), etc.) used to transmit a file via Internet signals (e.g., over the Internet 122 ) may differ from those used via satellite (e.g., the satellites 106 , 108 ). In other words, transmission protocols and/or modulation techniques are specific to physical communication paths, that is, they are dependent upon the physical media and/or transmission medium used to communicate the data. However, the content (e.g., a file representing a title) transported by any given transmission protocol and/or modulation is agnostic of the transmission protocol and/or modulation, that is, the content is transmission medium independent. [0053] The same pre-packetized and, optionally, pre-encrypted, content data file that is broadcast via satellite may be available for download via Internet, and how the asset is stored, decoded and/or played back by the user devices 110 is independent of whether the program was received by the user devices 110 via satellite or Internet. Further, because the example content processing system 102 of FIG. 1 broadcasts a live program and a non-live program (e.g., a movie) by applying the same encoding, packetization, encryption, etc., how a program (live or non-live) is stored, decoded and/or played back by the user devices 110 is also independent of whether the program is live or not. Thus, user devices 110 , 112 may handle the processing of content, programs and/or titles independent of the source(s) and/or type(s) of the content, programs and/or titles. In particular, example delivery configurations and signal processing for the example content delivery system of FIG. 2 a are discussed in detail below. [0054] Referring now to FIG. 2 b , an alternative content processing system 102 ′ suitable for web-based systems is illustrated. The system in FIG. 2 b may also be used together with that of FIG. 2 a so that different methods for distribution can take place. The content processing system 102 ′ shares many components with those of the content processing system 102 . Therefore, the detail associated with these elements will not be described again. The same reference numerals are used to describe the same elements. This embodiment is different from the embodiment illustrated in FIG. 2 a in that the content processing system 102 ′ is used for web-based devices. Various devices may be web-based devices and include those illustrated in FIG. 1 as reference numerals 114 - 122 . The web-based devices may be WiMax, WiFi, or otherwise wireless broadband-capable. Various types of content are provided by the content provider 104 , are provided to the workflow system 220 in a similar manner to that illustrated in FIG. 2 . In this embodiment, various license information, tier assignments and pricing availability are provided to the content management system 221 from the licensing/contracts 222 and ad sales 224 . Various types of information that are entered into the content management system 221 may be referred to as business rules. The various business rules may be added manually or may be added automatically based upon various contracts with various contract dividers. The business rules may also include the pricing, the availability, and the type of target such as a set top box, a mobile device or a web device. Also, the availability, such as timing of the content, may be provided. The content management system 221 provides encoding commands such as the various types of targets, material identifications, and the like. The workflow management system 220 provides the content management system 221 collects various asset metadata including the file name, duration of the file, and the like. [0055] The content management system 221 links the business rules with the content. [0056] The content management system 221 provides the enterprise integration module 242 with billing data such as various pay-per-view numbers, publishing dates, and prices. This information may be provided to an on-demand web services 282 . [0057] The content management system 221 may also provide a content list or inventory to a web portal 284 . Account information may be provided to the web portal 284 from the enterprise integration module 242 . Inventory metadata may be provided from the web portal to the on-demand web service 282 . A digital rights management (DRM) license server 286 may be used to provide content license information to the web portal 284 . The web portal 284 may be used to provide inventory metadata to the DRM license server 286 . [0058] A digital rights management server 288 may receive content licenses from the digital rights management license server 286 . The content management system 221 may provide digital rights management parameters to a digital rights management packager 290 . The digital rights management packager 290 may provide an encrypted content file to the content repository 274 for storage therein. The content repository 274 may also receive encoded content files and posters from the workflow management system 220 . The file posters and other information may be associated with the various content files when stored within the content repository 274 . It should be noted that the content files may be encrypted or non-encrypted and may also have the digital rights associated therewith. One suitable example for providing digital rights is using a Windows Media® management-type system. [0059] The content management system 221 provides a distribute command to the content distribution system 260 . The file location, publication dates, expiration dates, purge dates, and the like may be provided to the content distribution system. The content distribution system communicates upload commands to the content delivery network 280 . In this embodiment, the content delivery network 280 may be a web-based network. As will be evident to those skilled in the art, various types of content delivery networks may be used for various types of content. In one aspect of the disclosure, one content delivery network may be provided for each different type of user device. For example, for distributing video to a cellular phone, a cellular phone content delivery network may be used. For a set top box, a set top box content delivery network may be used. Different rights and different encoding schemes may be used for the corresponding different user devices. [0060] The content delivery network 280 provides content to the user devices 110 or 112 . The user devices may generate download commands by communicating with the web service 282 . The web service 282 may communicate inventory metadata account information that is requested. For example, a content list of available content may be provided to the user devices 110 / 112 . [0061] The digital rights management server 288 may provide licenses that are requested by the system. The web portal 284 may grant pre-delivery licenses to the user device 110 / 112 . Download commands from the web service 282 may be provided to the content delivery network 280 to initiate download of content from the content delivery network 280 . [0062] The web-based device may obtain the content list from the web portal 284 so that content available for downloading to the user device may be provided to the user device. Upon selection from the list, a particular piece of content may be provided to the user device. The enterprise integration module 242 generates a bill in response to the downloading of content from the system. The billing information is coordinated with the information from the content user so that the proper user is billed. [0063] Referring now to FIG. 3 , the user device 110 may be one of any variety of devices, for example, a set-top box, a home media server, a home media center (HMC), a personal computer (PC) having a receiver card installed therein, etc. A display device 300 such as a television set, a computer monitor, a portable media player or the like may be coupled to the user device 110 . The user device 110 may be an integrated receiver decoder, a satellite television receiver or the like for displaying and/or playback of received programming. [0064] The receive antenna 140 ( 124 on a mobile device) receives signals conveying a modulated multiplexed bitstream from the satellites 106 , 108 . Within the receive antenna 140 , the signals are coupled from a reflector and feed to a low-noise block (LNB) 302 , which amplifies and frequency downconverts the received signals. The LNB 302 output is then provided to a receiver 304 , which receives, demodulates, depacketizes, demultiplexes, decrypts and decodes the received signal to provide audio and video signals to the display device 300 or a recorder 306 , or both. The memory device 306 may be implemented separately from or within the user device 110 . The receiver 304 is responsive to user inputs to, for example, tune to a particular program. [0065] To store received and/or recorded programs and/or assets, the memory device 306 may include any of a variety of storage devices such as a hard disk drive, DVR, or other types of memory devices. The memory device 306 may be used to store the packetized assets and/or programs received via the satellites 106 , 108 and/or the CDN 280 . In particular, the packets stored on memory device 306 may be the same encoded and, optionally, encrypted packets created by the content processing system 102 and transmitted via the satellites 106 , 108 and/or made available for download via the CDN 280 . [0066] The memory device 306 may also be a device capable of recording information on, for instance, analog media such as videotape or computer readable digital media such as a hard disk drive (HDD), a digital versatile disc (DVD), a compact disc (CD) and/or any other suitable media. [0067] To communicate with any of a variety of clients, media players, etc., the illustrated example the user device 110 includes one or more connection interface modules 308 (e.g., USB, serial port, Firewire, etc.). The connection interface module 306 may act as a network interface that implements, for example, an Ethernet interface. Should a device be strictly web-based, the LNB 140 and antenna 140 may not be used. [0068] Each user device 110 may connect to the communication network such as the Internet 122 via any of a variety of technologies, for instance, a voice-band and/or integrated services digital network (ISDN) modem connected to a conventional PSTN, a wireless broadband connection (e.g., IEEE 802.11b, 802.11g, etc.), a broadband wired connection (e.g., ADSL, cable modems, etc.), a wired Ethernet connection (e.g., local area network (LAN), wide area network (WAN), etc.), a leased transmission facility (e.g., a digital signal level 1 circuit (a.k.a. a DS1), a fractional-DS1, etc.), etc. [0069] The user device 110 may also include a control module 310 that is used to control the operation of the various components within the user device. [0070] A user interface 312 may, for example, be a set of push buttons or a remote control interface. The user interface 312 is used to make selections, input various data, and change the parameters of the user device 110 . The user interface 312 may be used together with a graphical user interface displayed on the display device associated with the user device. [0071] It should also be noted that the user devices 110 / 112 may be configured in a similar manner to those illustrated in FIG. 3 through reference number 110 . Such devices may include an internal antenna rather than an external dish-type antenna that is illustrated in the fixed device as 140 . Also, external antennas are possible such as a phased array antenna. [0072] The recording device 306 may also be partitioned into a network partition 320 and a user partition 322 . Different types of content or assets may be stored in the network partition 320 or the user partition 322 . The content stored in the different partitions may relate to the tier of the content. This will be further described below. [0073] Referring now to FIGS. 4 a and 4 b , a packet 400 having a header 402 and a data portion 404 is illustrated. The header 402 may include a program map table (PMT) 406 , an SCID/PID portion 408 , and a cyclic redundancy check portion 410 . This is representative of the output of the VTPS and the file stored in the content repository. The data portion 404 may be encrypted or not encrypted, while the header portion 402 is preferably not encrypted. A signal may be broadcast from the content distribution network with this type of format. [0074] In FIG. 4 b , a second packet 420 having a reformatted header 422 and a data portion 424 is illustrated. The data portion 424 may be unchanged from data portion 404 . The reformatted header 422 includes a second SCID/PID 426 that has been changed. The header 426 of the packet 420 has its identification (SCID/PID) reconfigured so that it may be broadcast by the satellite. Because the SCID/PID is changed, the CRC portion 428 is also changed to conform to this change. [0075] Referring now to FIG. 5 , a method of operating the communication system is set forth. In this embodiment, the general method for maintaining the files within the system is set forth. Each content delivery network may have different lifecycle parameters associated therewith. Each content delivery network may act according to the method of FIG. 5 using different lifecycle parameters including publication, purge, end times, and the like. In step 510 , content with metadata is received in the communication system. As mentioned above, the content provider 104 may provide the content in various forms. In step 512 , the content is packetized in the VTPS 223 . Also, as mentioned above, the VTPS may also encrypt the packets or at least the data portions of the packets. In step 514 , the packets, whether encrypted or not, are stored in the content repository 274 . In step 516 , a time for publication is determined. The publication time corresponds to the time that the content is available for download by one of the user devices from the content delivery network 280 . Various content within the content repository may have different publication times. In step 518 , the earliest publication time for the various content is determined. In step 520 , the content file is transferred to the content delivery network 280 in response to the publication time. That is, the earliest publication time may be used to transfer content to the content delivery network first. The content may be transferred prior to the publication time so that it is available at the publication time. This is in contrast to a typical satellite broadcasting system and to the broadcast TPS system 250 described in FIG. 2 . In a satellite system, the content is broadcast at the air time. [0076] In step 522 , metadata corresponding to the content file is transferred to the content delivery network 280 . In step 524 , the metadata may be changed according to information from the content management system. For example, the publication time, the publication end time, and a purge time may be added to the metadata. In step 526 , the content file is published according to the publication time in the metadata. In step 528 , the content may be transferred to the user device. In step 530 , the user device may utilize the content by viewing the content on the display device. In step 532 , publication is complete at the publication end time. In step 534 , the content is purged from the content delivery network according to a purge message. [0077] Referring now to FIG. 6 , a state diagram of the method of FIG. 5 is illustrated. The method begins in step 600 in which the content is placed in the content repository 274 after possible encryption and packetizing from the VTPS 223 . In step 602 , delivery is scheduled by the content management system 221 . The content distribution system 260 begins content file transfer to a content delivery network 280 with metadata in step 604 . In step 606 , the content with the metadata is transferred. In step 608 , the content delivery system completes the content file transfer to the content delivery network 280 . In step 610 , the content is fully delivered to the content distribution or delivery network 280 . In step 612 , an add operation is received by the content delivery network. An upload status message from the content delivery network (CDN) with a successful status code is provided. [0078] In step 614 , publication is scheduled by setting a publication time. After step 614 , step 616 may be performed. In step 616 , the content delivery network 280 may receive a publish operation. Also in step 616 , an upload status message from the content delivery network may be provided to the content distribution system with a successful status code. In step 618 , the content is published. [0079] Referring back to step 614 , if an update operation message is received and the upload status message from the content delivery network with a successful status code with the published stop time is in the past at 620 , step 622 may be performed. Step 622 ends the publication according to the publication stop time. [0080] Referring back to step 614 , if a receive update operation is received and an upload status message from the content delivery network has a successful status code where the publish start time is in the future in step 624 , step 622 completes the publication. [0081] Referring back to step 618 , when the content is published in 618 and an unpublished operation is received with an upload status message from the content delivery network with a successful status code and a published time in the future, step 630 is performed which brings the system back to the published scheduled block 614 . [0082] Referring back to step 618 , if an unpublished operation message is received in step 636 , and the upload status message from the content delivery network with a successful status code has a publication time in the past, step 622 is performed which completes the publication. In step 618 , if a purge operation message is received from the content distribution system and the upload status message from the content distribution network with a successful status code is provided in step 638 , the content is purged in step 640 . [0083] Referring back to step 622 , if the publication is complete and a published operation is received with an upload status message from the content delivery network with a successful status code in step 644 , the content is again published in step 618 . [0084] Referring back to step 622 , if the publication is complete and a purge operation upload status message is received from the content delivery network with a successful status code in step 650 , step 640 purges the content from the system. In step 642 , the content may be removed from the content repository. [0085] Referring back to the publication schedule times block 614 , if a receive purge operation is received that blocks and an upload status message from the content delivery network has a successful status code, step 640 is performed in which the content is purged. [0086] Referring now to FIG. 7 , another method for operating the present disclosure is illustrated. In this example, business rules and content are combined to provide a user selection list and ultimately deliver content to the users. In step 710 , business rules are determined. The business rules may be determined and entered into the content management system 221 of FIG. 2 a or 2 b . The business rules may include various characteristics including the dollar amount, the various targets, such as which user devices are to receive the content, and various other profiles. In step 712 , the business rules are entered into the content management system and include the targets. The business rules may be entered by an operator in response to various distribution agreements. In step 714 , the targets are provided to the workflow system. In step 716 , content that is obtained by the workflow system is provided to the content management system 221 . The workflow system provides the content with material IDs that are used for further identification once it is received by the content management system. Each content has a material ID associated therewith. In step 718 , the material ID is associated with the content. [0087] In step 720 , the content and business rule ID is provided to the content management system. In step 722 , the business rules are associated with the content in the content management system. In step 724 , the content is encrypted according to the business rules. Encryption may take place at the digital rights management packager in FIG. 2 b or the encryption module 272 illustrated in FIG. 2 a . Encryption may take place according to the business rules. More specifically, the content may be encrypted depending on the end user device or target for which the content is destined. Various types of encryption may be provided to various contents for use in the various systems. That is, when stored in the content repository, several different versions of the content encrypted in different ways may be stored therein. In step 726 , the encrypted content is stored in the content repository. [0088] In step 728 , a guide or title list is generated. The guide or title list may also be referred to as an inventory list. The inventory or title list is generated in response to the content available in the content repository. Preferably, elements of the list are only provided for content available for the different types of targets or devices. That is, when the content list is received by the various devices, only the content that is available to that device is preferably received. The elements of the list may be compiled by the content management system 221 . In step 730 , the guide, title list or inventory is communicated to the user devices. The title list may be provided to the user devices in various ways including through a satellite, through a terrestrial system, through a terrestrial wireless system, through a web-based system, or the like. The content list may be provided in a different way or using a different communication means than the content is provided. For example, a list may be provided through the satellite, whereas the content may be received through a broadband or Internet-based system. Communication to the user devices may also take place on a web-based system. The user devices may be used to obtain information on a website that is in communication with the user device. [0089] In step 732 , a selection is formed at the user device. The selection may be performed by entering or selecting the content from a user interface at the user device. A graphical user interface may have a selection box thereon for selecting. The selection box may be moved using cursors or other devices. Specialized selection buttons or buttons that exist on a system may be used for forming a selection. A signal identifying the selection is formed and communicated to the content processing system. In step 734 , once a selection is selection, billing information is updated so the proper user device account may be updated. In step 736 , the content delivery network is selected. The content delivery network may be selected depending on the type of content selected. That is, various content delivery networks may be provided in a particular system. However, only one of the content delivery networks may be used for delivering content to that particular user device based upon the formatting and the like. [0090] In step 740 , the content is played back or stored in the user device. It should be noted that the playback may be performed while recording the content. [0091] Referring now to FIG. 8 , a specific method for operating the content management system is illustrated. Steps 710 - 722 of FIG. 7 are shared in this embodiment. In step 810 , the content type is determined. The content type is based upon the target described above. The target corresponds to the various types of user devices. In this example, a web-based and non-web-based-type system is employed. However, the same decision blocks may be used for various other types of target devices. It should also be noted that more than two different types of targets may be provided. However, in such a system, the same types of logic may be used. In step 820 , the system determines whether or not the content is destined for a web-based system. In step 822 , if content is for a web-based system, the block diagram of FIG. 2 b may be utilized. In step 824 , digital rights management (DRM) may be applied. Digital rights management may be windows media-based digital rights management or various other types of digital rights management. The digital rights management may also include various types of encryption. In step 826 , the content with the applied digital rights management and/or encryption is stored in the content repository. In step 828 , a list is provided for the content available at a web portal. After step 828 , steps 832 - 740 of FIG. 7 may be performed. [0092] Referring back to step 820 , if the system is not a web-based system, step 830 may be performed. In step 830 , the schematic of FIG. 2 a may be used to process the content. In step 832 , encryption is applied to the content based on the target type. [0093] In step 834 , the content, with the applied encryption, is stored in the content repository. In step 836 , a content list is generated for the particular target. In step 838 , the content list may be communicated through the program guide or other means. For a satellite-based system, the program guide may be communicated through the satellite. The content list available from the content delivery network may be periodically updated and communicated through the satellite. [0094] After step 838 , steps 732 - 740 of FIG. 7 may be performed. [0095] When the content is provided to the various content delivery networks, various life cycles, purge times, and the like may be associated with the content. The content may have different life cycles, purge times, and other characteristics when provided to each content delivery network. It should also be noted that the same content may be provided through different content delivery networks with different timing characteristics. The different content delivery network may have the same or different types of encryption as well. The various purge times and other life-cycle components are provided in the metadata as described above. [0096] The example in FIG. 8 is provided for web and non-web-based system. The examples may easily be extended to other types and numbers of systems and targets. [0097] Those skilled in the art can now appreciate from the foregoing description that the broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, the specification and the following claims.

A system 100 includes a content management system 221 having a first set of business rules for a first content including a first target and a second set of business rules for a second content including a second target. The system 100 also includes a workflow system 220 in communication with the content management system 221 and receives the first target and the second target. The work flow system obtains first content with a first business rule identification and second content with a second business rule identification. The content management system 221 associates the first content with the first set of business rules and associates the second content with the second set of business rules. A processing system 290, 272 processes the first content to form first processed content in response to the first business rules and processing the second content to form second processed content in response to the second business rules. A content repository 274 stores the first processed content and the second processed content.

BACKGROUND OF THE INVENTION This invention relates generally to an arrangement for transforming a rotary movement of a smooth shaft into a thrust movement of a nut and more specifically, the invention relates to a roller nut for effecting such transformation. The roller nut employed in the arrangement according to this invention is of the type where several roller cages having annular configuration surround the shaft at different angles to each other and are held together in a common housing whereby center passages of the roller cages are in engagement with the smooth surface of the shaft. In the construction of machines and apparatuses, screws are frequently needed that should be capable of providing thrust movements over long distances. The machining of threads for the long screws of this type brings along several difficulties, especially when the screws are supposed to have a high degree of accuracy so that neither play nor wear between the bolt and nut take place. It is also frequently required that the bolt and nut arrangement of this kind have a smooth cooperation with minimum friction. Screw or bolt nuts have been known which employ rolling elements arranged for rolling in correspondingly formed grooves in the bolt and/or in the nut, thus avoiding any sliding movement and thereby also the wear. As an example of this known type are circulating on cyclic bolt nuts in which the bolts upon completion of one or more turns of the thread are guided to return to the beginning of the thread. Such screw drives however are hard to manufacture and consequently very expensive so that in many cases they cannot be used. Known are also frictional screws consisting of one or more rings which are pressed by resilient forces against the smooth surface of the shaft in such a manner as to be able to perform a screw-like motion when the planes of the rings and of the shaft intersect each other at the same angle. For example, in the German Pat. No. 1,057,411 a roller ring drive is described in which the aforementioned angles are adjustable so that the screw motion has an adjustable pitch. Nevertheless, technological expenses in making this embodiment of drives having minimum sliding friction are too high even if a screw motion having a single fixed pitch only is to be designed. Moreover, the drives having an adjustable pitch angle have the disadvantage that the shaft is displaced laterally from the center of the ring if transverse forces act against the ring and no additional guide between the ring housing and the shaft is provided. It is true that the rings lying upon the shaft are in balance due to their contact pressure but they do not have a stable transverse position since the almost punctiform line or area of their rolling contact lies on the swing axis of the rings. Consequently, additional lateral guides are necessary in which, however, sliding motions with frictional losses will result and also the wear. In roller ring drives having three rings the center ring is twice as much loaded as the two outer rings (FIG. 3 of the German Patent No. 1, 057 411). The maximum rolling capacity is thereby determined by the allowable specific surface pressure in the point or line of rolling and by the bearing strength or capacity of the inner ring. Since, as mentioned above, the prior art rings bear against the shaft almost at one point only, the contact pressure forces are distributed on the ring supporting balls more irregularly than in the case of a simple support of the shaft where the shaft occupies the entire inner ring. For this reason the bearing capacity or the strength of the bearing cannot be fully utilized. SUMMARY OF THE INVENTION It is, accordingly, an object of this invention to overcome the disadvantages of the prior art. More particularly, it is an object of the present invention to provide an improved roller or rolling nut having only one frictional thread lead for attaining an increased thrust force. Another object of this invention is to provide a rolling nut wherein the position of the shaft relative to the nut is stable even against transversely or laterally acting forces. Still another object of this invention is to provide a rolling nut that is assembled of simple parts, is easily accessible and occupies a small space only. In pursuance of the above objects, and others which will become apparent hereafter, one feature of this invention resides, briefly stated, in an arrangement where the contact line or area between a roller cage or ring and the shaft is made as large as possible but the bevel angle defined by the end points of the contact line and the center point of the roller ring is within the range of 60°. In a preferred embodiment of this invention the housing of the roller nut is assembled of two equal parts whereby the dividing surface of the two housing halves lies in a plane passing through the axis of the shaft and the center of the rolling surfaces. The resulting parts of the housing have the same configuration and are interchangeable. The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof will be best understood from the following description in specific embodiments when read in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWING FIG. 1 shows in a front view, partly in section, the bevel angle defined by the contact line between the shaft and a roller ring or roller cage and the center of the shaft in the arrangement of this invention; FIG. 2 is a plan cut-away view, partly in section, of the rolling nut of this invention; FIG. 3 is a perspective view partly in section of a roller cage in contact with the shaft; FIG. 3a is a front view, partly in section, of the arrangement of FIG. 3; FIG. 3b is a side view, partly in section, of the arrangement of FIG. 3 during rotation of the threaded shaft; FIG. 4 is a side view, partly in section, of an embodiment of the roller nut of this invention; FIG. 5 is a front view of the nut of FIG. 4; and FIG. 6 is a sectional front view of a modification of the roller nut of this invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 and 2 show a roller ring or roller cage 10 surrounding a smooth shaft 11 and having larger inside diameter than the diameter of the shaft. As seen from FIG. 2, the axis of the shaft 11 is deviated about a pitch angle beta from the center axis of the roller cage 10. The inside diameter of the roller cage 10, the diameter of the shaft 11 and the shape of the rolling surface of the cage are designed so that the roller ring is in contact with the shaft surface not at one point but on a relatively long arc defined by end points 13 and 14. By means of this relatively long line of contact, the position of the shaft relative to the ring is stabilized also against transverse forces. Also the contact presses are transferred to a larger section of the roller ring or cage via the inner ring section, the rolling bodies and the outer ring of the roller cage. Consequently, the rolling cage has an increased load capacity. Theoretically, the sliding surface of the rolling cage 10 and its inside diameter might be selected so that the beveled angle between the end points 13 and 14 of the contact surface between the cage 10 and the shaft 11 and the center of the ring 10 be almost 180°. This ideal case, however, cannot be realized for the reason that the velocity of rolling is different in each point on the surface of rolling. For example, in the center of the surface of rolling or of contact, the velocity has its maximum; if the point in the rolling surface is shifted about 90° relative to the center point, the velocity is zero. Naturally, two bodies may roll properly one upon the other only then, when the points of their contact have the same velocities. In this case the condition for the satisfactory rolling action is not fulfilled and besides the rolling friction there result also sliding frictions which increase proportionally to the velocity differences. From experience the deviations of rolling velocities should not exceed the center rolling velocity by ±6 percent. The thrust of feed velocity in roller ring drives is determined as known by mathematical relation V o =K·tan β whereby the factor K includes the constant magnitudes of the rotation rate and the diameter of the shaft. β, as mentioned above, is the angle between the axis of the roller ring and the axis of the shaft. If a rolling point n is located at a distance defined by angle γ (FIG. 3) from the center of the rolling surface or arc 13 and 14, the thrust- or feed velocity V n in the point n is V n =K·tan β·cos γ. For the allowable deviation of about ±6%, there results for the cosinus γ a value of 1-2·0.06=0.88 and therefrom the value of the largest permissible angle γ is 28.2° and for the entire length of the rolling surface between the points 13 and 14, the value 2×28.2=56.4°. From this computation it is apparent that the bevel angle between the ring 10 and the shaft 11 should be selected as large as possible but it may not exceed an arc of about 60° if the deviation between the velocities in the surface of contact and the center velocity is to be kept within the limits of ±6 percent. In known roller ring drives each roller ring has its own housing which again is swingably supported in a common housing. The common housing takes upon itself all forces that result due to the contact pressure between respective roller rings and the shaft. In contrast, in the roller nut according to this invention the roller rings or roller cages need not be swingably supported in the common housing since the pitch angle β is to be kept constant. Separate housings for the roller cages are no longer needed when the roller cages are directly supported in the common housing. The division of the common housing, which is necessary for the installation of the roller cages, is according to this invention designed so that the two parts of the housing are equal and interchangeable. By this advantageous measure the manufacture of the housing is substantially simplified since for example each rolling nut is assembled only of two kinds of components, namely of roller cages and of common housing parts. FIGS. 4 and 5 illustrate the common housing 16 and the position of the roller rings or roller cages 10 in one of the housing halves. In this example there are employed four roller cages 10. The pressure forces between the roller rings and the shaft are generated by elastical elements such as springs of resilient materials. In the embodiment shown in FIG. 6 the two intermediate roller cages 10 are passed against the shaft 11 by two pressure springs 22 located in recesses 20 and 21. The recesses are provided in each corner of housing parts 16, and 16' and are directed about an angle of 45° to the center of the housing. This space saving arrangement permits the application of a maximum spring volume since the edges of the rectangular housing 16 offer the required space and therefore no additional space is necessary. By arrow 19 is indicated the resulting force component of the two pressure springs 20 and 21 acting each at approximately 45° against the roller ring or cage 10 and the shaft 11. In rolling nuts having the rolling cages as disclosed for example in the German Pat. No. 1 210 647 an intermediate rolling cage is pressed by springs against the shaft and the reaction force is transferred from the opposite side to the lateral or outer rolling rings and therefrom to the common housing. In the device according to this invention two intermediate rollers 10 arranged in accordance with FIGS. 4 and 6, are pressed against the shaft 11 and the reaction forces are taken on by the lateral roller rings or cages 10'. The contact forces in all four roller cages become equal and the utilization of the permissible load upon the roller cages is optimum. For example, the rolling nut having four roller cages may be loaded twice as much as the nut having only three roller cages. It is necessary however that in both cases, namely in nuts having three as well as four roller cages, the cages be so arranged within the common housing that they contact minute surfaces on the shaft and at the same time that they be well guided laterally. This requirement is fulfilled by the application of the two pressure springs 22 (FIG. 6), namely by their inclined arrangement against each other and under 45° to the dividing plane of the housing. This arrangement does not interfere with the equalness and interchangeability of the two housing halves 16 and 16' but in addition it brings the advantage that without changing anything in the employed component parts it is possible during assembly of the roller nut of this invention to adjust the rolling cages either for the left-hand thread of the shaft or for the right-hand thread. To change the direction of thrust, it is needed only to remove springs 22 from the upper recesses as shown in FIG. 6 and replace them into the empty lower recesses. By this exchange, the rolling surfaces in the remaining lateral roller cages are automatically transferred to the opposite side of the shaft 11 and the condition for changing the direction of the pitch, or to provide the left hand or the right hand pitch, is fulfilled. The determination of the position of the two pressure springs has to be made during the installation and assembly of the roller nut. It is possible of course to construct roller nuts where the direction of pressure of the two springs 22 can be switched over even during the assembled and operative state of the roller nut. In this manner it would be possible without any changes in the direction of rotation of the shaft to induce a back-and-forth movement of the roller nut. As can be seen from FIG. 5, also the threaded holes or bole holes in the housing halves for receiving screws 23 and 24 used for connecting the two parts of the housing 16 are arranged in such a manner that both halves of the housing 16 remain equal. The main advantage of the arrangement of this invention results from the fact that due to the increased bevel angle between the end points of the area of rolling and the center of the roller cages (FIGS. 1 and 2) and due to the application of four instead of three roller cages, an approximately four-fold thrust load is possible in comparison with prior art devices of this kind. As an other advantage of the rolling nut of this invention it can be considered the fact that if an excessive resistance acts against the movement of the nut or if the resistance is greater than the allowable thrust, the nut of this invention having four rollers starts sliding whereas in usual threaded spindles or worm gears the threads might become damaged. Because of the low value of the specific pressure on the roller surface, in the case of slippage or sliding of the roller cages, no damage can occur in the rolling body and therefore unhardened, commercially available steel rods can be employed for the shafts. In spite of this, the efficiency of the roller nut of this invention remains high since only a low-loss rolling friction takes place in the contact surfaces. In contrast to normal screws where the self-stopping starts already at a pitch angle of about 10°, in the embodiment according to this invention is at angles between 2° to 3°. For practical use the pitch is an integer fraction of the diameter of the shaft; for example, 9° pitch angle is for 0.5 shaft diameter etc. The spring pairs 22 can be created so as to be pressure adjustable. This adjustment of the spring pressure makes it possible that the total thrust of the roller nut can be adjusted to a particular technological application in which it is employed such as for example in the overload protection. It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above. While the invention has been illustrated and described as embodied in a rolling nut including four roller cages, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

The arrangement for transforming rotary movement of a smooth shaft into a thrust movement by means of a rolling nut that comprises a housing and, within the housing, four inclined roller cages each defining a center passage having an inside diameter larger than the diameter of the shaft and each engaging an arcuate surface section of the shaft; the end points of the section of engagement forming with the center point of the corresponding roller cage a bevel angle within the range of 60° and the distance between the two points being sufficient for insuring a stable position of each cage on the shaft even if the cages are loaded laterally. The intermediate two roller cages are urged in contact with the shaft by a pair of springs, respectively.

FIELD OF THE INVENTION [0001] This invention concerns an electronic device cabinet having a main body and a cover that is rotatably attached to the cabinet main body, and in particular, an engagement member having a simplified construction for engaging said cover and for controlling the open and closed state of said cover. BACKGROUND OF THE INVENTION [0002] Heretofore known as cabinets for entertainment devices that employ optical disks, such as CD players, DVD players and the like, are cabinets that have a cover whose end is attached rotatably to a cabinet main body and in which the cover is opened and closed using elastic force. Such a cabinet is usually constructed in such a way that the cover is attached rotatably to the inner side of the cabinet main body by a hinge or other mechanism, a spring or other impelling means is provided inside the cabinet main body, and the cover is opened by releasing the elastic force of the spring. Provided on the cabinet main body in a location away from the attachment of the cover is usually an engaging member that advances and retracts with respect to the cover, and the cover can be closed by engaging the end of the cover with this engaging member. This engaging member usually has a sloping surface that comes into contact with a button or other pressing member, and when the operator presses the button, the pressing force acts via the sloping surface as a force in the advance-and-retract direction of the engaging member, and it moves away from the cover end. When the operator releases his hand from the button, it is necessary to restore the engaging member to its original position and engage the cover with the engaging member, so a spring or other impelling means is provided on the advance-and-retract direction base end part of the engaging member. [0003] However, in such a conventional electronic device cabinet the engagement structure of the cover consists of a button, engaging member, and impelling means, with a large number of parts, which creates the problem that much work is required during assembly, and it is difficult to assemble the electronic device efficiently. Thus, during assembly a spring or other impelling means must be mounted on the base end part of the engaging member in a bent state, which complicates the assembly operation. OBJECTS OF THE INVENTION [0004] It is an object of the present invention, therefore, to provide an electronic device cabinet and an electronic device having a reduced assembly operation. [0005] It is a further object of the present invention to provide an electronic device cabinet and an electronic device having an engagement member for engaging the cover of the cabinet and for controlling the open and closed state of the cover. [0006] It is a further object of the present invention to provide an electronic device cabinet and an electronic device having an engagement member with an impelling means that is formed integrally with the engagement member. [0007] It is a further object of the present invention to provide an electronic device cabinet and an electronic device having an engagement member with an impelling means that can be withdrawn from and inserted into the electronic device cabinet in a simple operation. [0008] Still other objects and advantages of the invention will become clear upon review of the following detailed description in conjunction with the appended drawings. SUMMARY OF THE INVENTION [0009] An electronic device cabinet having a cabinet main body and a cover whose end is attached rotatably to the cabinet main body, is provided with an engaging member that advances and retracts with respect to the end of said cover and holds said cover in closed state by engaging said end of said cover. The engaging member has an engaging part main body that engages the end of said cover and an impelling means that impels this main body in the advance-and-retract direction, both the engaging part main body and the impelling means being formed integrally. Because of such integrated construction, the engaging part main body and the impelling means can be attached just by fitting the engaging member onto the cabinet main body, which greatly simplifies the assembly operation. Such cabinet can be used is an entertainment device such as a CD or DVD player or a game device, and using the construction of the present invention on these electronic devices can simplify the structure of the cabinet, which is desirable in making electronic devices smaller and lighter, and in reducing their cost. It is desirable that the impelling means have a symmetric construction for attributing a uniform force on said engagement member, and be formed in the shape of a ring. It is also desirable that a guide is provided on said cabinet main body for regulating the movement of the engaging part main body. It is also desirable to constitute said engaging member as an integral molding of injection-molded polyacetal, because polyacetal is a good sliding material and has good fatigue resistance. [0010] It is also desirable that there be formed in said cabinet main body an opening into which the cover is press-fitted, and that there be provided on the circumferential edge of this opening a depression outside of which the circumferential edge of said cover is exposed in the state in which the cover is press-fitted into said opening. [0011] It is also desirable that said cabinet main body have a pair of accommodation members or cabinet halves that, by engaging with each other, accommodate inside them a device main body that has electronic components, etc., that there be formed in the cabinet main body an opening part that exposes connection terminals for external device connection that are provided on said device main body, and that this opening part straddle the boundary part of the pair of accommodation members. [0012] Here, the connection terminals for external device connection might include, but are not limited to, for example, controller connectors (terminals) to which controllers are connected and audio and video output terminals for outputting signals from the device main body to a television receiver, as well as power supply terminals, ect. for supplying electric power to the device main body from an external power source. [0013] Also, the opening part that straddles the boundary part (engagement line) of the pair of accommodation members might include but not be limited to, for example, an opening part that consists of openings formed in each of the pair of accommodation members facing the boundary part, as well as an opening part, etc. that consists of an opening formed in one or the other of the pair of accommodation members facing the boundary part. [0014] Thus, the pair of accommodation members that constitute the cabinet main body is normally formed by injection molding using a metal mold that has an upper mold (cavity) and a lower mold (core). In doing so, if for example one is to form in the accommodation members an opening part that exposes connection terminals provided on the device main body, the accommodation members are formed by (1) engaging the upper and lower molds and inserting into the metal mold a slide core that moves horizontally, (2) injecting resin into the metal mold, (3) moving the slide core and removing it from inside the metal mold, and (4) raising the upper mold and separating the molding from the mold. But this requires additional steps for moving the slide core, which creates the problem of detracting from the productivity of the accommodation members. [0015] Thus if an opening part is formed that straddles the boundary part of the pair of accommodation members instead of forming an opening part inside the accommodation members, then it suffices to form in each accommodation member an opening facing the boundary part, which makes a slide core unnecessary, reduces the number of manufacturing steps, and thereby improves the productivity of the accommodation members. BRIEF DESCRIPTION OF THE DRAWINGS [0016] [0016]FIG. 1 is a perspective view showing a living room including an electronic device and cabinet of the present invention. [0017] [0017]FIG. 2 is a perspective view showing an entertainment device of the present invention. [0018] [0018]FIG. 3 is a perspective view showing the entertainment device of FIG. 2 with its cover open. [0019] [0019]FIG. 4 is a cross-sectional view showing the open-close button portion of said entertainment device of the invention. [0020] [0020]FIG. 5 is a plan view showing the engaging member of the present invention. [0021] [0021]FIG. 6 is a cross-sectional view showing the attachment of the engaging member of the invention with the cabinet main body of the invention. [0022] [0022]FIG. 7 is an exploded perspective view showing the attachment of the engaging member with a portion of the cabinet. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0023] The following detailed description is of the best mode or modes of the invention presently contemplated. Such description is not intended to be understood in a limiting sense, but to be an example of the invention presented solely for illustration thereof, and by reference to which in connection with the following description and the accompanying drawings one skilled in the art may be advised of the advantages and construction of the invention. In the various views of the drawings, like reference characters designate like or similar parts. [0024] [0024]FIG. 1 shows part of a living room 100 in which is set up a television receiver 3 , which outputs images and sound, etc., an entertainment device 1 , which is an electronic device that is connected to this television receiver 3 , and a controller 2 , which is an operation device that sends instructions to entertainment device 1 . Entertainment device 1 for example reads a game program, etc. recorded on an optical disk, etc. and executes it according to instructions from controller 2 operated by the user (game player). [0025] As shown in FIG. 2, entertainment device 1 comprises a device main body (not pictured), which has electronic parts, etc., and entertainment device cabinet 10 , which has cabinet main body 10 A, upper case 11 and lower case 12 , which accommodate the device main body by engaging together, and it is preferably formed in a flat square shape. Upper case 11 and lower case 12 are preferably formed by injection molding. [0026] Upper case 11 has a flat roughly circular cover 13 provided in the middle and upper case main body 14 provided around this cover 13 . Cover 13 is made in such a way that one press-fits it into opening 14 E to close said cover 13 . Formed on the circumferential edge of opening 14 E is depression 14 F, where the circumferential edge of said cover 13 is exposed to the outside in the state in which cover 13 is press-fitted into said opening 14 E (see FIG. 2). Lower case 12 , which covers the device main body from below, is made in such a way that its end engages with the end of upper case main body 14 . The part where these ends engage with one another is the boundary part of lower case 12 and upper case 11 . [0027] On the left side of cover 13 is power button 15 , which is operated when turning the power to the device on or off, and on the right side of cover 13 is open-close button 16 , which is operated when opening or closing said cover 13 . Two slots 17 , which are connection terminals for external device connections, are exposed on the side of cabinet 10 that appears in the front in FIGS. 2 and 3. Each slot 17 has a memory card insertion part 18 , which is positioned toward the top, and a controller connection part 19 , which is positioned toward the bottom. Memory card insertion part 18 is for inserting a memory card or other external auxiliary memory device, and its insertion hole 18 A, which straddles the boundary part (engagement line) of upper case main body 14 (upper case 11 ) and lower case 12 , is preferably formed in a rectangular shape, with its longer direction being horizontal. Provided on this memory card insertion part 18 is cover 18 B for protecting the connection terminals provided inside it. Insertion hole 18 A is formed by openings 31 and 32 , which are formed in upper case main body 14 (upper case 11 ) and lower case 12 , respectively, facing the boundary of upper case main body 14 and lower case 12 . Controller connection part 19 is an input-output terminal for the input and output of signals; to which is connected the connection terminal (not shown) formed on the end of a controller cable that extends from controller 2 (see FIG. 1). Insertion hole 19 A is preferably formed in a rectangular shape, with its longer direction being horizontal, and is preferably shaped so that its corners at the bottom are rounder than its corners at the top. Shaping insertion hole 19 A in this way prevents the connection terminal (not shown) of controller 2 from being connected in the wrong orientation. Also, because the shape of insertion hole 19 A is made with a structure that is different from the shape of insertion hole 18 A of memory card insertion part 18 , there is no danger of mistakenly inserting an external auxiliary memory device into insertion hole 19 A of controller connection part 19 , and vice versa. [0028] Positioned on the side opposite the side on which these slots 17 are positioned, are a power connector (not shown), to which an AC adaptor (not shown) is connected and which is a power supply terminal supplying electric power from an external power source (not shown) to the device main body, and video and audio output terminals (not shown) for outputting to television receiver 3 video signals, audio signals, and various other signals recorded on an optical disk (not pictured). Also, the opening part (not shown) through which this power source connector and these video and audio output terminals are exposed to the outside is formed, like the aforementioned insertion hole 18 A, by an opening formed on lower case 12 facing the boundary of upper case main body 14 and lower case 12 . [0029] As shown in FIG. 3, cover 13 comprises a roughly flat round disk covering unit 21 , which covers disk mounting part 20 onto which optical disk 4 is mounted, and an attachment part 22 , which extends from part of the circumferential edge of disk covering unit 21 and whose end is rotatably attached to upper case main body 14 by a hinge mechanism. Provided inside upper case main body 14 is spring 14 A, whose one end comes into contact with cover 13 ; which biases the cover 13 into the open position as shown in FIG. 3. [0030] Provided on part of the circumferential edge of disk covering unit 21 and protruding toward the lower case 12 side is rod-shaped member 21 A, which presses an open-closed detection switch (not pictured) that detects whether cover 13 is open or closed, and square-shaped engagement piece 21 B, in the middle of which is formed recess 21 C. Rod-shaped member 21 A and engagement piece 21 B are formed on said disk covering unit 21 in a position corresponding to or aligned with the position of open-close button 16 . [0031] As shown in FIG. 4, open-close button 16 includes a pressing member 23 , which is exposed to the outside and adapted to be pressed by a user, and engaging member 24 , which is positioned on upper case main body 14 below pressing member 23 . Pressing member 23 has pressing part 23 A, whose cross-section is preferably in the shape of a squared-off “C” and which is a flat round shape, and contact part 23 B, which is formed roughly in the middle on the engaging member 24 side of this pressing part 23 A, whose tip comes into contact with said engaging member 24 , and whose side surface is of rectangular shape. [0032] As shown in FIGS. 4 - 7 , engaging member 24 advances and retracts (arrow A in FIG. 4) with respect to engagement piece 21 B of disk covering unit 21 ; and holds cover 13 in a closed state by engaging engagement piece 21 B; and has engaging part main body 25 , which engages engagement piece 21 B, and impelling means 26 , which impels engaging part main body 25 in the advance-and-retract direction; and is preferably constituted as an integral molding of injection-molded polyacetal. Engaging part main body 25 comprises a flat protruding-shaped main body upper part 27 , which is exposed to the outside when pressing member 23 is removed, and a flat protruding-shaped main body lower part 28 , which is formed on the lower side of this main body upper part 27 and is a little smaller than said main body upper part 27 . Main body upper part 27 fits snugly between a pair of guides 14 B formed in upper case main body 14 , thus regulating the movement of engaging member 24 perpendicular to the advance-and-retract direction. Formed on the tip of main body upper part 27 is sloping surface 27 A, which slopes downward toward the middle of disk mounting part 20 (see FIG. 4). The tip of sloping surface 27 A protrudes into disk mounting part 20 when button 16 is not being pressed downwardly and when impelled toward disk mounting part 20 by impelling means 26 . In this way, cover 13 can be held in the closed state by engaging tip 27 A in recess 21 C of engagement piece 21 B. Main body lower part 28 fits snugly into opening 14 C (FIG. 7), which is formed in upper case main body 14 and is roughly the same as the flat shape of said main body lower part 28 , in this way also regulating the movement of engaging member 24 perpendicular to the advance-and-retract direction. Formed approximately in the middle of main body upper and lower parts 27 and 28 respectively is flat square-shaped through-hole 29 . Among the inside surfaces that form through-hole 29 , together with being perpendicular to the longitudinal direction of engaging part main body 25 , the inside surface formed on the impelling means 26 side is sloping surface 29 A, which slopes toward disk mounting part 20 . Contact part 23 B of aforesaid pressing member 23 makes contact with this sloping surface 29 A (FIG. 4). Thus when the operator presses pressing member 23 , sloping surface 29 A is pressed by contact part 23 B, and by the pressing force that acts on this sloping surface 29 A, engaging member 24 moves in a direction away from engagement piece 21 B. In other words, the pressing force caused by pressing member 23 is converted by sloping surface 29 A into a force in the advance-and-retract direction of engaging member 24 , thereby allowing engaging member 24 to be separated from engagement piece 21 B. [0033] Impelling means 26 is formed in ring shape in plan view, and is formed and positioned so as to be mutually symmetrical with respect to the centerline along the longitudinal direction of engaging member 24 . One end of impelling means 26 facing engaging part main body 25 comes into contact with receiving part 14 D, which is formed in upper case main body 14 and has an L-shaped cross-section. In this way, impelling means 26 maintains the prescribed elastic force between engaging part main body 25 and receiving part 14 D. When the operator removes his hand from pressing part 23 A or closes cover 13 , engaging member 24 is automatically restored to its original position by impelling means 26 , thus making it possible to automatically engage cover 13 by engaging member 24 . Engaging member 24 fits main body lower part 28 snugly into opening 14 C in a state in which the part that comes into contact with receiving part 14 D of impelling means 26 is bent, and after it is fitted in, upper case main body 14 can be attached by releasing the bend of impelling means 26 and engaging said impelling means 26 into receiving part 14 D. [0034] The operation of opening and closing cover 13 of such an entertainment device 1 is as follows. [0035] First, when cover 13 is closed (FIGS. 2 and 4), that is, if the tip 27 A of main body upper part 27 is engaged in recess 21 C of engagement piece 21 B, then when the operator presses member 23 , contact part 23 B of pressing member 23 is inserted into through-hole 29 of engaging part main body 25 and presses against sloping surface 29 A. The pressing force applied by contact part 23 B against 29 A causes engaging member 24 to move in the direction away from engagement piece 21 B. In this way, the tip 27 A of main body upper part 27 comes away from engagement piece 21 B, and cover 13 is released by the elastic force of spring 14 A (FIG. 3). [0036] When the operator releases his hand from pressing part 23 A, the pressing force on sloping surface 29 A disappears, and the impelling force of impelling means 26 causes engaging part main body 25 to move toward disk mounting part 20 , and engaging member 24 returns to its original position. [0037] If cover 13 is closed after optical disk 4 is mounted on disk mounting part 20 , when said cover 13 is pressed toward disk mounting part 20 , the lower surface of engagement piece 21 B presses sloping surface 27 A of the tip of main body upper part 27 , and engaging member 24 moves away from engagement piece 21 B. In addition, by pressing cover 13 toward disk mounting part 20 , engaging member 24 , which had moved away from engagement piece 21 B, moves toward recess 21 C of engagement piece 21 B, and the tip of main body upper part 27 engages with said engagement piece 21 B. In this way, cover 13 can be closed. [0038] Thus, because engaging part main body 25 and impelling means 26 are integrated, engaging part main body 25 and the impelling means 26 can be attached just by fitting engaging member 24 onto upper case main body 14 , which simplifies the assembly operation of the electronic device cabinet of the invention. In addition, because impelling means 26 is constituted symmetrically about the engaging member 24 , the impelling force in the advance-and-retract direction can be made to act on engaging member 24 uniformly left and right. In addition, the structure of impelling means 26 can be simplified by constituting it in a ring shape. [0039] Moreover, because formed on upper case main body 14 is guide 14 B that regulates the movement of engaging part main body 25 along the advance-and-retract direction and is positioned perpendicular to the advance-and-retract direction of engaging member 24 , engaging member 24 can be mounted along guide 14 B, which further simplifies the assembly operation of the cabinet of the invention. [0040] And since engaging member 24 is preferably made of polyacetal, because polyacetal is a good sliding material and has good fatigue resistance, one can slide engaging part main body 25 smoothly along upper case main body 14 and maintain the impelling force of impelling means 26 for a long time. [0041] In addition, because depression 14 F is provided on the circumferential edge of opening 14 E of upper case main body 14 , after cover 13 is attached to upper case main body 14 , when doing a confirmation that said cover 13 is attached, etc., it is simple to open and close said cover 13 by latching a finger onto the circumferential edge of cover 13 that is exposed in depression 14 F. This makes it easy to confirm attachment of cover 13 , etc. Furthermore, because depression 14 F is provided on the circumferential edge 14 E of upper case main body 14 and is dimensioned such that the base of the depression 14 F is aligned with or below the height of an inserted optical disk 4 (see FIG. 3), access to an inserted optical disk, and in particular the edge of such a disk, for removal or the like can be made easier. [0042] And because insertion hole 18 A is formed straddling the boundary part of upper case main body 14 and lower case 12 , it suffices to form in each of upper case main body 14 and lower case 12 an opening in which one side is missing, which eliminates the former need for a slide core. This can reduce the number of manufacturing steps and increase the productivity of upper case 11 and lower case 12 . [0043] This invention is not limited to the aforesaid embodiment but includes other compositions, modifications, etc. including, but not limited to the following. [0044] For example, the material of the engaging member is not limited to polyacetal; one may also use a thermoplastic resin such as, for example, nylon or polycarbonate. Other appropriate materials may also be used. [0045] In the above embodiment, while a guide is formed on the main body for guiding the movement of the engagement member, such a guide may not be necessary if, for example, the lower part of the main body of the engaging member is press-fit into an opening and there is no movement at all of engaging member 24 perpendicular to the advance-and-retract direction. [0046] Moreover, while in the aforesaid embodiment the impelling means is formed in the shape of a ring, it could also be formed in the shape of a spiral or wave. Other shapes are also contemplated. [0047] Also, while in the aforesaid embodiment it is preferred that the impelling means is positioned symmetrically with respect to the engagement member in the advance and retreat direction, it could also be constituted asymmetrically if desired. [0048] In addition, while depression 14 F is preferably provided on the circumferential edge of opening 14 E, it need not be present if, for example, the cover can be opened and closed simply by latching with a claw, etc. [0049] While the present invention has been described at some length and with some particularity with respect to the several described embodiments, it is not intended that it should be limited to any such particulars or embodiments or any particular embodiment, but it is to be construed with references to the appended claims so as to provide the broadest possible interpretation of such claims in view of the prior art and, therefore, to effectively encompass the intended scope of the invention.

An electronic device cabinet for an electronic device is provided with a cover and an engaging member that holds the cover in a closed state. The engaging member has an integrally formed impelling member that acts upon the engaging member and furthers the interengagement with said cover. The integrally formed engagement member and impelling member can be attached to the cabinet in a simple maneuver, thereby simplifying the overall assembly of the electronic device cabinet.

SUMMARY OF THE INVENTION This invention relates to horns as used for welding thermoplastic parts by high frequency vibrations in the sonic or ultrasonic frequency range, and, more specifically, refers to the manufacture of such horns. Horns, known also as solid horns, concentrators, rods, tools, amplitude or velocity transformers, etc., see "Ultrasonic Engineering" (book) by Julian R. Frederick, pp. 87-103, John Willey & Sons, Inc., New York, NY, 1965, are used to couple vibratory energy in the sonic or ultrasonic frequency range from an electroacoustic converter to a workpiece to be welded. As larger workpieces are welded, requiring the transfer of energy of one kW or more, the horns generally made from titanium metal, aluminum or steel become increasingly larger and more massive. For a frequency of 20 kHz, rectangular bar horns may have a dimension ranging from 3 to 12 inches (8 to 30 cm) along each side by 5 to 51/2 inches (12.7 to 14 cm) high. In order to provide efficient energy transfer from the converter unit, which is coupled to the input surface of the horn, to the output surface of the horn, which is in contact with the workpiece, horns of such dimension require the provision of longitudinal slots through the horn body, particularly through the nodal region, for interrupting Poisson couplings, i.e. vibrations propagated crosswise to the desired direction of energy transfer, see U.S. Pat. No. 3,113,225 entitled "Ultrasonic Vibration Generator, issued to C. Kleesattel et al, dated Dec. 3, 1963. The machining or milling of deep slots through a massive metal block is slow, difficult to accomplish and expensive, and very frequently leaves tool marks and rough spots within the interior of the horn body. Such marks and spots cause locations of high mechanical stress concentration when the horn is rendered resonant, resulting frequently in the early fracture of the horn. Moreover, a typical titanium metal composition suitable for horns is not readily available in plate stock beyond four inches of thickness. Therefore, in order to obtain a larger solid block, a special cast must be produced with many thousand pounds minimum. As is well known, castings may have interior flaws and defects that are not normally present in rolled plate stock and, hence, give rise to additional problems. Therefore, the instant invention discloses the manufacture of large size horns from more readily available bar or plate stock for providing individual horn sections. Such sections are then assembled in juxtaposed position and welded together by electron beam welding or laser beam welding to form a unitary structure. Several advantages will immediately become apparent. Because machining of individual sections is performed prior to welding, it is possible to modularize the horn, that is, machine sections in larger lots and then assemble the horn from prefabricated sections, thereby achieving maximum economics and efficiency. Fabricating the horn from bar or plate stock provides flexibility and access to the interior surfaces of the horn. This accessibility makes it possible to provide a radius at the inside surfaces of the slots and to tune horn sections by banding or other acoustic techniques. Slots can be machined into the horn sections using tools which are easier to control, thus achieving improved slot quality, better finish and dimensional accuracy, aside from lower tooling costs and a shorter machining time. In summary then, the overall result of fabricating horns from individual sections which are welded together constitutes a significant cost reduction, improvement of the quality of the horn, and a technological advantage in that the completed horn is substantially free of internal stress concentration points and hidden defects. One of the principal objects of this invention, therefore, is the provision of an improved horn construction, particularly horns of comparatively large size. Another principal object of this invention is the provision of horn for welding parts in the sonic and ultrasonic frequency range which horns, while comparatively large in size, are substantially free from areas of internal stress concentration and defects. Another principal object of this invention is the provision of horns which can be manufactured in a more economic manner. A further object of this invention is the manufacture of horns from individually machined sections which are welded together to form a unitary body. A further and other object of this invention is the manufacture of individual horn sections, assembling the sections in juxtaposed position and then welding the sections to one another. A still further object of this invention is the manufacture of substantially large and massive horns by machining individual sections from plate stock, assembling a plurality of machined and slotted sections in juxtaposed position, welding the sections to one another, finishing the welded horn by machining one or more of the exposed surfaces, and fine tuning the assembled horn for the predetermined operating frequency. Other and still further objects of this invention will be more clearly apparent when reading the following description in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of a typical horn used for welding large workpieces; FIG. 2 is an end view of a typical raw plate stock metal bar prior to machining; FIG. 3 is a side view along lines 3--3 of the bar shown in FIG. 2; FIG. 4 is an end view, similar to FIG. 2, of the bar machined for providing horn end sections; FIG. 5 is a side view along lines 5--5 of the bar shown in FIG. 4; FIG. 6 is an end view showing a bar similar to the bar in FIG. 2, but machined for providing horn center sections; FIG. 7 is a side view of the bar along lines 7--7 in FIG. 6; FIG. 8 is a side view of a plate stock bar, either per FIGS. 4 and 5 or 6 and 7 and illustrates cutting the bar to provide a plurality of individual horn sections; FIG. 9 is an end view of a horn end section provided with milled slots through its thickness; FIG. 10 is a side view along lines 10--10 in FIG. 9; FIG. 11 is an end view of a horn center section with milled slots through its thickness; FIG. 12 is a side view along lines 12--12 in FIG. 11; FIG. 13 is a perspective view showing a horn assembled from respective machined plate stock sections prior to welding, and FIG. 14 is a perspective view of a cylindrical horn made in accordance with the teachings of this invention. DETAILED DESCRIPTION Referring now to the figures and FIG. 1 in particular, there is shown a horn 10 made typically from titanium metal, aluminum, or steel. Titanium is a preferred metal on account of its ability to be subjected to higher mechanical stress than steel or aluminum. For a typical operating frequency of 20 kHz, the dimension X may range from 3 to 12 inches (8 to 30 cm) while the height of the horn must correspond precisely to one half wavelength (λ/2) of the high frequency waves travelling longitudinally therethrough from the input surface 12 to the opposite output surface 14. At 20 kHz, this dimension is approximately 5 to 51/2 inches (12.7 to 14 cm) depending on the metal used. The horn illustrated is a rectangular or square bar horn having an input surface 12 for receiving thereat high frequency vibrations from an electroacoustic converter unit, not shown, an output surface 14 for transmitting such vibrations to a workpiece in forced contact with the horn, two opposite end surfaces 16 and 18 and two opposite side surfaces 20 and 22. The horn 10 is provided with a plurality of slots which traverse the horn body, namely a first plurality of slots 24 which traverse the horn body from side surface 20 to side surface 22, and a second plurality of slots 26 which traverse the horn 10 from the end surface 16 to the end surface 18. The purpose of the slots, as stated above, is to interrupt Poisson couplings. The horn also includes a threaded hole 28 for receiving a threaded stud for coupling an electroacoustic converter to the input surface 12 of the horn 10. In the past, the horn 10 was machined from a solid block and the slots 24 and 26 had to be milled or otherwise machined by cutting through the rather massive block of metal. It will be apparent that such a cutting operation is difficult and time consuming. In addition, the tool cutting through the interior of such a metal block leaves rough spots, chatter marks, etc., thereby creating locations of high mechanical stress concentration when the horn is rendered resonant which condition, in turn, would lead to a premature fracture of the horn. In addition, the procurement of a massive titanium metal block, as stated above, is difficult and expensive, and if the block is a casting, hidden internal defects may be present. The present invention is directed to assemble a horn as shown from individually machined bar stock sections. Referring now to FIGS. 3 through 12 and FIGS. 2 and 3 in particular, there is shown an elongated rectangular plate or bar 30 having two end surfaces 16a and 18a, two side surfaces 20a and 22a and a top surface 12a which becomes a part of the input surface 12, and a bottom surface 14a which later becomes a part of the output surface 14. It should be understood that at a later state of the assembly, the surfaces 12a and 14a may require machining in order to accurately adjust the distance between the surfaces 12a and 14a for corresponding precisely to one half wavelength of the sound wave travelling longitudinally therethrough from the input surface 12 to the output surface 14, see FIG. 1. This is known as the tuning process well understood by those skilled in the art. FIGS. 4 and 5 illustrate the step of machining the bar 30 for providing end sections of the horn 10. A flat recessed portion 26a is machined into the side 20a with a half rounded radius at the top and at the bottom. The recessed portion 26a actually comprises, what may be termed, a "half slot" of slot 26 and when juxtaposed with a central section, machined similarly, a complete slot 26, see FIG. 1, is formed. FIGS. 6 and 7 show the machining of a central section using a rectangular bar stock 30a, same as bar stock 30, but providing a recessed portion 26a in both side surfaces, see FIG. 6. Again, each recessed portion is machined to form a "half slot 26" and for forming a complete slot with a juxtaposed, similarly machined, bar stock section. It will be noted that an outer horn section 30 has a recess 26a machined only in one side surface, whereas a central horn section 30a has a recess 26a machined in both side surfaces. The recesses 26a can be machined rather simply using conventional milling or honing tools and, since the entire surface of the recessed portion 26a is exposed, such surface can be provided with a fine and smooth finish, eliminating rough spots always present when milling slots with end milling tools along deep and inaccessible recesses. Referring now to FIG. 8, which illustrates merely the cutting of the bar 30, an end horn portion, or a bar 30a, a central horn portion, into a plurality of sections of the required length by a suitable cross cut 32 to yield respective horn sections 10a or 10b as will be shown in FIGS. 9 and 10, and 11 and 12 respectively. With reference to FIGS. 9 and 10, an end horn section 10a still requires the milling of cross slots 24. Since the section 10A is relatively thin when compared to the prior construction of the horn seen in FIG. 1, the slots can be milled rather quickly and a radius, if desired, can be provided at the area where the slots break through the side surfaces of the horn. The same process is applied to the center section 10b, providing the slots 24 through thickness of the particular bar section and providing, moreover, a smooth finish along all surfaces. FIG. 13 illustrates the assembly of the sections machined as described heretofore in connection with FIGS. 2 to 12. The horn is assembled from juxtaposed sections prepared individually. As seen, there are, for example, two end sections 10a and two central sections 10b, and slots 26 formed as a result of the recessed portions 26a. Also the slots 24 penetrate through each section and are aligned with one another to form slots all the way through the horn body. Subsequently, the sections 10a and 10b are welded together at their abutting surfaces by electron beam welding or laser beam welding to form a unitary body. After welding, stress relieving may be required, such as by annealing. After annealing several final steps include the drilling and tapping of the hole 28, insertion of a stud, removing any exposed weld bead, cleaning up of slot ends, if desired, by using an end miller, and fine tuning of the horn to its predetermined high frequency by adjusting the distance between the input surface 12 and the output surface 14. It will be apparent that several modifications in the procedure described above can be made without deviating from the invention. For instance, the cross slots 24 shown in FIGS. 9 to 12 can be provided in the respective bar 30 or 30a prior to cutting the bars into appropriate sections as shown in FIG. 8. Moreover, when a sufficiently large quantity of horns are to be manufactured, bar stock, especially aluminum or steel, can be obtained in extruded form with recesses 26a present, thus obviating this machining step. FIG. 14 depicts a cylindrical horn made in accordance with the teachings of the present invention. The horn 40 as shown is dimensioned to be resonant as a half wavelength resonator at the predetermined frequency between the input surface 42 and output surface 44. As shown, the horn is made from three juxtaposed sections, namely two end sections 46 and 48 and a central section 50, welded together along abutting surfaces which are indicated by dashed lines 52. A plurality of slots 54 are provided and each section 46, 48 and 50 is provided with a recess which constitutes essentially a half slot as previously illustrated and described. When the sections 46, 50 and 48 are placed into juxtaposed relationship, full slots 54 result. Again, the sections 46, 48 and 50 can be machined individually with the surface receiving the recessed portion, forming a part of the internal slot, fully accessible so that this surface can be machined and polished to eliminate tool marks. A threaded hole 56 is provided for receiving a threaded stud for mechanically coupling the horn to an electroacoustic converter. As stated above, the sections 46, 48 and 50 can be fabricated from readily available bar stock. If additional slots are to be provided on the horn 40, the horn will comprise, quite obviously, a greater quantity of individual sections, all welded together by laser or electron beam welding along abutting surfaces. Moreover, the sections 46, 48 and 50 can be provided with additional slots using conventional milling tools, but since these sections are of smaller thickness than a complete horn, the slotting process is greatly simplified. Equipment for laser beam welding is available from Hamilton Standard, Hartford, CT, and a machine rated 7.5 kW, 150 kV has been found suitable. Similarly, machines for laser beam welding are available from Coherent, Inc., Auburn, CA, model Everlase rated 3 kW. While there have been described and illustrated a preferred embodiment of the invention and certain modifications thereof, it will be apparent to those skilled in the art that various further changes and modifications may be made therein without departing from the broad principle of this invention, which shall be limited only by the scope of the appended claims.

A horn for coupling high frequency vibrations from an electroacoustic converter unit to a workpiece, such as is used for welding thermoplastic workpieces by ultrasonic vibrations, is constructed by machining sections of the horn and welding the sections together using electron beam welding or laser beam welding. The respective sections can be made from bar or plate stock. This construction eliminates the machining of deep, inaccessible slots, and as most of the surfaces to be machined are accessible, a fine surface finish can be provided, thus eliminating tool marks which cause the existence of areas of high mechanical stress concentrations when the horn is rendered resonant. Also significant economic advantages are achieved when manufacturing large, massive slotted horns in this manner.

This application is a continuation-in-part of Ser. No. 09/295,660, filed Apr. 21, 1999, entitled BANDWIDTH EFFICIENT QAM ON A TDM-FDM SYSTEM FOR WIRELESS COMMUNICATIONS which claims the benefit of U.S. provisional application No. 60/107,934, filed Nov. 11, 1998, which Ser. No. 09/295,660 application is hereby incorporated herein by reference. CROSS-REFERENCE TO RELATED APPLICATIONS This application is related to the following co-pending and commonly assigned patent applications: Ser. No. 09/302,078, filed Apr. 28, 1999, entitled IMPROVED NYQUIST FILTER AND METHOD; and Ser. No. 09/450,487, filed Nov. 29, 1999, entitled METHOD AND APPARATUS FOR TRACKING THE MAGNITUDE OF CHANNEL INDUCED DISTORTION TO A TRANSMITTED SIGNAL; all of which applications are hereby incorporated herein by reference. TECHNICAL FIELD The present invention relates generally to communications, and more particularly to synchronization to a sampled signal in a communication system. BACKGROUND Wireless communications arc becoming more popular as technology develops. Many people are now communicating through mobile telephones, pagers, radio frequency (“RF”) devices and others. As this trend toward heavier usage of the frequency spectrum continues, there is an ongoing need to optimize the communication channels between the communication units in wireless telecommunications systems. One optimization issue that arises with wireless communications is the need to maximize the throughput or utilization of a communication channel. For example, in the United States, the Federal Communications Commission (“FCC”) has allocated only a limited portion of the frequency spectrum for trunked private two-way RF communication. The reserved portion of the spectrum is divided into predefined frequency channels. Each communication channel generally requires a certain amount of available bandwidth to transmit substantive information (e.g., data, audio, video, multimedia, or some combination). Other factors being equal, the more of the transmitted signal that is used for the transmission of substantive information, the more efficient the utilization of the allocated bandwidth. In addition to the substantive information, however, there is also a certain amount of overhead information that typically must be transmitted in the communication channel. One type of overhead information is control information that is exchanged between the communication units. For example, in a mobile telephone communication system, a base unit and terminal unit may exchange control information such as power control instructions, packet length arbitration, system ID information, service option, frequency, channel, gain, error, checking, and the like. Another type of overhead information is synchronization information. Synchronization is generally utilized in coherent communications systems, wherein a unit that is initially operating asynchronously with respect to another unit is required to synchronize with the signals transmitted by the other unit. To synchronize, a receiving unit generally determines the timing of the information in a signal transmitted by a transmitting unit, and synchronizes its processing with the timing of the transmitted information. For example, in a mobile telephone communication system, a base station (or central cell or master or repeater) transmits a communication signal. Generally, a terminal unit (or roaming unit or subscriber unit) within range of the base station must acquire the transmitted signal before information can be exchanged. The terminal unit is initially operating asynchronously, and is not synchronized with the transmitted signal. As part of the signal acquisition process, the terminal unit generally has to align its frequency and timing with the transmitted signal. In the prior art, specific synchronization information is generally inserted into the transmitted signal by the transmitting unit. The receiving unit uses this known synchronization information to determine the best timing at which to sample the incoming signal. Synchronizing with the incoming signal generally results in the receiving unit sampling at the timing interval at which there is the least interference from neighboring signals, thus establishing a reliable communication channel. A prior art receiving unit typically uses a feedback loop to vary the frequency of its crystal oscillator to change the sample time until a signal lock is raised. The specific synchronization information of the prior art generally consists of a fixed symbol pattern in the transmitted signal. The receiver searches for these synchronization symbols by decoding the sampled potential symbol points into bits, and performing correlation over a large portion of the sampled signal until a symbol pattern in the sampled signal matches the fixed symbol pattern. A problem with prior art systems is that the synchronization symbols are overhead information, and utilize part of the available bandwidth in the communication channel. This reduces the amount of bandwidth available for the transmission of substantive information, and thus reduces the maximum throughput of substantive information in the communication channel. Another problem in the prior art is that the synchronization symbol values and patterns generally must be predetermined and programmed into both the transmitting unit and the receiving unit to enable the receiving unit to search for the same synchronization symbols that the transmitting unit is actually sending. Because the synchronization symbols are inserted only periodically into the transmitted signal, another problem in the prior art is that the receiving unit generally only uses a small portion of the incoming signal for calculating the proper synchronization time, while the rest of the transmitted signal does not provide usable synchronization information. Thus the receiving unit may have to monitor the incoming signal over a significant period of time in order to receive sufficient information for synchronization. SUMMARY OF THE INVENTION These problems are generally solved or circumvented, and technical advantages are generally achieved, by a system and method for information (e.g., symbol) content-independent synchronization. Generally, a communication signal filters a signal at some point (or at multiple points) during transmitter and receiver processing. In particular, a pulse shaping filter may be implemented for a variety of reasons, including limiting the overall bandwidth of the signal, minimizing the effects of noise, and reducing stop band energy. A preferred embodiment of the present invention takes advantage of a property of pulse shaping filters, specifically, that the relative energy distribution of the output waveform with respect to the information bearing point of the signal is determinable. For example, the information bearing point in the signal is at or near the point having the highest average energy. A preferred embodiment of the present invention thus measures a variable of the signal (e.g., magnitude), which is related to the energy distribution, and uses this variable to determine the signal's information bearing point. In addition, for purposes of the preferred embodiments of the invention, the average relative energy content of the signal is independent of the specific symbol values or information content in the signal. By measuring a variable of the incoming signal that is generally independent from specific symbol values, the preferred embodiments of the present invention are able to synchronize with a signal without requiring the insertion of any special symbols or fixed symbol patterns into the signal for synchronization. In accordance with a preferred embodiment of the present invention, a method comprises receiving a transmitted signal, wherein the signal comprises a periodic information bearing point at an information rate and wherein an information period is the inverse of the information rate; sampling the transmitted signal at sample points at a sampling rate greater than the information rate, wherein a sample period is the inverse of the sample rate; filtering the signal with a pulse-shaping filter, measuring a variable of the signal at the sample points, wherein the variable is independent of information content in the signal; determining the location of the information bearing point in the signal based on the information content-independent variable; and synchronizing processing of the signal with the information bearing point. In accordance with another preferred embodiment of the present invention, a system capable of synchronizing with a received signal comprises an analog-to-digital converter receiving an information signal, wherein the signal comprises a periodic information bearing point at an information rate and wherein an information period is the inverse of the information rate; a pulse-shaping filter coupled to receive a digital signal from the analog-to-digital converter, wherein the digital signal comprises sample points at a sampling rate greater than the information rate and wherein a sample period is the inverse of the sample rate; and a synchronization unit coupled to receive a pulse-shaped sampled signal from the filter. The synchronization unit comprises a detector determining values of a variable of the signal at the sample points, wherein the variable is independent of information content in the signal; an accumulator for accumulating the detected values for each of the sample points which occurs at the same relative sample location within each information period, wherein there are (sample rate)/(information rate) sample locations within each information period; sample bins for storing the accumulated values for the sample locations; and a comparable for comparing the accumulated values in the sample bins, wherein the location of the information bearing point in the signal is determined based on the accumulated information content-independent values. An advantage of a preferred embodiment of the present invention is that symbol synchronization may be accomplished in a blindly adaptive manner. That is, a receiving unit does not need to know any information about the actual values of the transmitted symbols in order to synchronize to the signal. A further advantage of a preferred embodiment of the present invention is overhead information is reduced. No special symbols or symbol patterns are required for symbol synchronization, because a symbol value-independent variable (e.g., peak average energy) is used for synchronization. The bandwidth for substantive information in a channel is thus increased. A further advantage of a preferred embodiment of the present invention is that symbol synchronization may be accomplished more quickly than with prior art methods. because information from all incoming symbols is used for synchronization. A receiver does not need to wait for the proper time in the symbol sequence for special synchronization symbols. In addition, continuous synchronization may be performed to keep track of variations in the transmitted signal due to, e.g., component drift. Yet another advantage of a preferred embodiment of the present invention is that multiple sampled points around a symbol may be used (e.g., with template matching), thus allowing faster and more accurate symbol synchronization. The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures or processes for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. BRIEF DESCRIPTION OF THE DRAWING For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawing, in which: FIG. 1 is a block diagram of a preferred embodiment radio system; FIG. 2 is a block diagram of a preferred embodiment base unit; FIG. 3 is a block diagram of a preferred embodiment terminal unit in receiving mode; FIGS. 4a and 4b illustrate the organization of a single forward time slot of information and a single reverse time slot of information, respectively; FIG. 5 is a plot of the impulse response of a pulse shaping filter; FIG. 6 is a plot of magnitude versus sample number as used by a preferred embodiment of the present invention; and FIG. 7 is an energy matching template as used by a preferred embodiment of the present invention. DETAILED DESCRIPTION The making and using of the presently preferred embodiments are discussed in detail below. It should be appreciated, however, that the present invention provides many applicable inventive concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed are merely illustrative of specific ways to make and use the invention, and do not limit the scope of the invention. The present invention will be described with respect to a specific content, namely a trunked radio system utilizing quadrature amplitude modulation (“QAM”). The invention also applies, however, to other types of communications systems, such as cellular telephones (digital and analog), microwave communications, satellite communications, and others. In particular, the invention will be discussed with respect to the system disclosed in co-pending patent application Ser. No. 09/295,660, filed Apr. 21, 1999, entitled BANDWIDTH EFFICIENT QAM ON A TDM-FDM SYSTEM FOR WIRELESS COMMUNICATIONS. FIG. 1 illustrates an exemplary radio system 100 . System 100 could be a cellular telephone system, a two-way radio dispatch system, a localized wireless telephone or radio system or the like. Base unit 102 can communicate over transmission medium 104 to one or more terminal units 106 . Transmission medium 104 in this example represents the wireless communication spectrum. Terminal units 106 can be mobile units, portable units, or fixed location units and can be one-way or two-way devices. Although only one base unit is illustrated, radio system 100 may have two or more base units, as well as interconnections to other communication systems, such as the public switched telephone network, the internet, and the like. In the preferred embodiment, the system provides for full duplex communications. The teachings of the present invention, however, apply to half duplex systems, as well as to time division duplex, simplex and other two-way radio systems. In some preferred embodiments, each base unit 102 transmits on only a single (e.g., 25 kHz bandwidth) frequency channel. Hence for a system that is licensed to operate on ten channels, ten base stations would be required. In alternative embodiments, the base station can be configured to transmit and receive across multiple channels. This feature would be particularly beneficial for those systems which are licensed to operate across several contiguous channels. In the preferred embodiment, the system uses two-ring differential QAM with a 16 point constellation and Gray coding for signal encoding. The teachings of the present invention, however, apply to other modulation schemes, such as three-ring QAM, star QAM, square QAM, coherent QAM, phase shift keying (“PSK”), differential PSK (“DPSK”), and the like. Details of portions of the base unit and terminal units illustrated in FIG. 1 are provided in the following descriptions. FIG. 2 is a block diagram of base unit 102 operating in receiver mode, while FIG. 3 is a block diagram of terminal unit 106 operating in receiver mode. A skilled practitioner will note that several components of a typical ratio transmitter/receiver not necessary to an understanding of the invention have been omitted. FIG. 2 is a block diagram of receiver 200 in base unit 102 . Signals from terminal units 106 are received by RF receiving circuitry (not shown). A/D converter 202 receives the signal from the RF receiving circuitry and converts it to a digital signal, which is fed to one or more sub-channel paths. A detailed discussion of the sub-channel paths is provided in patent application Ser. No. 09/295,660. Complex multiplier 204 removes the frequency offset corresponding to a particular sub-channel from the incoming signal. The signal is then frequency channelized by the square root Nyquist matched filter 206 . The filtered signal is passed to symbol synchronization block 208 , which calculates the proper sapling point where there exists no (or minimal) inter-symbol interference signal. As disclosed by patent application Ser. No. 09/295,660, that is accomplished by calculating the magnitude of the sample points over time and selecting the highest energy points (corresponding to the synchronized symbol sample points). The signal is then passed on to magnitude tracking block 210 and to phase tracker 214 . A detailed discussion of the remainder of the base unit receiver circuitry, including blocks 218 - 226 , is provided in patent application Ser. No. 09/295,660. FIG. 3 is a block diagram of receiver 300 in terminal units 106 . Signals from the base unit or another terminal unit are received by RF receiving circuitry 302 where the RF signal is down-converted and filtered before being passed to A/D converter and mixer 306 for the in-phase (“I”) component and 308 for the quadrature (“Q”) component. Also at this point, the frequency offset associated with the sub-channel selection is removed from the signal components by mixing into the received signal a signal complementary to the offset signal. The complementary offset signal is determined by sub-channel frequency offset control information, as illustrated by clock 310 and depends on the sub-channel upon which the terminal unit is receiving. The digital signals are then demodulated to a real binary signal in demodulator 304 . The digital binary signal is then de-coded and further processed in blocks 318 - 328 as described in the disclosure of patent application Ser. No. 09/295,660. Slot and symbol synchronization is provided for in synchronization block 312 . Symbol synchronization is performed first. As disclosed by patent application Ser. No. 09/295,660, symbol synchronization is accomplished by sampling the incoming signal and time averaging the samples. Then the sample points with the highest average power at the over-sample rate are detected. Preferably, the actual sample point is determined using a quadratic interpolation based on the three sample points with the highest average power. Symbols can then be identified using known digital signal processing techniques. Once the receiver has synchronized on the symbol time and locations, slot synchronization is accomplished using slot sync symbols, by identifying patterns representing the known sync symbols, which should repeat every 120 symbols (i.e., every slot or time frame). The control and synchronization signals as disclosed by patent application Ser. No. 09/295,660 are illustrated in FIGS. 4(a) and 4(b) . FIG. 4(a) illustrates the structure for a single time slot 402 on the forward channel, i.e., transmitted from the base unit to a terminal unit. Time slot 402 is logically divided into sync, control, and voice portions. Each outbound (i.e., forward channel) time slot begins with a synchronization portion 404 to allow for timing synchronization between the base and terminal unit(s). In the preferred embodiment, sync portion 404 is three symbols long. Each symbol is preferably associated with four bits of data. The value of each symbol is determined by the phase and amplitude change between the time of the impulse within a symbol period and the time of the impulse one symbol period later. Alternatively, the value of each symbol could be determined by the absolute phase and amplitude at a particular point within the symbol period. The former technique is known as differentially incoherent modulation and the latter as coherent modulation. Each symbol period is preferably about 250 μs in duration. As such, 120 symbols can be transmitted during the 30 ms time slot 402 . Voice or data is transmitted during the voice portions of the time slot 406 , 408 , and 410 . Each voice portion transmits 32 symbols of information, as indicated by the numbers in parentheses. Control signals are interleaved with the voice information, as shown by control portions 412 , 414 , and 416 , providing a total of 20 symbols of control information per slot. Finally, a one symbol portion of the slot 418 is reserved for future needs. The first data symbol value (in the case of time slot 402 , the first voice symbol of voice portion 408 ) will be equal to the phase and amplitude change between the impulse time of the last symbol period of sync portion 404 and the impulse time of the first symbol of voice portion 406 . The last symbol will be equal to the phase and amplitude change between the 119 th impulse time and the 121 th pulse time. A base generated time slot 402 begins with the first impulse and ends immediately before the 121 th impulse, which is the first amplitude of the next time slot. In the event there is no information (voice or data) to be transmitted, a pseudo-random pattern will be inserted into the voice portions of the slot and transmitted along with control signals. Note that for purposes of demonstrating the logical structure, voice and control symbols are shown separately. In actual practice, prior to transmission, the voice and control bits are interleaved prior to QAM modulation, such that voice bits and control bits can be interleaved in the same symbol for transmission. FIG. 4(b) illustrates the organization of a time slot 420 transmitted by a terminal unit, as disclosed by patent application Ser. No. 09/295,660. As with the base unit generated time slot, time slot 420 is 30 ms long, providing for 120 symbols of 250 μs duration. Voice portions 422 , 424 , and 426 are interspersed with control portions 428 , 430 , and 432 . Time slot 420 provides for a one symbol long sync portion 434 . The first data symbol for time slot 420 will be equal to the phase and amplitude change between the last sync impulse of sync portion 434 and the first impulse of voice portion 432 . The last data symbol will be the phase and amplitude change between the second to last and last impulses of voice portion 426 . As discussed above, a terminal unit transmits only during its assigned time slot, then turns its transmitter off. Time slot 420 provides for a ramp up period 436 of two symbols duration and a ramp down portion 438 of one symbol period duration. The ramp periods are used to control out-of-band energy and to allow the terminal unit to stabilize after the transmitter is turned on prior to transmitting during the time slot and to avoid signal degradation due to the effects of the transmitter beginning to power off at the end of the time slot. Further protection is provided by a bank portion 440 of three symbol periods duration to compensate for propagation delay at the end of the time slot (i.e., to ensure that a signal received from a far removed terminal does not overlap with the signal received from a near by terminal due to the differing propagation delays associated with the near and far terminals) Due to these signal ramp up and dead symbol periods, a terminal generated time slot will not begin and end with a symbol period that contains an impulse. Ideally, a time slot generated by a terminal unit will begin at the same time as the base unit generated time slot and the impulses generated by the terminal unit will be coincident with impulses generated by the base unit. Propagation delays, however, prevent this ideal alignment. For this reason, sync symbols are inserted in the terminal unit signals. Additionally, time slot 420 has a reserved portion 442 of one symbol duration for further expansion. In some preferred embodiments, the reserved symbols 418 , 442 are used for additional symbol synchronization control. In the currently preferred embodiment, reserved symbol 442 is used for a ramp down signal. Alternatively, the specific symbol types and order within a transmit or received slot may be changed depending on the application. Returning now to FIG. 2 , and in particular to Nyquist filter 206 in FIG. 2 , the information-bearing point in the output of pulse shaping Nyquist filter 206 is the point in the signal with minimum inter-symbol interference. Patent application Ser. No. 09/302,078, filed Apr. 28, 1999, entitled IMPROVED NYQUIST FILTER AND METHOD, provides a detailed discussion of the properties and implementation of Nyquist filters in a communications system. However, any type of Nyquist filter may be used with the present invention, including a raised cosine filter or other filters such as those disclosed in patent application Ser. No. 09/302,078. In a preferred embodiment, the pulse shaping filter uses a pair of matched filters, one for transmit and one for receive. The convolution of the transmit filter with the receive filter forms the complete pulse shaping filter. Inter-symbol interference is generally avoided because the combined filter impulse response reaches unity at a the information bearing point and is zero periodically at every other information point (Nyquist sampling rate). FIG. 5 illustrates an example of Nyquist filter impulse response 500 . Peak 502 occurs at the information bearing point, and zeros 504 occur at the other points at the information rate. At a point in the signal other than the information bearing point, the output waveform from the Nyquist filter may have associated with it the energy of perhaps five to ten symbols. Generally, only at the information bearing point is the energy of output waveform from the Nyquist filter associated with only one symbol. In addition, it is at this point that the signal has the highest energy, on average. Therefore, in a preferred embodiment, symbol synchronization block 208 determines the single sample point that has the highest energy, on average. This point represents the information bearing sample point, allowing synchronization to the signal. Fixed symbol values or patterns are therefore not required for symbol synchronization. Preferably, the variable used to measure the average energy of the waveform is the sum of the squares of the I and Q components. Alternatively, magnitude or any other variable that approximates signal energy may be used. In addition, the energy of either the I or Q component by itself may be used. A specific example using the sum of the squares of I and Q will now be discussed. Receive square root Nyquist filter 206 samples at a 52 kHz rate, while the information symbol rate is only 4 kHz in the preferred system. This results in thirteen samples for every symbol. One of the oversampled points is nearest the correct information bearing sample point. Note that at acquisition nothing is known about timing, and the information bearing time point may not lie at a sample boundary time, but be between two sample times. To accomplish the averaging process, the magnitude squared at every sample is calculated and thirteen samples per symbol period are accumulated. The sample point with the largest accumulated value represents the sample closest to the information-bearing symbol time. The symmetry of the pulse-shaping filter is also exploited to give a subsample time estimate of the information-bearing time point. A quadratic fit is used to interpolate to the optimum sampling time. The equation for the magnitude squared is: MAG 1 =(I 1 2 +Q 1 2 ) The accumulation over a 120 symbol slot is performed by: SUM_MAG k = ∑ 1559 j = 0 ⁢ ( I k + 13 ⁢ ⁢ j ) 2 + ( Q k + 13 ⁢ ⁢ j ) 2 , where k varies 0 to 12 Preferably, the process is repeated and summed for 16 slots, although longer or shorter summation periods may be used. This results in 13 bins of sample information collected over a total of 16 slots, each bin representing the average energy of the signal at a particular sample interval within the information interval. The largest SUM_MAG value represents the sample point nearest the information-bearing time point. In a preferred embodiment, the total accumulated values are used to represent the average energy. Alternatively, each total value could be divided by the number of samples taken for each bin, but this is generally not necessary because the average energy is a relative quantity from one sample bin to the next. Preferably, a quadratic fit is used to further refine the symbol time estimate. The fit is performed as follows: Let M denote the index of the symbol with the highest magnitude squared, so that SUM_MAG represents the highest sum. The interpolated index in terms of samples and fractions of a sample becomes INTER_VAL=M−b/2 o , with b=(SUM_MAG m−1 −SUM_MAG m−1 )/2 a=(SUM_MAG m−1 +SUM_MAG m+1 )/2−SUM_MAG m . It may occur that M is an end point (0 or 12) of the SUM_MAG array. If M=12, then SUM_MAG m+1 =SUM_MAG. If M=0, then SUM_MAG m−1 =SUM_MAG 12 . The SUM_MAGs array is interpreted in a modulo 13 fashion. Generally, for acquisition, it is important only to align to one of the correct sampling times (modulo 13 ) since nothing has been determined for slot alignment up to this step in the acquisition process. The algorithm uses the value INTER_VAL to interpolate between samples to obtain an estimate of the symbol value time. Quadratic interpolation places the index of the symbol value between M−1 and M or between M and M+1. Both the in-phase and quadrature-phase values are interpolated. The interpolation for I and Q has the following form. If the index of the interpolated value is between M−1 and M+1 samples, the interpolated value is constructed by truncating to the lower integral sample value (which is N,N=integer value of INTER_VAL,DELT is fractional part of INTER_VAL). The residual denoted by DELT is then used to interpolate the data by: I IN =(1−DELT)I N +DELT I N+1 , Q IN =(1−DELT)Q N +DELT Q N+1 , where N can be either M or M−1, and subscript ‘IN’ denotes interpolated value. FIG. 6 illustrates simulated plot 600 representing magnitude squared versus sample bin number. In this example, the highest energy point is first sample point 604 . Sample points 602 and 606 are the next highest sample points. After performing a modulo 13 quadratic fit calculation on sample points 602 , 604 and 606 , the interpolated value would fall on an exact sample boundary point, sample point 604 . Alternatively, for other sample point values, the interpolated value may occur between sample points, and not on a boundary. Although the preferred embodiment utilizes a quadratic interpolation, any other curve estimating algorithm may be used, such as a polynomial equation using more sample points, or a template matcher may be used. Although synchronization must be maintained during the time that the communication channel is being utilized, subscriber units generally are not manufactured to the same tolerances as the repeater, and they tend to drift. Therefore the same synchronization process is preferably repeated over and over in a continuous process. Preferably 16 slots worth of samples are binned up and the synchronization is calculated, then the next 16 slots worth of samples are binned up, and the synchronization recalculated. Alternatively, synchronization could be performed at periodic intervals. As another alternative, if high quality oscillators are used, synchronization could be performed only once at acquisition, or a limited number of times. As another alternative, the sample measuring periods for different synchronization could overlap with each other. An averaging filter might also be used on multiple synchronization results. As yet another alternative, the number of sample bins or the total number of samples could be varied. A preferred method of using the estimated information time point is to reset a counter every sixteen slots when a new estimate is made. The counter preferably enables sampling to synchronize the input data stream to the Nyquist filter. The receive Nyquist matched filter is generally only well matched at points where the information time point occurs at a sample point, and is not as well matched between two sample points. Thus, interpolating between two sample points to get symbol information may lead to some system degradation when compared to sampling at the correct time point. In one embodiment, the acquisition symbol synchronization algorithm may run continuously on the received data stream, while the steady state symbol synchronization algorithm may run on every other slot. As discussed above, with a pulse shaping filter the energy variation on average along the entire waveform is determinable. Accordingly, a template matching algorithm may be used in another preferred embodiment. Alternatively, both peak average energy detection and template matching may be used. In practical use, a terminal unit generally does not have to acquire the base unit as quickly as the base unit must acquire the terminal unit. This is because typically a terminal unit is powered on and begins searching for a base unit. The time spent finding and synchronizing with a base unit is not time critical. However, once a connection is made and a user initiates a transmit signal from the terminal unit to the base unit, the base unit must synchronize with the terminal unit very quickly to establish the full communication channel. In a preferred embodiment for the terminal units, only the peak average energy detection algorithm is used. In a preferred embodiment for the base unit, the template matching algorithm is used during initial signal acquisition, and then the base unit switches over to peak average energy detection. This is because the template matching approach is generally faster and more accurate than the peak average energy detection approach. Template matching makes use not only the point with the highest average energy, but multiple or even all of the energy points, because the template matcher assumes that the entire waveform has a certain energy distribution, on average. With the template matching approach, the 13 measured sample bins are run across the template as a sliding window to determine the best correlation between the measured data and the template. The mean of the measured data is subtracted to normalize for the correlation. The point in the correlation that has the highest correlation peak is the point in the waveform at which the measured samples align with the template. A quadratic fit is still preferably performed to interpolate between sample points, as with the peak energy approach. The template approach is generally faster than peak detection because it uses 13 times the information, and thus not as many sample points are needed to arrive at a valid correlation. The template approach is also generally more accurate than peak detection because any local errors in the measured data are mitigated by comparing all 13 sample points to the template at once. In a preferred embodiment, the template is pre-computed and stored. It has 26 points; which is twice the number of bins of measured data (i.e., 13). In this way the sliding window of 13 bins will always match up at some point in the template, no matter at which sample point the measurement starts. Alternatively, a partial template containing only a portion of the waveform may be used, for example, centered about the highest average energy point. A specific example of a template matcher will now be described. In a preferred embodiment, at the end of the slot, a template match is used to refine the estimate of symbol synchronization. The initial 20 symbols allow a coarse estimate of symbol synchronization to be made, so that the trunking/control data can be decoded. The end-of-the-slot template match allows a more refined estimate of symbol synchronization to be made, based on all the received data. The estimate is then used for the next slot of received data. FIG. 7 illustrates the template. To use template 700 shown in FIG. 7 , the magnitude squared at every sample is calculated, and thirteen samples per symbol period are accumulated. The accumulation is accomplished over the acquisition (special) slot/slots (two are possible). Preferably, the summation is not performed over every possible sample point within a receive slot, but is restricted to starting at the 65 th point and ending at 1494 th , although other valued could be used. Numbering starts at zero. The accumulation is performed as: SUM_MAG k = ∑ 114 j = 5 ⁢ ( I k + 13 ⁢ ⁢ j ) 2 + ( Q k + 13 ⁢ ⁢ j ) 2 , where k varies from 0 to 12. After accumulation the mean of all the SUM_MAGs is subtracted from each SUM_MAG k (where k goes from 0, . . . , 12). The SUM_MAG vector is then correlated to template 700 . Template 700 is 26 points in length. The k th correlation is performed as: Corr k = ∑ 12 j = 0 ⁢ ( temp k + j ) ⁢ ( SUM_MAG k ) . The k value giving the highest correlation peak represents the sample point that is closest to the information-bearing point. An interpolation scheme is used to further refine the symbol time estimate. Let M denote the index of the Symbol with the highest correlation peak. The interpolated index in terms of samples and fractions of a sample becomes INTERP+VAL=M−b/2 o , with b=(SUM_MAG m−1 −SUM_MAG m+1 )/2 a=(SUM_MAG m−1 +SUM_MAG m+1 )/2−SUM_MAG m . If a=0, then INTERP_VAL=M. It can happen that M is an end point (0 or 12) of the SUM_MAGS array. If M=12, then SUM_MAG M+1 =SUM_MAG 0 . If M=0, then SUM_MAG M−1 =SUM_MAG 12 . The SUM_MAGs array is interpreted in a modulo 13 fashion. The preferred algorithm uses the value INTER_VAL to interpolate between samples to obtain an estimate of the symbol value. Quadratic interpolation places the index of the symbol value between M=1 and M or between M and M+1. Both the in-phase and quadrature-phase values are interpolated. The interpolation for I and Q has the following form. If the index of the interpolated value is between M−1 and M+1 samples, the interpolated value is constructed by truncating to the lower integral sample value (which is N,N=integer value of INTER_VAL, DELT is fractional part of INTER_VAL). The residual denoted by DELT is then used to interpolate the data by I IN =(1−DELT)I N +DELT I N+1 , Q IN =(1−DELT)Q N +DELT Q N+1 , where N can be either M or M−1, and subscript ‘IN’ denotes interpolated value. Many of the features and functions discussed above can be implemented in software running on a digital signal processor or microprocessor, or preferably a combination of the two. Alternatively, dedicated circuits can be employed to realize the advantages of the above described preferred embodiments. Moreover, while being described thus far in terms of a radio frequency system, the present invention may also be applied to any number of different applications. For example, the present invention may be applied to wireline systems, cable modems, two-way fiber optic links, and point-to-multipoint microwave systems. Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alternations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed, that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.

A system and method for information content-independent synchronization with a received signal. A variable of the signal (e.g., average energy or magnitude) which is related to the energy distribution, is measured over a period of time. The signal's information bearing point is found at the point within the information period of the signal with the highest averaged energy. The point may be found, for example, by detecting the sample point with highest average energy, or by correlating multiple sample points to a stored template. Interpolation may be performed to locate an information bearing point that is between sample points. Because the relative energy content of the signal is effectively independent of the specific information content, synchronization with the information bearing point is accomplished without requiring the insertion of any special information content or fixed content patterns into the signal.

FIELD OF THE INVENTION This invention relates to autonomous private cellular systems operating in public cellular system frequency bands and, more particularly, to a system and method for manually searching for autonomous private systems. BACKGROUND OF THE INVENTION A wireless communication system, in the form of a cellular system, is designed to cover a large geographic area. The system is divided into numerous cells providing air interface between mobile stations and land-based systems. Each cell includes a base station for communicating with mobile stations. These wireless communication systems maintain a set of frequencies that are used for traffic channels and control channels. Frequency planning is necessary in order to determine which of the frequencies should be used at any given time. Recently, cellular-based system design is used as a foundation for smaller systems, such as private cellular or wireless office systems. These private cellular systems may share the frequency spectrum with the public cellular systems. The private cellular system user must be defined as a normal cellular subscriber in the subscriber database of the public cellular system, and the user's mobile station must be defined in both the private cellular system and the public cellular system. These are preconditions to enable the mobile station to roam between the public and private cellular system and to perform authentication. It will also be required for the mobile station to find the private cellular system. Use of neighbor cell pointers from the public system to the private system is not desirable, since it will increase the administration of the public system. Instead, a mechanism based on stored information in the terminal is preferred. Such a mechanism is defined in ANSI-136. A frequency re-plan is usually performed to give more capacity or to improve coverage. Since the public cellular systems have a limited spectrum based on the licensed frequency band, capacity is increased by increasing the number of frequencies in each cell site and/or installing more cell sites. Both methods bring new frequencies in use in the area affected. Since frequencies are re-used, other cell sites frequency use is also affected and they may have to re-tune their transceivers to other frequencies to accommodate the first change. This produces a rippling effect. The private cellular systems monitor the public cellular system and avoid frequencies used nearby in the public cellular systems. A change in the public cellular system's frequency use thus changes the frequency use of the private cellular systems. A mobile station will not automatically find an autonomous private cellular system if a frequency re-plan of the control frequency has taken place in either the private or public cellular systems. Also, the first time a mobile station wants to acquire service from a private cellular system, the appropriate parameters, such as the public service profile/private operating frequency (PSP/POF) parameters in the ANSI 136, Rev. A standard are not defined in the mobile station and it will not automatically find the private cellular system. If the mobile station cannot automatically find the private cellular system, due to, e.g., the stored PSP/POF information is not correct due to a frequency re-plan, then a manual search must be invoked. Presently, the ANSI-136 Rev. A standard outlines a manual search procedure to find a private cellular system. However, the search is limited to the frequency band the mobile station is presently camping on. As a result, autonomous private cellular systems operating on other bands cannot be found. In a publication entitled “Global Operators Forum Implementation Guide: Non - Public Mode Operation in TIA/EIA -136- A Compliant Mobile Stations ”, Version 4, December 1998, a modified manual search is proposed. In this proposal, the mobile station searches all bands if the private system is not found in the frequency band the mobile station was last camping on. Searching all bands can take more than fifteen minutes, resulting in substantial inconvenience for the end user. A mobile station designed according to ANSI-136 Rev. A can also be configured to find a private cellular system during a power-up scan. However, doing so limits the usage of the intelligent roaming database (IRDB) for public cellular system and provides undesirable behavior, such as long scanning times whenever a power-on is performed in the public cellular system and limited roaming capabilities. The present invention is directed to solving one or more of the problems discussed above in a novel and simple manner. SUMMARY OF THE INVENTION In accordance with the invention there is provided a unique and more robust manually initiated search procedure for private cellular systems in a mobile station, independent of the frequency band the mobile station was last camping on. Broadly, there is disclosed herein in a mobile station for use in both public cellular systems and private cellular systems, the private cellular system using select allocated frequency bands from the public cellular systems, a system for manually searching for one of the private cellular systems. The system comprises a memory storing information on select frequency bands. A transmitter and receiver is provided for communicating in the public cellular systems and the private cellular systems. An input initiates a manual search for one of the private cellular systems using the stored information on one of the select frequency bands. A programmed processor is operatively coupled to the memory, the transmitter and receiver and the input for operating the transmitter and receiver to search for the one private cellular system using the one of the select frequency bands. It is a feature of the invention that the memory stores a directory of the private cellular systems including identification information and a frequency band for each private cellular system. The input selects from the directory of private systems and the programmed processor operates the transmitter and receiver to search for the one of the private cellular systems on the stored frequency band for the selected private cellular system. It is another feature of the invention that the input can be used to update the directory. It is another feature of the invention that the memory stores plural predefined frequency bands. The input selects from the plural predefined frequency bands and the programmed processor operates the transmitter and receiver to search for the one of the private cellular systems on the selected predefined frequency band for one of the private cellular systems. It is another feature of the invention that the programmed processor is operated to initially search using strongest control channels found in the selected predefined frequency band. There is disclosed in accordance with another aspect of the invention the method of operating a mobile station used in both public cellular systems and private cellular systems, the private cellular systems using select allocated frequency bands from the public cellular systems, for manually searching for a private cellular system. The method comprises the steps of storing information on select frequency bands; initiating a manual search for one of the private cellular systems using the stored information on one of the select frequency bands; and operating a transmitter and receiver communicating in the public cellular systems and the private cellular systems to search for the one private cellular system using the one of the select frequency bands. Further features and advantages of the invention will be readily apparent from the specification and from the drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a generalized block diagram illustrating a mobile station communicating in both a public cellular system and a private cellular system; FIG. 2 is a block diagram of the mobile station of FIG. 1; FIG. 3 is a flow diagram illustrating a manually initiated search procedure in accordance with one aspect of the invention; FIG. 4 is a flow diagram illustrating operation of a manually initiated search procedure in accordance with another aspect of the invention; and FIG. 5 is a flow diagram illustrating updating of private cellular system information in a mobile station in accordance with the invention. DETAILED DESCRIPTION OF THE INVENTION Referring initially to FIG. 1, a telephone communication system 10 is generally illustrated. The communication system 10 consists generally of the public switched telephone network (PSTN) 12 shown connected to a private business premises 14 and the public land mobile network 16 . The business premises 14 includes a private branch exchange (PBX) 18 for communicating with the PSTN 12 in the conventional manner. A digital wireless office system (DWOS) 20 is a fully digital mobile communication system that provides a mobile extension to the PBX 18 . The DWOS 20 allows use of digital cellular phones based on cellular or PCS standard within an office environment. It operates on either one of the cellular bands (850 MHz) or one of the personal communication services (PCS) bands (1900 MHz). While the ANSI-136 standard is used as an exemplary embodiment in this application, the invention as described herein is applicable to all cellular standards where support for autonomous private cellular systems is provided. The DWOS 20 is a private cellular system that coexists with a public cellular system 26 in the PLMN 16 and uses the frequencies that are licensed to the operator of the particular network. The DWOS 20 automatically finds usable frequencies. A digital wireless office system mobile station 22 is adapted for communication both with the DWOS 20 and the public cellular system 26 . The mobile station 22 must be defined in both the DWOS 20 and the public cellular system 26 . The DWOS 20 interacts with a home location register (HLR) 24 using the ANSI- 41 protocol. A WOS SS 7 gateway (WGW) 28 is used for interworking between SS 7 and TCP/IP if TCP/IP is not used by the HLR 24 for communicating via an SS 7 network 30 . Other elements of the PLMN 16 connected to the SS 7 network are a conventional mobile switching center (MSC) 32 which is connected to the PSTN 12 , and a message center 34 . The MSC 32 is in turn connected to a base station 36 that communicates with the mobile station 22 in the conventional manner for public cellular systems. The DWOS mobile station 22 is reached either through its PLMN telephone number or a DWOS user number. The general communication principles involving the mobile station 22 and the DWOS 20 and PLMN 16 are known and are not specifically described herein. The present invention relates particularly to the system and method for conducting a robust manual search for an autonomous private cellular system, such as the DWOS 20 . Such a search might be necessary if a frequency re-plan of control frequencies has taken place in either the private or public cellular systems, or the first time the mobile station 22 wants to acquire service from the DWOS 20 . This search is independent of the system the mobile station 22 was last camping on. Referring to FIG. 2, the mobile station 22 is illustrated in block diagram form. The mobile station 22 includes an antenna 40 for sending and receiving radio signals between itself and the communication system 10 see FIG. 1 . The antenna is connected to a transmitter receiver 42 to broadcast and receive on the same antenna 40 . particularly the transmitter/receiver 42 includes a receiver that demodulates. demultiplexes, and decodes the radio signals into one or more channels. Such channels include a control channel and a traffic channel for speech or data. The speech or data are delivered to an output device of an input-output circuit 44 , such as speaker. The receiver delivers messages from the control channel to a processor 46 . The processor 46 controls and coordinates the functioning of the mobile station 22 responsive to messages on the control channel using programs and data stored in a memory 48 , so that the mobile station 22 can operate within the wireless network. The processor 46 also controls the operation of the mobile station 22 responsive to input from the input-output circuit 44 . This input may utilize a keypad or the like as a user-input device and a display to give the user information, as is well known. The transmitter/receiver 42 also includes a transmitter that converts analog electrical signals into digital data, encodes the data with error detection and correction information and multiplexes this data with control messages from the processor 46 . This combined data is modulated and broadcast via radio signal through the antenna 40 , as is conventional. The memory 48 , in accordance with the invention, stores a record or directory of private cellular systems. This directory includes an alphanumeric system name, system identity, such as PSID and SID in the ANSI-136 standard, and frequency band and hyperband for each such private cellular system. This record could be an extension of the record in IS-136 mobile stations used for automatic searching. The end user is able to edit the information in the record and to add information regarding new private systems using the input-output circuit 44 , see FIG. 2 . With reference to FIG. 3, a flow diagram illustrates a program for implementing a system name initiated manual search in accordance with the invention. At a block 50 , the mobile station 22 is on. However, the mobile station need not be camping on any particular cellular system. If the user wishes to initiate a manual system name search, then the user enters the directory or record of private cellular systems via an appropriate menu at a block 52 . A decision block 54 determines whether the user has requested to perform a manual search for a private cellular system or to edit the record. If the user selects the edit function, then at a block 56 the user edits the record of private systems. For each existing or new private system, the user must enter an alphanumeric name, the PSID, SID, and frequency band. The control then returns to the block 50 . If the user wishes to conduct a manual search from the block 54 , then at a block 58 the mobile station lists the available private cellular system names. A decision block 60 waits for the user to select one of the private cellular system names and then advances to a block 62 . The mobile station 22 uses the stored information for the selected private cellular system to attempt to obtain service via the transmitter-receiver 42 , see FIG. 2, on the selected system. If the mobile station 22 finds the private cellular system, then it starts camping on that private cellular system. Otherwise, the program returns to the start node. In addition to the system name initiated manual search, the mobile station 22 in accordance with the invention utilizes a band initiated search. This search is illustrated in the flow diagram of FIG. 4 . From a start node, a user selects a band initiated search via a menu at a block 70 . With the band initiated search, the end user specifies the band to search by choosing one band from a set of predefined bands, such as a, b, A, B, C, D, E, F in IS-136. A decision block 72 displays the available bands. The user then selects from these bands and at a block 74 the mobile station 22 searches all frequencies where a system can be found within the specified band. Conventionally, the mobile station 22 searches the whole band. The procedure can be accelerated by looking only at the two strongest control channels found in a sub-band. The mobile station then evaluates the rest of the band if a private cellular system is not found by the accelerated procedures. Two types of searches may be implemented using the band initiated search procedure. The first is a search for a private system identified by its PSID and SID and/or SOC. The second is a search for new private systems that accept a test registration in ANSI-136. If a band initiated search is initiated, or if no PSID, SID or SOC is defined for a system name initiated search, then a search procedure for new private systems is used. Referring to FIG. 5, a flow diagram illustrates a procedure for updating a private cellular system record at registration. This update procedure begins at a block 80 when the mobile station 22 has successfully registered on a private cellular system. This may be done, for example, after a new system search, and if the PSID is not in the phone's private cellular system record. Particularly, a decision block 82 determines if the PSID is in the record. If so, then the routine ends. If not, then at a decision block 84 the phone asks the user if the private cellular system should be stored in the record. If not, then the routine ends. If so, then the record is updated at a block 86 by storing the alphanumeric name, PSID, SID and frequency band in the private system record. This routine then ends. Thus, in accordance with the invention, the memory 48 stores information on both the select frequency bands available in the system and the record of private systems. This information can be used to manually search for a private cellular system using a system name initiated search, as illustrated relative to FIG. 3, or a frequency band initiated search, as illustrated in FIG. 4 .

A mobile station can be used in both public cellular systems and private cellular systems, the private cellular system using select allocated frequency bands from the public cellular systems. There is disclosed herein a system for manually searching for one of the private cellular systems. The system comprises a memory storing information on select frequency bands. A transmitter and receiver is provided for communicating in the public cellular systems and the private cellular systems. An input initiates a manual search for one of the private cellular systems using the stored information on one of the select frequency bands. A programmed processor is operatively coupled to the memory, the transmitter and receiver and the input for operating the transmitter and receiver to search for the one private cellular system using the one of the select frequency bands.

This invention was made with Government support under Contract F49620-94-1-10459P0001 awarded by the Air Force Office of Scientific Research and Contract CTS-931917 awarded by the National Science Foundation. The Government has certain rights in this invention. BACKGROUND OF THE INVENTION The present invention relates to polymeric materials and composites made by frontal polymerization More particularly, the present invention relates to functionally gradient polymers formed by frontal polymerization. Functionally gradient or graded materials (FGMs) are materials whose composition varies spatially in a controlled manner. Many different methods have been devised for forming functionally gradient materials. In one such process, centrifugal force was used to prepare gradients in a carbon fiber reinforced epoxy composite to produce composites with spatially varying conductivity. Additionally, several researchers have done work on preparing gradient interpenetrating polymer networks (IPNs). Most of the work developed by these individuals involves producing a gradient by diffusing one component into another pregelled component followed by curing, or producing a gradient in the polymer using a gradient of illumination. The diffusing method can require as much as 280 hours to produce a gradient over 10μ. Using the absorption of light to produce a gradient is limited to polymers with a thickness less than 1 mm. None of these techniques can be used to produce gradients in polymers which are several centimeters in thickness. Graded polymeric materials, such as Graded Refractive Index (GRIN) materials have found wide use in optical applications. These materials are prepared via interfacial gel polymerization, which is a slow process limited to producing gradients less than about 1 centimeter. Another type of gradient material with definite utility is an optical limiter based on a gradient of nonlinear optical dye dissolved in a polymer matrix. An optical limiter is a device that strongly attenuates intense optical beams but allows high transmittance at low level light. Such a device would be very useful for protecting human eyes from intense laser pulses. A discussion of the types of organic materials that exhibits such nonlinear absorption is contained in Perry et al., "Organic Optical Limiter with a Strong Nonlinear Absorptive Response," Science, 1996, pages 1533-1536. They found that metallophthalocyanine (M-Pc) complexes containing heavy central atoms work well. These dyes are compatible with poly(methyl methacrylate) and dissolve in the monomer. This affords the great advantage of inexpensive materials. Frontal polymerization is a method for converting monomer into polymer via a localized reaction zone that propagates through the coupling of the heat released by the polymerization reaction and thermal diffusion. Frontal polymerization was first discovered at the Institute of Chemical Physics in Chemogolovka, Russia by Chechilo and Enikolopyan in 1972. Polymerization fronts can exist with free-radical polymerization of mono- and multifunctional acrylates or epoxy curing. Frontal polymerization can be achieved in solution polymerization with monomers such as acrylamide, methacrylic acid and acrylic acid in solvents such as water and DMSO. Frontal polymerization reactions are relatively easy to perform. In the simplest case, a test tube is filled with the reactants. The front is ignited by applying heat to one end of the tube with an electric heater. The position of the front is obvious because of the difference in the optical properties of polymer and monomer. Under most cases, a plot of the front position versus time produces a straight line whose slope is the front velocity. The velocity can be affected by the initiator type and concentration but is on the order of centimeters per minute. The defining feature of thermal frontal polymerization is the sharp temperature gradient present in the front. The temperature can jump about 200° C. over a little as a few millimeters, which corresponds to polymerization in a few seconds at that point. In view of the foregoing, it would be a significant advancement in the art to provide a process for forming functionally gradient polymers which had a short reaction time and which could produce polymers several centimeters in thickness. Such a process and the polymeric materials created thereby are disclosed herein. BRIEF SUMMARY OF THE INVENTION The present invention is directed to functionally gradient materials and a process for forming the same. In a preferred embodiment, an ascending polymerization front is created in a reaction vessel. Pumps provide monomers or resins in a controlled ratio on top of the ascending front as it propagates to maintain a nearly constant thickness of unreacted monomers. The height of unreacted monomers is maintained such that the front is not extinguished, but progresses in a controlled manner. By varying the ratio of the monomers and/or the concentration of additives to the mixture, functionally gradient materials can be formed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is directed to functionally gradient materials and methods for forming them. As discussed above, frontal polymerization reactions are generally relatively easy to perform. In the simplest case, a test tube is filled with reactants and a front is ignited by applying heat to one end of the tube. The front then either ascends up the tube or descends down the tube, depending upon the point at which it was initiated. In a preferred embodiment of the present invention, the process is carried out in a cylindrical tube such as a test tube. However, it should be appreciated that reaction vessels having different cross-sectional areas can also be used. In the preferred embodiments, the cross-sectional area can vary from about 15 mm 2 to about 1 m 2 . The limiting factors on the upper end of the area are dependent in part upon the ability to simultaneously add additional reactants to the entire surface area and the ability of the front to progress in a uniform manner. According to the preferred embodiment of the present invention, the polymerization front is an ascending front in a vertical container. However, it will be appreciated by those skilled in the art that other configurations can also be used without departing from the spirit or scope of the invention. For example, the reactor may be tilted or possess a varying cross section. Frontal polymerization is often carried out at ambient temperature with the heat of reaction being sufficient to sustain the reaction as the front progresses through the material. However, in some systems it may be necessary to preheat the reactants or to provide additional localized heat as the front progresses to maintain the polymerization reaction. The process of the present invention can be utilized to make many different types of functionally gradient polymers. In one preferred embodiment, the functionally gradient polymer comprises a polymer matrix having an optical dye dissolved therein. The concentration of the dye varies along the length of the polymer sample. This is achieved by varying the amount of dye added to the monomer that is added to the top of the polymerization front. It will be appreciated by those skilled in the art that there are many different ways of varying the concentration of the dye. For example, the dye can be added by a separate pump as the monomer is being added such that its concentration gradually changes, by varying the relative flow rates of the two feedstreams. Alternatively, the dye solution can be premixed with the monomer in the inlet reservoir by a separate pump such that the inlet stream's dye concentration varies with time. Many different types of dyes and additives can be used in the present invention. Examples of additives include plasticizing agents, rubber toughening agents and inert fillers. The latter can be affected to great advantage because the rapid reaction in the front prevents sedimentation of the filler. For example, diethyl phthalate can be used to prepare a gradient of plasticization. Rubber particles (from ground car tires) or poly (butadiene) can be used as rubber toughening agents. Silica gel or calcium carbonate can be used as inert fillers. In another preferred embodiment of the present invention, functionally gradient polymers in which the mechanical properties of the polymer vary along the length are formed. In one embodiment, the mechanical properties of the polymer are modified by varying the amount of cross-linking that occurs in the polymer. This can be achieved by changing the ratio of monomers that are added to the system or by varying the amount of cross-linking agent that is added to the system. Examples of suitable systems include multifunctional acrylates with a monoacrylate and/or an epoxy resin with its curing agent. Polymeric materials with a gradient in the copolymer composition can be achieved by varying the comonomer feedstreams. The invention can be further understood by reference to the following examples: EXAMPLE 1 Tri(ethylene glycol) dimethacrylate (TGDMA) and benzyl acrylate were used as monomers in a polymerization reaction. They were stored over molecular sieves, dried over CaH 2 and then filtered before use. Lupersol 231 was used as an initiator. A peristaltic pump was used to supply the monomers into a test tube having an inner diameter of 22 millimeters in which an ascending front was propagated. The polymerization reaction was initiated by heating the bottom of the test tube with an electric heater. The ratio of the monomers was varied from 100% TGDMA/0% benzyl acrylate at the beginning to 5% TGDMA/95% benzyl acrylate at the end. The sample diameter was 2.2 cm and its length 10 cm. The flow rate of monomers into the test tube was 3 mL/minute. The characteristics of the resulting functionally gradient polymer were a rigid material at the high TGDMA end smoothly graded into a rubbery, crosslinked material at the low TGDMA concentration. EXAMPLE 2 Tri(ethylene glycol) dimethacrylate (TGDMA) was used as the monomer in a polymerization reaction. Tricaprylmethylammonium persulfate was used as an initiator in this experiment producing dye gradients. The main advantage of this initiator is its gasless nature under decomposition. This permitted the formation of bubble-free optical materials. Aluminum phthalocyanine chloride was used as a dye. The dye was dissolved in the TGDMA, and the solution was used as a coloring component. A peristaltic pump was used to supply the reactive material into a test tube in which an ascending front was propagated. The inner diameter of the test tube was 12 mm. The test tube was exposed to ambient pressure and temperature conditions. The dye concentration was gradually increased in the TGDMA reservoir as the monomer was added to the system until it reached its saturation point. The dye concentration varied in the final sample from saturated (dark green) to zero over a distance of 5 cm. The process of the present invention can be utilized in many different types of polymer systems such as reactive acrylates, acrylamides in solution, and cationically and amine cured epoxies. The process will work with essentially any polymer system that will support frontal polymerization. It can be used for graded IPNs using binary frontal polymerization as well as graded rubber toughened epoxies using frontal curing. While the present invention has been described with respect to the presently preferred embodiments, numerous changes and substitutions can be made to the products and processes of the present invention without departing from the scope of the invention. Accordingly, all changes or modifications which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Functionally gradient polymeric materials are formed by a process that utilizes an ascending polymerization front. A polymerization front is initiated in a reaction vessel containing a monomer solution. Additional monomers or resins are added on top of the polymerization front to maintain a substantially constant level. The composition of the monomers and/or additives are varied as they are added to the reaction vessel to form a functionally gradient polymeric material.

CROSS-REFERENCES TO RELATED APPLICATIONS [0001] This application is a Continuation of U.S. application Ser. No. 13/287,199, filed on Nov. 2, 2011 (now pending), which in turn is a Divisional of U.S. application Ser. No. 12/185,042, filed on Aug. 1, 2008 (now U.S. Pat. No. 8,071,825), which claims priority benefit of U.S. Provisional Application No. 60/953,528, filed on Aug. 2, 2007, which in turn is also a Continuation-In-Part of U.S. application Ser. No. 11/619,592, filed Jan. 3, 2007 (now U.S. Pat. No. 8,084,653), which claims priority benefit of U.S. Provisional Application No. 60/755,485, filed Jan. 3, 2006, each of which are incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] (1) Field of Invention [0003] This invention relates to novel methods for preparing fluorinated organic compounds, and more particularly to methods of producing fluorinated olefins having a fluorine on an unsaturated non-terminal carbon. [0004] (2) Description of Related Art [0005] Hydrofluorocarbons (HFCs), in particular hydrofluoroalkenes such as tetrafluoropropenes (including 2,3,3,3-tetrafluoro-1-propene (HFO-1234yf) and 1,3,3,3-tetrafluoro-1-propene (HFO-1234ze)) have been disclosed to be effective refrigerants, fire extinguishants, heat transfer media, propellants, foaming agents, blowing agents, gaseous dielectrics, sterilant carriers, polymerization media, particulate removal fluids, carrier fluids, buffing abrasive agents, displacement drying agents and power cycle working fluids. Unlike chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs), both of which potentially damage the Earth's ozone layer, HFCs do not contain chlorine and, thus, pose no threat to the ozone layer. [0006] Several methods of preparing hydrofluoroalkenes are known. For example, U.S. Pat. No. 4,900,874 (Ihara, et. al) describes a method of making fluorine containing olefins by contacting hydrogen gas with fluorinated alcohols. Although this appears to be a relatively high-yield process, commercial handling of hydrogen gas at high temperature is generally unsafe. Also, the cost of producing hydrogen gas, such as building an on-site hydrogen plant, can be, in many situations, prohibitive. [0007] U.S. Pat. No. 2,931,840 (Marquis) describes a method of making fluorine containing olefins by pyrolysis of methyl chloride and tetrafluoroethylene or chlorodifluoromethane. This process produces a relatively low yield and a very large percentage of unwanted and/or unimportant byproducts. [0008] The preparation of HFO-1234yf from trifluoroacetylacetone and sulfur tetrafluoride has been described. See Banks, et al., Journal of Fluorine Chemistry , Vol. 82, Iss. 2, p. 171-174 (1997). Also, U.S. Pat. No. 5,162,594 (Krespan) discloses a process wherein tetrafluoroethylene is reacted with another fluorinated ethylene in the liquid phase to produce a polyfluoroolefin product. SUMMARY OF INVENTION [0009] One aspect of the invention involves methods of producing hydrofluoroalkenes, more preferably fluorinated olefins having a fluorine on an unsaturated non-terminal carbon and even more preferably in certain preferred embodiments 2,3,3,3-tetrafluoro-l-propene (HFO-1234yf). In preferred forms, this aspect of the invention is directed to methods comprising converting at least one compound of Formula (I): [0000] C(X) m CCl(Y) n C(X) m   (I) [0000] to at least one compound of Formula (II) [0000] CF 3 CF═CHZ   (II) [0000] where each X, Y and Z is independently H, F, Cl, I or Br, and each m is independently 1, 2 or 3, preferably 2 or 3, and n is 0 or 1. In certain preferred embodiments, compounds of Formula I include CH 2 ═CClCCl 3 , CCl 2 ═CClCH 2 Cl, and 1,1,1,2,3-pentachloropropane. As used herein and throughout, unless specifically indicated otherwise, the term “converting” includes directly converting (for example, in a single reaction or under essentially one set of reaction conditions) and indirectly converting (for example, through two or more reactions or using more than a single set of reaction conditions). [0010] In certain preferred embodiments of the invention, the compound of Formula (I) comprises a compound wherein n is 0, each X is independently H or Cl, and Z is H. Such preferred embodiments include converting at least one C3 alkene in accordance with Formula (IA): [0000] C(X) 2 ═CClC(X) 3   (IA) [0000] to at least one compound of formula (II) [0000] CF 3 CF═CHZ   (II) [0000] where each X is independently H or Cl. Preferably the one or more compounds of Formula (IA) are tetrachloropropene(s), and are even more preferably selected from the group consisting of CH 2 ═CClCCl 3 , CCl 2 ═CClCH 2 Cl, and combinations of these. In certain highly preferred embodiments, the at least one C3 alkene in accordance with Formula (IA) comprises, and preferably comprises in a major proportion based on all compounds of Formula (I), CCl 2 ═CClCH 2 Cl. [0011] In certain preferred embodiments the converting step comprises first exposing the compound of Formula (I), and preferably Formula (IA), and even more preferably CCl 2 ═CClCH 2 Cl, to one or more sets of reaction conditions, but preferably a substantially single set of reaction conditions, effective to produce at least one chlorofluoropropane, more preferably a propane in accordance with Formula (IB): [0000] CF 3 CClXC(X) 3   Formula (IB) [0000] where each X is independently F, Cl or H, preferably where one X is F and the remaining X's are H, and then exposing the compound of Formula (IB) to one or more sets of reaction conditions, but preferably a substantially single set of reaction conditions, effective to produce a compound of Formula (II), most preferably HFO-1234yf. In certain preferred embodiments, at least one of said X in Formula (IB) is Cl. In such embodiments, it is generally preferred that X on the non-terminal carbon is H, and even more preferably that in addition that at least two, and more preferably all three X on the terminal carbon are also H. [0012] As used herein, the term “substantially single set of reaction conditions” means that the reaction is controlled to correspond to be within a set of reaction parameters that would ordinarily be considered to be a single stage or unit operation. As those skilled in the art will appreciate, such conditions permit a degree of design variability within each of the process parameters relevant to the conversion step. [0013] The preferred conversion step of the present invention is preferably carried out under conditions, including the use of one or more reactions, effective to provide an overall Formula (I) conversion of at least about 50%, more preferably at least about 75%, and even more preferably at least about 90%. In certain preferred embodiments the overall conversion of Formula (I) is at least about 95%, and more preferably at least about 97%. Further, in certain preferred embodiments, the step of converting the compound of Formula (I) to produce a compound of Formula (II) is conducted under conditions effective to provide an overall Formula (II) yield of at least about 75%, more preferably at least about 85%, and more preferably at least about 90%. In certain preferred embodiments an overall yield of about 95% or greater is achieved. [0014] In the preferred embodiments in which the conversion step comprises exposing a compound of Formula (I), and even more preferably CC1 2 =CC1CH 2 C1, to one or more sets of reaction conditions effective to produce at least one chlorofluoropropane, more preferably a propane in accordance with Formula (IB), such an exposing step preferably comprises exposing the compound of Formula (I) to one or more set of reaction conditions, but preferably substantially a single set of reaction conditions, effective to provide an overall conversion of Formula (I), and preferably Formula (IA) of at least about 75%, and more preferably at least about 90%, and more preferably at least about 97%, such conditions also preferably being effective to provide a Formula (IB) selectivity yield of at least about 10%, more preferably at least about 15%, and even more preferably at least about 20%. [0015] One preferred aspect of the present invention provides a process for the production of 2-chloro-1,1,1,2-tetrafluoropropane (HCFC244bb) comprising reacting a compound selected from the group consisting of 1,1,2,3-tetrachloropropene, 1,1,1,2,3-pentachloropropane (HCC-240db), 2,3,3,3-tetrachloropropene and combinations of these with a fluorinating agent, preferably hydrogen fluoride, in a liquid phase reaction vessel in the presence of a liquid phase fluorination catalyst. [0016] Another preferred aspect of the invention provides a process for the production of 2,3,3,3-tetrafluoropropene comprising (i) reacting, preferably in a continuous process, at least one compound selected from the group consisting of 1,1,2,3-tetrachloropropene, 1,1,1,2,3-pentachloropropane (HCC-240db), and 2,3,3,3-tetrachloropropene with a fluorinating agent, preferably hydrogen fluoride, in a liquid phase reaction in the presence of a liquid phase fluorination catalyst to produce a reaction product comprising 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb); and then (ii) reacting, preferably by dehydrohalogenating, the 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) under conditions effective to produce 2,3,3,3-tetrafluoropropene. BRIEF DESCRIPTION OF THE DRAWINGS [0017] FIG. 1 is a chart showing the yield of HFC-1234yf according to an embodiment of the invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS [0018] One beneficial aspect of the present invention is that it enables the production of desirable fluoroolefins, preferably C3 fluoroolefins, using relatively high conversion reactions. Furthermore, the present methods in certain preferred embodiments permit the production of the desirable fluoroolefins, either directly or indirectly, from relatively attractive starting materials. For example, tetrachloropropene, and 1,1,2,3 tetrachloropropene (CCl 2 ═CClCH 2 Cl) in particular, is a compound that in certain embodiments is an advantageous starting material. [0019] In certain preferred embodiments, at least a first compound in accordance with Formula (I), and preferably a compound in accordance with Formula (IA), is exposed to one or more reaction conditions effective to produce a second compound in accordance with Formula (I), and preferably a compound in accordance with Formula (IB), which in turn is exposed to one or more reaction conditions effective to produce a reaction product containing one or more of the desired fluoroolefins, preferably one or more compounds of Formula (II), and even more preferably HFO-1234yf. Thus, in preferred embodiments, the conversion step comprises a series of at least two reaction stages or conditions. In one preferred aspect of the present invention, the conversion step comprises: (a) reacting a compound of Formula (IA), such as tetrachloropropene, preferably in a liquid phase reaction in the presence of at least a first catalyst to produce at least one compound of Formula (IB), such as a monochloro-tetrafluoro-propane, preferably 2-chloro-1,1,1,2-tetrafluoropropane (HFC-244bb); and (b) reacting said compound of Formula (IB), in a gas and/or liquid phase, to produce the desired HFO, preferably HFO-1234yf. [0020] In certain preferred embodiments, the present methods comprise converting at least one tetrachloropropene and/or at least one pentachloropropane to a reaction product containing the desired tetrafluoropropene, preferably 2,3,3,3-tetrafluoropropene (HFO-1234yf). Although it is contemplated that the converting step in certain embodiments may effectively be carried out in a single reaction stage and/or under a single set of reaction conditions, it is preferred in many embodiments that the converting steps comprise a series of two reaction stages or conditions. In one preferred aspect of the present invention, the conversion step comprises: (a) reacting at least one tetrachloropropene (preferably, 1,1,2,3-tetrachloropropene and/or 2,3,3,3-tetrachloropropene), or at least one pentachloropropane (1,1,1,2,3-pentachloropropane) or mixtures of two or more thereof, in a liquid and/or gas phase reaction in the presence of at least a first catalyst to produce at least one C3 hydrochlorofluorocarbon such as a mono-chloro-tetrafluoro-propane, preferably HCFC-244bb; and (b) reacting said C3 hydrochlorofluorocarbon, such as a monochloro-tetrafluoropropane compound, in a gas and/or liquid phase and preferably in the presence of at least a catalyst, preferably a second catalyst which is different than the first catalyst, to produce the desired tetrafluoropropene, preferably HFO-1234yf. [0021] Each of the preferred reaction steps is described in detail below, with the headings being used for convenience but not necessarily by way of limitation. I. Fluorination of the Compound of Formula (IA) [0022] One preferred reaction step in accordance with the present invention may be described by those reactions in which the compound of Formula (IA) is fluorinated to produce a compound of Formula (IB). In certain preferred embodiments, especially embodiments in which the compound of Formula (IA) comprises C(X) 2 ═CClC(X) 3 , where each X is independently H or Cl, the present converting step comprises reacting said Formula (IA) compound(s) by fluorinating, preferably in a liquid phase and with HF as a fluorinating agent, said compound(s) to produce a compound of Formula (IB), namely, [0000] CF 3 CClX′C(X′) 3   Formula (IB) [0000] where each X′ is independently F, Cl or H. The preferred fluorination of the compound of Formula (IA) is preferably carried out under conditions effective to provide a Formula (IA) conversion of at least about 50%, more preferably at least about 75%, and even more preferably at least about 90%. In certain preferred embodiments the conversion is at least about 95%, and more preferably at least about 97%. Further, in certain preferred embodiments, the conversion of the compound of Formula (IA) comprises reacting such compound under conditions effective to produce at least one compound of Formula (IB), such as monochlorotetrafluoropropane (preferably HCFC-244bb) at a selectivity of at least about 10%, more preferably at least about 15%, and more preferably at least about 20%. [0023] In certain preferred embodiments in which the feed material comprises tetrachloropropene, the present converting step is carried out under conditions effective to provide a tetrachloropropene conversion of at least about 40%, more preferably at least about 55%, and even more preferably at least about 70%. In certain preferred embodiments the conversion of tetrachloropropene is at least about 90%, and more preferably about 100%. Further, in certain preferred embodiments, the conversion of the tetrachloropropene to produce a C3 hydrochlorofluorocarbon is conducted under conditions effective to provide a C3 hydrochlorofluorocarbon selectivity of at least about 85%, more preferably at least about 90%, and more preferably at least about 95%, and even more preferably about 100%. [0024] In a particularly preferred embodiment, the invention relates to a continuous method for producing a compound of Formula (IB), preferably including 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb), by either a liquid phase fluorination, a vapor phase fluorination, or a combination of liquid and vapor phase fluorinations. In certain preferred embodiments, the feed to the fluorination reaction comprises at least one chlorocarbon or mixed chlorocarbon feed material, preferably selected from the group consisting of 1,1,1,2,3-pentachloropropane (HCC-240db), 2,3,3,3-tetrachloropropene, and 1,1,2,3,-tetrachloropropene (HCC-1230xa. The compounds in the feed are reacted with a fluorinating agent, such as hydrogen fluoride, to produce a reaction product stream comprising a compound according to Formula (IB), such as 2-chloro-1,1,1,2-tetrafluoropropane, hydrogen fluoride, and hydrogen chloride. [0025] In certain embodiments, it is preferred that the fluorination reaction step is carried out in the liquid phase, and preferably under a substantially single set of reaction conditions, and it is contemplated that the reaction can be carried out batch wise, continuous, or a combination of these, with continuous reaction being preferred. In a preferred form of a continuous process, the Formula (I) compound, such as 1,1,2,3-tetrachloropropene, and the fluorinating agent, such as HF, are preferably fed, preferably substantially simultaneously, to the reactor after the reactor reaches the desired temperature. The temperature and pressure of the fluorination reaction are generally within about the same range for both the batch and continuous modes of operation. [0026] For embodiments in which the reaction comprises a liquid phase reaction, preferably a catalytic process is used. In general, it is contemplated that any liquid phase fluorination catalyst may be used. Lewis acid catalyst, metal-halide catalysts, including antimony halides, tin halides, tantalum halides, titanium halides, transition metal-halides, such as iron halides, niobium halide, and molybdenum halide, transition metal oxides, Group IVb metal halides, a Group Vb metal halides, fluorinated chrome halide, a fluorinated chrome oxide and combinations of two or more of these, are preferred in certain embodiments. Metal chlorides and metal fluorides are particularly preferred. Examples of particularly preferred catalysts of this type include SbCl 5 , SbCl 3 , SbF 5 , SnCl 4 , TaCl 5 , NbCl 5 , MoCl 6 , TiCl 4 , FeCl 3 , a fluorinated species of SbCl 5 , a fluorinated species of SbCl 3 , a fluorinated species of SnCl 4 , a fluorinated species of TaCl 5 , a fluorinated species of TiCl 4 , a fluorinated species of NbCl 5 , a fluorinated species of MoCl 6 , a fluorinated species of FeCl 3 , and combinations of two or more of these. Pentavalent metal halide, particularly pentavalent antimony halides are preferred in many embodiments. Antimony chlorides, such as antimony pentachloride, and/or fluorinated antimony chlorides are preferred in many embodiments. [0027] In certain preferred embodiments, a liquid phase catalyst as described above is charged into a fluorination reactor prior to heating the reactor. The catalyst may (or may not) be activated with anhydrous hydrogen fluoride HF (hydrogen fluoride gas) and/or Cl 2 (chlorine gas) before use depending on the state of the catalyst. [0028] In preferred liquid phase fluorination of Formula (I) compounds, preferably Formula (IA) compounds, the reaction is at least partially a catalyzed reaction, and is preferably carried out on a continuous basis by introducing a stream containing the compound of Formula (I), preferably Formula (IA), into one or more reaction vessels. The stream containing the compound of Formula (I), and preferably Formula (IA), which may be preheated if desired, is introduced into a reaction vessel, which is maintained at the desired temperature, preferably from about 30° C. to about 200° C., more preferably from about 50° C. to about 150° C., more preferably from about 75° C. to about 125° C., even more preferably in certain embodiments from about 90° C. to about 110° C., wherein it is preferably contacted with catalyst and fluorinating agent, such as HF. [0029] It is generally preferred that the fluorinating agent is present in the reactor in substantial excess. For example, for embodiments in which the fluorinating agent is HF, it is preferred that the reactor be fed with HF in an amount to produce an HF:Formula (IB) ratio in the reactor product stream (on a molar basis) of at least about 4:1, more preferably from about 4:1 to about 50:1, more preferably from about 4:1 to about 30:1 and most preferably from about 5:1 to about 20:1. [0030] With respect to the feeds to the reactor, including the fluorination agent, it is generally considered that water will react with and deactivate the catalyst. Therefore it is preferred that the feed be substantially free of water. With respect to embodiments in which HF is used as a fluorinating agent, substantially anhydrous HF is preferred. By “substantially anhydrous” is meant that the HF contains less than about 0.05 weight % water and preferably contains less than about 0.02 weight % water. However, one of ordinary skill in the art will appreciate that the presence of water in the catalyst can be compensated for by increasing the amount of catalyst used. HF suitable for use in the reaction may be purchased from Honeywell International Inc. of Morristown, N.J. [0031] Although it is contemplated that residence times in the reactor may vary widely within the scope of the present invention, it is preferred in certain embodiments that for continuous reactions the residence time is relatively short. The residence time or contact time in certain preferred embodiments is from about 1 second to about 2 hours, preferably from about 5 seconds to about 1 hour and most preferably from about 10 seconds to about 30 minutes. The quantity of catalyst is generally selected to ensure that the desired level of fluorination is achieved in view of the other process conditions which apply, such as the residence times described above. For example, less than about 5 seconds, more preferably less than about 3 seconds, and even more preferably about 2 seconds or less. [0032] Without necessarily being bound to any particular theory of operation it is believed that the preferred fluorination reaction proceedings in accordance with the following reaction equation: [0000] CCl 2 ═CClCH 2 Cl+4HF→CF 3 CClFCH 3 +3 HCl [0033] It is expected that by-products of the reaction will include CF 3 CCl═CH 2 (HFO-1233xf), CClF 2 CCl═CH 2 (HFO-1232xf), and that one or both of these could be recycled, completely or partially, to improve the overall yield of the desired CF 3 CClFCH 3 (HCFC-244bb). [0034] In general, it is contemplated that any reactor suitable for a fluorination reaction may be used in accordance with the preferred aspects of the present invention. Preferably the vessel is comprised of materials which are resistant to corrosion as Hastelloy, Inconel, Monel and/or fluoropolymer-lined. Such liquid phase fluorination reactors are well known in the art. [0035] Preferably in certain embodiments, the vessel contains catalyst, for example a fixed or fluid catalyst bed, packed with a suitable fluorination catalyst, with suitable means to ensure that the reaction mixture is maintained with the desired reaction temperature range. [0036] In general it is also contemplated that a wide variety of reaction pressures may be used for the fluorination reaction, depending again on relevant factors such as the specific catalyst being used, the temperature of the reaction, the amount of fluorinating agent being used, and other factors. The reaction pressure can be, for example, superatmospheric, atmospheric or under vacuum and in certain preferred embodiments is from about 5 to about 200 psia, and in certain embodiments from about 30 to about 175 psia and most preferably about 60 psia to about 150 psia. [0037] In certain embodiments, an inert diluent gas, such as nitrogen, may be used in combination with the other reactor feed(s). [0038] It is contemplated that the amount of catalyst used will vary depending on the particular parameters present in each embodiment. In certain preferred embodiments, the catalyst is present in an amount of from about 2% to about 80%, and preferably from about 5% to about 50%, and most preferably from about 10% to about 20%, based on the mole percent of the desired reaction product, preferably a compound in accordance with formula (IB), and even more preferably HCFC-244bb. Fluorination catalysts having a purity of at least 98% are preferred. [0039] The catalysts can be readily regenerated by any means known in the art if they become deactivated. One suitable method of regenerating the catalyst involves flowing a stream of chlorine through the catalyst. For example, from about 0.002 to about 0.2 lb per hour of chlorine can be added to the liquid phase reaction for every pound of liquid phase fluorination catalyst. This may be done, for example, for from about 1 to about 2 hours or continuously at a temperature of from about 65° C. to about 100° C. [0040] In another embodiment, the fluorination reaction is done in the vapor-phase. In preferred aspects of the vapor phase reaction, the fluorinating agent, such as HF (hydrogen fluoride gas) is fed continuously through the catalyst bed. After a short time with substantially only the HF feed stream, a compound according to Formula (I), and preferably Formula IA, such as 1,1,2,3-tetrachloropropene, is fed continuously through the catalyst bed at a fluorinating agent Formula (I) mole ratio, preferably HF/1,1,2,3-tetrachloropropene mole ratio, of about 4:1 to about 50:1 and preferably of about 4:1 to about 30:1 and more preferably of about 5:1 to about 20:1. The reaction is preferably carried out at a temperature of from about 30° C. to about 200° C. (preferably from about 50° C. to about 120° C.) and at a pressure of about 5 psia to about 200 psia (pounds per square inch absolute) (preferably from about 30 psia to about 175 psia). The catalyst may be supported on a substrate, such as on activated carbon, or may be unsupported or free-standing. It may be preferred in certain embodiments to activate the catalyst, such as with anhydrous hydrogen fluoride HF (hydrogen fluoride gas) and/or Cl 2 (chlorine gas) before use depending on the state of the catalyst. If desired, the catalyst can be kept activated by the continuous or batch addition of Cl 2 or a similar oxidizing agent. [0041] Any vapor phase fluorination catalyst may be used in the invention. A non-exhaustive list include Lewis acids, transition metal halides, transition metal oxides, Group IVb metal halides, a Group Vb metal halides, or combinations thereof. Non-exclusive examples of liquid phase fluorination catalysts are an antimony halide, a tin halide, a tantalum halide, a titanium halide, a niobium halide, molybdenum halide, an iron halide, a fluorinated chrome halide, a fluorinated chrome oxide or combinations thereof. Specific non-exclusive examples of vapor phase fluorination catalysts are SbCl 3 , SbCl 5 , SbF 5 , SnCl 4 , TaCl 5 , TiCl 4 , FeCl 3 , CrF 3 , Cr 2 O 3 bulk or supported, and fluorinated Cr 2 O 3 bulk or supported. Catalyst supports include carbon, alumina, fluorinated alumina, or aluminum fluoride, alkaline earth metal oxides, fluorinated alkaline earth metals, zinc oxide, zinc fluoride, tin oxide, and tin fluoride. [0042] In general, the effluent from the fluorination reaction step, including any intermediate effluents that may be present in multi-stage reactor arrangements, may be processed to achieve desired degrees of separation and/or other processing. For example, in embodiments in which the reactor effluent comprises a compound of Formula (IB), such as HCFC-244bb, the effluent will generally also include HF and HCl. Some portion or substantially all of these components of the reaction product may be recovered from the reaction mixture via any separation or purification method known in the art such as neutralization and distillation, or in the reaction product may be fed in its entirety or in part, but without any separation of components, to the next step, i.e., dehydrohalogenation of the compound of Formula (IB). It is contemplated, therefore, that the desired compound of Formula (IB), such as HCFC-244bb, can be used in subpure form, or optionally in partially pure form or impure form with at least a portion of the effluent from the HCFC-244bb production step used as the feed to the dehydrohalogenation step. [0043] In a continuous mode of operation, the desired compound(s) of Formula (IB), such as HCFC-244bb, and other reaction products, such as hydrogen chloride, are preferably continuously removed from the reactor. II. Dehydrohalogenation of Formula (IB) [0044] One preferred reaction step in accordance with the present invention may be described by those reactions in which the compound of Formula (IB) is dehydrohalogenated, preferably in certain embodiments dehydrochlorinated, to produce a compound of Formula (II). In certain preferred embodiments, the compound of Formula (IB) comprises a monochloro-tetrafluoro-propane, more preferably, 2-chloro-1,1,1,2-tetrafluoropropane (HCFC244bb), which is exposed to reaction conditions to produce a reaction product according to Formula (II), preferably comprising tetrafluoropropene, preferably 2,3,3,3-tetrafluoropropene HFO-1234yf. [0045] In certain preferred embodiments, the stream containing the compound of Formula (IB) is preheated to a temperature of from about 150° C. to about 400° C., preferably about 350° C., and introduced into a reaction vessel, which is maintained at about the desired temperature, preferably from about 200° C. to about 700° C., more preferably from about 300° C. to about 700° C., more preferably from about 300° C. to about 450° C., and more preferably in certain embodiments from about 350° C. to about 450° C. [0046] Preferably the vessel is comprised of materials which are resistant to corrosion as Hastelloy, Inconel, Monel and/or fluoropolymers linings. Preferably the vessel contains catalyst, for example a fixed or fluid catalyst bed, packed with a suitable dehydrohalogenation catalyst, with suitable means to heat the reaction mixture to about the desired reaction temperature. [0047] Thus, it is contemplated that the dehydrohalogenation reaction step may be performed using a wide variety of process parameters and process conditions in view of the overall teachings contained herein. However, it is preferred in certain embodiments that this reaction step comprises a gas phase reaction, preferably in the presence of catalyst, and even more preferably in the presence of a fixed bed catalytic reactor in the vapor or gas phase. [0048] In preferred embodiments, the catalyst is a carbon- and/or metal-based catalyst, preferably activated carbon (in bulk or supported form), a nickel-based catalyst (such as Ni-mesh), metal halides, halogenated metal oxides, neutral (or zero oxidation state) metal or metal alloy and combinations of these. Other catalysts and catalyst supports may be used, including palladium on carbon, palladium-based catalyst (including palladium on aluminum oxides), and it is expected that many other catalysts may be used depending on the requirements of particular embodiments in view of the teachings contained herein. When metal halides or metal oxides catalysts are used, preferably mono-, bi-, and tri-valent metal halides, oxide and their mixtures/combinations, and more preferably mono-, and bi-valent metal halides and their mixtures/combinations. Component metals include, but are not limited to, Cr 3+ , Fe 3+ , Mg 2+ , Ca 2+ , Ni 2+ , Zn 2+ , Pd 2+ , Li + , Na + , K + , and Cs + . Component halogens include, but are not limited to, F, Cl − , Br − , and I − . Examples of useful mono- or bi-valent metal halide include, but are not limited to, LiF, NaF, KF, CsF, MgF 2 , CaF 2 , LiCl, NaCl, KCl, and CsCl. Halogenation treatments can include any of those known in the prior art, particularly those that employ HF, F 2 , HCl, Cl 2 , HBr, Br 2 , HI, and I 2 as the halogenation source. When neutral, i.e., zero valent, metals, metal alloys and their mixtures are used. Useful metals include, but are not limited to, Pd, Pt, Rh, Fe, Co, Ni, Cu, Mo, Cr, Mn, and combinations of the foregoing as alloys or mixtures. The catalyst may be supported or unsupported. Useful examples of metal alloys include, but are not limited to, SS 316, Monel 400, Inconel 825, Inconel 600, and Inconel 625. [0049] Of course, two or more any of these catalysts, or other catalysts not named here, may be used in combination. [0050] The gas phase dehydrohalogenation reaction may be conducted, for example, by introducing a gaseous form of a compound of Formula (IB) into a suitable reaction vessel or reactor. Preferably the vessel is comprised of materials which are resistant to corrosion, especially to the corrosive effects of hydrogen chloride (to the extent that such material is formed under the dehydrohalogenation conditions) as mentioned above. Preferably the vapor phase reaction vessel contains catalyst, for example a fixed or fluid catalyst bed, packed with a suitable dehydrohalogenation catalyst, with suitable means to heat the reaction mixture to about the desired reaction temperature. The reaction vessel may employ single or multiple tubes packed with a dehydrohalogenation catalyst. [0051] The compound of Formula (IB), preferably HCFC-244bb, may be introduced into the reactor either in pure form, partially purified form, or as portion or entirety of the reactor effluent from the preceding step. The compound of Formula (IB), such as HCFC-244bb, may optionally be fed with an inert gas diluent such as nitrogen, argon, or the like. In a preferred embodiment of the invention, the compound of Formula (IB), such as HCFC-244bb, is pre-vaporized or preheated prior to entering the reactor. Alternately, the compound of Formula (IB), such as HCFC-244bb, may be vaporized in whole or in part inside the reactor. [0052] While it is contemplated that a wide variety of reaction temperatures may be used, depending on relevant factors such as the catalyst being used and the most desired reaction product, it is generally preferred that the reaction temperature for the dehydrohalogenation step is from about 100° C. to about 800° C., more preferably from about 150 ° C. to about 600 ° C., and even more preferably from about 200 ° C. to about 550 ° C. [0053] In general it is also contemplated that a wide variety of reaction pressures may be used, depending again on relevant factors such as the specific catalyst being used and the most desired reaction product. The reaction pressure can be, for example, superatmospheric, atmospheric or under vacuum. The vacuum pressure can be from about 5 torr (0.0966 psig) to about 760 torr (14.69 psig). [0054] In certain embodiments, an inert diluent gas, such as nitrogen, may be used in combination with the other reactor feed(s). When such a diluent is used, it is generally preferred that the compound of Formula (I), preferably Formula (IB), comprise from about 50% to greater than 99% by weight based on the combined weight of diluent and Formula (I) compound. [0055] It is contemplated that the amount of catalyst use will vary depending on the particular parameters present in each embodiment. Contact time of the compound of Formula (IB), such as HCFC-244bb, with the catalyst in certain preferred embodiments ranges from about 0.5 seconds to about 120 seconds, however, longer or shorter times can be used. [0056] Preferably in such dehydrofluorination embodiments as described in this section, the conversion of the Formula (IB) compound is at least about 10%, more preferably at least about 20%, and even more preferably at least about 30%. Preferably in such embodiments, the selectivity to compound of Formula (II), preferably HFO-1234yf, is at least about 70%, more preferably at least about 85% and more preferably at least about 95%. [0057] In certain preferred embodiments, the process flow is in the down or up direction through a bed of the catalyst. It may also be advantageous to periodically regenerate the catalyst after prolonged use while in place in the reactor. Regeneration of the catalyst may be accomplished by any means known in the art, for example, by passing air or air diluted with nitrogen over the catalyst at temperatures of from about 100° C. to about 400° C., preferably from about 200° C. to about 375° C., for from about 0.5 hour to about 3 days. [0058] In general, the effluent from the dehydrohalogenation reaction step, including any intermediate effluents that may be present in multi-stage reactor arrangements, may be processed to achieve desired degrees of separation and/or other processing. For example, in embodiments in which the reactor effluent comprises a compound of Formula II, such as HFO-1234yf, the effluent will generally also include HCl and unreacted compound of the Formula (IB). Some portion or substantially all of these components of the reaction product may be recovered from the reaction mixture via any separation or purification method known in the art such as neutralization and distillation. It is expected that unreacted compound of the Formula (IB) could be recycled, completely or partially, to improve the overall yield of the desired CF 3 CF═CH 2 (HFO-1234yf). Optionally but preferably, hydrogen chloride is then recovered from the result of the dehydrochlorination reaction. Recovering of hydrogen chloride is preferably conducted by conventional distillation where it is removed from the distillate. [0059] Alternatively, HCl can be recovered or removed by using water or caustic scrubbers. When a water extractor is used HCl is removed as an aqueous solution. When caustic is used, HCl is just removed from system as a chloride salt in aqueous solution. [0060] In an alternate embodiment of the invention, dehydrohalogenation of HCFC-244bb can also be accomplished by reacting it with a strong caustic solution that includes, but is not limited to KOH, NaOH, Ca(OH) 2 and CaO at an elevated temperature. In this case, the strength of the caustic solution is preferably from about 2 wt % to about 100 wt %, more preferably from about 5 wt % to about 90 wt % and most preferably from about 10 wt % to about 80 wt %. The caustic:Formula (IB) mole ration, preferably the caustic:HCFC-244bb mole ratio, preferably ranges from about 1:1 to about 2:1; more preferably from about 1.1:1 to about 1.5:1 and even more preferably from about 1.2:1 to about 1.4:1. The reaction may be conducted at a temperature of from about 20° C. to about 100° C., more preferably from about 30° C. to about 90° C. and even more preferably from about 40° C. to about 80° C. As above, the reaction may be conducted at atmospheric pressure, super-atmospheric pressure or under vacuum. The vacuum pressure can be from about 5 torr (0.0966 psig) to about 760 torr (14.69 psig). In addition, a solvent or phase transfer catalyst such as Aliquat 336 may optionally be used to help dissolve the organic compounds in the caustic solution. This optional step may be conducted using solvents that are well known in the art for said purpose. Thereafter, the Formula (II) compound, preferably HFO-1234yf, may be recovered from the reaction product mixture comprised of unreacted starting materials and by-products by any means known in the art, such as by extraction and preferably distillation. In certain preferred embodiments, the mixture of HFO-1234yf and any by-products are passed through a distillation column. For example, the distillation may be preferably conducted in a standard distillation column at atmospheric pressure, super-atmospheric pressure or a vacuum. Preferably the pressure is less than about 300 psig, preferably less than about 150 psig and most preferably less than 100 psig. The pressure of the distillation column inherently determines the distillation operating temperature. [0061] Preferably in such dehydrofluorination embodiments as described in this section, the conversion of the Formula (IB) compound is at least about 60%, more preferably at least about 75%, and even more preferably at least about 90%. Preferably in such embodiments, the selectivity to compound of Formula (II), preferably HFO-1234yf, is at least about 70%, more preferably at least about 85% and more preferably at least about 95%. EXAMPLES [0062] Additional features of the present invention are provided in the following examples, which should not be construed as limiting the claims in any way. Example 1 Continuous Liquid Phase Preparation of CF 3 CFClCH 3 (HCFC-244bb) from CCl 2 ═CClCH 2 Cl [0063] A 1.5″ 1D×24″ long PFA-lined pipe was filled with 550 grams of antimony pentachloride liquid phase fluorination catalyst. This was heated to approximately 95° C., and then fluorinated with 5 moles of anhydrous hydrogen fluoride. Then a continuous feed of 1,1,2,3-tetrachloropropenewas begun, simultaneous with continuous feed of HF. These feeds were maintained in a mole ratio of HF to 1,1,2,3-TCP of about 17:1, with a residence time of about 1 second. The reactor was maintained at about 96° C. Volatiles from the run were collected in a dry ice cold trap, analyzed, and found to produce a nearly total conversion of the 1,1,2,3-tetrachloropropene, with selectivity of about 22% to 2-chloro-1, 1,1 ,2-tetrafluoropropane (244bb), and selectivity of about 33% to 2-chloro-3,3,3-trifluoropropene (1233xf), and selectivity of about 27% to precursor 2,3-dichloro-3,3-difluoropropene (1232xf) and selectivity of >12% to overchlorinated species 1223xd attributed to excess Cl 2 feed to the reactor to keep the catalyst active. EXAMPLE 2 Continuous Liquid Phase Preparation of CF 3 CFClCH 3 (HCFC-244bb) from CCl 2 ═CClCH 2 Cl [0064] Example 1 was repeated except 515 grams of antimony pentachloride was used, mole ratio of HF to 1,1,2,3-TCP is about 30:1, and the residence time was about 2.1 seconds, and the pressure in the reactor was allowed to build to about 14 psig. Volatiles from the run were collected in a dry ice cold trap, analyzed, and found to produce a nearly total conversion of the 1,1,2,3-tetrachloropropene, with selectivity of about 16.7% to 2-chloro-1, 1,1 ,2-tetrafluoropropane (244bb), and selectivity of about 33.5% to precursor 2-chloro-3,3,3-trifluoropropene (1233xf), and selectivity of about 34.6% to precursor 2,3-dichloro-3,3-difluoropropene (1232), and selectivity of >10.0% to overchlorinated species 1223xd attributed to excess Cl 2 feed to the reactor to keep the catalyst active. Example 3 Batch Liquid Phase Preparation of CF 3 CFClCH 3 (HCFC-244bb) from CCl 2 ═CClCH 2 Cl [0065] To a 1 Liter monel Parr reactor is added 83 grams of SbCl 5 and 300 grams of HF. After heating to 85° C., the HCl and noncondensibles are vented to a DIT. Then 50 grams of CCl 2 ═CClCH 2 Cl are quickly added. The mole % ratio of SbCl 5 to CCl 2 ═CClCH 2 Cl is 50/50. There is an immediate exotherm and the temperature rises to 97° C. almost instantaneously. The variac controlling the heater is turned off and the reaction held between 97 and 87° C. for an hour. The pressure rises to 400 psig and levels off. A vapor sample is taken into gas bags containing DI H 2 O (to absorb the HF and HCl prior to analysis). A GC of the gas bag sample shows 53.5 GC area % 244bb, 1,46 GC area % overfluorinated species HFC245cb, 6.6 GC area % overchlorinated species 1223xd along with 1233xf precursor, 1232xf precursor, and some C6 compounds that may be dimers. The conversion of CCl 2 ═CClCH 2 Cl on a GC area % basis is 100%. Example 4 Conversion of CF 3 CFClCH 3 (HCFC-244bb) to CF 3 CF═CH 2 in Continuous Gas-Phase [0066] This example illustrates the continuous vapor phase dehydrochlorination reaction of 2-chloro-1,1,1,2-tetrafluoropropane (244bb)→2,3,3,3-tetrafluoropropene (1234yf)+HCl. The dehydrochlorination catalyst is 10 wt % CsCl/90 wt % MgF 2 . [0067] Conversion of HCFC-244bb into HFO-1234yf was performed using Monel reactor (ID 2 inch, length 32 inch) equipped with a Monel preheater (ID 1 inch, length 32 inch) which was filled with Nickel mesh to enhance heat transfer. The reactor is filled with 2.0 L of pelletized 10 wt % CsCl/90 wt % MgF 2 dehydrochlorination catalyst. Nickel mesh is placed at the top and at the bottom of reactor to support the catalyst. Multi-point thermocouple is inserted at the center of the reactor. The catalyst is pretreated in dry N2 flow for 6 hours at the temperature of 480° C. Then the feed with the composition 95GC % 244bb/3.1GC % 1233xf/0.35GC % 245cb is introduced into the reactor at the rate of 1.0 lb/hr. The feed is vaporized prior entering the reactor preheater. The bottoms of the distillation column is discharged and recycled into the reactor. The feed rate is maintained constant at 1.0 lbs/hr and both temperature and pressure are varied. Temperature gradient throughout the reactor is within about 3-5° C. The productivity of the catalyst is estimated at 3-6 lbs/hr/ft 3 . The highest productivity is observed at 470° C. and 45 psig, and the lowest productivity is observed at 480° C. and 3 psig pressure. The reaction products are fed into the caustic scrubber to remove HCl by-product. Then the product stream is passed through a column filled with desiccant to remove residual moisture. Oil-less compressor was used to feed crude product into the distillation column that was maintained at 30-45 psig pressure. Distillation was performed in a continuous mode and the take-off rate was equal to the rate of production of HFO-1234yf in the reactor. The purity of distilled 1234yf is 99.9GC%+. GC analysis of the distillate shows presence of light impurities with a ppm level of heavy impurities. [0068] The following conversions and selectivities are achieved: 480° C. at 3 psig˜244bb conversion˜30%, Selectivity to 1234yf˜97% 480° C. at 20 psig˜244bb conversion˜47%, Selectivity to 1234yf˜96% 470° C. at 20 psig˜244bb conversion˜36%, Selectivity to 1234yf˜97% 470° C. at 45 psig˜244bb conversion˜53%, Selectivity to 1234yf˜96% 460° C. at 45 psig˜244bb conversion˜38%, Selectivity to 1234yf˜98% Reaction Data [0074] Conditions: Feed 95GC % 244bb/3.1GC % 1233xf/0.35GC % 245cb; 2.0 L of 10 wt % CsCl/90 wt % MgF 2 catalyst; 1.0 lb/hr feed rate. [0000] Time on-stream conversion Selectivity to Temperature Pressure (hrs.) of 244bb (%) 1234yf (%) (° C.) (psig) 0.25 93.30 82.42 484.30 3.00 0.80 67.61 90.38 489.00 3.90 1.43 47.78 94.14 479.80 3.50 2.27 31.98 97.34 479.80 3.40 3.32 29.36 97.70 478.80 3.80 4.32 26.24 97.56 478.70 2.80 5.23 28.45 97.88 480.30 2.90 6.20 30.53 98.01 480.30 3.20 6.80 30.91 98.13 478.40 3.30 7.37 28.36 97.88 478.80 2.90 7.93 29.01 97.84 479.30 3.10 8.48 29.95 97.91 478.30 3.30 9.05 26.61 96.76 479.60 2.70 9.62 27.98 96.12 476.80 2.90 10.20 28.84 96.66 480.20 3.00 10.70 29.70 97.16 480.50 3.10 11.22 29.30 97.62 480.30 3.30 11.72 30.47 97.65 480.70 3.30 12.25 29.57 97.59 480.30 3.30 12.75 29.83 97.92 480.00 3.50 13.27 30.10 98.23 479.60 2.80 13.78 28.73 97.02 480.10 2.80 14.28 29.54 97.31 480.80 2.90 14.80 29.95 98.05 479.80 2.90 15.30 29.71 97.98 480.60 3.00 15.80 30.50 98.14 480.80 2.90 16.32 30.68 97.96 481.50 3.10 16.83 32.21 97.79 482.50 3.10 17.35 30.37 97.68 478.00 3.20 17.85 27.67 97.18 479.20 3.30 18.40 28.06 96.50 477.50 3.20 18.95 27.84 96.58 478.20 3.40 19.50 28.85 96.66 482.30 3.40 20.18 32.52 97.55 480.00 3.40 20.87 29.15 97.47 480.10 3.20 22.90 64.16 97.20 478.90 17.40 23.65 47.32 96.23 477.80 17.50 24.32 47.80 96.81 478.60 17.00 25.00 47.45 96.83 479.40 16.90 26.02 47.10 96.84 479.50 18.50 26.78 46.99 97.34 478.60 20.00 27.38 48.61 97.45 478.80 20.00 28.22 47.00 97.41 477.80 20.00 28.93 48.53 96.40 480.00 20.00 29.63 46.61 96.10 477.70 20.00 30.23 49.28 96.14 480.80 20.00 30.83 44.30 96.11 477.70 20.00 31.45 48.53 96.18 479.50 20.00 32.05 45.03 97.45 477.70 20.00 32.72 48.94 97.09 480.10 20.00 33.30 45.10 96.24 478.00 20.00 33.83 46.72 96.25 479.70 20.00 34.37 49.04 96.21 479.30 20.00 34.90 46.86 96.34 477.80 20.00 35.42 41.57 97.52 474.60 20.00 35.95 38.83 97.44 469.40 20.00 36.48 31.20 97.45 468.40 20.00 37.02 34.86 96.45 470.10 20.00 37.55 35.41 96.44 470.20 20.00 38.07 37.17 97.71 469.90 20.00 38.63 36.72 97.31 471.10 20.00 39.15 36.66 97.68 470.00 20.00 39.67 37.41 97.85 470.80 20.00 40.20 36.43 97.86 469.40 20.00 40.73 36.10 97.98 469.20 20.00 41.27 35.34 97.97 470.50 20.00 42.05 37.63 96.08 472.00 20.00 42.57 38.60 97.20 470.30 20.00 43.12 57.72 96.75 469.60 45.00 43.65 53.72 95.42 467.10 45.00 44.17 51.28 94.83 468.70 45.00 44.68 51.60 96.39 467.50 45.00 45.20 52.52 96.36 469.80 45.00 45.72 53.43 96.65 468.90 45.00 46.77 51.14 95.44 468.50 45.00 48.15 53.38 97.23 470.70 45.00 49.32 54.53 97.21 470.90 45.00 50.88 51.94 97.21 469.40 45.00 52.35 39.24 97.70 459.60 45.00 53.75 39.15 97.19 459.30 45.00 55.03 38.45 97.63 458.30 45.00 56.57 37.19 97.61 457.50 45.00 57.85 37.44 97.88 458.90 45.00 58.93 38.18 97.91 458.80 45.00 59.98 37.98 98.04 460.10 45.00 61.05 39.77 97.43 463.00 45.00 62.10 42.11 97.92 462.20 45.00 63.20 41.11 97.74 459.10 45.00 64.27 39.64 98.05 460.60 45.00 65.32 40.98 97.70 461.40 45.00

Disclosed are processes for the production of fluorinated olefins, preferably adapted to commercialization of CF 3 CF═CH 2 (1234yf). In certain preferred embodiments the processes comprise first exposing a compound of Formula (IA) C(X) 2 ═CClC(X) 3   (IA) where each X is independently F, Cl or H, preferably CCl 2 ═CClCH 2 Cl, to one or more sets of reaction conditions, but preferably a substantially single set of reaction conditions, effective to produce at least one chlorofluoropropane, preferably in accordance with Formula (IB): CF 3 CClX′C(X′) 3   Formula (IB) where each X′ is independently F, Cl or H, and then exposing the compound of Formula (IB) to one or more sets of reaction conditions, but preferably a substantially single set of reaction conditions, effective to produce a compound of Formula (II) CF 3 CF═CHZ   (II) where Z is H, F, Cl, I or Br.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [0001] — CROSS REFERENCE TO RELATED APPLICATION [0002] — BACKGROUND OF THE INVENTION [0003] The present invention relates to a “patch-clamp” for investigating ion transport through cellular membranes and in particular to a patch-clamp system that may provide real-time tracing of ion channel activity with a bandwidth of up to 500 MHz. [0004] The lipid bilayers that make up cell membranes include ion channels that control the flow of ions into and out of cells. Certain ion channels open in response to signaling molecules including naturally occurring signaling molecules and drug molecules. In the development of therapeutic drugs it is necessary to determine the effect of the drug on ion channels either to avoid adverse effects or to create a positive therapeutic effect for the treatment of ion-channel related diseases. [0005] Analysis of the response of ion channels may be conducted with a so-called “patch-clamp”, traditionally a micropipette adhered to the surface of a cell by a slight suction. An electrical connection across the membrane of the cell is then made by one of a number of techniques, for example, by applying a sharp suction pulse to the pipette to open a hole in the cell wall. Measurement of small electrical changes across the cell membrane made by a miniature electrode inserted into or near the opening may then be used to deduce the flow of ions through the ion channels. The small amounts of electrical current involved in these measurements require an extremely high resistance seal between the pipette and the cell wall (a giga-ohm seal). [0006] Drug screening often requires making many ion-channel measurements. Accordingly the pipette having a single opening has been replaced with a plate having multiple small pores each of which may accept a cell. The plate array allows the parallel processing of multiple cells and may be more readily integrated into automated equipment. [0007] The sensitivity of measurements of small current flows through ion channels is significantly limited by the poor electrical characteristics of a bare electrode immersed in the aqueous medium inside or outside of the cell. As a result, rapid changes in ionic transport cannot be resolved in the time domain. SUMMARY OF THE INVENTION [0008] The present invention provides a high-frequency measurement of cell wall impedance changes due to ion channel activity. This differs from the typical “direct current” measurements of currents or voltages adopted in the prior art. By construction of a “tank circuit” incorporating the impedance of the cell membrane, changes in the resonance of this tank circuit may be used to accurately and quickly assess changes in the cell wall membrane. The high-frequency measurements allow electrodes to be formed as waveguides having far higher sensitivity and response rates than a bare electrode immersed in aqueous medium. [0009] Specifically the present invention provides a high frequency patch-clamp system using an electrically insulating support providing support region for holding a cellular membrane fixed with respect to the electrically insulating support. A first and second electrode on opposite sides of the support region, separated by the cellular membrane, are connected to circuitry providing a high-frequency signal across the first and second electrodes to determine changes of impedance across the cellular membrane from measurement of a change in electrical resonance. It is thus one object of at least one embodiment of the invention to employ an alternating current measurement technique to improve the sensitivity of ion channel measurements. It is another object of the invention to eliminate the need for manipulation of freestanding electrodes during the patch-clamp process. [0010] The support region may be an aperture through the electrically insulating support forming a lip on a first side of the aperture sized to accept a cellular membrane spanning the lip to form a giga-ohm seal with the electrically insulating support. [0011] It is thus an object of the invention to permit both AC and DC measurements, the latter employing the aperture. [0012] At least one of the first and second electrodes may be a waveguide attached to the electrically insulating support. [0013] It is thus an object of at least one embodiment of the invention to permit waveguide-like electrodes to provide a high-frequency response. [0014] The waveguide may be a strip-line. [0015] It is thus an object of at least one embodiment of the invention to provide a waveguide that may be readily fabricated on an insulating substrate. [0016] The circuitry may be a tank circuit incorporating a capacitance across the cellular membrane as a capacitance of the tank circuit. [0017] It is thus another object of the invention to provide a simple method of measuring impedance changes across a cellular membrane by monitoring a tank circuit resonance. [0018] The circuit includes at least one inductor in series with a capacitance. [0019] It is thus an object of at least one embodiment of the invention to provide a simple method of tuning the tank circuit for convenient measurement. [0020] The electrically insulating support may be a planar support and includes multiple apertures and lips each associated with a least one different second electrode for parallel measurements of cellular membranes at each of the multiple apertures. [0021] It is thus an object of at least one embodiment of the invention to provide a system suitable for high throughput measurement. [0022] The high-frequency signal may be in excess of one MHz. [0023] It is thus an object of at least one embodiment of the invention to permit measurement of extremely small impedance values. [0024] The impedance measured may be capacitance of the cellular membrane. [0025] It is thus an object of at least one embodiment of the invention to permit measurement of membrane capacitance in lieu of current or voltage transfer. [0026] Alternatively, the impedance measured may be resistance of the cellular membrane. [0027] It is thus an object of at least one embodiment of the invention to permit conventional current flow measurements as manifest in resistance. [0028] The first electrode may include two separated portions wherein the high-frequency signal is applied to one portion and monitored at the second portion. [0029] It is thus an object of at least one embodiment of the invention to permit either reflected or transmitted energy measurements or both to be made. [0030] These particular features and advantages may apply to only some embodiments falling within the claims and thus do not define the scope of the invention. BRIEF DESCRIPTION OF THE DRAWINGS [0031] FIG. 1 is an elevational cross-section of a prior art patch-clamp used for whole-cell recording; [0032] FIG. 2 is an elevational cross-section of a planar patch-clamp implementing the present invention allowing reflected or transmitted energy measurement; [0033] FIG. 3 is a schematic representation of a four-port tank circuit implemented using the patch-clamp of FIG. 2 ; [0034] FIG. 4 is the plot of a frequency resonance of the tank circuit of FIG. 3 , measurable in the present invention to determine capacitive or resistive impedance across the cell membrane; [0035] FIG. 5 is a perspective view of a multiport planar patch-clamp system using the present invention; [0036] FIG. 6 is a perspective view of an experimental apparatus implementing the present invention and [0037] FIG. 7 is a figure similar to that of FIG. 2 showing patch-clamp of the present invention applied to an intact cell membrane. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0038] Referring now to FIG. 1 , a prior art whole-cell patch-clamp 10 may employ a micropipette 12 having an aperture 14 to which a cell 16 is drawn by suction. The cell 16 may attach to the aperture 14 to create a giga-ohm seal to a lip 18 of that aperture. The cell 16 may otherwise be suspended in a liquid medium 20 providing an environment desired for a particular experiment. [0039] A sharp suction may be used to open a hole 21 in the cell wall of the cell 16 providing a low resistance path from the interior cytoplasm of the cell through a solution 24 to a microelectrode 26 within the micropipette 12 . The microelectrode 26 is typically a silver electrode coated with silver chloride for electrochemical stability. [0040] A sensitive current detector 30 may be connected between the microelectrode 26 and the liquid medium 20 to measure the passage of ions 32 through channels in the cell wall. The current detector 30 may provide for a voltage-clamping action, if desired, using a conventional voltage feedback circuit. Generally the bare microelectrode 26 provides electrical characteristics that severely limit the frequency of the measure of ionic currents. Further, only resistive impedance of the cell wall may be determined. [0041] Referring now to FIG. 2 , the present invention provides an insulating substrate 40 having an aperture 42 providing a lip 44 on one side of the substrate 40 that may be spanned by a cellular membrane 46 , for example, using the whole cell technique described above, or by a variety of other techniques well known in the art. A first electrode 48 may be positioned on one side of insulating substrate 40 and lip 44 while a second electrode 50 may be positioned on the other side of the insulating substrate 40 and lip 44 so that the first electrode 48 and second electrode 50 are on opposite sides of the cellular membrane 46 . Each of electrodes 48 and 50 may connect via terminals 52 and 54 to measurement circuitry 70 that will apply a high-frequency signal across electrodes 48 and 50 . [0042] An additional first electrode 48 ′ may also be positioned on the same side of the substrate 40 as electrode 48 to join thereto at the lip 44 but to extend to a second terminal 52 ′ at which transmission through the network may be measured as will be described. [0043] Electrode 50 may communicate with a solution 24 supporting the underside of the cellular membrane 46 and may for example be a silver/silver-chloride electrode of a type known in the art to minimize artifacts created by oxidation-reduction reactions at the metallic surface. As such, electrode 50 will be considered ground for the purpose of discussion. [0044] Electrodes 48 and 48 ′, where they contact the liquid medium 20 , may also be silver/silver-chloride material; however, in the preferred embodiment, for most of their lengths they may be insulated from the liquid medium 20 and, in this insulated portion, electrodes 48 and 48 ′ may preferably be a micro-strip-line having a controlled and well-defined electrical characteristic such as will provide a waveguide for high frequency transmission of electrical signals. Such micro-strip-lines may, for example, provide a conductor sandwiched between a well-characterized dielectric in turn sandwiched between ground planes to provide the necessary boundary conditions for waveguide propagation. The fabrication of the micro-strip-lines may be made by using well-known integrated circuit techniques or surface coating methods. [0045] Referring now to FIG. 3 , the device of FIG. 2 provides a four terminal network 56 in which terminal 52 and terminal 54 provide input terminals for application of a radiofrequency signal (for example, on the order of 100 MHz) and optional measurement of reflected energy, and terminal 52 ′ and 54 provide output terminals for measurement of transmitted energy. [0046] Terminal 52 may lead to electrode 48 through an inductor 60 being preferably a discreet inductor (for example, on the order of 20 nH) but possibly being formed by the length of electrode 48 itself which may be used to tune the tank circuit as will be described. Electrode 48 may in turn connect to ground ( 50 ) through a coupling capacitive 62 through the cellular membrane 46 and through a small resistance 64 representing the giga-ohm seal between the substrate 40 and the cellular membrane 46 and a parallel resistive component through the cellular membrane 46 . [0047] The junction of electrode 48 and capacitance 62 is also connected with electrode 48 which may then join with an inductor 66 which leads to terminal 54 . [0048] The circuit so described will be recognized as a tank circuit providing for series resonance between the inductors 60 and capacitance 62 . This resonance may be measured between terminals 52 and 54 as a reflected energy by measurement circuitry 70 or between terminals 52 ′ and 54 as a transmitted energy by measurement circuitry 70 ′. Such analyzers may, for example, provide for a frequency sweep measuring reflected or transmitted energy or may provide for parallel resonance measurements by broadband excitation and frequency analysis for using the fast Fourier transform or other similar technique. [0049] Referring now to FIG. 4 , the measured resonance 72 will show an amplitude (power, voltage, current) as a function of frequency having a peak at a center frequency 74 determined by the inductance 60 and capacitance 62 , and having a width 76 (Q=f/□f) determined by the resistance and dielectric losses 64 . As will be understood in the art, changes in the capacitance 62 will be reflected in movement of the center frequency 74 of the resonance 72 by a frequency shift whereas changes in the resistance 64 will be reflected in changes in the width 76 of the resonance 72 . [0050] Monitoring the resonance 72 will provide extremely high time resolution of ion transfer events through the cellular membrane 46 . Either or both of resistance and capacitance can be measured in this manner and it will be understood that a selection of component values of the inductors 60 and 66 and capacitance 62 (the latter which may be controlled through the selection of aperture size) can be used to accentuate one or the other of these measurements. [0051] Referring now to FIG. 5 , the substrate 40 may include multiple apertures 42 each having a dedicated set of electrodes 48 and 48 ′ to permit high throughput analysis of multiple cells at each of the apertures 42 . The inductors 60 and 66 may be discrete inductors placed on the surface of the substrate 40 using conventional electrical assembly techniques. [0052] Referring now to FIG. 6 , terminals 54 and 52 may be implemented through a standard high-frequency coaxial connector as may terminals 52 ′ and 54 . The impedance of the micro-strip-lines may be set to approximate a standard impedance of approximately 50 ohms to provide impedance matching with subsequent measurement circuitry 70 and with the tank circuit by proper selection of the component values and device dimensions and/or the use of matching networks (not shown). [0053] A chamber 77 of solution may be placed underneath the substrate 40 and connected to the electrodes 50 on the underside of substrate 40 . Liquid medium 20 may be limited in extent about the aperture 42 to limit its effect on the transmission of high-frequency signals through electrodes 48 and 48 ′. [0054] Referring now to FIG. 7 , if simultaneous DC and AC measurements through the cellular membrane 46 are not required (such as can be conducted using the system of FIG. 2 ), the present invention can be used with an intact cell 80 resting on the insulating substrate 40 without an aperture 42 (or with an optional aperture 42 only used to stabilize the cell 80 with a slight negative pressure). In this case, the measurement is an AC measurement of series capacitance 82 a and 82 b , the first from electrode 48 through the cellular membrane 46 into the cellular fluid 84 and the second from the cellular fluid 84 through the cellular membrane 46 to electrode 48 ′. As shown in this figure, normally the electrodes 48 will be covered with a dielectric layer 86 separating them from the liquid medium 20 to eliminate resistive mode conduction. [0055] It is specifically intended that the present invention not be limited to the embodiments and illustrations contained herein, but include modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims.

A patch-clamp system employs a high-frequency characterization of cell wall membranes. Changes in the frequency response of a tank circuit incorporating the cell wall membrane impedance provides highly sensitive and highly time-resolved measurements of ion channel activity.

BACKGROUND OF THE INVENTION The present invention relates generally to automatic gain control circuits and, more specifically, to automatic gain control circuits used in radio receivers having digital signal processing. Automatic gain control (AGC) systems for radio receivers are well-known. AGC systems typically include an amplitude detector, a filter or integrator in a feedback path, and one or more gain-controlled amplifiers operating at radio frequencies (RF) and/or intermediate frequencies (IF). The purpose of AGC is to maintain the output signal approximately at a constant level as the RF signal varies over a wide range. It is known that for an AGC loop to maintain constant bandwidth over a wide range of input signals, the amplifier control characteristic must be such that the gain is an exponential function of the control input, which is typically expressed as a voltage. In other words, the control input must have a logarithmic relationship to the desired gain. If this condition is met, a plot of gain versus control input will be a straight line, and the characteristic is described as log-linear. The log axis is commonly stated in decibels (dB), a scaled logarithmic unit. High frequency receivers having an AGC range ("dynamic range") of up to approximately 125 dB are known in the art. Conventional receivers have analog circuitry throughout for amplification, filtering, frequency translation (mixing), and detection (demodulation). Although an AGC circuit can easily be designed for such receivers, it is well-known that a design tradeoff exists between responsiveness and stability. To provide responsiveness, the receiver IF filter is commonly included within the AGC feedback loop. However, the presence of poles from the IF filter within the feedback loop inherently decreases stability. To avoid instability that would otherwise be introduced by the poles from the IF filter, the bandwidth of the AGC loop is commonly made very narrow. Newer receivers may use a combination of analog and digital signal processing to improve performance and manufacturability with maximal economy. Typically, such receivers have an analog input section for amplifying a weak RF input signal and converting it to a (lower) IF. The receiver digitizes the IF signal using an analog-to-digital (A/D) converter and performs the final frequency translation, filtering, and demodulation functions digitally. The relatively narrow dynamic range of economical A/D converters reduces the utility of conventional analog AGC circuits in receivers having both analog and digital signal processing because the dynamic range of the IF signal would need to be reduced to accommodate the A/D converter before performing AGC. To illustrate this point, it is desirable to provide at least 125 dB dynamic range in such receivers. Economical A/D converters generally have a maximum of 16 bits of resolution, yielding a maximum dynamic range of less than 98 dB between signal and a noise floor. It is a desirable design practice, however, to limit the dynamic range of the signal to about 65 dB to maintain a suitable signal-to-noise ratio (SNR). Therefore, it would be desirable in such a receiver to perform AGC while reducing the input signal dynamic range by about 60 dB in the analog input section to accommodate an economical 16 bit A/D converter. These problems and deficiencies are clearly felt in the art and are solved by the present invention in the manner described below. SUMMARY OF THE INVENTION The present invention comprises a front-end AGC loop and a back-end AGC loop with a signal feeding forward from the front-end loop to the back-end loop. The present invention may be used in a radio receiver that has an IF filter between the output of the front-end loop and the input of the back-end loop. A RF/IF input section consisting of analog circuitry receives a RF input signal, amplifies it, and converts it to a (lower frequency) IF signal. The gain of the RF/IF input section amplifier is controllable. An A/D converter digitizes the IF signal and provides the digitized signal to the front-end AGC loop, which produces a front-end feedback signal to control the gain of the analog RF/IF section amplifier. Thus, the front-end AGC loop automatically adjusts the amplitude of the IF signal to maintain it within the dynamic range of the A/D converter. The narrowest IF filter of the receiver may be between the two AGC loops, rather than within an AGC loop as is common in conventional receivers. The IF filter receives the gain-controlled output of the RF/IF section and provides a filtered IF signal to the back-end AGC loop, which produces a back-end feedback signal. The back-end feedback signal represents the total gain of the AGC system. The back-end AGC loop has a digital controllable-gain element, such as a multiplier. The front-end feedback signal is fed forward to the back-end AGC loop, which subtracts the front-end feedback signal from the back-end feedback signal. The resultant signal is provided to the digital controllable-gain element. The back-end AGC loop automatically adjusts the amplitude of the filtered IF signal to compensate for amplitude adjustments performed by the front-end AGC loop. Thus, the present invention maintains a substantially constant output signal level while preventing overloading of the A/D converter. Stability is maximized because neither AGC feedback loop includes a narrowband IF filter, which would otherwise introduce poles (in the S-plane) into the AGC loop. The back-end loop does not include any filter and, although the front-end loop may include a roofing filter for establishing an upper bound on receiver bandwidth, such a filter is wider than the widest IF filter bandwidth. The linkage between the front-end loop and the back-end loop is feedforward, not feedback, and thus has no effect on stability. The present invention eliminates the tradeoff between responsiveness and stability inherent in AGC circuits known in the art because signal leveling is postponed until after the IF filter. The present invention may also be used to provide an accurate indication of signal strength. If log-linear gain characteristics are maintained in both the front-end and back-end AGC loops, the back-end feedback signal, which represents the total gain of the AGC system, provides an accurate indication of signal strength over the entire dynamic range of the system. With the exception of the portions of the present invention that are specifically described as analog circuitry or as digital circuitry, any portion of the present invention may be constructed using any suitable hardware, software or combination thereof, including programmable signal processors and discrete digital logic circuitry with discrete integrated circuits, programmable logic circuits, or custom integrated circuits. The present invention accommodates dynamic range limitations of an A/D converter, avoids side effects from undesired signals, maximizes both stability and responsiveness, and can provide an accurate indication of signal strength. The foregoing, together with other features and advantages of the present invention, will become more apparent when referring to the following specification, claims, and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS For a more complete understanding of the present invention, reference is now made to the following detailed description of the embodiments illustrated in the accompanying drawings, wherein: FIG. 1 is a schematic block diagram of an AGC system with two AGC loops and a feedforward signal from one loop to the other; FIG. 2 is a schematic block diagram of the AGC system of FIG. 1, showing an embodiment of the AGC loops; and FIG. 3 illustrates a tailoring function of an AGC loop. DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in FIG. 1, a front-end AGC loop 10 comprises a front-end amplitude controlling means 12 for controlling the amplitude of an input signal 14 and a front-end control signal generating means 16 for producing a front-end amplitude control signal 18. Amplitude controlling means 12 provides a front-end gain-controlled signal 20, which is fed back to amplitude control signal generating means 16. An IF filter 22 also receives front-end gain-controlled signal 20 and provides a filtered gain-controlled signal 24. A back-end AGC loop 26 comprises a back-end amplitude controlling means 28 for controlling the amplitude of filtered gain-controlled signal 24 and a back-end control signal generating means 30 for producing a back-end amplitude control signal 32. Amplitude controlling means 28 provides a back-end gain-controlled signal 34, which is fed back to amplitude control signal generating means 30. Front-end amplitude control signal 18 is fed forward to back-end control signal generating means 30, which produces back-end amplitude control signal 32 in response to a combination of signal 34 and signal 18. A suitable front-end AGC loop 10 and back-end AGC loop 26 are illustrated in FIG. 2. An analog RF/IF section 38 receives input signal 14, amplifies the weak RF signal in accordance with front-end amplitude control signal 18, and converts it to a fixed (lower frequency) IF signal 40. RF/IF section 38 preferably includes a suitable fixed bandwidth "roofing" filter (not shown), such as a quartz crystal filter, for establishing an upper bound on receiver bandwidth. An A/D converter 42 digitizes IF signal 40 to provide front-end gain-controlled signal 20. Front-end gain-controlled signal 20 is provided both to IF filter 22 and to suitable means for estimating signal level, such as a front-end amplitude modulation (AM) detector 44. AM detector 44 may digitally sum the squares of several successive samples of signal 20, thereby providing a front-end signal level estimate signal 46 substantially equivalent to that of an analog square-law AM detector. A front-end summing means 48 subtracts signal level estimate signal 46 from a predetermined front-end reference signal 50 to produce a front-end amplitude error difference signal 52. Thus, amplitude error difference signal 52 is positive when signal level estimate 46 is less than reference signal 50, i.e., when the AGC system of the present invention is in "decay" mode, and amplitude error difference signal 52 is negative when signal level estimate 46 is greater than reference signal 50, i.e., when the AGC system of the present invention is in "attack" mode. The amplitude error is self-limiting in the positive direction because it can never be more positive than reference signal 50. A front-end tailoring means 54 applies a non-linear gain or "tailoring," as it is commonly referred to in the art, to amplitude error difference signal 52. The tailoring, shown in FIG. 3, provides: a low gain (K D ) for positive values of amplitude error difference signal 52, thereby providing a slow AGC decay; a high gain (K A ) for negative values of amplitude error difference signal 52 up to a predetermined limit, thereby providing a rapid AGC attack; and a fixed negative value for negative values of amplitude error difference signal beyond the predetermined limit. The limiting prevents extremely strong signals, suddenly applied, from reducing the gain so fast that the front-end AGC loop overshoots and throws the AGC system into a slow decay mode. A digital integrator 56 integrates the front-end tailored error signal 58. Because front-end amplitude control signal 18 is limited to a predetermined range, a front-end limiting means 60 provides minimum and maximum limits to integrator 56 that correspond to that range. The range is preferably between 60 and 65 dB to accommodate a 16 bit A/D converter 42. When no strong signal 58 is present, the output of integrator 56 will hold at the maximum gain value to maximize gain and minimize receiver noise figure. The result of the integration represents the desired front-end gain in logarithmic units. Although this result may be converted to analog form, scaled, and provided directly to RF/IF section 38, it is preferable to provide it to a front-end linearizer 62 to compensate for any non-linearities in the analog circuitry of RF/IF section 38. Linearizer 62 may comprise any suitable means, such as a polynomial calculation. A front-end D/A converter 64 converts the linearized control signal to analog form and provides it to RF/IF section 38. The combination of linearizer 62 and the gain control circuit of RF/IF section 38 have a control sensitivity (in dB per digital unit) that is predetermined and substantially constant. In the above-described embodiment, front-end AGC loop 10 thus comprises RF/IF section 38, A/D converter 42, AM detector 44, summing means 48, tailoring means 54, integrator 56, limiting means 60, linearizer 62, and D/A converter 64. IF filter 22 is between front-end AGC loop 10 and back-end AGC loop 26. IF filter 22 receives the output of A/D converter 42. IF filter 22 may be any suitable type of digital filter known in the art and, as will be recognized by those skilled in the art, may comprise multiple discrete and selectable filters as well as a frequency translator. The final filter of IF filter 22 may be substantially narrower in bandwidth than the roofing filter of RF/IF section 38. IF filter 22 is preferably either implemented in floating point arithmetic or carries enough bits of integer precision to accommodate the fairly wide dynamic range of the signal at this point in the system. IF filter 22 also has an inherent time delay, the value of which can easily be determined. IF filter 22 may provide output samples at a lower sample rate than that of A/D converter 42 and in complex form rather than real. A digital multiplier 66 multiplies filtered gain-controlled signal 24 by back-end amplitude control signal 32 to produce back-end gain-controlled signal 34. Back-end gain-controlled signal 34 may be provided in digital form directly to other digital signal processing devices (not shown) or may be provided to a demodulator 68 and a back-end D/A converter 70 to reproduce the transmitted audio frequency signal 72. In a manner similar to that described above with respect to front-end loop 10, back-end gain-controlled signal 34 is provided to a suitable means for estimating signal level, such as a back-end amplitude modulation (AM) detector 74. AM detector 74 may digitally sum the squares of several successive samples of signal 34, thereby providing a back-end signal level estimate signal 76 substantially equivalent to that of an analog square-law AM detector. If the signal is in quadrature (I,Q) baseband form, the amplitude detector may implement the sum of the squares of I and Q or the square-root thereof if the true amplitude is preferred. A back-end summing means 78 subtracts signal level estimate signal 76 from a predetermined back-end reference signal 80 to produce a back-end amplitude error difference signal 82. Thus, amplitude error difference signal 82 is positive when signal level estimate 76 is less than reference signal 80, i.e., when the AGC system of the present invention is in decay mode, and amplitude error difference signal 82 is negative when signal level estimate 46 is greater than reference signal 80, i.e., when the AGC system of the present invention is in attack mode. The amplitude error is self-limiting in the positive direction because it can never be more positive than reference signal 80. A back-end tailoring means 84 applies a non-linear tailoring in the same manner as discussed above with respect to front-end tailoring means 54. A back-end digital integrator 86 integrates the tailored back-end error signal 88. Because the total gain of the receiver is limited to a predetermined range, a back-end limiting means 90 provides minimum and maximum limits to integrator 86 that correspond to that range. The range may be manually selected by an operator according to the type of modulation to be received. The result of the back-end integration represents the desired total gain 92 of the receiver in logarithmic units. These units should have the same scale factor as the front-end gain values, discussed above. A total gain summing means 94 subtracts front-end amplitude control signal 18, which represents the front-end gain of the receiver, from total gain 92 to produce back-end amplitude control signal 96. A suitable digital delay line 96 having a delay equal to that of IF filter 22 may be interposed in signal 18 between front-end AGC loop 10 and back-end AGC loop 26 to equalize the delays. A back-end linearizer 98 performs an exponential function on back-end amplitude control signal 96 to provide the necessary log-linear relationship. A function of 2 x is preferred because that function may conveniently be implemented in digital logic. Using such a function as the scaling factor, the output of back-end linearizer 98 is log -linear with a sensitivity of 6.02 dB per digital unit (for a total gain span in the receiver of 21.25 digital units). Front-end linearizer 62 should provide the same sensitivity factor over the 60.2 dB analog control range, for a span of 10 digital units. In the above-described embodiment, back-end AGC loop 26 thus comprises multiplier 66, AM detector 74, summing means 78, tailoring means 84, integrator 86, limiting means 90, total gain summing means 94, and linearizer 98. In considering the operation of the present invention it should be noted that the bandwidth of front-end AGC loop 10 is wider than the bandwidth of back-end AGC loop 36 but narrower than the bandwidth of IF filter 22. If, while receiving a moderate strength desired signal within the bandpass of the selected filter of IF filter 22, a very strong signal were to appear within the bandwidth of the roofing filter but not IF filter 22, the present invention would cause several effects. Front-end AGC loop 10 would react quickly to keep the strong signal from overloading A/D converter 42, and both the undesired and desired signals would rapidly drop in amplitude at the output of A/D converter 42. In addition, in the output of IF filter 22 the desired signal amplitude would drop rapidly, but after the time delay created by filter 22. IF filter 22 filters out the undesired signal. Through feedforward, the rapidly changing gain of RF/IF section 38 is provided to back-end AGC loop 26 via digital delay line 96. Because the value of this delay equalizes the delay through IF filter 22, back-end AGC loop 26 increases its gain, which is represented by back-end amplitude control signal 32, at the proper rate and precise time required to compensate for the action taken in front-end AGC loop 10. For this compensation to be accurate, the sensitivities of AGC loops 10 and 26 should be matched over their entire operating range. This compensation prevents back-end gain-controlled signal 34 from dropping abruptly upon the appearance of the undesired signal and then recovering at a rate determined by the bandwidth of back-end AGC loop 26. It also prevents the reverse action when the undesired signal vanishes. At all times it minimizes stress in back-end AGC loop 26 caused by actions in front-end AGC loop 10. It should also be noted that total gain 92 accurately corresponds to the level of the received signal over the entire dynamic range if linearizers 62 and 98 produce an accurate log-linear relationship. Thus, total gain 92 could be provided directly to a signal strength readout (not shown). Obviously, other embodiments and modifications of the present invention will occur readily to those of ordinary skill in the art in view of these teachings. Therefore, this invention is to be limited only by the following claims, which include all such other embodiments and modifications when viewed in conjunction with the above specification and accompanying drawings.

Two automatic gain control (AGC) loops are connected by a feedforward signal. An intermediate frequency (IF) filter may be located between the output of the front-end loop and the input of the back-end loop. Stability and responsiveness are improved because neither AGC loop includes a narrowband filter. The front-end loop may include an analog gain-controlled element, but the remainder of the invention may be implemented digitally. The front-end loop prevents overloading of the A/D converter that feeds the gain-controlled signal to the remainder of the invention, and the back-end loop compensates for actions taken in the front-end loop.

BACKGROUND [0001] Alternating Current (AC) power control provides a unique set of challenges to those working in the field. There are few solid state electrical devices, such as thyristors and triacs, that will allow AC power to be controlled directly. For both thyristor and triacs the switching times are comparatively long. These long switching times typically limit these devices to low frequency applications, typically AC frequencies of 50-60 Hz. Additionally, full wave rectification to convert AC to direct current (DC), to facilitate work with DC, can result in, among other things, undesirable current harmonics and high frequency conducted emissions that, if not filtered, result in unacceptable noise going back to the power company on the AC power supply lines. BRIEF DESCRIPTION OF THE DRAWINGS [0002] Embodiments of the present invention will be described referencing the accompanying drawings in which like references denote similar elements, and in which: [0003] FIG. 1 illustrates an AC MOSFET switch, including anti-parallel diodes, in accordance with one embodiment. [0004] FIG. 2 illustrates a more detailed look at an AC MOSFET switch, including intrinsic parasitic diodes of the MOSFETs, in accordance with one embodiment. [0005] FIG. 3 illustrates current that is delivered to a load when one embodiment of the AC MOSFET switch is utilized to control current. [0006] FIGS. 4A-4C illustrate a power filter and its effects on the current drawn by a load driven by an AC MOSFET switch, in accordance with one embodiment. [0007] FIG. 5 illustrates an AC MOSFET switch design including a snubbing device, in accordance with one embodiment. [0008] FIG. 6 illustrates a single IC device containing two NMOS type MOSFET devices of an AC MOSFET switch, in accordance with one embodiment. DETAILED DESCRIPTION OF EMBODIMENTS [0009] Although specific embodiments will be illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a wide variety of alternate and/or equivalent implementations may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. This application is intended to cover any adaptations or variations of the embodiments discussed herein. Therefore, it is manifestly intended that this invention be limited only by the claims. [0010] The following discussion is presented in the context of MOSFET devices. It is understood that the principles described herein may apply to other transistor devices. [0011] Refer now to FIG. 1 wherein an AC MOSFET switch 110 , including anti-parallel diodes 112 114 , is illustrated, in accordance with one embodiment. For the MOSFETs 142 144 illustrated, the sources of the MOSFET devices are coupled at junction 102 . In one embodiment, MOSFETs 142 144 are power MOSFETs. In addition, the gates are electrically coupled at junction 104 . These couplings are to facilitate the operation of the two MOSFETs 142 144 as a single AC MOSFET switch. Thus, by applying a gate to source voltage, V GS , greater than the threshold voltage, V TH , to the two MOSFETs 142 144 , both MOSFETs conduct current 120 . [0012] Also illustrated in FIG. 1 are two diodes 112 114 . These diodes 112 114 , which may be parasitic or explicit, are anti-parallel to their respective MOSFETs. As described in further detail below, these diodes 112 114 may be utilized to bypass the intrinsic anti-parallel diodes of the MOSFETs. Thus, as illustrated, the anodes of the diodes 112 114 are coupled to the sources of the diodes' respective MOSFET and the cathodes are coupled to the respective drains. [0013] FIG. 1 also illustrates the AC MOSFET switch in use in controlling power to a load. As previously mentioned, AC MOSFET switch 110 comprises two MOSFETs 142 144 . AC MOSFET switch 110 controls current 120 through load 130 . This may be accomplished by switch control circuit 140 which applies the gate-source voltages for the two MOSFETs 142 144 forming the AC MOSFET switch 110 . In the embodiment illustrated, charge pump biasing circuit 150 supplies current to switch control circuit 140 from line (L) 172 and neutral (N) 174 connections of the AC power source. [0014] FIG. 2 illustrates a more detailed look at an AC MOSFET switch, utilizing P type MOSFETs, including intrinsic parasitic diodes 232 234 of the MOSFETs 242 244 , in accordance with one embodiment. Also illustrated are antiparallel diodes 212 214 which may be utilized to bypass the intrinsic anti-parallel diodes 232 234 of the MOSFETs. Note that the sources of both MOSFETs 242 244 are coupled 204 to each other. In addition, the gates of both MOSFETs 242 244 are coupled 206 to each other. When a voltage, V SG 280 less than a threshold voltage V TH is applied, the MOSFETs 242 244 will be “turned-off” and the internal reverse biased PN junctions will substantially prevent current from flowing through the MOSFETs. [0015] When a voltage, V SG 280 greater than a threshold voltage V TH is applied to the common sources and gates of MOSFETs 242 244 are turned on to facilitate the flow of current through the AC MOSFET switch. Note that current will flow in the reverse direction in MOSFET 242 or 244 depending on the polarity of the AC voltage source. That is, in the reverse direction as is normally used in DC circuits, that is drain to source in an N type MOSFET or source to drain in a P type MOSFET. The reverse current flow causes no problem as the MOSFET transistor is truly a bidirectional device, that is, current may flow from drain to source or source to drain once the proper gate voltage is applied and the conductive channel forms. Normally, during reverse polarity across the source/drain of a MOSFET, an internal PN junction, represented by parasitic diodes 234 and 232 in FIG. 2 , will eventually turn on allowing current 271 to flow. Note that parasitic diodes 234 and 232 are not separate from the MOSFET 244 and 242 ; e.g. parasitic diode 234 is a PN junction that is part of the structure of transistor 244 . Once the gate voltage is removed the parasitic diode conducts during reverse current flow which makes a single MOSFET unsuitable for the control of alternating current 271 273 . The common source configuration of MOSFET 242 and 244 of FIG. 2 results in one of the parasitic diodes in a reverse biased state which substantially prevents current flow through the parasitic diodes 232 234 when the MOSFETs are in either the conducting or nonconducting states. [0016] Referring again to FIG. 1 , switch control circuit 140 and charge pump circuitry 150 are utilized to provide control for the application of the voltage to the gates of MOSFETs 142 144 . In the embodiment illustrated, switch control circuit 140 may be an externally controlled pulse width modulation circuit. In the embodiment illustrated, charge pump 150 utilizes the AC line to power the pulse width modulation circuitry. In addition, the frequency of the modulated control signal may be fixed, whereas the duty cycle of the modulation, as described below, is utilized to determine the power to be delivered to the load 130 . In an alternative embodiment the gate and source of the AC MOSFET may be driven by a circuit which has a minimum conduction time combined with a variable frequency to determine the power to be delivered to the load 130 . [0017] FIG. 3 illustrates current that is delivered to a load when one embodiment of the AC MOSFET switch is utilized to control current. For example, as discussed above with respect to FIG. 1 , the switch control circuit 140 may be a pulse width modulation circuit. In such a case, the power delivered to the load 130 can be controlled by changing the duty cycle of the pulse control signal. FIG. 3 illustrates an example input voltage 310 from the line and neutral. Illustrated also, in the dark shaded regions 320 , are the periods where the AC MOSFET switch 110 is switched on to allow current to flow through the load 130 . The voltage 310 and current 320 are normalized so that they share a common envelope. Thus, in the illustrated embodiment, a 50% duty cycle signal driving the gate to source voltage will result in an effective power of one half the total power available being delivered the load. By utilizing a pulse width modulation technique, the level of power delivered to the load can be adjusted by controlling the width of the pulses generated by the pulse width modulation of the switch control circuit. The equation governing the power transfer to the load is: Pavg = Vrms 2 R · d . Where V rms is the Root Mean Square (rms) voltage of the AC power source, R is the resistance of the load and d is the duty ratio of the pulse width modulator driving the AC MOSFET. By inspection of this equation, the power transferred to the load is a linear function of the duty ratio of the pulse width modulator. The load is at zero power when the duty ratio is zero and at maximum power when the duty ratio is 1. [0018] In an alternative embodiment in which the gate and source of the AC MOSFET switch are driven by a circuit which has a minimum conduction time combined with a Variable Frequency Oscillator (VFO) the power delivered to the load 130 is determined by P=V 2 ÷R×f×T min Where V is the rms voltage of the AC power source, R is the resistance of the load, f the frequency of the VFO driving the AC MOSFET and T min the minimum conduction time allowed. By inspection, this equation shows that the power transferred to the load is a linear function of the frequency of the VFO. The load is at zero power when the VFO frequency is 0 and at maximum power when the period of the frequency of the VFO is equal to or less than the minimum allowed conduction time T min . [0019] The above examples operate to facilitate the switching of the alternating current at relatively higher frequencies. There are advantages to switching the current at relatively higher frequencies. Switching frequencies out of the audio range (e.g. greater than 20 KHz) can be utilized to reduce human factor issues associated with audible switching noise. Another advantage of operation at higher frequencies may be a reduction in switching and conduction losses. Implementations operating at significantly lower frequencies spend more time in the linear region of operation. Spending more time in the linear region during switching may dissipate significant amounts of additional energy in the form of heat as relatively slow transitions are made through this linear region. In addition, because of the relatively low voltage drops associated with the disclosed switching of alternating current, less energy is dissipated from the product of the current flowing across the voltage drops of the devices. In addition, the AC MOSFET switching circuit above does not introduce significant harmonics into the alternating current. This can reduce costs associated with filtering these harmonics to meet international regulatory requirements. [0020] FIG. 4A illustrates input circuitry for an AC MOSFET switch, in accordance with one embodiment. Illustrated is a filter stage 410 to provides a high frequency short to ground to any transients or conducted emissions that occur across the inputs. Illustrated also is a filtering stage 420 to provide smoothing of the alternating current drawn by the load 430 . The effect of this filter is to smooth the harmonic rich current drawn by the pulse width modulated, or VFO driven load, such that the power source experiences a continuous current flow with virtually no harmonic current content. [0021] In the embodiment, switch control circuit 450 switches the current 472 delivered to the load as illustrated in FIG. 4B . During times of switching, assuming a purely resistive load, the current 472 through the load 430 will follow the line voltage provided, that is, it will be in phase. When the switch is turned off, the current delivered to the load will drop to zero 474 . Thus, as can be seen there will be dramatic shifts or steps in the current drawn by the load as the switch turns on and off. These step changes in the current represent unwanted current harmonics placed on the AC power source which may exceed regulatory limits. To solve this problem, filtering stage 420 is added to the circuit. FIG. 4C illustrates the current drawn from the AC power source at the line and neutral connections by the switched load as a result of the filtering stage 420 . When the switch is turned off, the filtering stage 420 smoothes current 476 drawn by the load 430 . In the case in which the switch is driven by a pulse width modulator, the total instantaneous current drawn by the circuit may be the sum of the fundamental current and the instantaneous value of the ripple current. This instantaneous current may be expressed as i L ⁡ ( t ) = V · d R · sin ⁡ ( 2 · π · f o · t ) + π 2 4 · ( 1 - d ) · ( f c f s ) 2 · V · d R · sin ⁡ ( 2 · π · f o · t ) · sin ⁡ ( 2 · π · f s · t ) . where f C is the resonant frequency of filtering stage 420 , f S is the switch frequency of the pulse width modulator, f O is the frequency of the AC power source, d is the duty cycle of the pulse width modulator, V is the peak source voltage, and R is the load resistance 430 . Under direct examination of this equation it is noted that, as the switch frequency of the pulse width modulator is increased, the resultant alternating current waveform at the Line and Neutral connections smoothes dramatically. [0022] FIG. 5 illustrates an AC MOSFET switch design including a snubbing device 580 , in accordance with one embodiment. Snubbing device 580 is utilized for dissipating energy stored in the circuit. Stored energy in a circuit exists due to various factors associated with the circuit such as: parasitic inductance associated with the wiring providing the AC current, parasitic inductance in the components leads, and inductance in the load itself. Snubber designs are designed to capture a portion of the stored energy in a circuit, when the circuit is switched off. These snubber designs are to reduce, among other things, the resonance of the circuit. However, these snubber designs are not engineered to dissipate all the energy; they are simply designed to dissipate enough energy to reduce resonance and the resulting resonant “over” voltages that may otherwise occur. [0023] To dissipate all the energy in the circuit, a significantly larged sized capacitor 573 may be used in snubber 580 design. It is desirable to have the resistance 577 approximately match the resistance in the load 530 . Thus, if the load resistance is approximately 20 ohms, then the resistance of the snubber should be selected to be about 20 ohms. In addition, the stored inductance 575 for a typical circuit driving the AC MOSFET switch has been measured at approximately 100 nanoHenries. In some snubber designs, a capacitor capable of capturing about ⅕ of the energy stored in the inductive parasitics may be utilized. As mentioned, this capacitor size is utilized to simply avoid resonance of the circuit. However, the remaining energy is dissipated via heat in the switching element or as Radio Frequency (RF) emissions. To avoid this heat or RF emissions, a larger snubber circuit may be utilized. [0024] In order to have the snubber dissipate substantially all the stored energy of the circuit, the energy dissipated by the snubber should equal the energy stored due to the inductance of the circuit. Thus, ½ LI 2 =½ CV 2 , where I=V/R ½ L ( V/R ) 2 =½ CV 2 Solving for C we find that: C=L/R 2 Thus, the capacitor used is directly related to the value of the parasitic inductance. [0025] Dissipating heat may be undesirable as it may result in damage to the circuit. A solution to this may be to include a heat sink. However, the addition of the heat sink may add cost to the design. In addition, generation of RF emissions may be undesirable as it may result in poor classification during RF certification proceedings for the device containing the AC MOSFET switch. To protect from RF emissions, a shield for the RF emissions may be provided. Again, however, the addition of a shield may add cost to the design. [0026] Thus, in one embodiment, the capacitor that is part of the snubber illustrated in FIG. 5 is designed to capture substantially all of the stored energy in the circuit associated with the AC MOSFET switch. In this manner, the design of RF shield and the design of any heat dissipating devices may be reduced. [0027] FIG. 6 illustrates a single integrated circuit (IC) device 600 containing two NMOS type MOSFET devices of an AC MOSFET switch, in accordance with one embodiment. In an alternative embodiment, two PMOS type MOSFET devices may be utilized in the construction of an AC MOSFET switch. Recall that the two sources from the two MOSFETs are logically coupled to each other in the AC MOSFET switch. By fabricating the two MOSFETs in a single package on an IC, the two MOSFETs may share a common source region 610 on the IC. In the embodiment illustrated in FIG. 6 , a common source region 610 is implanted into the die containing the AC MOSFET switch. The sharing of the common source region 610 may allow the use of a single source lead emanating from the package containing the two MOSFETs of AC MOSFET switch. This, in turn, may result in decreased conduction resistance due to the elimination of one source lead and the source lead's associated wire bonding parasitics, such as ohmic resistance from the die to a package lead. For example, in one embodiment, the elimination of one of the source leads may reduce the impedance by 70 milliohms, corresponding to the impedance associated with one of the leads to the AC MOSFET switch. [0028] 70 milliohms may be a substantial portion of the overall resistance associated with the AC MOSFET switch. For example, assume an R DSON of 100 milliohms for each MOSFET in the AC MOSFET switch. Thus, with a 70 milliohm resistance for each lead for the source and drain, the overall path impedance across the source and drain is 240 milliohms. Two discrete series devices have an effective resistance through the AC MOSFET switch of 480 milliohms. Recall that the external source lead in the AC MOSFET is used for the application of gate bias and as a conduction path for certain types of snubber applications during switch turn off. By design the external source connection 610 has very low current flow and does not introduce series resistance to the AC MOSFET switch when the switch is conducting. This fact allows the conduction resistance of the AC MOSFET switch to be reduced by 140 milliohms, or a reduction in effective resistance 30% by using a common source region on the die of the AC MOSFET and the elimination of one lead. Since the power dissipated is directly related to the resistance, this results in a 15% reduction in power loss, for the embodiment described. Fabrication of the AC MOSFET switch on a single die also allows one of the gate terminals of the discrete implementation to be eliminated. The result of the common source region and eliminated gate terminal is a four pin device with two high current drain connections and two lower current gate and source connections. One pin of the four pin device is coupled to each of the gates of the two MOSFETs. Another pin is coupled to the common source region, and each of the two remaining pins are coupled to a different one of the drains. [0029] Thus, embodiments of an AC MOSFET switch design have been disclosed. This design generally allows for faster operation of the AC MOSFET switch to, among other things, allow operation significantly above the audio frequency spectrum (e.g. greater than 20 kHz). The AC MOSFET switch operation generally utilizes higher frequencies which, in turn, allows the device to be used in a broad range of AC power control, thus reducing the use of rectification and the resulting induction of harmonics to the power line. These advantages reduce the use of expensive filtering and allow for better operation in environments containing persons such as the home or office environment. The designs may also allow for single IC design of the AC MOSFET switch in many applications. This may reduce the number terminal thus reducing loss due to lead resistance.

An alternating current (AC) switching circuit comprises a first Field Effect Transistor (FET) having a first source, a first gate and a first drain and a second FET having a second drain, a second source coupled to the first source and a second gate coupled to the first gate. The AC switching circuit also comprises a first diode coupled to the first source and first drain and a second diode coupled to the second source and second drain.

RELATED APPLICATION This application is a continuation-in-part of application Serial No. 432,006, filed January 9, 1974, now abandoned. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to glass compositions suitable for strengthening by ion exchange and particularly relates to the strengthening of SiO 2 --Na 2 O--Al 2 O 3 --ZrO 2 glasses by potassium ion exchange. 2. Brief description of the Prior Art U.S. Pat. Nos. 3,485,702 and 3,752,729, both to Mochel, deal with an improved glass composition of the SiO 2 --ZrO 2 --Al 2 O 3 --alkali metal oxide systems for chemical strengthening. These references disclose that the incorporation of 5 to 25 percent, preferably 10 to 25 percent by weight of ZrO 2 in the glass composition results in deep ion exchange penetrations with resultantly high compressive stresses in relatively short periods of time. Unfortunately, these high ZrO 2 containing glasses are not compatible with conventional float and updraw forming methods because of high melting and forming temperatures and unfavorable liquidus temperature-viscosity relationships. U.S. Pat. No. 3,772,135 to Hara et al. discloses glass compositions for chemical strengthening that represent some improvement in temperature-viscosity relationships, but still exhibit undesirably high melting temperatures, and disadvantageously limit the ZrO 2 content to low levels or eliminate it completely. The liquidus is defined as the temperature at which devitrification or uncontrolled crystallization of the glass first appears as the temperature is lowered. At temperatures slightly below the liquidus, devitrification occurs, sometimes at a relatively rapid rate, and if uncontrolled could ruin the flat glass sheets, severely curtailing production yields. Somewhat related to liquidus and a problem of devitrificaton is the working range of the glass. The working range is defined for the purposes of this invention as the temperature interval between the glass-forming temperature which is usually taken as the glass temperature when the log of the viscosity of the glass is equal to 4 and the liquidus temperature. Melting and forming temperatures are defined for the purposes of this invention as the temperature at which the viscosity of the glass is equal to about 100 poises and 10,000 poises, respectively. In flat glass manufacturing, it is desirable for a glass to have low melting and forming temperatures to enable easy working of the glass, to conserve fuel and to prevent excessive thermal deterioration of the glass melting and forming equipment. Further, in flat glass manufacturing, particularly by the float and the updraw process, it is desirable that the glass have a low liquidus temperature and a wide working range. A low liquidus temperature insures against devitrification in cold spots of the furnace and a wide working range insures against devitrification. In the glass forming area of the furnace. In the case of manufacturing glass by the updraw process such as the Pittsburgh Process by liquidus temperature of the glass is about 1840° F. and the working range of the glass is about 70° F. Commercial float glass has a liquidus temperature of about 1830° F. and a working range of about 45° F. ZrO 2 has a pronounced effect on the liquidus temperature and the working range in the family of glasses disclosed in the above-mentioned Mochel patents. With ZrO 2 concentrations above about 51/4 percent, liquidus temperatures begin to increase quite rapidly with increasing ZrO 2 . With ZrO 2 concentrations above 51/2 percent by weight, a serious problem develops with respect to float or updraw forming. With these particular glasses, a narrow working range, and in many instances a negative working range, is established, that is, the liquidus temperature is higher than glass-forming temperature and devitrification occurs rather quickly. This could have disastrous effects if such glasses were formed on a commercial scale by the updraw or float methods. In addition, many of the glasses disclosed in the above-mentioned patents have high melting and forming temperatures making them undesirable for commercial flat glass manufacturing. It is apparent from the above that it would be desirable to provide a family of glass compositions of the SiO 2 --Na 2 O--AL 2 O 3 --ZrO 2 system for use in chemical strengthening which would be more suitable for forming by the updraw and float processes than those SiO 2 --Na 2 O--Al 2 O 3 --ZrO 2 systems disclosed in the prior art. More particularly, it would be desirable to provide a family of glass compositions for ion exchange which have lower melting and forming temperatures and a wider working range than those glass compositions of the SiO 2 --Na 2 O--Al 2 O 3 --ZrO 2 systems disclosed in the prior art for ion exchange. Besides the references mentioned above, other relevant prior art consists of U.S. Pat. Nos. 3,790,430 to Mochel; 3,498,773 to Grubb et al.; 3,524,737 to Doyle et al.; 3,433,611 to Saunders et al.; 3,416,936 to Sproul, Jr.; 2,252,466 to Hanlein; 3,499,776 to Baak et al.; 2,877,124 to Welsch; 2,978,341 to Bastian et al.; 3,357,876 to Rinehart and British Pat. No. 1,115,972. SUMMARY OF THE INVENTION In accordance with this invention, there is provided an improved method for strengthening an alkali metal oxide aluminosilicate glass article in which the alkali metal ions in the surface of the glass article are replaced by larger monovalent metal ions. The improved method is carried out by bringing the surface of the glass article into contact with the source of the larger monovalent metal ions by retaining the glass at an elevated temperature, usually around the glass strain point, to place a compression layer in a surface of the glass article. The improvement of the invention comprises forming the article to be strengthened from an alkali metal oxide-zirconia-aluminosilicate glass consisting essentially of by weight on the oxide basis of about: ______________________________________ Percent by WeightComponent Broad Range Preferred Range______________________________________SiO.sub.2 50-58 52-57Na.sub.2 O 8-23 10-19K.sub.2 O 0-15 0-10Na.sub.2 O + K.sub.2 O 13-25 17-23Al.sub.2 O.sub.3 7-17 9-13ZrO.sub.2 1-4.5 2-4.5Al.sub.2 O.sub.3 + ZrO.sub.2 10-21 12-17CaO 0-10 0MgO 0-6.5 4-6CaO + MgO 2.5-10 4-6TiO.sub.2 0-7 1-6TiO.sub.2 + (MgO + CaO) 4-14 5-12______________________________________ When the glass components are maintained within the above prescribed ranges, the glasses have low melting and forming temperatures and have lower liquidus temperatures and greater working ranges than comparable glass compositions containing greater than 5 percent by weight ZrO 2 . In fact, with many of the glass compositions of the present invention, devitrification generally occurs so slowly that it is difficult to detect any evidence of devitrification regardless of temperature. At the same time, the glass compositions of the present invention exhibit desirable ion exchange characteristics for purposes of chemical strengthening. BRIEF DESCRIPTION OF THE DRAWING The FIGURE is a graph of viscosity versus temperature plots for various glasses of the invention and glasses of the prior art. DETAILED DESCRIPTION EXAMPLES 1 - 2 The preferred embodiments of the invention employ glasses having the following calculated glass compositions which can be made by conventional melting and forming techniques. ______________________________________ Percent by Weight on the Oxide BasisComponent Example 1 Example 2______________________________________SiO.sub.2 56.0 54.5Na.sub.2 O 18.0 18.0Al.sub.2 O.sub.3 12.0 10.0MgO 4.5 5.0K.sub.2 O 3.0 3.0ZrO.sub.2 4.5 4.5TiO.sub.2 2.0 5.0______________________________________ The glass of Example 2 is a better melting glass, i.e., melts at lower temperatures and has a lower viscosity versus temperature curve, than the glass of Example 1. However, the glass of Example 1 has better optical properties, i.e., is less colored and has slightly better radiant energy transmitting properties. The glasses of the present invention such as set forth above in the preferred embodiments, have extremely good melting and forming properties, being more akin to commercial sheet and float glass than to an ion exchange glass. The FIGURE compares the viscosity-temperature relation of the above glasses with similar relations for commercial sheet glass sold under the trademark PENNVERNON (registered trademark of PPG Industries, Inc.), commercial float glass, for a commercially available ion exchange glass, and for glasses numbered 1, 2, 3 and 10 in Table I of U.S. Pat. 3,485,702, in the viscosity range of 10 2 .0 to 10 5 .0 poises. The calculated composition of PENNVERNON sheet glass is as follows: SiO 2 , 73 percent; Na 2 O, 13.3 percent; CaO, 8.2 percent; MgO, 3.7 percent; Al 2 O 3 , 1.2 percent; Fe 2 O 3 , 0.1 percent; K 2 O, 0.2 percent; SO 3 , 0.2 percent. The commercial float glass had the following actual composition: 73.06 percent SiO 2 , 13.64 percent Na 2 O, 0.03 percent K 2 O, 8.86 percent CaO, 3.86 percent MgO, 0.12 percent Al 2 O 3 , 0.30 percent SO 3 , and 0.13 percent Fe 2 O 3 . The actual composition of the commercially available ion exchange glass is as follows: 61.98 percent SiO 2 , 13.08 percent Na 2 O, 3.27 percent K 2 O, 3.21 percent MgO, 17.56 percent Al 2 O 3 , 0.064 percent Fe 2 O 3 , 0.64 percent TiO 2 , 0.04 percent Cl - , 0.14 percent CaO, 0.07 percent As 2 O 5 , and 0.04 percent SO 3 . The calculated compositions for the glasses numbered 1, 2, 3 and 10 in Table I of U.S. Pat. No. 3,485,702 are as follows: ______________________________________ Percent by WeightComponent 1 2 3 10______________________________________SiO.sub.2 66 60 59 52Al.sub.2 O.sub.3 10 10 10 10ZrO.sub.2 5 11 12 15Na.sub.2 O 16 16 16 16K.sub.2 O 3 3 3 7______________________________________ U.s. pat. No. 3,772,135 (Hara et al.) discloses only one specific example of a ZrO 2 -containing glass (Example 5), which has the following composition by weight: 62% SiO 2 , 10% Al 2 O 3 , 1% ZrO 2 , 1% TiO 2 , 9% Na 2 O, 9% K 2 O, 4% MgO, and 4% ZnO. The tremendous melting advantage of the glasses of the present invention such as specified above in Examples 1 and 2 over the commercially available ion exchange glass and the ion exchange glass of the prior art is obvious. The melting temperatures or the temperatures corresponding to 100 poises (log 10 of the viscosity in poises is equal to 2.0) are as follows: ______________________________________ Temperature at viscosityGlass of 100 poises ° F.______________________________________Example 1 2700Example 2 2575Commercial Sheet Glass 2705Commercial Float Glass 2622Commercial Ion ExchangeGlass 3185 (estimated value)U.S. Patent 3,485,702 (Mochel)Example 1 3022Example 2 2955Example 3 2953Example 10 2788U.S. Patent 3,772,135 (Hara et al)Example 5 2889______________________________________ The glass-forming temperature is conventionally taken as the temperature at a viscosity level of about 10,000 poises (log 10 of the viscosity in poises is equal to 4.0). Thus, as indicated by the viscosity curves of FIG. 1, the forming temperature of the glass of Example 1 will be about 75° to 80° F. higher than the drawing temperature for commercial sheet glass and for commercial float glass. The glass of Example 2 had a forming temperature approximately equal to both commercial float and commercial sheet glass. The high temperature viscosity properties of the commercial sheet and float glass and the glasses of Examples 1 and 2 are presented in the table below. These high temperature viscosity properties, unless otherewise indicated, were measured according to the procedure described in "Measurements of Absolute Viscosity by the Use of Concentric Cylinder", H. R. Lillie, J. Amer. Ceram, Soc., 12, No. 8, 505 (1929). See also U.S. Pat. No. 3,056,283 to Tiede. Table I__________________________________________________________________________ Temperature ° F.Log of the Viscosity Commercial Commercial Glass of Glass of Commercial Ion U.S. Patent 3,485,702 in Poises Sheet Glass Float Glass Ex. 1 Ex. 2 Exchange Glass 1 2 3 10__________________________________________________________________________2 2705 2622 2700 2575 3185 3022 2955 2953 27883 2230 2169 2250 2175 2690 2503 2517 2522 24094 1920 1873 1980 1900 2305 2151 2223 2232 215Liquidus Temperature° F. - proceduredescribed in J. Soc.Glass Techn., 24,101-108 (1940) byE. Preston 1840 1830 * * 1560** 2025** 2331**Working Range ° F. 30 43 >125 >125 663 207 -174__________________________________________________________________________ *Attempts to determine the liquidus temperature and the working ranges o the glasses of Examples 1 and 2 were not successful. An alternate procedure, other than the one specified in the above table, was then used to determine the liquidus temperature and working range. Small platinum packets are filled with glass crushed in a hardened steel mortar and the packets positioned in sand along the temperature gradient of a gradient wound tube furnace. After a soak period of at least 66 hours, the packets are removed and quenched in water. The contents of each packet are then examined for the presence of crystals in the following manner. The fused glass is powdered in an agate mortar and a portion of the powder is place on a microscope slide, along with a drop or two of oil with an index of refraction close to that of the glass. The submerged glass particles are then viewed with a microscope at 100X to 200X between crossed polarizers. In the absence of crystals the field remains dark. Birefringent crystals will rotate the plane of polarization of the light coming through the first polarizer and thus appear as bright areas in the dark field. In the glasses of Examples 1 and 2, no crystals were detected, thus indicating a working range of at least 125° F. **Liquidus values reported in U.S. Patent 3,485,702. The following series of tests give an indication of the chemical strengthening propensity of the glasses of Examples 1 and 2 in comparison to the commercially available ion exchange glass as described above. TEST SPECIMENS The test specimens used for evaluating strength are of two types: the first type of test specimen is a 2 inch by 2 inch by 0.100 inch ground and polished square. All plates are re-annealed. The second type of test specimen is a nominal 3 millimeter (mm) diameter rod approximately 21/2 inches in length. Melts made in 4 inch diameter platinum crucibles provide glass for the test specimens. A melt consists of 750 grams of the oxide glass, homogenized during melting by about 4 hours of continuous stirring. Rods are drawn directly from the melt. The 2 inch square specimens are made from 1/4 inch cast plates. It is the practice to re-anneal all plates and rods to remove thermal history frozen into the plates or rods when formed. EXCHANGE TREATMENTS All exchange treatments take place in molten KNO 3 , the times and temperatures of the exchange depend upon the desired combination of compression layer thickness and strength. SPECIMEN ABRASION Following ion exchange and prior to testing, all strength samples are given 1 of 3 types of abrasion. The first type of abrasion is referred to as heavy abrasion. By this method of abrasion, a 3/4 inch diameter circular area, centrally located on a 2 inch square specimen, is blasted with 2 cubic centimeters (cc) of 100 grit Al 2 O 3 with an air pressure of 30 psi. This is the type of abrasion used in testing chemically strengthened glass for aircraft applications. The second type of abrasion is referred to as light abrasion. In the practice of this invention, this type of abrasion is used with 2 inch square specimens for tests that apply to automotive and/or architectural applications. A 1/2 inch diameter circular area, centrally located on a specimen, is abraded with 10 cc of 25-30 grit silicon carbide that falls freely in a normal direction onto the area from a height of 12 inches. The third type of abrasion is referred to as tumble abrasion. This type of abrasion is applicable to rods. A 16 ounce jar containing 10 rod specimens and 200 cc of 240 grit silicon carbide rotates about its main axis at a speed of about 167 rpm for 30 minutes. TEST METHODS Using a Rhiele testing machine, the 2 inch squares are evaluated for modulus of rupture by the method of concentrically loading, with the abraded surface placed in tension. The diameter of the load ring is 3/4 inch. That of the support ring is 11/2 inches. The modulus of rupture (MOR) corrected for both overhang and membrane effects is obtained as a computer solution of the following expression: W = 2.160 σ h.sup.2 + 2.325 × 10.sup..sup.-15 σ.sup.3 /h.sup. 2 where W is the load at fracture, σ is the modulus of rupture and h is the glass thickness. The test method for rods employs a 4 point loading configuration with a 11/2 inch support span and a 3/4 inch load span. The modulus of rupture for rods is given by the expression: σ = 8WL/π ab.sup.2 where W is the load at fracture, L is the distance between load and support points, a is the large diameter of the rod, b is the small diameter of the rod. Table II presented immediately below shows the average modulus of rupture for the glass of Examples 1 and 2 given two different exchange treatments, both of which produce compression layers about 7 mils thick. A compression layer of this thickness is believed desirable for most use in aircraft applications. The results are also for samples given a heavy type of abrasion as described above. Table II__________________________________________________________________________Abraded MOR of Glasses of Examples 1 and 2and Commercially Available Ion Exchange GlassGlass Exchange Conditions Layer Depth Abraded MOR__________________________________________________________________________Example 1 24 hours - 950° F. - 7 mils 57,800 psi KNO.sub.3Example 2 " " 56,800 psiComm. Ion " 8 mils 57,700 psiExchange GlassExample 2 48 hours - 900° F. - 7 mils 69,400 psi KNO.sub.3Comm. Ion " 8 mils 59,200 psiExchange GlassExample 1 96 hours - 850° F. - 7 mils 77,900 psi KNO.sub.3Comm. Ion " 8 mils 66,200 psiExchange Glass__________________________________________________________________________ With respect to potential aircraft use, it is clear that glasses of Examples 1 and 2 are as applicable as the commercially available ion exchange glass. The suggested range of flexural strength for automotive windshield glass is 40,000 to 50,000 psi. Table III below shows the specific exchange conditions needed to provide the 2 inch square specimens of the glasses of Example 1 with nominal 2, 3 and 4 mil compression layers and an average strength falling within the suggested range. Tests were conducted with 2 inch by 2 inch by 0.100 inch ground and polished squares and light abrasion was used. Table III______________________________________Exchange Conditions for 2, 3 and 4 mil Compression LayersOn Glass of Example 1With Modulus of Rupture in the 40,000-50,000 psi RangeExchangeTemperature Time Layer Depth MOR______________________________________1050° F. 0.5 hour 2.0 mils 45,200 psi1050° F. 1.1 hours 2.9 mils 42,300 psi1025° F. 3.0 hours 4.0 mils 46,500 psi______________________________________ The strength corresponding to a given compression layer thickness can be increased by carrying out the exchange at lower salt bath temperatures for longer times. Table IV below summarizes the results of modulus of rupture tests using tumble abraded rods of the glasses of Examples 1 and 2 exchanged at different temperatures for a period sufficient to produce 2 mil compression layers. Table IV__________________________________________________________________________Modulus of Rupture for Rods of Glasses of Examples 1 and 2With 2 mil Compression Layer Produced at Different TemperaturesGlass of Example 1 Glass of Example 2Exchange ExchangeTreatment Layer Depth MOR Treatment Layer Depth MOR__________________________________________________________________________4 hours - 900° F. - 2 mils 88,700 psi 4 hours - 900° F. - 2 mils 90,300 psiKNO.sub.3 KNO.sub.32 hours - 950° F. - " 77,200 psi 2 hours - 950° F. - " 80,300 psiKNO.sub.3 KNO.sub.31 hour - 1000° F. - " 66,100 psi 1 hour - 1000° F. - " 69,900 psiKNO.sub.3 KNO.sub.31/2 hour - 1050° F. - " 50,700 psi 1/2 hour - 1050° F. - " 49,000 psiKNO.sub.3 KNO.sub.3__________________________________________________________________________ By way of comparison, the glass of Example 5 in U.S. Pat. No. 3,772,135 (Hara et al.), after being ion-exchanged in KNO 3 at 1000° F. for 1 hour, was found to have a compression layer depth of 1.8 to 1.9 mils but an abraded rod MOR of only 17,600 psi. When ion-exchanged for 4 hours in KNO 3 at 900° F., Hara's Example 5 glass exhibited an abraded rod MOR of 47,100 psi and a compression layer depth of 2.2 mils. As has been mentioned, the glasses of the present invention are practically non-devitrifiable which makes them amenable to forming in sheet form by the updraw and float process. In sheet form, the glasses can be used to make chemically tempered glass patio and storm doors. Formerly, strengthened glass patio and storm doors have been thermally tempered. However, there are a number of advantages associated with chemical tempering over thermal tempering. As the glass becomes thinner, it becomes increasingly more difficult to store sufficient internal energy by the thermal tempering method to produce small particles which are required by the safety codes for storm and patio doors, when fractures occur. On the other hand, with chemical tempering, it becomes easier to develop the necessary internal stress for small fracture particles when the glass becomes thinner, thus satisfying practically all of the safety codes. Also, with thermal tempering, there is a decided tendency for thin glass to distort when heated to temperatures required for thermal tempering. Distortion during chemical tempering is minimal, regardless of glass thickness. However, because of the slow rate of penetration of the strengthening ion and the low level of surface compressive stress produced, it is virtually impossible to generate sufficient internal stress in conventional soda-lime-silica glass by chemical means to satisfy the safety code for tempered storm and patio doors regarding particle size. However, glasses of the present invention can be sufficiently tempered by chemical means to satisfy the tempered glass safety code. The following table shows the exchange times needed to produce center tension levels of 2100, 2500, 3000 and 4000 millimicrons (mu) per inch for the glass of Examples 1 to 2 of nominal 0.10 inch thickness. The center tension levels are expressed in terms of retardation measured by the graduated quartz wedge technique. __________________________________________________________________________Glass of Example 1 Glass of Example 2Center Tension Salt Temperature Exchange Time Center Tension Salt Temperature Exchange__________________________________________________________________________ Time2100 mu/inch 975° F. 7.2 hours 2100 mu/inch 975° F. 9.0 hours2500 mu/inch 975° F. 11.5 hours 2500 mu/inch 975° F. 15.4 hours3000 mu/inch 975° F. 19.6 hours 3000 mu/inch 975° F. 27.2 hours4000 mu/inch 975° F. 48.3 hours 4000 mu/inch 975° F. 65.6 hours__________________________________________________________________________ It will require shorter exchange times to produce the same stress levels in thinner glass. For example, to produce center tension levels of 2100 to 4000 mu/inch in the above glass of 0.0750 inch thickness will require the following exchange times. __________________________________________________________________________Glass of Example 1 Glass of Example 2Center Tension Salt Temperature Exchange Time Center Tension Salt Temperature Exchange__________________________________________________________________________ Time2100 mu/inch 975° F. 2.3 hours 2100 mu/inch 975° F. 3.3 hours2500 mu/inch 975° F. 3.6 hours 2500 mu/inch 975° F. 5.0 hours3000 mu/inch 975° F. 5.9 hours 3000 mu/inch 975° F. 8.0 hours4000 mu/inch 975° F. 13.1 hours 4000 mu/inch 975° F. 20.2 hours__________________________________________________________________________ The ion strengthened special glasses such as described above are stronger than fully heat tempered soda-lime-silica glass. The modulus of rupture of the above chemically tempered glass is at least two times that of fully heat treated soda-lime-silica glass. On this basis, tempered glass such as described above of 0.090 inch thickness will have the same load bearing strength as 0.125 inch fully heat tempered soda-lime-silica glass. Full temper by thermal quench is presently limited to glasses of 0.125 inch and above for soda-lime-silica glass. Thus, with the special glasses of the present invention and chemical tempering, it is possible to reduce the lower thickness limit for fully tempered glass by 29 percent or more without jeopardizing safety or load bearing strength. The glass compositions referred to above can be produced from conventional glass-making materials properly compounded and thoroughly mixed so as to yield, when reacted, glasses of the desired composition. Suitable batch materials include glass sand, soda ash (sodium carbonate), caustic soda (sodium hydroxide), magnesite, dolomite, talc, aluminum hydrate, feldspar, aplite, nepheline syenite, zircon sand, carbon and cullet. Besides the above-mentioned batch, melting and refining agents, such as Sb 2 O 5 , As 2 O 5 , Na 2 SO 4 and NaCl could also be incorporated in the glass batch. Various glass coloring agents such as compounds containing iron, cobalt, nickel, coal, silver, chromium, copper and selenium may also be added in small concentrations to the glass batch to color the final glass without impairing its desirable ion exchange properties. For the production of glass by the updraw or float process, the well-mixed batch ingredients are fed on a continuous basis to a tank furnace to be melted and refined. The batch ingredients can be fed to the furnace as loose batch or alternately, they can be first pelletized on an inclined, rotating disc pelletizer or the like using caustic soda as a binding agent and as a total or partial replacement for soda ash. The tank furnaces for the updraw and float process are similar to most glass-making furnaces in that they are usually gas-fired and of the regenerative type well known in the art. In the updraw process, such as the Pittsburgh Process, the glass is drawn vertically upwards between rollers from the surface of a bay or drawing kiln which is located at the working end of the tank. A detailed description of the updraw process, more particularly the Pittsburgh Process may be found in Glass Manual, Pittsburgh Plate Glass Company, published in 1946. The float process for the forming of flat glass consists of floating glass sheet upon the surface of a bath of molten metal, usually tin. The float process is well known in the art and is fully described in U.S. Pat. No. 3,083,551. After the glass has been properly melted, refined and formed as generally described above, it should have the following composition as determined by a standard wet chemical and spectrophotometric analysis: ______________________________________ Percent by Weight on the Oxide Basis______________________________________Component Broad Range Preferred Range______________________________________SiO.sub.2 50-58 52-57Na.sub.2 O 8-23 10-19K.sub.2 O 0-15 0-10Na.sub.2 O + K.sub.2 O 13-25 17-23Al.sub.2 O.sub.3 7-17 9-13ZrO.sub.2 1-4.5 2-4.5Al.sub.2 O.sub.3 + ZrO.sub.2 10-21 12-17CaO 0-10 0MgO 0-6.5 4-6CaO + MgO 2.5-10 4-6TiO.sub.2 0-7 1-6TiO.sub.2 + (MgO + CaO) 4-14 5-12______________________________________ With regards to the individual components, SiO 2 is the glass former and is needed to produce high temperature stability and chemical durability in the glass. Concentrations lower than the recommended amount, that is, lower than 50 percent, decrease the durability, whereas higher concentrations, that is, higher than 58 percent, require higher melting temperatures and decrease the melting rates. Sodium oxide is present as a flux to reduce the melting temperature of the glass. Also, is is present to provide the sites necessary for subsequent ion exchange. K 2 O is an optional ingredient which provides fluxing activity to the glass melt. Its presence is due usually to the use of nepheline syenite in the batch material which is a particularly desirable batch ingredient because of its cheapness and plentiful supply. Also, K 2 O is believed to increase ion exchange rates. When the K 2 O content is reduced, the reduction should be compensated for by an increase in the Na 2 O content to maintain the viscosity level. When the Na 2 O concentration is greater than the broad range specified above, that is, greater than 23 percent, the chemical durability of the glass, as measured by exposure to sulfuric acid, sodium hydroxide and water, will suffer. On the other hand, when the percentage by weight of Na 2 O or Na 2 O plus K 2 O is below the range specified, that is, below 13 percent by weight, the melting temperature of the glass will be exceedingly high. The effect of varying the K 2 O and Na 2 O contents may be seen in Table XII. With regards to the alkali metal oxides, Li 2 O has been found to decrease the rate of ion exchange and to impair the strength of the resultant chemically tempered glass article of the above compositional family, and, therefore, the glasses of the present invention should be substantially free of Li 2 O. By the expression substantially free of Li 2 O is meant that there is no purposeful addition of a lithium compound to the glass batch. Any LiO 2 which is analytically determined in the final glass is present in the impurity quantities, that is, less than 0.1 percent by weight. Al 2 O 3 is present in the glass to promote the ion-exchange properties of the glass, such as increasing the rates of ion exchange. Also, higher Al 2 O 3 concentrations increase the strain point which results in the possibility of higher ion exchange temperatures and faster and deeper ion exchanges and penetrations. Concentrations of alumina lower than the recommended amount, that is, less than 7 percent by weight, decrease the ultimate strength obtainable in the glass, whereas higher concentrations than recommended, that is, higher than 17 percent, decrease the melting rate and result in poor acid durability. The strength of the resultant chemically tempered glass articles are dependent upon the combined total of ZrO 2 plus Al 2 O 3 . However, the Al 2 O 3 plus ZrO 2 concentration should not be greater than 21 percent because of difficulty in melting. With high Al 2 O 3 plus ZrO 2 contents, the batch is not as soluble in the melt as it is with lower concentrations. Also, the Al 2 O 3 plus ZrO 2 concentration should not be below 10 percent by weight because the degree of potential strengthening in the glass will diminish to an undesirably low level. EXAMPLES 3-9 The ZrO 2 content is essential in obtaining low temperature melting properties while maintaining credible strength and good chemical durability. To demonstrate the role of ZrO 2 in glass, this oxide was completely replaced by an equivalent amount of SiO 2 and with Al 2 O 3 . The replacement with Al 2 O 3 will most nearly preserve strength, insomuch as strength was found to be dependent on the total Al 2 O 3 plus ZrO 2 content. Tables V and VI show the effects of these replacements on strength and other various properties. Table V__________________________________________________________________________SiO.sub.2 for ZrO.sub.2 Substitution to Reduce StrengthComponent Example 2 Example 3 Example 4 Example 5 Example 6__________________________________________________________________________SiO.sub.2 54.5 55.5 56.5 57.5 59Na.sub.2 O 18.0 18.0 18.0 18.0 18.0Al.sub.2 O.sub.3 10.0 10.0 10.0 10.0 10.0MgO 5.0 5.0 5.0 5.0 5.0K.sub.2 O 3.0 3.0 3.0 3.0 3.0ZrO.sub.2 4.5 3.5 2.5 1.5 0TiO.sub.2 5.0 5.0 5.0 5.0 5.0Abraded RodMOR in psi.sup.1 65,900 52,100 49,100 41,100 36,370Temperatureat 10.sup.2.0poises ° F. 2575 2590 -- 2624 2638__________________________________________________________________________ 1 - Ion exchange conditions - 1 hour at 1000° F. in molten KNO.sub.3 ; MOR's 4-point loading, nominal 2 mils compressed layer. Table VI__________________________________________________________________________Effect of ZrO.sub.2 on Strength, Melting Properties and Acid Durability Percent by Weight on the Oxide BasisComponent Example 1 Example 2 Example 7 Example 8 Example 9__________________________________________________________________________SiO.sub.2 56.0 54.5 56.0 58.0 53.5Na.sub.2 O 18.0 18.0 18.0 16.0 17.0Al.sub.2 O.sub.3 12.0 10.0 16.5 16.5 11.0MgO 4.5 5.0 4.5 4.5 5.0K.sub.2 O 3.0 3.0 3.0 3.0 3.0ZrO.sub.2 4.5 4.5 -- -- 4.5TiO.sub.2 2.0 5.0 2.0 2.0 6.0Physical PropertiesTemperature at10.sup.2.0 poises 2696° F. 2575° F. 2807° F. 2924° F. 2602° F.Annealing Point 1070° F. 1070° F. 1067° F. 1105° F. 1094° F.Abraded MOR (Rods).sup.1 66,100 psi 69,900 psi 55,900 psi -- 78,300 psiWeight Loss inAcid.sup.2 0.01 mg/cm.sup.2 0.01 mg/cm.sup.2 1.21 mg/cm.sup.2 0.02 mg/cm.sup.2 0.01 mg/cm.sup.2__________________________________________________________________________ .sup.1 - 1 hour - 1000° F. - KNO.sub.3 - Tumble abrasion; 4-point loading, nominal 2 mils compression layer. .sup.2 - Unexchanged 2 inch square boiled 30 minutes in 0.5 weight percen H.sub.2 SO.sub.4. From the above Tables V and VI, it is clear that the elimination of ZrO 2 is damaging in three respects: it directly raises the melting temperature, strength is decreased, and it caused a serious breakdown in resistance to attack in an acid environment. To restore acid resistance will require a substantial reduction of Na 2 O. This increases viscosity even more and leads to a viscous glass. For example, glass 8 in the above table contains 2 percent less Na 2 O than glass 7. This change caused the temperature corresponding to the viscosity at 100 poises to increase another 117° F. for a total increase of 228° F. over the corresponding temperature for glass 1. But the data presented in the above table shows that even with this increase in viscosity, the restoration of acid durability is still not complete. Therefore, from the data in Tables V and VI it is shown that ZrO 2 plus Al 2 O 3 should not be diminished if strength is to be preserved. They also show that there must be a combination of ZrO 2 and Al 2 O 3 present to maintain high strength and good chemical durability in a low temperature melting glass. It is concluded that the ZrO 2 content should be at least 1.0, and preferably 2 to 4.5 percent by weight and ZrO 2 plus Al 2 O 3 content of 10-21, and preferably 12-17 percent by weight. The ZrO 2 component of glasses is directly responsible for lowering the melting requirements of the soda-zirconia-aluminosilicate ion exchange glasses of the present invention. The partial substitution of the ZrO 2 for Al 2 O 3 (without reducing strength) is indirectly responsible for reducing the melting requirement much more. It does this by permitting a substantial increase in the use of Na 2 O without seriously degrading acid durability. ZrO 2 is therefore important principal ingredient for a strong glass that will melt at low temperatures and will offer good resistance to attack in acid, neutral and alkaline environments. EXAMPLES 10 - 13 Titania (TiO 2 ) also has a pronounced effect on melting temperature and an apparent effect on the development of strength in the chemically strengthened glasses of the invention. The following examples are presented to show the effects of TiO 2 on strength and melting properties. Table VII__________________________________________________________________________Effect of TiO.sub.2 on Strength and MeltingComponent Example 2 Example 10 Example 11 Example 12 Example 13SiO.sub.2 54.5 55.5 56.5 57.5 53.5Na.sub.2 O 18.0 18.0 18.0 18.0 18.0Al.sub.2 O.sub.3 10.0 10.0 10.0 10.0 10.0MgO 5.0 5.0 5.0 5.0 5.0K.sub.2 O 3.0 3.0 3.0 3.0 3.0ZrO.sub.2 4.5 4.5 4.5 4.5 4.5TiO.sub.2 5.0 4.0 3.0 2.0 6.0Temperatureat 10.sup.2.0poises ° F. 2579 2612 2633 2667 2557AnnealingPoint° F. 1059 1063 1054 1054 1067Abraded RodMOR in psi.sup.1 60,095 48,075 56,640 44,314 66,684__________________________________________________________________________ .sup.1 Ion exchange conditions - 1 hour at 1000° F. in molten KNO.sub.3 ; MOR's 4-point loading, nominal 2 mils compression layer. The reduction of TiO 2 from a high of 6.0 percent in Example 13 to 2 percent in Example 12 caused the melting temperature to increase about 110° F. Further, TiO 2 appears to have an effect on strength developed in chemically tempered glass. With the exception of Example 10, there is a steady increase in strength as the TiO 2 content is increased from 2 to 6 percent. EXAMPLES 14-26 To show the effect that ZrO 2 concentrations have on the liquidus temperature and working range of ion exchange glasses, glasses having the following calculated glass compositions were made by conventional melting and forming techniques. Table VIII__________________________________________________________________________Role of ZrO.sub.2 on Working Range and LiquidusComponent Example 14 Example 15 Example 16 Example 17 Example 18 Example 19 Example__________________________________________________________________________ 20SiO.sub.2 56.75 57.0 57.25 57.5 58.0 59.0 60.0Na.sub.2 O 16.0 16.0 16.0 16.0 16.0 16.0 16.0Al.sub.2 O.sub.3 13.5 13.5 13.5 13.5 13.5 13.5 13.5MgO 4.5 4.5 4.5 4.5 4.5 4.5 4.5K.sub.2 O 3.0 3.0 3.0 3.0 3.0 3.0 3.0ZrO.sub.2 6.25 6.0 5.75 5.5 5.0 4.0 3.0Temperature at10.sup.2.0 poises, ° F. -- 2848 -- -- 2875 2896 2911Temperature at10.sup.4.0 poises, ° F. ≃2134 2134 ≃2134 ≃2134 2138 2139 2139LiquidusTemperature, ° F. 2336 2240 2240 2146 NCD* NCD* NCD*Working Range, ° F. -202 -106 -106 -12 >125 >125 >125__________________________________________________________________________Component Example 21 Example 22 Example 23 Example 24 Example 25 Example 1 Example__________________________________________________________________________ 26SiO.sub.2 61.0 54.5 54.5 55.0 55.5 56.0 56.5Na.sub.2 O 16.0 18.0 18.0 18.0 18.0 18.0 18.0Al.sub.2 O.sub.3 13.5 12.0 12.0 12.0 12.0 12.0 12.0MgO 4.5 3.5 4.5 4.5 4.5 4.5 4.5K.sub.2 O 3.0 3.0 3.0 3.0 3.0 3.0 3.0ZrO.sub.2 2.0 7.0 6.0 5.5 5.0 4.5 4.0TiO.sub.2 -- 2.0 2.0 2.0 2.0 2.0 2.0Temperature at10.sup.2.0 poises, ° F. 2934 2697 2687 2677 2697 2696 2722Temperature at10.sup.4.0 poises, ° F. 2136 2015 1998 1984 1990 1981 2002LiquidusTemperature, ° F. NCD* 2050 1996 1944 1926 NCD* NCD*Working Range, ° F. >125 -35 2 40 64 >125 >125__________________________________________________________________________ *No crystals determined. The above experiments show that when ZrO 2 is maintained below 5 percent by weight, within the range of 2 to 4.5 percent by weight, devitrification generally occurs so slowly that it is difficult to detect any evidence of devitrification under the conditions given. On the other hand, glass compositions containing greater than 5 percent by weight ZrO 2 have narrow working ranges and may even have liquidus temperatures above the forming temperatures, resulting in a negative working range and could pose a serious problem with respect to float or updraw forming. It should be mentioned at this point where it is stated in the specification and claims that the glass compositions of the present invention have working ranges greater than 125° F. what is meant is that no detectable crystals developed when the glass was heated for at least 66 hours at a temperature range extending from above the temperature corresponding to 10 4 .0 poises to at least 125° F. below such temperature. The method for determining liquidus temperatures and for detecting crystals is as described above. That is, small platinum packets are filled with glass crushed in a hardened steel mortar and the packets positioned in sand along the temperature gradient of a gradient wound tube furnace. After a soak period of at least 66 hours, the packets are removed and quenched in water. The contents of each packet are then examined for the presence of crystals in the following manner. The fused glass is powdered in an agate mortar and a portion of the powder is placed on a microscope slide, along with a drop or two of oil with an index of refraction close to that of the glass. The submerged glass particles are then viewed with a microscope at 100X to 200X between crossed polarizers. In the absence of crystals, the field remains dark. Birefringent crystals will rotate the plane of polarization of the light coming through the first polarizer and thus appear as bright areas in the dark field. EXAMPLES 27-29 MgO and CaO are employed as fluxes to decrease the melting temperature. Preferably, MgO is the total source of alkaline earth metal oxide in the glass batch. MgO provides for enhanced strength in the resultant chemically strengthened article. Strength is decreased somewhat if CaO is substituted for MgO as Table IX below shows. Table IX__________________________________________________________________________Component Example 2 Example 27 Example 28 Example 29__________________________________________________________________________SiO.sub.2 54.5 54.5 54.5 54.5Na.sub.2 O 18.0 18.0 18.0 18.0Al.sub.2 O.sub.3 10.0 10.0 10.0 10.0MgO 5.0 3.5 2.0 0K.sub.2 O 3.0 3.0 3.0 3.0ZrO.sub.2 4.5 4.5 4.5 4.5TiO.sub.2 5.0 5.0 5.0 5.0CaO 0 1.5 3.0 5 ##STR1## 0 0.3 0.6 1.0Abraded RodMOR.sup.1 (psi) 65,200 61,400 48,200 45,100__________________________________________________________________________ .sup.1 All rods exchanged for 1 hour in KNO.sub.3 at 1000° F. test; 4-point loading. From the above table, it can be seen that the glasses representing substitutions for MgO all contain 5 percent alkaline earth metal oxide (MgO plus CaO). It is evident from the data in the above table that as CaO replaces MgO, there is a decrease in strength. The decrease is a maximum when the replacement is complete. Even in this instance, however, strength would appear to remain adequate for most potential uses. CaO is shown to be a somewhat better flux than MgO, insomuch as high temperature viscosity decreases with its substitution for MgO, and acid durability remains unchanged. The working range in most instances will be adequate for updraw as well as for float forming. In addition, the simple substitution of CaO for MgO on a partial or total basis offers a means of controlling the strength of the glass in the manufacturing stage. With regards to the total MgO plus CaO content, higher than recommended contents, that is, higher than 10 percent by weight, result in slow penetration of the strengthening ions, and contents lower than 2.5 percent by weight result in viscous high melting glasses. As has been mentioned above, TiO 2 is a preferred component because it assists in obtaining low temperature melting properties while maintaining credible strength and good chemical durability. However, in certain applications, it might be desirable to reduce or eliminate TiO 2 in order to reduce batch costs or when introducing iron into the glass to make and infrared radiation absorbing glass for ion exchange purposes. To compensate for the viscosity increases that accompany the reduction or elimination of TiO 2 , one or more of the fluxing components of the glass should be increased. Besides the above-mentioned components, the final glass composition can also contain minor amounts, that is, less than 1 percent by weight of various oxides and anions such as As 2 O 5 , Sb 2 O 5 , SO 4 .sup. -2 and Cl - which result from the incorporation of melting and fining agents in the glass batch materials. Coloring agents in the form of transition metal oxides, such as iron, nickel and cobalt oxides in concentrations on the order of 5 percent or less can also be present in the final glass composition. Higher concentrations, that is, on the order of 5 percent, are used when a densely colored glass is desired. Lower concentrations, i.e., on the order of 1 percent or less, are used for higher visible light transmittance glasses. Table X below lists various glass compositions which contain coloring metal oxides and which are suitable for tinted spectacle lenses and architectural applications. Table X______________________________________Component Example 30 Example 31 Example 32______________________________________SiO.sub.2 54.5 53.6 49.5Na.sub.2 O 18.0 18.0 18.0Al.sub.2 O.sub.3 10.0 10.0 10.0MgO 5.0 5.0 5.0K.sub.2 O 3.0 3.0 3.0ZrO.sub.2 4.5 4.5 4.5TiO.sub.2 5.0 5.0 5.0CoO 0.011 0.011 --NiO 0.063 0.063 --Fe.sub.2 O.sub.3 -- 0.8 5.0Shade neutral olive green rose smoke% LuminousTransmittance(Illuminant C)0.079 inch 58.2 percent 49.8 percent 14.3 percent0.250 inch 21.8 percent 13.5 percent --______________________________________ The chemical strengthening treatment presently used for imparting the necessary impact resistance to conventional crown spectacle lenses (e.g., a glass having the following analyzed composition: SiO 2 , 67.42 percent; Al 2 O 3 , 1.98 percent; Na 2 O, 8.45 percent; K 2 O, 8.80 percent; CaO, 9.09 percent; ZnO, 2.90 percent; TiO 2 , 0.34 percent; Sb 2 O 5 , 1.02 percent) consists of a 16-hour soak in KNO 3 at 470° C. (878° F.). This treatment produces a compression layer on the surface of this glass that is about 2 mils thick. A compression layer of the same thickness, but with a considerably higher stress level, can be produced in the above three types of glasses (Examples 30-32) in only one hour or less. Besides the reduced strengthening time and higher surface stress values, the above glasses offer other advantages over many conventional crown spectacle glass compositions in that the above glasses are essentially non-devitrifiable. These latter characteristics make the glass particularly compatible and especially suitable for conventional melting and pressing operations or for any method of producing ophthalmic glass blanks or glass sheets. The following tabulation compares some of the properties of the above three glass compositions to the corresponding properties of a conventional ophthalmic crown glass such as the one mentioned above. Table XI______________________________________ Conventional Ophthalmic Glasses of Crown Glass Example 30*______________________________________Temperature at 10.sup.2.0 poises 2667° F. 2583° F.Temperature at 10.sup.4.0 poises 1888° F. 1899° F.Annealing Point 1026° F. 1068° F.KNO.sub.3 Exchange Bath Temperature 900° F. 1000° F.Exchange Time for 2 milcompression layer 16 hours 1 hourAverage abraded modulusof rupture (Rods) 35,800 psi 67,800 psi(Tumble abrasion)______________________________________ *Properties for Glasses 31 and 32 would be comparable. The tinted glass compositions of the present invention are not restricted to exchange treatment time and temperatures as cited above. Alternate exchange treatments that will produce a nominal 2 mil compression layer on these glasses are shown in the following tabulation, together with the average tumble abraded modulus of rupture (MOR) values for rods of glass. __________________________________________________________________________ Glass of Example 31*KNO.sub.3 Temperature Exchange Time Average Abraded MOR**__________________________________________________________________________1050° F. 1/2 hour 49,000 psi1000° F. 1 hour 64,800 psi 950° F. 2 hours 76,200 psi 900° F. 4 hours 87,800 psi__________________________________________________________________________ *Comparable results obtainable with Glasses 30 and 32. **Tumble abrasion Other optional ingredients such as ZnO, SrO, PbO, P 2 O 5 and BaO can be present in the final glass composition in concentrations of up to 2 percent by weight. The total amount of optional ingredients, that is, the total amount of melting and fining agents, transition metal oxides and other optional ingredients such as those mentioned immediately above, in total, should constitute no more than 5 percent by weight of the final glass composition. Examples 33 through 43 set forth in Table XII illustrate additional ion exchange glass compositions falling within the scope of the present invention, and show the effect of varying the total Na 2 O + K 2 O content and the Na 2 O to K 2 O ratio of the glass. The alkali metal exchange strengthening treatments contemplated by the present invention are achieved by contacting the surface of the base glass with an alkali metal salt having an atomic diameter larger than sodium at an elevated temperature and for a period of time long enough to obtain a substantial exchange for the larger atomic diameter alkali metal for sodium and other exchangeable alkali or other metals in the base glass having atomic diameters smaller than the alkali metal employed for strengthening. The alkali metal strengthening treatment is usually conducted at temperatures around the strain point of the base glass, that is, with glass of the invention, about 925°-1050° F. for a sufficient period of time to replace to a marked extent the sodium and other available smaller atomic diameter metal or metals by the larger atomic diameter alkali metal or metals of the treating salt. When highest ultimate strengths are desired, the treatment temperature is usually below the strain point, i.e., 25° to 150° F. below the strain point. Where lower strengths are adequate and speed of operation is important, the treatment may be conducted at temperatures slightly above the strain point of the glass, that is, about 25° to 100° F. above the strain point, if the treatment is conducted quickly so as not to relax excessively the compressive stresses induced in the surface of the glass by the ion exchange. TABLE XII__________________________________________________________________________Component Example 33 Example 34 Example 35 Example 36 Example 37 Example 38 Example__________________________________________________________________________ 39SiO.sub.2 57.5 54.5 54.5 54.5 54.5 50.5 50.5Na.sub.2 O 18.0 21.0 15.0 12.0 9.0 23.0 20.0K.sub.2 O -- -- 6.0 9.0 12.0 -- 3.0Al.sub.2 O.sub.3 10.0 10.0 12.0 12.0 10.0 12.0 12.0ZrO.sub.2 4.5 4.5 4.5 4.5 4.5 4.5 4.5MgO 5.0 5.0 5.0 5.0 5.0 5.0 5.0TiO.sub.2 5.0 5.0 5.0 5.0 5.0 5.0 5.0Annealing Point° F. 1109 1067 1075 1082 1112 1054 1049Temp. at 100poises, ° F. 2674 2534 2647 2718 2789 2471 2576Temp. at 10,000poises, ° F. 1966 1867 1947 2002 2066 1832 1859Compression layerdepth, mils* 1.4 2.0 2.2 2.6 2.8 2.3 2.6Compression layerdepth, mils** 1.4 1.9 2.5 3.1 3.3 2.3 2.5Abraded rod MOR,psi* 59,400 35,900 56,100 61,900 51,300 26,500 47,100Abraded rod MOR,psi** 70,200 69,000 77,800 66,700 56,200 66,000 75,800__________________________________________________________________________Component Example 40 Example 41 Example 42 Example 43__________________________________________________________________________SiO.sub.2 50.5 50.5 50.5 50.5Na.sub.2 O 16.0 13.0 10.0 18.0K.sub.2 O 7.0 10.0 13.0 7.0Al.sub.2 O.sub.3 10.0 10.0 10.0 12.0ZrO.sub.2 4.5 4.5 4.5 4.5MgO 5.0 5.0 5.0 5.0TiO.sub.2 5.0 5.0 5.0 5.0Annealing Point° F. 1060 1076 1101 1011Temp. at 100poises, ° F. 2589 2651 2724 2488Temp. at 10,000poises, ° F. 1912 1966 2032 1830Compression layerdepth, mils* 2.7 3.1 3.4 3.2Compression layerdepth, mils** 2.7 3.3 3.7 3.4Abraded rod MOR,psi* 55,500 58,900 53,000 24,800Abraded rod MOR,psi** 77,400 77,900 56,100 63,400__________________________________________________________________________ *Ion exchanged 1 hr. at 1000° F. in molten KNO.sub.3 **Ion exchanged 4 hrs. at 900° F. in molten KNO.sub.3 The length of the treatment period depends upon several factors including, among others, the specific composition of the base glass, the relative rate of exchange of a given larger atomic diameter alkali metal, and the specific treatment temperature. The temperature period can range from short contact periods of about several minutes up to a period of 100 hours. However, for treatment temperatures in excess of about 850° F. and ranging from about 900° F. to 1025° F., contact periods of about 10 minutes to 50 hours are usually sufficient depending on the thickness of the compression layer desired. In fact, when higher treatment temperatures are used, that is, 1050° to 1100° F., the base glass compositions can be provided with greatly enhanced surface compressive stresses and load strengths by treatment times ranging from 8 minutes to 2 hours depending on the thickness of the compression layer desired. Longer periods of contact are not objectionable to obtain a given set of objectives so long as the surface compressive strength and the load strength induced by the alkali metal strengthening treatment is substantially retained over the entire treatment period at the treatment temperatures employed. The results of the larger atomic diameter alkali metal strengthening treatment is to deplete the sodium content on the surface and thereby generate a surface which is in compression for a specified depth of penetration and is rich in the larger atomic diameter alkali metal, for example, potassium, cesium and rubidium, of the alkali metal treating salt employed for strengthening. When potassium is employed as the larger atomic diameter alkali metal, the penetration of potassium into the surface of the treated glass usually takes place to a depth of about 25 to 250 microns, although other depths are obtainable by varying the ion exchange process parameters, as is known in the art. The potassium metal salt causes the imposition of enhanced surface compressive stress to a greater depth than obtainable when using cesium or rubidium salts. Also, as between potassium, cesium and rubidium, potassium strengthening salts are more readily available and hence less expensive. The alkali metal salt strengthening treatment is conducted conveniently by immersing the base glass into a molten bath of the larger atomic diameter alkali metal strengthening salt for a sufficient period of time to secure the desired exchange and penetration of the larger atomic diameter alkali metal into the surface of the base glass. To effect this treatment, the alkali metal strengthening salt is placed in a suitable container, for example, stainless steel tanks, or other inert receptacle, and heated to a temperature at which it is molten. Usually the temperature of treatment will vary between the threshold temperature at which the alkali metal treating salt becomes molten and a temperature around the strain point of the base glass being strengthened, and any convenient treating temperature between the melting point of the alkali metal strengthening salt and the temperature at the glass strain point or slightly above can be used. Prior to immersion of the base glass into the molten alkali metal salt treatment bath, the base glass article is preferably heated to a temperature within the range of 50° F. above or below the temperature at which the alkali metal exchange treatment is to be conducted, that is, the temperature at which the alkali metal salt is maintained during treatment. More preferably, the glass article is preheated to a temperature fairly close approximating that at which the exchange strengthening treatment is conducted. In a typical method of performing this invention, the preheated base glass in sheet form is dipped into a molten bath of potassium nitrate maintained at a temperature of about 800° to 1100° F. and treated for a period of about 8 minutes to about 100 hours. This strengthening treatment causes introduction of potassium into the surface of the base glass by replacement of potassium for the sodium and other exchangeable smaller atomic diameter metals or other electropositive elements in the surface of the base glass at the time of treatment, thereby developing high surface compressive stress and load strength in the glass and depleting the sodium content at the surface. The treated glass article is then removed from the molten potassium nitrate treating bath and cooled gradually to a temperature roughly approximating room temperature, that is, a temperature ranging from 200° F. down to and even below room temperature. Following cooling, the glass is usually subjected to aqueous rinsing to remove excess treating salt. Instead of a potassium treating salt, a molten cesium or rubidium salt, for example, rubidium or cesium nitrate, can be employed for strengthening the base glass. In such a case, the rubidium and cesium from the treating salt exchanges for the sodium and potassium, each being a smaller atomic diameter alkali metal than rubidium and cesium, thereby incorporating rubidium or cesium into the surface of the base glass to produce rubidium or cesium exchange strengthened glass. Obviously, mixed salt ion exchange treating baths could be used such as mixed molten potassium and cesium salt baths. The alkali metal salt used for the strengthening treatment should be fairly stable at the treatment temperatures employed. Typically, satisfactory salts are those of the mineral acids, such as sulfates, nitrates, chlorides, fluorides and phosphates of potassium, cesium and rubidium, which are low in alkalinity and do not seriously deface or etch the base glass article. The foregoing discussion has related to employing a single larger atomic diameter alkali metal exchange strengthening treatment, and for most purposes, a single exchange treatment is widely satisfactory to secure the desired results. However, it is also within the purview of this invention to strengthen the SiO 2 --Na 2 O--Al 2 O 3 --alkaline earth metal oxide-ZrO 2 glass by subjecting it to a series of alkali metal salt exchange treatments. In such similarly conducted experiments, each successive treatment is conducted using an alkali metal salt having a larger atomic diameter than the alkali metal employed for a prior exchange strengthening treatment. Such successive later exchange treatment or treatments, all of which are preferably conducted at temperatures below the glass strain point, can serve to increase the magnitude of surface compressive stress and even thickness of the surface compressive stress zone. For example, the base glass can be subjected first to potassium exchange strengthening treatment, using molten potassium nitrate treating salts, followed by a further alkali metal strengthening treatment using a molten salt of an alkali metal having an atomic diameter larger than potassium, for example, a molten rubidium salt, such as molten rubidium nitrate. The effect of the second alkali metal strengthening treatment is to deplete the potassium and other available exchangeable lower atomic diameter alkali metals at the surface of the glass, thus replacing them with rubidium. By this means the magnitude of the compressive stress at the surface of the glass and hence its load strength can be increased. Moreover, if desired, the sodium-potassium exchange strengthened glass can be subjected to further successive alkali metal exchange treatments using first rubidium and then a cesium salt, respectively. Usually when strengthening the base glass compositions by the use of such successive alkali metal salts exchange strengthening treatments, the glass is cooled between each exchange treatment to a temperature ranging from 200° F. down to and even below room temperature. Following cooling, the glass is usually subjected to aqueous rinsing or to other cleansing prior to subsequent exchange treatments to remove excess treating salts. The glass is then preheated prior to a subsequent exchange treatment or treatments. However, it is also within the purview of the present invention to avoid the loss in time and thermal energy required in cooling the glass to room temperature between exchange treatments, and then preheating the glass to temperatures approximating those at which the subsequent exchange treatment or treatments are to be conducted, by cleansing the glass without first cooling to room temperature by impinging the flowing preheated air or other inert gases (which have been preheated to the treatment temperature to be employed in the subsequent exchange treatment) upon a surface of the treated glass, thereby serving to remove excess molten treating salts. Instead of gases, absorbing clays or silica powders can be employed for high temperature cleansing and these materials can serve to absorb excess molten salt. While the various above-mentioned exchange strengthening treatments can be conducted effectively by immersion of the base glass in a molten salt of a larger atomic diameter alkali metal salt, other methods of contact can be used. For example, the base glass can be sprayed or otherwise provided with an adhering coating of the potassium and the coated glass can be heated to a temperature at which the potassium salt is molten to effect a non-immersion exchange strengthening. Furthermore, the alkali metal treating salt can be mixed with a coherent, inert carrier or diluent, for example, thixotropic clay, to form a paste which is adherent to the glass and the paste, then applied to the glass prior to or simultaneously with or even shortly after heating the glass to treatment temperatures. The paste should usually contain from about 15 to 80 percent by weight of alkali metal salt to achieve non-immersion exchange strengthening within reasonably rapid treating periods. The present invention can be employed to produce strengthened glass articles of all types, for example, sheet, wind screens, automobile windshields, side windows and back windows, building materials, architectural glass or spandrels, skylights, bottles, plates, casseroles, saucers, cups, bowls and other tableware, drinking glasses and goblets, viewing closures, such as window panes and glass doors, safety glass and other laminated viewing closures and structures, glass insulation structures wherein a plurality of glass sheets are arranged in spaced fashion with a layer of air or fluorocarbon serving as the insulation medium, television safety glass implosion and/or explosion shields, ophthalmic lenses for eye glasses, goggles, etc., glass roofs or transparent domes in vehicles and buildings, and experimental devices such as glass engine parts.

Disclosed are improved glass compositions of the SiO 2 --Na 2 O--Al 2 O 3 --ZrO 2 system for use in chemical strengthening. The improvement of the invention resides in proportioning the components so as to provide better melting glass compositions with lower liquidus temperatures and greater working ranges than normally associated with such systems. Such glasses are better suited for forming by the updraw or float methods.

This application is a continuation of, and claims priority of, U.S. patent application Ser. No. 10/372,040, filed Feb. 21, 2003, entitled “Quick Change Filter And Bracket System With Key System And Universal Key Option”, issuing as U.S. Pat. No. 6,926,826 on Aug. 9, 2005, which claims priority of U.S. Provisional application Ser. No. 60/358,692, filed Feb. 21, 2002, entitled “Quick Change Filter and Bracket System with Key System and Universal Key Option,” wherein the above applications are incorporated herein by this reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to brackets and piping manifolds for holding water filters, and more specifically, brackets and manifolds that allow quick change-out of the filters. The invention relates to a bracket system that may accommodate a plurality of filters in series and/or parallel flow, and is adaptable to many different flow schemes, media and liquids. The invented system used a pivotal system, wherein a top bracket pivots away from each filter so that the filters may be lifted up out of the bracket system. 2. Related Art Manifold systems have been developed to accommodate multiple filters or water treatment tanks for increasing filter capacity and for allowing quick replacement of the filters. In 1972, Warren disclosed (U.S. Pat. No. 3,685,539) a multi-station system comprising a plurality of filters attached to a vacuum manifold. In 1973, Bjork disclosed (U.S. Pat. No. 3,753,495) a water conditioning unit with a filtering tank and a water softening tank connected to a manifold. In 1992–1994, Posner et al. disclosed a manifold system that comprises horizontally-removable filters that include a “means for effective evenly distributed filtration” that includes a first conical stage filter near the filter inlet and a second conical stage filter near the filter outlet, with a charcoal element between the conical filters. Each Posner filter is removable in a horizontal direction, that is, perpendicularly to the plane of the piping manifold, which plane is typically vertical. The Posner fittings are stationary snap-together and snap-apart connections that are parallel in fixed horizontal planes. SUMMARY OF THE INVENTION The present invention comprises a bracket system that holds a filter in quick-release fashion and that may comprise conduits for flow in or out of one or both ends of the filter. The bracket system may be expanded by using a plurality of brackets in modular fashion to create a “bank” of several filters. The invented system therefore features a high degree of flexibility for changing the number of filters and the flowscheme of the filter bank, including flow between two or more filters to a storage or treatment vessel that is separate from the bank of filters. The bracket system comprises pairs of brackets. Each pair includes a top bracket and a bottom bracket, which capture the top end and bottom end of a filter, respectively. Several pairs of brackets may be positioned near each other to hold a plurality of fitters generally side-by-side or in other arrangements. Fittings are included in the brackets for sealing to the inlet and outlet ports of the filters to connect the ports to flexible tubing or other conduit. The conduit extends from the fittings to establish many different flowschemes in and out of the filters and between the filters and/or the separate storage and treatment vessels. Each bracket may be made to include fitting configurations of various types, that is: 1. One fitting, that is, a single fitting for attachment to an inlet port or an outlet port; 2. Two fittings, that is, “double fittings” for connection to both an inlet port and an outlet port; or 3. No fittings, wherein the particular bracket, either top or bottom bracket, is intended for support of the filter but not for conducting of fluid. Single-fitting brackets are placed on both ends of flow-through filters, for example, to allow flow into the filter top end and out of the filter bottom end. Double-fitting brackets are used at one end of a central-return-tube-style filter, preferably the top end, to allow flow in and out of a single end of the filter. For such return-tube filters, the bottom bracket typically contains no fittings or conduit, because the bottom bracket serves only to support and retain the filter. Brackets intended for the various fitting configurations may be made the same or substantially the same, that is, having the basic structure for more than one configuration but having one or more fittings blocked off for use with different filters. For example, a bottom bracket may be formed to have a post that, in some flowschemes, fluidly communicates with a port in the filter, or, in other flowschemes, may have its internal passage blocked and have no attached conduit, so that there is no fluid communication. Or, the filter may have only an indentation in its bottom end rather than a port, so that a post with an internal passage still does not communication with the internals of the filter. The brackets serve as support, securement, and quick-connect and quick-disconnect fluid conduit means. To fulfill these objects, the preferred top and bottom brackets have pivotal features that allow the filter to “clear” the brackets during removal. The top brackets are preferably adapted to pivot off of the filters, so that the filters may be lifted up off of the bottom brackets. Additionally, the bottom brackets may be pivotal, so that lifting the filters up from the bracket system is facilitated by allowing the filter to also pivot out away from the top modules. Thus, the top bracket preferably comprises a lid that has a substantial vertical component to its movement, to clamp down over the top filter connection for retaining the filter top in place, and then to move up and away from the top filter connection for removal of the filter. The bottom bracket comprises a base that vertically receives the bottom surface of the filter, and, optionally, a vertical fitting for forming a fluid connection with the bottom of a flow-through filter. Preferred Key System Preferred embodiments include a key system wherein a portion of a fluid cartridge-holder connection is structurally adapted so that only matched filter cartridges and holders can cooperate to allow installation of the filter cartridge in the holder and/or to form a fluid seal. In other words, each filter cartridge and holder combination or “set” is “keyed” so that only that particular filter cartridge design mates with that holder. According to the invention, there are created various cartridge-holder sets that each have the adaptation, but the adaptation is slightly offset for each set compared to the other sets. This way, a filter cartridge from one set may not be mixed with a cartridge from another set, and, therefore, a filter cartridge may not be installed on any but its own matching holder. The adaptation preferably involves a varying location of a “key” protrusion and a “lock” recess combination, such as a tab-slot combination, typically with mating protrusion(s) and recess(es) being at a certain angle on a circumference for one cartridge-holder set and a mating protrusion(s) and recess(s) of a similar or identical shape being at a different angle on the circumference for another cartridge-holder set, and so on, for each similarly-shaped-but-differently-located-adaptation cartridge and holder set. In other words, the key protrusion and the lock recess are selectably locateable around cooperating perimeters of a filter cartridge and its holder. The key and lock structures (hereafter typically called “key protrusion” or “protrusion” and “lock recess” or “recess,” respectively) are preferably rigidly molded or otherwise permanently placed on/in the filter cartridge and holder, and so they are not considered moveable. They are, however, easily changed in the molding or other manufacturing process, that is, they are easily selectable by locating them at different angles/locations around a circumferential surface. This system may include a plurality of sets of filters and holders, each set having a differently-located key and lock, wherein the key and lock of each set cooperate with each other to allow that filter to be installed in that holder, but that filter may not be installed in any other holder because the key or lock of that filter does not cooperate with the key or lock of the other holder. The term “key or lock” is used because the key protrusions may be placed on either the filter or the holder, and the lock recess may therefore be placed on the other item. Thus, for example, a water or beverage filtration facility, experimental pilot plant, or other filter user may control filter cartridge placement accurately. A facility with multiple, different filtering applications may have filter cartridges on hand for each of the applications, but the cartridges will not be confused. For example, in a facility in which there are two different applications, many of the two different types of filter cartridges may be kept in stock and even may be mixed during storage or handling, but the filter cartridges will not be mixed when installed into the filter holders. This is because the filter holder and the filter cartridges for the first application are “keyed” differently than the filter holder and the filter cartridges for the second application. The terms “keying” or “keyed” refer generally to how and where the entire key system is located or accomplished, that is, to the positioning or style of either one or both of the cooperating key and lock structures, rather than specifically to only the location of the “key protrusion.” All the filter cartridges for the first application are keyed the same, that is, to match the first application holder, and all the filter cartridges for the second application are keyed the same, to match the second application holder. The keying for the first application and the keying for the second application does not need to be very different, but may be merely, for example, a slightly different angular position for the two protrusions and recesses. Also, a filter manufacturer may control his product lines more carefully by using the invented key system. A manufacturer may key his holders and filter cartridges differently for different countries, different clients, different distributors, or for different time periods. This technique may be used to prevent unauthorized or low-quality copies of the manufacturer's filter cartridges from easily being made. With so many differently-keyed cartridges in the marketplace provided by the original manufacturer, the incentive to provide cheap, low quality copies will be minimized, due to the expense of retooling for each “key and lock” set. The key system may include many different protrusion and recess structures, for example, tabs and slots (typically thin or elongated bar and channel structures or elongated dove-tail structures), bumps and holes (typically rounded or mounded structures with cooperating valleys or holes), wedges and wedge-shaped wells (typically circular section structures); and many other shapes. Preferably, the invented system also includes an optional universal key feature that may be supplied to the client/customer, wherein a single “universal cartridge” is made that may be used on a plurality of differently-keyed filter holders. The “universal” cartridge may be, for example, a cleaning cartridge, a sanitization cartridge, a media regeneration cartridge, a special treatment cartridge, or a testing cartridge, wherein it is more convenient and economical for the user to have a universal cartridge fitting all of the user's or manufacture's variously-keyed holders. This may be, for example, because the user wants to use a single universal cartridge for cleaning of all his various filtration or treatment processes and does not want to invest in differently-keyed cleaning cartridges for each differently-keyed holder. Also, this way, a manufacturer that supplies different customers with large volumes of differently-keyed holders and cartridges (for their main filtration and treatment process) may supply all the customers with the same universal-key cartridge for special or infrequent processes such as cleaning or media regeneration. This allows the manufacturer to maintain profitability even on the small volumes of cleaning or other infrequent-use cartridges that are required, by saving the expense of manufacturing and monitoring proper shipment of many differently-keyed cleaning cartridges. The universal cartridge includes a “lock recess” or “key protrusion” (depending on whether the system is a recess-on-cartridge or a protrusion-on-cartridge system) at every location where any of the holders involved have a corresponding recess or protrusion. For example, if a manufacturer produces holders and cartridges that are keyed with recesses and protrusions at 30 degree increments, the universal cartridge for the holders involved will have recesses or protrusions at every 30 degrees. For example, if a manufacturer produces holders and cartridges that have recesses and protrusions on fluid connectors at 12 o'clock and 5 o'clock for one client and at 3 o'clock and 11 o'clock for another client, that manufacturer may produce a universal cleaning cartridge with recesses or protrusions at all of the positions of 12, 3, 5, and 11 o'clock. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side perspective view of one embodiment of the invention, which comprises four pairs of brackets, with four filters in various stages of removal, the brackets being shown without tubing between the brackets. FIG. 2 is a front view of the filters and brackets of FIG. 1 . FIG. 3 is a front view of an embodiment of a bottom bracket, filter top, and top bracket for a down-flow filter system. FIG. 4A is a schematic front view of one embodiment of a bottom bracket, including one side-extending fitting and a blocked opposite-side fitting. FIG. 4B is a schematic side view of another embodiment of a bottom bracket with one rearward-extending fitting and flexible tubing illustrated as extending in two alternate directions. FIG. 5A is a schematic of one embodiment of a flow scheme possible according to the invention, which includes two pairs of brackets with an inlet at the top and an outlet at the bottom and two pairs of brackets with both inlet and outlet in the top bracket, and intermediate storage or treatment. FIG. 5B is a schematic flow diagram of another embodiment of the invention, including 5 filters in series with intermediate storage/treatment after the first filter, and each filter and its respective brackets featuring a different flow direction and/or fitting location. FIG. 6 is a perspective view on an alternative embodiment of a filter holder, a bracket with keyed structure on connection tubes that connect to and fluidly seal to an alternative embodiment of filter cartridge. FIG. 7 is a bottom, cross-sectional view of the filter holder of FIG. 6 , viewed along the lines B—B in FIG. 8 . FIG. 8 is an end view of the filter holder of FIGS. 6 and 7 . FIG. 9 is a top view of the filter holder of FIGS. 6–8 . FIG. 10 is a detail view of Section A of FIG. 9 , of the filter holder of FIGS. 6–9 . FIG. 11 is a front, cross-sectional view of the filter holder of FIGS. 6–10 , viewed along the line A—A in FIG. 9 . FIG. 12 is a front view of the filter holder of FIGS. 6–11 . FIG. 13 is a detail view of the inlet and outlet tubes of the filter holder of FIGS. 6–12 , viewed as detail B of FIG. 12 . FIG. 14 is a partial side view of one embodiment of a filter cartridge, which is adapted to cooperate with the filter holder of FIGS. 6–13 . FIG. 15 is a partial side view of a filter cartridge of the type cooperating with the filter holder of FIGS. 6–13 , but with an alternatively-angled key system structure. FIG. 16 is a partial side view of a filter cartridge of the type cooperating with the filter holder of FIGS. 6–13 , but with an alternatively-angled key system structure. FIG. 17 illustrates a partial side view of an embodiment of a universal cartridge that is adapted to fit into all the filter holders that receive the differently-keyed cartridges shown in FIGS. 14–16 . FIG. 18 a illustrates a perspective view of an embodiment of holder according to the invention with tabs on inlet and outlet tubular connectors at 11 o'clock and 12 o-clock, respectively. FIG. 18 b is a top view of the holder in FIG. 18 a. FIG. 18 c is front side view of the holder in FIG. 18 a and 18 b. FIG. 19 a is a perspective view of the top of a filter cartridge keyed for use with the holder of FIGS. 18 a–c. FIG. 19 b is a top view of the embodiment of FIG. 19 a. FIG. 19 c is a front side view of the embodiment of FIGS. 19 a and b. FIG. 20 a illustrates a perspective view of another embodiment of holder according to the invention, with tabs on inlet and outlet tubular connectors at 11 o'clock and 3 o-clock, respectively. FIG. 20 b is a top view of the holder in FIG. 20 a. FIG. 20 c is front side view of the holder in FIGS. 20 a and 20 b. FIG. 21 a is a perspective view of the top of a filter cartridge keyed for use with the holder of FIGS. 20 a–c. FIG. 21 b is a top view of the embodiment of FIG. 20 a. FIG. 21 c is a front side view of the embodiment of FIGS. 20 a and b. FIG. 22 is a side view of a top end of a universal cartridge keyed for use with both of the holders of FIGS. 18 a–c and 20 a–c. FIG. 23 is a side view of a top end of a universal cartridge keyed for use with a plurality of holders with keys are various positions 45 degrees apart, starting at “straight up at 12 o'clock” and spaced every 45 degrees from that position. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the Figures, there are shown several, but not the only, embodiments of invented bracket and filter system. FIG. 1 illustrates a four-filter system 10 having four pairs of brackets, comprising four top brackets 12 and four bottom brackets 14 that are arranged side-by-side (“aligned”) in two parallel horizontal rows. Alternative arrangements may include non-aligned locations for the brackets with a variety of spacings and patterns, as long as the top bracket and the bottom bracket of each pair of brackets are appropriately spaced apart vertically to receive the filter 11 . Each pair of brackets may be located generally independently of the others as long as the conduit between them and to/from intermediate storage and treatment is long enough. This allows a great variety of arrangements and spacings, as well as many flowschemes and liquid treatment options. As may be seen in FIGS. 1 and 2 , each top bracket 12 comprises at its rear an attachment plate 20 for attachment to a wall or other preferably vertical surface. Connected to the plate are two side-by-side fittings, one for fluid flow into the filter and one for fluid flow out of the filter. Each of the fittings has a first end 22 and a second end 24 , wherein the first ends are tubular protrusions extending out from the bracket generally horizontally toward the front of the bracket for connection to the inlet port and outlet port of a filter. The fittings extend back from their first ends 22 and preferably bend at about 90° to turn opposite directions to place their second ends 24 at opposite sides of the bracket. The second ends 24 are adapted for connection to conduit 40 (not shown in FIGS. 1 , 2 , and 3 , but shown in FIGS. 4B , 5 A, and 5 B), which is preferably flexible tubing, but may also be a rigid tube, pipe, or other connector. Flexible tubing is normally used for flow schemes in which the conduit runs from the top bracket to some location other than another top bracket immediately adjacent, because the conduit normally includes several bends and curves. For example, the flexible tubing may extend from the first top bracket to a storage tank, and then back to a top bracket or to a bottom bracket. For conduit paths that require few or no bends/curves, rigid or partially rigid conduit is effective. For example, a rigid connector may extend straight from a second end of one top bracket to an adjacent second end of an adjacent top bracket. An example of a rigid tube connector may be two collet-style connectors joined by a short length of pipe or flexible tubing. In embodiments in which the two first ends are side-by-side parallel to each other, the two second ends are preferably opposite-facing on the same axis. Each of the two fittings of the top bracket is preferably isolated from the other, in that fluid must flow through one bracket into the filter, and through the filter to reach the other fitting and out to another bracket or separate storage/treatment. Alternatively, if a bracket is temporarily not to be used for a filter, the inventor envisions that a jumper tube or connector may be installed between the two fittings to allow flow from one fitting to the other without going through a filter. Also, the inventor envisions that, instead of bending at 90°, fittings may extend straight back from the first ends 22 through the attachment plate 20 for connection to conduit 40 behind or passing through attachment plate. This would be practical for embodiments designed to hang on a grid or other non-solid surface that would allow conduit to pass back and forward through the grid. The top bracket 12 includes a lid 30 pivotally connected to the attachment plate 20 , by way of one or more arms rotatably disposed around the fittings near the second ends. The lid 30 is generally an inverted-cup-shape with a top wall 32 , side walls 34 , front wall 36 , and an interior space 38 . The lid pivots between a raised position, as indicated at “U” (for up), to a lowered position indicated at “D” (for down). With the lid in the raised position, the first ends of the fittings and the top end 42 of the filter (especially the inlet port 44 and outlet port 46 ) are exposed, and the filter may be pulled away from the fittings. In the lowered position, the lid is lowered over the first ends and the filter ports 44 , 46 , in effect, enclosing the fitting-port connection on the top, front, and two sides. In this lowered position, the lid and especially the front wall 36 , retains the filter top end 42 in the bracket 12 , because it cannot be pulled out or fall out from the fittings. Preferably, an elastic band (not shown) or other biasing member is installed to bias the lid into the lowered position. This way, a person my temporarily raise the lid to remove a filter top end, but, as soon as he/she lets go of the lid, it snaps back down, pivoting relative to the attachment plate and the fittings to rest in the lowered position. The bottom bracket 14 that is adapted for cooperation with the double-fitting top bracket discussed above does not need to include a fitting for connection to a port. Because both inlet and outlet fittings, in such an embodiment, are positioned at the top bracket, the bottom bracket need only be a support system for the bottom end 52 of the filter. For such embodiments, the base 54 and its post 56 do not carry fluid or convey fluid to conduits or other filters or vessels, but rather serve for support, alignment, and securement of the filter. The base 54 portrayed in FIGS. 1 and 2 includes a post 56 that may be received in an indentation in the bottom of the filter for alignment of the filter in the base, but in an embodiment in which the filter top end 42 includes both inlet and outlet ports 44 , 46 , the indentation is not a port and the indentation, and therefore the post, are not in fluid communication with the filter. The bottom bracket 14 has a rear attachment plate 60 for attachment to the vertical wall and two spaced arms 64 , 64 ′ that extend out from the plate 60 . Pivotally connected to the arms 64 , 64 ′ is the base 54 with a bottom wall 66 and a side wall 68 surrounding and defining an interior space 70 for receiving the bottom end 52 of the filter. The base 54 is biased by an elastic band (not shown) or other member to remain in a position with the base generally on a horizontal plane and vertically receiving the filter. When force is applied to pivot the base, it pivots on a horizontal axis that is parallel to the plate of the bracket, to a tilted position slightly outward away from the plate. This pivoting typically occurs when the filter top end is pivoted out slightly away from the top bracket so that the filter clears the top bracket when lifted up out of the bottom bracket (see two filters on left of FIGS. 1 and 2 ). In some embodiments, it is envisioned there may be room for some pivoting of the filter bottom end relative to the base, but, in most embodiments, it is preferred that the filter have a close fit in the base and is not pivotal relative to the base. Therefore, when the filter is tilted outward, the base pivots outward with it, typically about 15–25° from a vertical plane. The filter is then lifted up out of the base at that angle relative to vertical, which may reasonably be considered generally vertically. The biasing member returns the base to its upright position after the filter is removed. For alternative embodiments, in which the filter top and top bracket have only one fitting and port 44 , or no fittings or port, the bottom bracket is adapted to carry and direct fluid in and/or out of the filter. In embodiments in which the bottom bracket includes one fitting for a filter port, the bottom bracket preferably includes tubular post 56 in the center of he base, as illustrated by FIG. 3 . The post upends into the interior space to be slidably received in a port in the filter bottom end 52 . The post upends perpendicularly from the base bottom surface, to be vertical when the base is in its upright position. The port into which the post is received runs axially into the filter, preferably at the central axis of the filter. The post's axial fluid passage 70 is thereby placed in fluid communication with the filter and serves as a fitting for connection to conduit for conducting fluid to/from the filter. An effective system using a fluid-conducting bottom bracket is to have fluid enter the filter top end via a top bracket fitting and a top inlet port 44 , flow down through the filter 11 either in axial and/or radial flow to a bottom outlet port. From the bottom outlet port, fluid flows into the hollow post 56 in the base, to a conduit 40 that conducts the fluid to another bracket (either top or bottom) or intermediate storage or treatment. Alternatively, the post may serve as an inlet to the filter, which would then be a flow up filter. Alternatively, the bottom bracket may include both an inlet and an outlet fitting, for embodiments in which the top bracket does not include any fluid fitting or conduit. This could be accomplished by providing two vertical posts upending from the base and in fluid communication with an inlet and outlet port in the bottom end of the filter, for example, an inlet offset from the central axis of the filter and the outlet at the central axis of the filter. As illustrated schematically in FIGS. 4A and 4B , the post represents the first end of the bottom bracket fitting, which further includes a second end 57 adapted for connection to the conduit 40 . Various fitting styles may be provided on the bottom bracket fitting second ends. FIG. 4A illustrates schematically a bottom bracket 12 with a fitting extending from its first end (post 56 ) to bend about 90° to open at its second end 57 at the side. In this embodiment, the fitting second end 57 and a protrusion 59 opposite the second end both pivot in the arms, so that the pivotal axis extends through the central cavity 61 of the fitting second end. FIG. 4B shows an embodiment in which the fitting second end 57 ′ extends in an L-shape rearward and transverse to the pivotal axis. In such an embodiment, the fitting second end 57 ′ conveniently connects to a flexible tubing 40 that extends back through the plate 60 , or through a grid wall. Or, the tubing may extend up to loop up to a top bracket of the adjacent filter or to intermediate storage/treatment. Several of many flow schemes are possible with the invented system shown schematically in FIGS. 4A and 4B . Filters of many designs and contents may be used with the invented bracket system. For example, down flow (either radial and/or axial), up flow (either radial and/or axial), or central return tube styles with both inlet and outlet at one end may be used. Many filtration and treatment media may be used including carbons, bolides, blocks, granules, fibrous, or other materials and/or even media void spaces. The base 54 of the bottom bracket illustrated in FIGS. 1 , 2 and 4 B is preferably removable from the plate, by means of a snap-in or slide-in connection between the base and the arms 64 , 64 ′. As shown in FIGS. 1 and 4B , the pivotal members 67 received in holes 69 in the arms are flattened. When the base is pivoted about 90°, the flattened pivotal members 67 align their lengths with the slot opening 71 leading out from the holes in the arms, and can then slide out of the arms. This feature, or other removable adaptation, allows one to remove the base with its fitting for maintenance or replacement. Preferred Embodiment of Top Bracket FIGS. 6–12 illustrate a particularly preferred version of a piece of the top bracket 12 , with tubular connector for connecting to a filter cartridge top. Bracket member 210 is the piece that seals with, and fluidly-communicates with, a filter cartridge at its top end. It is the two tubular connectors, therefore, that create a physical connection and fluid communication between the bracket and cartridge, and the lid 30 (not shown in FIGS. 6–12 ) helps lock the filter onto the tubular connectors. The bracket member 210 shown in FIG. 6–12 includes both inlet and outlet tubular connectors, for conducting fluid both into and out of the filter cartridge. Thus, the bottom bracket corresponding to such an embodiment would not include any fluid communication ports/tubular connectors. The bracket 210 shown in FIGS. 6–12 includes, as an option but not a necessity, a keyed system to control what filters are inserted into particular brackets. The keyed system includes tabs that protrude from the inlet and outlet tubular connectors that would be part of a keyed system, to make the tubular connectors' outer surface not perfectly cylindrical, wherein the protruding tabs would be sized to fit into correspondingly positioned and properly sized slots in the inner surface of the filter cartridge ports. Thus, the tabs of the tubular connectors (shown) and the slots (not shown) of the filter cartridge ports, therefore, may form a “key system” which can be used to keep unauthorized or improper filter cartridges from being placed on a particular bracket 210 . For various sets of brackets and their proper filter cartridges, the tab and slot location/position would be differently arranged, so, for example, a “Type A” filter cartridge could only be inserted into a “Type A” bracket, and a “Type B” filter cartridge could only be inserted into a “Type B” bracket. Type A could be a pre-filter, for example, and its tab and slot could be positioned, for example, at “one-o'clock on the tubular connectors and ports. Type B could be a microbial treatment filter cartridge, for example, and its tubular connectors and ports, for example, could be positioned at “four o'clock.” Thus, by placement of the Type A and Type B brackets in a particular order, one could ensure that the cartridges are always in the correct order. In FIG. 6 is shown the bracket 210 that serves several function: mounting means for securing the bracket to a wall of other surface, fluid receiving means, inlet tube for conveying liquid to the filter connected; outlet tube for conveying liquid from the filter; and fluid dispensing means for sending the filtered/treated liquid downstream to another filter, process, storage, or use. Specifically, plate 212 may be attached to a wall or other surface for supporting several brackets in various flow configurations. Inlet 214 and outlet 216 are at opposite ends of a conduit device 218 , and may be used so that inlet 214 receives fluid from an upstream pipe or other conduit and that outlet 216 delivers filtered fluid (that has exited the filter cartridge) to its downstream destination. The conduit device 218 directs flow into the inlet tube 220 so that the fluid may flow into the filter cartridge, and then receives flow from the cartridge into the outlet tube 222 so that it may flow out through outlet 216 . As part of the preferred, but not necessary, key system, male tubes 220 and 222 have “stand out” or tabs 225 , 225 ′ on their outer cylindrical surfaces for a key system, such as discussed above, which are preferred but not required. As best seen in FIGS. 6 and 7 , tube 220 and tube 222 have tabs 225 , 225 ′ protruding about 30 degrees offset from each other (tab 225 of tube 220 out to the left in FIG. 14 and tab 225 ′ of tube 222 down about 30 degrees from the tab 225 of tube 220 ). The cooperating filter cartridge 228 shown schematically in FIG. 15 has female inlet and outlet tubes 230 and 232 (which may also be called an inlet port and outlet port), and one may notice that tubes 230 and 232 have matched or “mating” internal slots 227 , 227 ′ to receive the tabs 225 , 225 ′. Alternatively, of course, filter cartridges might be made with male tubes and tabs and cooperating holders may be made with female tubes and slots. The bracket 10 in FIGS. 6–13 typically is installed in a process with the plate 212 vertically attached to a vertical wall. Thus, tubes 220 and 222 extend out horizontally, and the filter cartridge is pushed onto the tubes 220 , 222 so that the tubes 220 and 222 support and connect with the filter cartridge. Associated with the tubes 220 , 222 , 230 , 232 are o-rings or other sealing structure to provide liquid-tight communication between the bracket and the cartridge. Although it is not shown, one may see from FIGS. 6–13 that liquid-tight seals are made between piping or other conduit and the inlet 214 and outlet 216 . Additionally, a fastening device may be added to further secure the cartridge in sealed relationship with the tubes 220 , 222 , such as lid 30 . One may see that, by varying the radial location of the tabs and slots, one could arrive at many “keys” and “locks” for the cartridge-holder sets. For example a holder could have an inlet tube with a tab at 60 degrees from a reference point and the outlet tube could have a tab at 120 degrees relative to that reference point, as long as the proper cartridge for that holder is made with the same offset and the same absolute location of slots. FIGS. 6–14 illustrate only one set of the many possible combinations of possible tab radial locations, which are extremely numerous because the radial location of each of the tubes may be varied in each set, and may be varied independently. FIGS. 151 and 16 illustrate two of the many other possible key system structures. For example, in the top end of elongated filter cartridge 228 ′ of FIG. 15 , the female inlet tube (port) 230 ′ is keyed at about 110 degrees, and the female outlet tube (port) 232 ′ is keyed at about 290 degrees. In the top end of elongated filter cartridge 228 ″ of FIG. 16 , the inlet tube 230 ″ is keyed at about 195 degrees and the outlet tube 232 ″ is keyed at about 170 degrees. The bracket 10 in FIGS. 12–19 typically is installed in a process with the plate 212 vertically attached to a vertical wall. Thus, tubes 220 and 222 extend out horizontally, and the filter cartridge is pushed onto the tubes 220 , 222 so that the tubes 220 and 222 support and connect with the filter cartridge. Associated with the tubes 220 , 222 , 230 , 232 are o-rings or other sealing structure to provide liquid-tight communication between the bracket and the cartridge. Although it is not shown, one may see from FIGS. 12–19 that liquid-tight seals are made between piping or other conduit and the inlet 214 and outlet 216 . Additionally, a fastening device may be added to further secure the cartridge in sealed relationship with the tubes 220 , 222 . Key System with Universal Key Feature General Comments In general, key system structures are located on surfaces of surfaces of filter cartridges (or “filters”) and holders that contact each other during connection of the cartridge to the holder. This may be either surfaces that are involved in mainly providing a physical connection between the cartridge and holder or that also are involved in providing a fluid connection between the cartridge and the holder. The preferred keyed system detailed herein involves the structure that create a fluid seal between the filter cartridge and the holder, for example, the inlet and outlet ports of the filter cartridge and the respective, cooperating ports/tubes in the holder that convey liquid to and from the cartridge. In this type of embodiment, the protruding and recessed structures are located around the inner and outer circumference of a tubular connector, comprising a male tube and female receiver, that allow connection of the filter cartridge and the holder, wherein fluid is conducted through the tubular conductor(s) once the cartridge seals to the holder. An example of such a tubular connector key system includes one in which both the filter holder's inlet and outlet and both the filter cartridge's inlet and outlet are all tubular and are all keyed. For example, a filter holder's inlet tube and an outlet tube (that direct flow to a cartridge and from the cartridge, respectively) each have an elongated axial tab that protrudes out from the outer cylindrical surface of the inlet tube and outlet tube at a chosen circumferential (also called “radial” or “angular” to imply non-axial) location or locations (that is, at different places on the circumference of the tube surfaces). Likewise, the inner cylindrical surfaces of the cartridge's cooperating female tubes (into which the holder inlet tube and outlet tube slide and seal) have channels or “slots” recessed into the surfaces at corresponding circumferential positions. This way, the holder inlet and outlet tubes slide into the cartridge ports, with the holder tabs sliding into the cartridge slots without significant resistance. Another cartridge with slots at a different circumferential location, on either one of its ports, would not receive the holder tubes and, hence, could not be accidentally or incorrectly installed in that particular holder. In such a case, where the filter cartridge has two tubes (inlet and outlet ports), each of the ports could have a different slot circumferential location, as long as the holder is made to match. For example, the holder's inlet tube tab (and corresponding slot on the cartridge inlet port) could be at “straight up” at 0 degrees, while the tab on the holder's outlet tube (and corresponding slot on the cartridge outlet port) could be at 30 degrees offset relative to the inlet tabs and slots. With this type of system, for example, varying additional different cartridge and holder sets each by an additional 30 degrees, many different sets of keyed cartridges and cooperating holders may be made. Many other amounts besides 30 degrees could be chosen, but this amount of offset gives many different combinations while providing an offset easily seen and judged by a person. The inlet tabs and slots and the outlet tabs and slots may be varied independently, for example, many sets may have the inlet tabs and slots at zero (0) degrees, while the sets may have differently-positioned outlet tabs and slots. Or, sets may have inlet tabs and slots that vary from set to set by 10 degrees, while those sets' outlet tabs and slots may vary by 15 degrees, for example. The mathematics of such a system suggest that practically an “endless” number of sets with different key system structures may be designed. Other keyed system styles, besides the tubular connector type, are envisioned. In keyed systems, in general, generally flat or smooth surfaces of the filter cartridge and the holder that conventionally would contact each other to instead include a key system structure that ensures that only a particular type of filter cartridge may be installed in a particular holder. The key system structure of the various sets of filter cartridge and cooperating holders/valve-heads is typically invisible once the filter cartridge is installed. While this may result in differently-keyed filter cartridges having substantially similarly-shaped outer housings, a manufacturer may include indicia on the outer surface of the filter cartridge to indicate the different media or other filter differences. Also, a user may look at the key system structure as long as the filter cartridge is uninstalled. In any event, when the user attempts to install a cartridge, only properly-keyed cartridges can be installed into the holder/valve-head/manifold. As an alternative to the tubular connector type system, another example of a key system structure is on structures that are involved in providing physical connection, rather than fluid connection. Such a key system structure may be on a shoulder of a filter cartridge that fits up into a valve-head holder. These areas are surfaces that do not normally liquid-seal to each other, but must clear each other if the end of the filter cartridge is to fit up inside the interior cavity of the valve-head. The top circumferencial shoulder of the filter cartridge and the inner surface of a valve-head, typically have areas that come in very close contact, but that are not directly involved in forming a liquid seal between the cartridge and the valve-head. These non-liquid-sealing areas may be keyed so that only a cartridge with a certain keyed surface shape may extend far enough up into the valve-head to be installed and locked into place. For example, tabs or other protrusions may be provided on the top surface of a filter spaced outward from an inlet-outlet neck, but external to the liquid-receiving passages. These filter cartridge protrusions may mate or “nest” in identically-located recesses on the inside surface of the valve-head that receives the cartridge, wherein the valve-head recesses are also external to the cartridge/valve-head liquid-receiving passages. The keyed structure on the filter shoulder and the inner surface of the valve-head holder may be said to be located around the outer circumference of a shoulder of the top end of the filter cartridge and the cooperating or corresponding inner circumference of the valve-head cavity. Preferably the protruding “key” structure comprises a plurality of protrusions located within an arc of about 90 degrees or less around the circumference on which it lies, or more preferably within about 70 degrees or less. The cooperating recess structure is preferably located in the cavity surface, facing the filter cartridge shoulder, and, likewise, the same number of recesses are located within the same amount of circumference, preferably about 90 or less, and, more preferably, about 70 degrees or less. In this type of embodiment, the protruding and recessed structures do not form a liquid seal(s) between the filter cartridge and the valve-head, because other structure typically nearer the central axis of the filter cartridge and head serve that purpose. While this preferred key system locates the protrusions on the filter cartridge shoulder and the recesses on the head, the opposite is envisioned, wherein the protrusions may be inside the filter head and the recesses may be on the filter cartridge. While the preferred keyed system includes keying of the holder and the filter cartridge, it may also include keying of an adaptor that is keyed to properly fit and cooperate with the keyed structure of the holder, and that has an unkeyed connected to a conventional, unkeyed filter cartridge. Preferred Universal Key Option For the tubular connector type keyed system, and for many of the various possible keyed systems for filter cartridges and filter holders, a universal key is desirable as an option for some circumstances. This universal key preferably takes the form of a filter cartridge that is adapted to fit any and all of the various differently-keyed holders that a manufacturer supplies to a single client/customer, or, alternatively, a filter cartridge that is adapted to fit any and all of the various differently-keyed holders that a manufacturer supplies to all of its clients/customers. As discussed above in the Summary, this allows an economical answer to the issue of providing differently-keyed main process filtration or treatment cartridges to a customer or to several customers while providing a single cleaning or other infrequent-use cartridge to a customer for all the customer's special applications, or to all customers for all their special applications. In other words, while there are good reasons to provide differently-keyed cartridges to different customers or to a single customer for his various uses, it may be important to have a single cartridge that is usable in all the customers' filtration/treatment systems, or at least in a plurality of differently-keyed holders. A universal key system preferably comprises a filter cartridge that is adapted to fit a plurality or all of the differently-keyed holders that a manufacturer makes or that are supplied to a client/user. For example, in FIG. 17 is shown schematically a top end 528 of (or may be formed as an adapter for) a filter cartridge that is adapted to fit onto all three of the holders for which the three cartridges 228 . 228 ′, 228 ″ in FIGS. 14–16 are made. That is, the FIG. 17 cartridge 528 has ports 530 and 532 that have multiple slots 561 , 562 , 563 , 564 , 565 , 566 that extend radially from the center of the ports and that are positioned so that cartridge 528 will slide onto and properly liquid-seal with the three holders. This way, cartridge 528 is “universally-keyed” with a total of six slots to fit a plurality of holders, which holders each have only one slot per port. As further examples of the preferred tubular connector style system, FIGS. 18 a–c illustrate views of a preferred male connector bracket, with one tab each on the inlet and outlet tubes. In FIGS. 19 a–c , there are shown various views of a cartridge that is keyed to cooperate with the holder of FIGS. 18 a–c. Likewise, FIGS. 20 a–c and FIGS. 21 a–c show views of an alternatively-keyed holder and cooperating cartridge, respectively. While these tubular connector systems include keyed systems in which each female or male connector only has a single slot or tab, alternative versions may have multiple tabs and slots on each female and male connector. FIG. 22 illustrates a universally-keyed cartridge top end (or adaptor) that is keyed to fit the holders of both FIGS. 18 a–c and 20 a–c. Note that the cartridge top end of FIG. 22 has two slots on one of the female connectors and one slot on the other of the female connectors, because the two holders of FIGS. 18 and 20 both have one tab position in common on one of the male connectors. FIG. 23 illustrates a universally-keyed cartridge top end (or adaptor) that is keyed to fit with any and all holders that have tabs on male connectors that are positioned straight up (at “12 o'clock”) and at various positions 45 degrees from that. For example, each of the two cartridge top end female connectors has eight slots radially extending out at straight up (0 degrees), 45 degrees, 90 degrees, 135 degrees, 180 degrees, 225 degrees, 270 degrees, and 315 degrees. This way, there are many combinations of one or more tabs on each of the male connectors that may be provided to a customer or customers, and the single cartridge in FIG. 23 will fit onto any of these 45 degrees version male holders. This way, the manufacturer may supply the same universally-keyed cleaning cartridge for many different customers that have requested differently-keyed cartridges for their main filtration/treatment processes. After reading this description, one may understand that a universal key cartridge may be supplied for various keyed systems. For example, a universal key cartridge may be made for a keyed system wherein a filter cartridge shoulder that does not liquid seal to a valve head may include the appropriate universal-keying to fit into several valve heads with different key structures. Or, a tubular connector type system may include otherwise-shaped tabs and slots, for example, such as rounded bump-shaped tabs and slots. By “holder” is meant any of a variety of devices that receive and seal to a replaceable filter or filter cartridge. This can include a valve head (including valving to shut off piping when the cartridge is removed), a filter bracket that supports the cartridge and provides fluid flow conduits into and out of the cartridge, and other devices that contact and are in fluid communication with the cartridge. By “filter” or “filter cartridge” is meant any container of filtration or treatment media that is connected to a holder for fluid communication with the holder to filter and/or treat the fluid brought into it via the holder. The keyed system invention may be applied to whatever structure of a filtering unit is inserted into the head or other holder, which might be a unitary filter or a filter cartridge encased partially in an outer housing below the level where the filter cartridge engages in the head. Although this invention has been described above with reference to particular means, materials and embodiments, it is to be understood that the invention is broad scope of the following claims.

A bracket system holds a filter(s) in quick-attach and quick-release fashion. Brackets are combined in modular fashion, with conduit between the brackets, to create a “bank” of filters easily changed in number, arrangement, and flow scheme. Top brackets and bottom brackets capture/support the top end and bottom end of a filter, respectively, and filter inlet and outlet ports preferably slide onto and off of cooperating tubes/ports in the bracket modules without tools or threaded connections. A retainer may pivot on and off of its respective filter, holding the filter in place and releasing the filter, respectively. After pivoting the retainer up from the filter, the filter may be lifted up off of its respective bottom module, so that the filter is substantially vertically and pivotally removable from the bracket system. A keyed system may ensure that only the appropriate filter fits into the appropriate filter holder, wherein the keyed system includes key protrusions and cooperating key recesses on the mating surfaces that form a fluid connection between the filter and the filter holder. Sets of holders and filters may be provided wherein each set has key structure at different radial locations on the members, so that filters from a particular set cannot be used with any other set's holder. A universally-keyed filter may also be supplied that has key structure that fits with and cooperates with more than one of the differently-keyed filter holders so that the universally-keyed filter may be used with the various sets' holders.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of: [0002] pending prior U.S. Provisional Patent Application No. 61/477,966, filed Apr. 21, 2011, Attorney's Docket No. OSM-7 PROV, entitled BONE PLATE, SCREW, AND INSTRUMENT; and [0003] This application is a continuation-in-part of: [0004] U.S. patent application Ser. No. 13/188,325, filed Jul. 21, 2011, entitled SPINOUS PROCESS FUSION IMPLANTS AND INSERTION COMPRESSION AND LOCKING INSTRUMENTATION, Attorney's Docket No. OSM-1 CIP 1. [0005] U.S. patent application Ser. No. 13/188,325 is a continuation-in-part of: [0006] U.S. patent application Ser. No. 12/853,689, filed Aug. 10, 2010, entitled SPINOUS PROCESS FUSION IMPLANTS, Attorney's Docket No. OSM-1. [0007] U.S. patent application Ser. No. 12/853,689 claims the benefit of: [0008] U.S. Provisional Patent Application No. 61/232,692, filed Aug. 10, 2009, entitled SPINOUS PROCESS FUSION IMPLANTS, Attorney's docket no. OSM-1 PROV; and [0009] U.S. Provisional Patent Application No. 61/366,755, filed Jul. 22, 2010, entitled INSERTION, COMPRESSION AND LOCKING INSTRUMENTATION, Attorney's docket no. OSM-5 PROV.; and is a continuation-in-part of: [0010] U.S. patent application Ser. No. 12/820,575, filed Jun. 22, 2010, entitled BONE TISSUE CLAMP, Attorney's Docket No. OSM-3. [0011] U.S. patent application Ser. No. 12/820,575 claims the benefit of: [0012] U.S. Provisional Patent Application Ser. No. 61/219,687, filed Jun. 23, 2009, entitled BONE TISSUE CLAMP, Attorney's Docket No. OSTE — 004USP1. [0013] All of the above named documents are incorporated herein by reference in their entirety. [0014] The following document is incorporated herein by reference: [0015] U.S. patent application Ser. No. 12/957,056, filed Nov. 30, 2010, entitled POLYAXIAL FACET FIXATION SCREW SYSTEM, Attorney's docket no. OSM-2. BACKGROUND [0016] The present disclosure relates to bone plates, screws and other fasteners, and related instruments. Examples include a screw and washer system with instruments, polyaxial screw and plate systems, bone clamp systems with spacers, sleeves, and/or cages, multi-level bone clamp systems, minimally invasive bone clamp systems, motion preserving systems, and instruments for handling plates, applying compression, and applying locking forces. More specifically, the present disclosure is set forth in the context of spinal surgery, such as spine fusion or motion preservation. BRIEF DESCRIPTION OF THE DRAWINGS [0017] Various embodiments of the disclosed technology will now be discussed with reference to the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. [0018] FIG. 1 is a transverse cross sectional view of a facet washer fixation system implanted in a facet joint, taken parallel to articular surfaces of the facet joint; [0019] FIG. 2 is a longitudinal cross sectional view of the facet washer fixation system and facet joint of FIG. 1 , taken along a center longitudinal axis of a screw of the system; [0020] FIG. 3 is an end view of a washer of the system of FIG. 1 with a portion of a cannula; [0021] FIG. 4 is a side view of the washer and cannula of FIG. 3 ; [0022] FIG. 5 is a side view of a rasp; [0023] FIG. 6 is a longitudinal cross sectional view of a polyaxial taper lock screw and plate system, taken along a center longitudinal axis of a screw of the system; [0024] FIG. 7 is a longitudinal cross sectional view of another polyaxial taper lock screw and plate system, taken along a center longitudinal axis of a screw of the system; [0025] FIG. 8 is a top cross sectional view of a modular spinous process clamp system; [0026] FIG. 9 is a longitudinal cross sectional view of a sleeve for use with the system of FIG. 8 ; [0027] FIG. 10 is a transverse cross sectional view of the sleeve of FIG. 9 ; [0028] FIG. 11 is a transverse cross sectional view of another sleeve for use with the system of FIG. 8 ; [0029] FIG. 12 is a transverse cross sectional view of yet another sleeve for use with the system of FIG. 8 ; [0030] FIG. 13 is a transverse cross sectional view of yet another sleeve for use with the system of FIG. 8 ; [0031] FIG. 14 is a side cross sectional view of another spinous process clamp system; [0032] FIG. 15 is a top cross sectional view of the system of FIG. 14 ; [0033] FIG. 16 is a top cross sectional view of a multi-level bone plate system; [0034] FIG. 17 is a side cross sectional view of the system of FIG. 16 ; [0035] FIG. 18 is an exploded top view of yet another bone plate system; [0036] FIG. 19 is an isometric view of a cage for use with the system of FIG. 18 ; [0037] FIG. 20 is a top view of another cage for use with the system of FIG. 18 ; [0038] FIG. 21 is a top view of yet another cage for use with the system of FIG. 18 ; [0039] FIG. 22 is a top exploded view of yet another bone plate system; [0040] FIG. 23 is an isometric view of a cage for use with the system of FIG. 22 ; [0041] FIG. 24 is an isometric view of another cage for use with the system of FIG. 22 ; [0042] FIG. 25 is a side view of the bone plate system of FIG. 22 with spinous processes; [0043] FIG. 26 is an end view of yet another bone plate system; [0044] FIG. 27 is a transverse cross sectional view of the bone plate system of FIG. 26 ; [0045] FIG. 28 is a top view of the bone plate system of FIG. 26 ; [0046] FIG. 29 is a transverse cross sectional view of the bone plate system of FIG. 26 after introduction of a plate and a post to a surgical site; [0047] FIG. 30 is a transverse cross sectional view of the bone plate system of FIG. 26 after introduction of another plate and locking components to the surgical site; [0048] FIG. 31 is a transverse cross sectional view of the bone plate system of FIG. 26 after final locking; [0049] FIG. 32 is a top cross sectional view of an interspinous process system; [0050] FIG. 33 is a top view of an extension plate coupled to an instrument; [0051] FIG. 34 is a side view of another instrument; [0052] FIG. 35 is a side view of yet another instrument; [0053] FIG. 36 is a side view of yet another instrument; [0054] FIG. 37 is an end view of an extension plate coupled to yet another instrument; [0055] FIG. 38 is a side view of a plate with non-spherical pads; [0056] FIG. 39 is a side view of a segmental multi-level spinous process plating system; [0057] FIG. 40 is a side view of another segmental multi-level spinous process plating system; [0058] FIG. 41 is a side view of a plate with an adjustable locking mechanism; [0059] FIG. 42 is a transverse cross sectional view of the plate and locking mechanism of FIG. 41 ; [0060] FIG. 43 is a side view of yet another segmental multi-level spinous process plating system; [0061] FIG. 44 is an isometric view of yet another cage for use with the system of FIG. 18 ; [0062] FIG. 45 is a cross sectional detail view of a plate and an instrument; [0063] FIG. 46 is a side view of another bone plate system; [0064] FIG. 47 is another side view of the bone plate system of FIG. 46 ; [0065] FIG. 48 is an exploded view of portions of the system of FIG. 46 ; [0066] FIG. 49 is a side view of a plate compressor instrument; [0067] FIG. 50 is a side view of a provisional locking arm for use with the compressor of FIG. 49 ; [0068] FIG. 51 is a side view of a final locking arm for use with the compressor of FIG. 49 ; [0069] FIG. 52 is a side view of a jaw portion of the compressor, provisional locking arm, and final locking arm of FIGS. 49-51 ; and [0070] FIG. 53 is another side view of the jaw portion of the compressor, provisional locking arm, and final locking arm of FIG. 52 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0071] The disclosed technology relates to bone plates, fasteners, and related instruments. The disclosure is made in the context of spine procedures, such as fusion or motion preservation. Those of skill in the art will recognize that the systems and methods described herein may be readily adapted to similar anatomy elsewhere in the body. Those of skill in the art will also recognize that the following description is merely illustrative of the principles of the technology, which may be applied in various ways to provide many different alternative embodiments. This description is made for the purpose of illustrating the general principles of this technology and is not meant to limit the inventive concepts in the appended claims. [0072] Referring to FIGS. 1-2 , a facet washer fixation system 10 may include a screw 12 and a washer 14 . [0073] The screw 12 may include a proximal head portion 16 and a distal shaft 18 . The proximal head portion 16 may have a larger diameter than the rest of the screw 12 . The proximal head portion 16 may include a torque transmission feature 20 . The torque transmission feature 20 may be an internal feature, such as a straight slot, cruciform slot, square socket, hex socket, or the like. The torque transmission feature 20 may also be an external feature, such as a tab, cruciate key, square key, hex key, or the like. The distal shaft 18 may include a threaded portion 22 to thread into bone. The entire length of the shaft may be threaded, or some portion or portions thereof. The screw 12 may be similar or identical to the facet fixation screw system 10 disclosed in U.S. patent application Ser. No. 12/957,056. [0074] The screw 12 may be made of a biocompatible material or a combination of biocompatible materials. For example, the screw 12 may be made of metal, polymer, ceramic, glass, carbon, composite, bone, or a combination of these materials. [0075] The washer 14 may be generally annular, curved, polygonal, asymmetric, or irregular. The washer 14 may have an aperture 24 through which at least a portion of the screw 12 may pass. The distal shaft 18 of the screw 12 may pass through the aperture 24 with clearance. [0076] The washer 14 may be made of a biocompatible material or a combination of biocompatible materials. For example, the washer 14 may be made of metal, polymer, ceramic, glass, carbon, bone, composite, or a combination of these materials. The material may stimulate bone formation on or in the washer. The material may include pores which communicate between the surface and the interior of the material. The pore morphology may be conducive to bone ingrowth. [0077] The screw 12 may be implanted so that it passes across a joint or discontinuity between two bones or bone fragments. The washer 14 may be implanted so that it lies in the joint, or between the two bones or fragments. Some bone may extend between the screw 16 and the washer 14 . [0078] FIGS. 1-2 illustrate an arrangement in which the screw 12 and washer 14 are implanted in a facet joint of a spine. The facet joint includes an inferior articular process 2 of a superior vertebra and a superior articular process 4 of an inferior vertebra. The screw 12 is oriented generally perpendicular to the articular surfaces of the facet joint. The screw head 16 rests against the inferior articular process 2 . The washer 14 is oriented generally parallel to, and between, the articular surfaces so that the inferior articular process 2 is between the screw head 16 and the washer. The inferior articular process 2 may fully encircle the distal shaft 18 . The aperture 24 receives the distal shaft 18 of the screw 12 . [0079] Referring to FIGS. 2-4 , the facet washer fixation system 10 may include a cannula 26 . The cannula 26 may include a proximal portion 28 and a distal portion 30 . The cannula 26 may also include an intermediate portion 32 which couples the proximal and distal portions 28 , 30 together. The cannula 26 may be a tubular structure with a longitudinal aperture 34 . The proximal portion 28 may include a grip feature 36 , which may be a flange, ear, tab, handle, or the like. The grip feature 36 may be textured, such as by knurling, grooves, roughening, or by the use of a high friction material such as silicone or rubber. The distal portion 30 may carry a washer holding feature 38 which holds the washer 14 in a desired orientation and at a particular distance from the distal portion 30 of the cannula 26 . The desired orientation may be influenced by the natural orientation of joint articular surfaces with respect to a selected screw trajectory. The washer holding feature 38 may include an arm 40 and a mount 42 , as shown in FIGS. 2-4 . The arm 40 may extend longitudinally from the distal portion 30 . The arm 40 may extend from one side of the distal portion 30 , and may include one or more bends along its length. More than one arm 40 may be included in the grip feature 36 . The mount 42 may extend from the free end of the arm 40 , and may be forked or bifurcated to receive the washer 14 within the fork. In the example shown, the mount 42 lies in a plane which is approximately perpendicular to a center longitudinal axis of the cannula 26 , although angles greater than or less than 90 degrees are contemplated. The mount 42 may be rigidly fixed to the arm 40 , flexibly coupled to the arm for resilient deflection, or hinged to the arm for free rotation. The mount 42 may include prongs 44 which mate with corresponding indentations 46 on the periphery of the washer 14 . The prongs 44 may slide, spring, snap, roll, or plunge into the indentations 46 . The mount 42 itself may flex or articulate to enable the prongs 44 to engage the indentations 46 . Other interconnections are contemplated, such as a skewer mount which spikes into the washer 14 . [0080] A method of using the screw 12 , washer 14 , and cannula 26 will now be described in the context of a facet joint fusion procedure. The washer 14 may be inserted into the mount 42 so that the prongs 44 engage the indentations 46 to hold the washer securely in the mount. The cannula may be positioned with the distal portion 30 resting against the inferior articular process 2 of the superior vertebra and the washer 14 and mount 42 within the joint space between the inferior articular process 2 and the superior articular process 4 of the inferior vertebra. The torque transmission feature 20 of the screw 12 may be coupled to a screw driver (not shown). The screw 12 and screw driver may be advanced through the aperture 34 of the cannula 26 until the distal shaft 18 of the screw rests against the inferior articular process 2 . The screw 12 may be driven through the inferior articular process 2 , through the aperture 24 of the washer 14 , and through the superior articular process 4 . Optional additional steps may include placing a guide wire through the cannula, articular processes 2 , 4 , and aperture 24 to establish a trajectory for the screw 12 to follow; drilling a pilot hole for the screw 12 through the inferior articular process 2 and/or the superior articular process 4 ; tapping a hole for the screw 12 through the inferior articular process 2 and/or the superior articular process 4 ; or using medical imaging to verify instrument and/or implant position. [0081] Referring to FIG. 5 , the facet washer fixation system 10 may include a rasp 48 . The rasp 48 may include a proximal portion 50 and a distal portion 52 . The proximal portion 50 may include an elongated shaft 54 . A grip feature (not shown) may be present on the proximal portion 50 . The distal portion 52 may include an aim 56 which carries a rasp head 58 in a particular orientation and at a particular distance from the distal portion 52 of the rasp 48 . The rasp head orientation and distance may be comparable to those for the mount 42 . The arm 56 may extend longitudinally from the distal portion 52 . The arm 56 may extend from one side of the distal portion 52 , and may include one or more bends along its length. More than one arm 56 may be included. The rasp head 58 may extend from the free end of the arm 56 . In the example shown, the rasp head 58 lies in a plane which is approximately perpendicular to a center longitudinal axis of the shaft 54 , although angles greater than or less than 90 degrees are contemplated. The rasp head 58 may be rigidly fixed to the arm 56 , flexibly coupled for resilient deflection, or hinged for free rotation. The rasp head 58 may be generally disc shaped, curved, polygonal, asymmetric, or irregular, and may include cutting features 60 on at least one surface. The cutting features may be blades, teeth, ridges, serrations, points, or other projecting asperities. The cutting features may instead be grooves, channels, or declivities. The rasp head 58 may be a hollow grater structure. The distal portion 52 may resemble the washer holding feature 38 of the cannula 26 . [0082] A method of using the rasp 48 will now be described in the context of the facet joint fusion procedure described above. The rasp 48 may be positioned with the rasp head 58 within the joint space between the inferior articular process 2 and the superior articular process 4 . The rasp 48 may be manipulated to move the rasp head 58 against one or both articular surfaces to roughen or remove articular cartilage, subchondral bone, and the like to prepare a space to receive the washer 14 . The rasp head 58 may be moved in a plane generally parallel to the articulating surfaces, although movement in other directions is contemplated. The rasp head motion may be reciprocating, oscillating, circular, oval, elliptical, figure-eight, or irregular. The rasp 48 may be in the cannula aperture 34 during use. A set or kit of variously sized and shaped rasps or rasp heads may be provided. The rasp or rasp head may be replaceable and/or disposable. [0083] Referring to FIG. 6 , a polyaxial taper lock screw and plate system 70 may include a washer 72 , a taper component 74 , a plate 76 , a pad 78 , and a fastener 80 . [0084] The washer 72 may be a generally annular component with a plate-facing surface 82 , or obverse, and an opposite reverse surface 84 . A threaded hole 86 may extend through the washer between the obverse and reverse surfaces 82 , 84 . The plate-facing surface 82 may include an indentation 88 or concavity around the hole 86 . The reverse surface 84 may be convex. The washer may include a torque transmission feature (not shown). For example, a hex key may be formed in an outer periphery of the washer. [0085] The taper component 74 may include a round, generally tubular body 90 with a flange 92 at one end and a full length central longitudinal hole 94 . The flange 92 may be at least partially received within the indentation 88 of the washer 72 . [0086] The plate 76 may include a bone-facing surface 94 , or obverse, and an opposite reverse surface 96 . A hole 98 may extend through the plate 76 between the obverse and reverse surfaces 94 , 96 . The hole 98 may receive the body 90 of the taper component 74 with clearance, line to line fit, interference fit, or taper fit. The bone-facing surface 94 may include an indentation 100 around the hole 98 . The indentation 100 may be spherical, conical, parabolic, elliptical, asymmetric, or irregular. The plate 76 may include a rim 102 , or lip, that encircles the indentation 100 . The internal diameter of the indentation 100 may be larger than the internal diameter of the rim 102 , so that the rim 102 forms a constriction around the indentation 100 . [0087] The pad 78 may be described as a polyaxial foot. The pad 78 may include a spherical plate-facing surface 104 and an opposite bone-facing surface 106 . The spherical plate-facing surface 104 may fit within the indentation 100 with clearance, line to line fit, or interference fit. The spherical surface 104 may have an external diameter that is larger than the internal diameter of the rim 102 , so that the pad 78 is retained with the plate 76 after initial assembly of the pad 78 to the plate 76 . The bone-facing surface 106 may include one or more spikes 108 . The pad 78 may include a central hole 110 . In the example of FIG. 6 , the hole 110 may extend perpendicular to the bone-facing surface 106 . In other examples, the hole 110 may extend at an acute angle to the bone-facing surface 106 . The hole 110 may receive a portion of the body 90 of the taper component 74 with clearance, line to line fit, interference fit, or taper fit. Alternately, the hole 110 may be the same size as the hole 94 in the taper component 74 , in which case, the taper component 74 may be integrally formed with the pad 78 . The pad 78 may share some or all of the characteristics of the pad 106 disclosed in U.S. patent application Ser. Nos. 12/853,689 and 13/188,325, which are incorporated by reference herein in their entirety. [0088] The fastener 80 may include a proximal head portion 112 and a distal shaft 114 . The proximal head portion 112 may be threaded, and may include a torque transmission feature 116 . The distal shaft 114 may include a threaded portion 118 to thread into bone. The fastener 80 may include an unthreaded shank portion 120 between the head portion 112 and the threaded portion 118 . The shank portion 120 may fit within the hole 110 of the pad 78 and/or the hole 94 of the taper component 74 with clearance, line to line fit, or interference fit. The proximal head portion 112 may thread together with the threaded hole 86 of the washer 72 . The threaded portion 118 of the distal shaft 114 may thread into bone. [0089] The polyaxial taper lock screw and plate system 70 may be assembled by forcing the spherical surface 104 of the pad 78 past the rim 102 and into the indentation 100 of the plate 76 , after which the pad remains captive to the plate; receiving the body 90 of the taper component 74 in the hole 98 of the plate, with the flange 92 adjacent to the reverse surface 96 of the plate; coupling the taper component to the pad, with the hole 94 of the taper component coaxial with the hole 110 of the pad and the bone-facing surface 106 of the pad faces outward from the indentation 100 ; receiving the head portion 112 and shank portion 120 of the fastener 80 through the holes 94 , 110 so that the distal threaded portion 118 of the fastener extends outwardly from the bone-facing surface 106 of the pad; and threading the proximal head portion of the fastener into the threaded hole of the washer 72 , with the obverse of the washer facing the plate. At first, the fastener 80 and washer 72 may be threaded together with fingertips. The fastener, polyaxial pad 78 , and taper component 74 may polyaxially pivot as a unit about the center of the spherical surface 104 within the indentation 100 . As the fastener and washer are threaded together, the fastener, polyaxial pad 78 , and taper component 74 may be drawn as a unit toward the washer until the polyaxial pad binds within the indentation 100 to lock the system 70 components rigidly together. [0090] In one method of use, the washer 72 , taper component 74 , plate 76 , pad 78 , and fastener 80 may be pre-assembled but not locked together. A first tool (not shown) may engage the torque transmission feature 116 of the fastener 80 , a second tool (not shown) may engage the torque transmission feature of the washer 72 , and a third tool (not shown) may stabilize the plate 76 . The three tools may nest, although this is not essential. In one example of a nested arrangement, the first tool is a hex driver which is received within the second tool, which is a hex socket. The second tool is received within the third tool, which is a tube terminating in a fork that fits over the width of the plate 76 . The first and second tools may be operated together to turn, or drive, the fastener 80 and washer 72 together to thread the fastener 80 into a bone without locking the system 70 components together. During this step, the bone-facing surface 106 of the pad 72 is brought into contact with the bone and the spikes 108 may penetrate the surface of the bone. The first tool may then be held in a fixed position while the second tool is operated to drive the washer 72 relative to the fastener 80 to lock the system 70 components together. During both steps, the third tool may hold the plate 76 in a fixed position. Tools which hold components in a fixed position while torque is applied elsewhere in the system 70 may be referred to as counter torque tools. [0091] In another method of use, the fastener 80 alone may be driven into bone, after which the pad 78 , plate 76 , taper component 74 , and washer 72 may be assembled to the installed fastener 80 . The washer 72 may be driven relative to the fastener 80 to lock the system 70 components together as described above. [0092] While the foregoing description describes a single instance of a fastener, pad, taper component, and washer assembled to a plate, multiple instances of these components are contemplated. For example, a plate may include two instances of the described components, such as one instance at each end of the plate. Additional intermediate instances may also be provided. The instances may lie along a straight line, or along any other geometric construct, or they may be randomly positioned on the plate. [0093] Referring to FIG. 7 , another polyaxial taper lock screw and plate system 130 may include a taper component 132 , a plate 134 , and a fastener 136 . [0094] The taper component 132 may include a threaded shaft 138 with a flange 140 at one end. The flange 140 may include a torque transmission feature 142 , such as a perimeter hex key, central hex socket, slot, or the like. [0095] The plate 134 may include a bone-facing surface 144 , or obverse, and an opposite reverse surface 146 . A hole 148 may extend through the plate 134 between the obverse and reverse surfaces 144 , 146 . The hole 148 may receive the shaft 138 of the taper component 132 with clearance, line to line fit, interference fit, or taper fit. The bone-facing surface 144 may include an indentation 150 around the hole 148 . The indentation 150 may be spherical, conical, parabolic, elliptical, asymmetric, or irregular. In this example, the indentation 150 is a frustoconical socket. The plate 134 is shown to have two instances of the hole 148 and indentation 150 , one at each end of the plate. [0096] The fastener 136 may include a proximal head portion 152 , a distal threaded shaft 154 , and an unthreaded shank 156 between the head portion 152 and the threaded shaft 154 . The head portion 152 may have a spherical outer surface 158 and a central threaded hole 160 . The spherical outer surface 158 may be at least partially received in the indentation 150 . The threaded hole 160 may thread onto the threaded shaft 138 of the taper component 132 . [0097] The polyaxial taper lock screw and plate system 130 may be assembled by seating the head portion 152 of the fastener 136 in the indentation 150 with the distal threaded shaft 154 extending outwardly from the obverse 144 of the plate 134 and threading the shaft 138 of the taper component 132 into the threaded hole 160 . At first, the fastener 136 and taper component 132 may be threaded together with fingertips. The fastener 136 and taper component 132 may polyaxially pivot as a unit about the center of the spherical surface 158 within the indentation 150 . As the fastener 136 and taper component 132 are threaded together, the fastener and taper component may be drawn toward the plate 134 until the spherical surface 158 binds within the indentation 150 to lock the system 130 components rigidly together. [0098] Referring to FIG. 8 , a modular spinous process clamp system 170 may include two plates 172 , 174 , a plurality of pads 176 , a locking mechanism 178 , and a sleeve 180 , or spacer. Plate 172 may be a first plate and plate 174 may be a second plate. The locking mechanism 178 may include a post 182 , a collet 184 , and a ring 186 . [0099] At least some of the components of system 170 may share characteristics of corresponding components disclosed in spinal fusion implant 100 of U.S. patent application Ser. No. 12/853,689 and 13/188,325. However, at least the following characteristics may differ from those disclosed in U.S. patent application Ser. Nos. 12/853,689 and 13/188,325. [0100] The plate 172 may include a spherical or conical socket 188 . The post 182 may include a complementary spherical enlargement 190 , or head, which fits into the socket 188 to form a polyaxial joint. However, a rigid plate-to-post interconnection may be substituted for the polyaxial joint in some examples. [0101] The plate 174 may lack extension walls. [0102] The sleeve 180 may at least partially encircle the post 182 and may be between the plates 172 , 174 when the system 170 is operatively assembled. The sleeve 180 may be an annular or tubular structure with a central longitudinal through hole 192 and an outer surface 194 . The sleeve 180 may be made from bone, ceramic, mineral, plastic, metal, glass, elastomer, or other biocompatible materials. [0103] Referring to FIG. 9 , another sleeve 200 may have a central longitudinal hole 192 and an outer surface 202 with a larger outer diameter at each end and a smaller outer diameter in the middle. This sleeve 200 may be described as having a waist or an hourglass figure, particularly when viewed in a longitudinal cross section. This sleeve 200 may also be described as having a concave outer profile when viewed in a longitudinal cross section through the center axis of the hole 192 . [0104] Referring to FIG. 10 , sleeve 180 may have a substantially annular transverse cross section. [0105] Referring to FIG. 11 , yet another sleeve 210 may have a central longitudinal hole 192 and a polygonal transverse cross section which is generally centered about the hole 192 . Sleeve 210 is shown with a parallelogram cross section, but other shapes are contemplated. [0106] Referring to FIG. 12 , yet another sleeve 220 may have a central longitudinal hole 192 and a polygonal transverse cross section which is asymmetrically disposed about the hole 192 . A polygonal cross section, such as the illustrated parallelograms of sleeves 210 , 220 , may complement the shape of an interspinous process gap. [0107] Referring to FIG. 13 , yet another sleeve 230 may have a central longitudinal hole 192 and an H-shaped longitudinal cross section. Sleeve 230 may also resemble a spool. Sleeve 230 may include enlarged flanges 232 , 234 , or rims, at each end and a reduced diameter midsection 236 . Sleeve 230 may be described as having a concave outer profile in longitudinal cross section. [0108] Any of the sleeves 200 , 210 , 220 , 230 may take the place of sleeve 180 in the system 170 . A kit of sleeves may be provided. The kit may contain several sleeve morphologies, and several sizes in each morphology. [0109] Referring to FIGS. 14-15 , another spinous process clamp system 250 may include curved plates 252 , 254 which may complement a spinal lordotic or kyphotic curve. The plates 252 , 254 may include slots 256 , or other arcuate guides such as grooves or rails, to permit longitudinal adjustment of pads 258 , locking mechanism 260 , or both. The system 250 may also include additional grips 262 between the plates 252 , 254 . While FIG. 15 shows two opposing grips 262 with the locking mechanism 260 , the grips 262 may be any number, and may be positioned anywhere between the plates. The grips may be static or movable relative to the plates 262 , 264 . [0110] Referring to FIGS. 16-17 , a multi-level bone plate system 270 may include a primary system 272 with a first locking mechanism 274 , and an augmentation system 276 with a second locking mechanism 278 . A locking mechanism 280 on each side of the construct links the primary and augmentation plates together. The locking mechanism 280 may include an arcuate or spherical mechanically locking interface 282 . While FIGS. 16-17 show one augmentation system 276 , other examples of this technology may include more augmentation systems mechanically linked in daisy chain fashion to address any number of spinal levels. Yet other examples may include augmentation systems linked to each end of the primary system 272 . [0111] Referring to FIG. 18 , an expandable interspinous plate system 300 may include plates 302 , 304 , pads 306 , a locking mechanism 308 , and a cage 310 . The locking mechanism may include a post 312 , a collet 314 , and a ring 316 . [0112] The cage 310 may occupy a position around the post 312 and between the plates 302 , 304 when the system 300 is operatively assembled. The cage 310 may reside in an interspinous process space when implanted as part of the system 300 . Referring to FIG. 19 , the cage 310 may be divided into two portions 318 , 320 which nest, or telescope, so that a width 322 of the cage may be increased or decreased as desired. In this arrangement, the cage 310 can adjust parallel to the post to fit precisely between plates 302 , 304 , and it may provide good exposure for loading materials into the cage. The cage 310 may be said to reversibly expand and contract. Each portion 318 , 320 may have a square channel shape. Nesting may be accomplished by making one channel narrower than the other so that the narrow channel is received within the wider channel, or by staggering two identical channels. Each end of each channel may be open or closed. The portions 318 , 320 include slots 324 , 326 , or openings, sized to accept the post 312 . The slots 324 , 326 may permit the cage 310 to pivot around the post 312 , therefore the cage 310 may assume an angled orientation relative to one or both of the plates 302 , 304 . [0113] Referring to FIG. 20 , another cage 330 may present an overall trapezoidal shape when its two portions 332 , 334 are nested. A first width 336 may be greater than an opposite second width 338 of the trapezoid. [0114] Referring to FIG. 21 , yet another cage 340 illustrates a narrow channel portion 342 nesting inside a wide channel portion 344 . [0115] Any of the cages 310 , 330 , 340 may enclose or support a bone graft, a scaffold for bone growth, or the like. The enclosed material may be a solid block or morselized pieces. Cages may be fenestrated or otherwise open to provide pathways for a bone fusion mass to develop. Cages may be load-bearing or load-sharing with the rest of the system 300 . For example, the cages may be open at cephalad and caudal faces for spinal fusions. [0116] Referring to FIG. 22 , another expandable interspinous plate system 360 may include a cage 370 which is adjustable in a direction generally parallel to the plates 362 , 364 , or generally perpendicular to the post. The cage 370 may include two portions 372 , 374 which nest or telescope so that a length 376 of the cage 370 may be adjusted as desired. The two portions 372 , 374 may be square channels, and may include open ended slots 378 , 380 which accept a post 382 and enable the cage 370 to pivot around the post 382 . The cage 370 may be rotated to an orientation in which the adjustment direction is substantially parallel to a physiologic load direction, which may subject a contained graft to compressive and/or tensile loads after implantation. Cage 370 may be fenestrated or otherwise open to provide pathways for a bone fusion mass to develop. [0117] Referring to FIG. 24 , another cage 390 may include at least a partial anterior wall 392 on one or both portions 394 , 396 . [0118] Referring to FIG. 25 , system 360 is shown implanted adjacent to spinous processes 384 , 386 . It can be seen that cage 370 rests between the spinous processes and at an acute angle relative to plate 362 . [0119] Referring to FIGS. 26-28 , a minimally invasive bone plate system 400 may include a curved post 402 , which may facilitate insertion of the post after placement of plates 404 , 406 . FIGS. 29-31 illustrate three steps in an example method of use. In FIG. 29 , plate 404 and post 402 may be inserted as a unit on one side of a series of spinous processes 384 , 386 , along direction arrow 401 . In FIG. 30 , plate 406 is attached over post 402 on the other side of the spinous processes. In FIG. 31 , the system 400 has been fully locked together around the spinous processes. [0120] Referring to FIG. 32 , an extension limiting interspinous process spacer system 420 may include plates 422 , 424 and locking mechanism 428 . The locking mechanism 428 may include a post 432 , a collet 434 , and a ring 436 . Each plate 422 , 424 may couple to the locking mechanism 428 at a polyaxial joint. The plates 422 , 424 may have smooth bone-facing or obverse sides 438 , 440 to permit the adjacent spinous processes to separate during spinal flexion. Spinal extension may be limited by the outside diameter of the post 432 . [0121] Referring to FIG. 33 , an instrument 450 provides three-point positive locking to an extension plate 460 . The instrument 450 includes two lateral connections 452 , 454 and a medial connection 456 . More specifically, the instrument may engage lateral cups 458 , or sockets, and a medial inner lip 461 , or edge, of a window 462 in an extension wall 464 . The lateral cups 458 may share some or all of the characteristics of the instrument connection feature 150 disclosed in U.S. patent application Ser. Nos. 12/853,689 and 13/188,325. [0122] Referring to FIGS. 34-35 , instruments 470 , 480 include positive locking through the lateral cups 458 . Instrument 470 includes an enlarged tip 472 which is received in the lateral cup 458 . Protruding from the tip 472 are forked tongues 474 which may be stored in a retracted position within the tip 472 or deployed to an extended flared position outside the tip. When the tip 472 is in the lateral cup 458 , the tongues 474 may be extended through the lateral cup to grapple with the obverse surface 466 of the plate 460 . Instrument 480 includes an enlarged tip 482 with a protruding deployable lever 484 that also grapples with the obverse 466 of the plate 460 . [0123] Referring to FIG. 36 , instrument 490 includes a fork 492 which grips an exposed lip 463 of the window 462 . [0124] Referring to FIG. 37 , instrument 500 includes a spherical expanding tip 502 which is received in the lateral cup 458 . The tip 502 expands when a shaft is driven through the tip 502 along its length. The tip 502 may be described as an expanding collet. FIG. 45 shows another example of an instrument 600 with a similar structure and function. [0125] Referring to FIG. 38 , a bone plate system 520 may include non-spherical or non-circular swiveling grips 522 , or pads. The range of motion of the non-spherical grips 522 may be selectively limited by the grip geometry. [0126] Referring to FIG. 39 , another multi-level bone plate system 540 may include chevron shaped plates 542 . Each plate 542 may include three pads 544 arranged in a triangle pattern complementary to the chevron shape. Each plate may also include a locking mechanism 546 . Consecutive plates 542 nest together as shown so that two plates may be secured to a single spinous process. The nesting shapes have sufficient clearance to permit angulation of consecutive plates to adapt to spinal lordotic, kyphotic, or scoliotic curves. [0127] Referring to FIG. 40 , yet another segmental multi-level bone plate system 550 includes S-bend plates 552 . Consecutive plates partially bypass each other so that two plates may be secured to a single spinous process. Although only two consecutive plates are shown in FIGS. 39-40 , more plates may be included depending on the number of spinal levels to be treated. [0128] Referring to FIGS. 41-42 , another bone plate system 560 includes a plate 562 with an elongated slot 564 which receives the locking mechanism 566 . In this arrangement, a polyaxial washer 568 may support a collet 570 in the slot 564 so that the locking mechanism 566 may be positioned as desired along the slot. [0129] Referring to FIG. 43 , another plate 580 for segmental multi-level fixation may have a generally T-shaped profile. Pads (not shown) may be located in the ends of the crossbar of the T so that two plates may be anchored to each spinous process. [0130] Referring to FIG. 44 , another cage 590 is shown. The cage 590 may be a box shape with four pillars 592 supporting two walls 594 . A hole 596 extends through both walls. Windows 598 are defined between the pillars. The hole 596 may receive a post of a locking mechanism, and the cage 590 may rest between two plates in an operative assembly. This cage may contain or support bone graft or other materials, such as osteogenic materials, within the box. [0131] Referring to FIG. 45 , a transverse cross sectional exploded view shows an instrument 600 and a portion of a plate 602 . [0132] Plate 602 includes an instrument connection feature 604 , which has an enlarged middle portion 606 between a first portion 608 and a second portion 610 . [0133] Instrument 600 includes an enlarged tip 612 and a plunger 614 . The enlarged tip 612 is received in the middle portion 606 of the instrument connection feature 604 . The tip 612 is hollow and includes at least one slit 616 to impart flexibility to the tip. In an extended position, the plunger 614 is received in the tip 612 and forces the tip to spread apart or enlarge for a tight fit in the middle portion 606 of the instrument connection feature 604 . The plunger 614 is actuated by an arm 618 which is coupled to a control (not shown). The plunger 614 moves between a disengaged or retracted position and an engaged, or extended position in response to the control. [0134] Referring to FIGS. 46-48 , another curved plate 630 includes a curved trough 632 . The trough may receive one or more pads 636 which may be movably mounted in the trough. For example, the trough 632 may include a spherical cup 634 for engagement with the pad 636 . In another example, a spherical surface 638 of the pad 636 may be directly retained and slidable in the trough 632 . [0135] Referring to FIG. 49 , a plate compressor 650 may include opposing jaws 652 , 654 , a main pivot 656 , opposing handles 658 , 660 , and an optional ratchet mechanism 662 . The plate compressor 650 may connect to the plates of any of the spinous process systems disclosed herein, and may urge the plates together and automatically maintain a compressive force between the plates until the ratchet bar 662 is released. [0136] Referring to FIGS. 50 and 52 - 53 , a provisional locking arm 670 may include a jaw 672 , a main pivot receiver 674 , and a handle 676 . The provisional locking arm 670 may be added to the plate compressor 650 by hooking the main pivot receiver 674 onto the main pivot 656 . The jaw 672 terminates in a collet fork 678 which isolates the applied force to push a collet component of a plate locking mechanism toward the plates for provisional locking. The provisional locking arm 670 may include a force indicator 680 which signals when a provisional locking force threshold has been reached. The force indicator 680 may be a beam. The signal provided by the force indicator may be visual, auditory, tactile, or any combination. The signal may be produced by differential deflection between the handle 676 and the force indicator 680 . [0137] Referring to FIG. 51 , a final locking arm 690 may include a jaw 692 , a main pivot receiver 694 , and a handle 696 . The final locking arm 690 may be added to the plate compressor 650 by hooking the main pivot receiver 694 onto the main pivot 656 , regardless of the presence or absence of the provisional locking arm 670 on the compressor 650 . The jaw 692 terminates in a ring 698 which isolates its applied force to push a ring component of a plate locking mechanism toward the plates for final locking. The final locking arm 690 may include another force indicator 700 calibrated for a final locking force threshold. [0138] When the provisional locking arm 670 and final locking arm 690 are coupled to the plate compressor 650 , the combination may have many of the characteristics set forth for the instrument 350 disclosed in U.S. patent application Ser. No. 13/188,325. [0139] The components of the systems disclosed herein are preferably formed of titanium or titanium alloy. In other embodiments, component parts may comprise cobalt-chrome and its alloys, stainless-steel, titanium and its alloys, titanium carbide, titanium nitride, ion-implantation of titanium, diffusion hardened metals, diamond like coatings, diamond-like carbon, zirconium nitride, niobium, oxinium or oxidized zirconium, ceramics such as alumina and zirconia, polymers, or other biocompatible materials. Any part may comprise a combination of any of the materials listed, and the systems may comprise parts made of differing materials. [0140] Any of the components disclosed herein may include surface treatments or additives in one or more of the component materials to provide beneficial effects such as anti-microbial, analgesic or anti-inflammatory properties. Any of the components disclosed herein may include coatings or treatments to provide surface roughening, including but not limited to knurling or porous coating, among others. Such treatments may be directionally applied to promote movement between component parts in one direction, and/or increase friction between component parts in another direction. [0141] The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. It is appreciated that various features of the above described examples and embodiments may be mixed and matched to form a variety of other combinations and alternatives. It is also appreciated that this system should not be limited simply to facet joint fixation. As such, the described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Systems for trauma and/or joint fusion implants and instruments include transarticular screw and intra-articular washer, polyaxial screw and plate, single- and multi-level polyaxial bone clamps, and minimally invasive adaptations.

BACKGROUND OF THE INVENTION This invention relates to a new method for inhibiting bone resorption that is mediated by the action of a class of cells known as osteoclasts, involving compounds that compete with osteoclasts for the osteoclasts' site of activity. Osteoclasts are multinucleated cells of up to 400 μm in diameter that resorb mineralized tissue chiefly calcium carbonate and calcium phosphate in vertebrates. They are actively motile cells that migrate along the surface of bone. They can bind to bone, secrete necessary acids and proteases and thereby cause the actual resorption of mineralized tissue from the bone. In the method of the present invention, aminoalkyl-substituted phenyl derivatives are administered in a pharmacologically effective amount that blocks osteoclasts from initiating bone resorption. These compounds have the general structural formula ##STR3## wherein n is an integer from 0 to 6; Y is CH 2 , O, SO 2 , CONH, --NHCO-- or ##STR4## R 1 and R 2 are independently hydrogen, C 1-8 alkyl, heterocyclyl C 0-4 alkyl, aryl C 0-4 alkyl, amino C 1-4 alkyl, C 1-4 alkylamino C 1-4 alkyl, C 3-8 cycloalkyl or C 1-6 dialkylamino C 1-6 alkyl wherein R 1 and R 2 may be unsubstituted or substituted with one or more groups chosen from R 3 , where R 3 is hydrogen, C 1-6 alkyl, hydroxy C 1-4 alkyl, carboxy C 1-4 alkyl, C 1-4 alkoxy C 1-4 alkyl, aryl C 0-4 alkyl, halogen, or CF 3 , R 4 is C 1-6 alkyl, aryl C 0-4 alkyl, heterocyclyl C 0-4 alkyl, and R 5 is hydrogen, C 1-6 alkyl, aryl C 0-3 alkyl, or C 1-6 alkylcarbonyloxymethyl, and the pharmaceutically acceptable salts thereof. A preferred group of compounds used in the method of the present invention are those defined for the general structural formula shown below wherein: ##STR5## n is an integer from 2 to 6; Y is CH 2 , O, or --NHCO--; R 1 and R 2 are independently, hydrogen, C 1-8 alkyl, aryl C 0-4 alkyl, or C 3-8 cycloalkyl, wherein R 1 and R 2 may be unsubstituted or substituted with one or more groups chosen from R 3 , where R 3 is hydrogen, C 1-6 alkyl, hydroxy, carboxy, C 1-4 alkyloxy, or halogen; and R 4 is C 1-6 alkyl, aryl C 1-4 alkyl, heterocyclyl C 1-4 alkyl, and the pharmaceutically acceptable salts thereof. A more preferred group of compounds used in the method of the present invention are those defined for the general structural formula shown below ##STR6## wherein: n is an integer from 2 to 4; Y is --CH 2 -- or O; R 1 and R 2 are independently hydrogen, C 1-8 alkyl, aryl C 1-3 alkyl, heterocyclyl C 1-3 alkyl, or C 5-6 cycloalkyl, wherein R 1 and R 2 may be unsubstituted or substituted with one or more groups chosen from C 1-6 alkyl, hydroxy, or C 1-4 alkoxy; and R 4 is C 1-6 alkyl, aryl, aryl C 1-2 alkyl, or heterocyclyl C 1-4 alkyl, and the pharmaceutically acceptable salts thereof. The pharmacologic activity of these compounds is useful in the treatment of mammals, including man. The current major bone diseases of public concern are osteroporosis, hypercalcemia of malignancy, osteopenia due to bone metastases, periodontal disease, hyperparathyroidism, periarticular erosions in rheumatoid arthritis, Paget's disease, immobilization-induced osteopenia, and glucocorticoid treatment. All these conditions are characterized by bone loss, resulting from an imbalance between bone resorption (breakdown) and bone formation, which continues throughout life at the rate of about 14% per year on the average. However, the rate of bone turnover differs from site to site, for example it is higher in the trabecular bone of the vertebrae and the alveolar bone in the jaws than in the cortices of the long bones. The potential for bone loss is directly related to turnover and can amount to over 5% per year in vertebrae immediately following menopause, a condition which leads to increased fracture risk. There are currently 20 million people with detectable fractures of the vertebrae due to osteoporosis in the United States. In addition, there are 250,000 hip fractures per year attributed to osteoporosis, which are associated with a 12% mortality rate within the first two years and 30% of the patients require nursing home care after the fracture. All the conditions listed above would benefit from treatment with agents which inhibit bone resorption. SUMMARY OF THE INVENTION By this invention there is provided a process for the treatment of mammals suffering from a bone condition caused or mediated by increased bone resorption, who are in need of such therapy, comprising the step of administering a pharmacologically effective amount of a compound of formula I, including the pharmaceutically acceptable salts thereof, to inhibit the activity of mammalian osteoclasts. DETAILED DESCRIPTION OF THE INVENTION The term "pharmaceutically acceptable salts" shall mean non-toxic salts of the compounds of this invention which are generally prepared by reacting the free base with a suitable organic or inorganic acid. Representative salts include the following salts: Acetate Benzenesulfonate Benzoate Bicarbonate Bisulfate Bitartrate Borate Bromide Calcium Edetate Camsylate Carbonate Chloride Clavulanate Citrate Dihydrochloride Edetate Edisylate Estolate Esylate Fumarate Gluceptate Gluconate Glutamate Glycollylarsanilate Hexylresorcinate Hydrabamine Hydrobromide Hydrochloride Hydroxynaphthoate Iodide Isothionate Lactate Lactobionate Laurate Malate Maleate Mandelate Mesylate Methylbromide Methylnitrate Methylsulfate Mucate Napsylate Nitrate Oleate Oxalate Pamaote Palmitate Pantothenate Phosphate/diphosphate Polygalacturonate Salicylate Stearate Subacetate Succinate Tannate Tartrate Teoclate Tosylate Triethiodide Valerate Additionally included are cations such as alkali metal and alkaline earth cations. The term "pharmacologically effective amount" shall mean that amount of a drug or pharmaceutical agent that will elicit the biological or medical response of a tissue, system or animal that is being sought by a researcher or clinician. The term "bone resorption activity" shall mean the process by which osteoclasts solubilize bone minerals and increase the activity of enzymes that degrade bone matrix. The term "alkyl" shall mean straight or branched chain alkane, alkene or alkyne with one or more degrees of unsaturation at any position. The term "aryl" shall mean phenyl or benzyl. The term "oxo" shall mean ##STR7## The term "heterocyclyl" shall mean a 5 or 6 membered mono- or polycyclic ring system containing 1, 2, 3 or 4 heteroatoms chosen from N, O or S. The term "halogen" shall mean F, Cl, Br or I. In the schemes and examples below, various reagent symbols have the following meanings: BOC: t-butoxycarbonyl. Pd-C: Palladium on activated carbon catalyst. DMF: Dimethylformamide. DMSO: Dimethylsulfoxide. CBZ: Carbobenzyloxy EtOAc: ethyl acetate THF: tetrahydrofuran HOAc: acetic acid CHCl 3 : chloroform MeOH: methanol CH 3 CN: acetonitrile TFA: Trifluroacetic acid BOP: Benzotriazol-1-yloxy-tris (dimethylamino) phosphonium hexofluorophosphate The compounds of the present invention can be administered in such oral dosage forms as tablets, capsules (each of which includes sustained release or timed release formulations), pills, powders, granules, elixers, tinctures, suspensions, syrups and emulsions. Likewise, they may also be administered in intravenous (bolus or infusion), intraperitoneal, subcutaneous or intramuscular form, all using forms well known to those of ordinary skill in the pharmaceutical arts. The dosage regimen utilizing the compounds of the present invention is selected in accordance with a variety of factors including type, species, age, weight, sex and medical condition of the patient; the severity of the condition to be treated; the route of administration; the renal and hepatic function of the patient; and the particular compound or salt thereof employed. An ordinarily skilled physician or veterinarian can readily determine and prescribe the effective amount of the drug required to prevent, counter or arrest the progress of the condition. Oral dosages of the present invention, when used for the indicated effects, will range between about 0.01 mg per kg of body weight per day (mg/kg/day) to about 100 mg/kg/day and preferably 1.0-100 mg/kg/day and most preferably 1.0 to 20 mg/kg/day. Intravenously, the most preferred doses will range from about 1 to about 10 mg/kg/minute during a constant rate infusion. Advantageously, compounds of the present invention may be administered in a single daily dose, or the total daily dosage may be administered in divided doses of two, three or four times daily. Furthermore, preferred compounds for the present invention can be administered in intranasal form via topical use of suitable intranasal vehicles, or via transdermal routes, using those forms of transdermal skin patches well known to those of ordinary skill in that art. To be administered in the form of a transdermal delivery system, the dosage administration will, of course, be continuous rather than intermittant throughout the dosage regimen. In the methods of the present invention, the compounds herein described in detail can form the active ingredient, and are typically administered in admixture with suitable pharmaceutical diluents, excipients or carriers (collectively referred to herein as `carrier` materials) suitably selected with respect to the intended form of administration, that is, oral tablets, capsules, elixirs, syrups and the like, and consistent with conventional pharmaceutical practices. For instance, for oral administration in the form of a tablet or capsule, the active drug component can be combined with an oral, non-toxic, pharmaceutically acceptable, inert carrier such as lactose, starch, sucrose, glucose, methyl cellulose, magnesium stearate, dicalcium phosphate, calcium sulfate, mannitol, sorbitol and the like; for oral administration in liquid form, the oral drug components can be combined with any oral, non-toxic, pharmaceutically acceptable inert carrier such as ethanol, glycerol, water and the like. Moreover, when desired or necessary, suitable binders, lubricants, disintegrating agents and coloring agents can also be incorporated into the mixture. Suitable binders include starch, gelatin, natural sugars such as glucose or beta-lactose, corn sweeteners, natural and synthetic gums such as acacia, tragacanth or sodium alginate, carboxymethylcellulose, polyethylene glycol, waxes and the like. Lubricants used in these dosage forms include sodium oleate, sodium stearate, magnesium stearate, sodium benzoate, sodium acetate, sodium chloride and the like. Disintegrators include, without limitation, starch, methyl cellulose, agar, bentonite, xanthan gum and the like. The compounds of the present invention can also be administered in the form of liposome delivery systems, such as small unilamellar vesicles, large unilamellar vesicles and multilamellar vesicles. Liposomes can be formed from a variety of phospholipids, such as cholesterol, stearylamine or phosphatidylcholines. Compounds of the present invention may also be delivered by the use of monoclonal antibodies as individual carriers to which the compound molecules are coupled. The compounds of the present invention may also be coupled with soluble polymers as targetable drug carriers. Such polymers can include polyvinylpyrrolidone, pyran copolymer, polyhydroxypropylmethacrylamide-phenol, polyhydroxyethylaspartamide-phenol, or polyethyleneoxide-polylysine substituted with palmitoyl residues. Furthermore, the compounds of the present invention may be coupled to a class of biodegradable polymers useful in achieving controlled release of a drug, for example, polylactic acid, polyglycolic acid, copolymers of polylactic and polyglycolic acid, polyepsilon caprolactone, polyhydroxy butyric acid, polyorthoesters, polyacetals, polydihydropyrans, polycyanoacrylates and crosslinked or amphipathic block copolymers of hydrogels. The novel compounds of the present invention were prepared according to the procedure of the following schemes and examples, using appropriate materials and are further exemplified by the following specific examples. The most preferred compounds of the invention are any or all of those specifically set forth in these examples. These compounds are not, however, to be construed as forming the only genus that is considered as the invention, and any combination of the compounds or their moieties may itself form a genus. The following examples further illustrate details for the preparation of the compounds of the present invention. Those skilled in the art will readily understand that known variations of the conditions and processes of the following preparative procedures can be used to prepare these compounds. All temperatures are degrees Celsius unless otherwise noted. ##STR8## EXAMPLE 1 ##STR9## 2-S(N-Benzyloxycarbonylamino)-3-[4-(3-chloropropyloxy)phenyl]propionic acid (1-1) N-CBZ-tyrosine (3 g, 9.9 mmole) (Bachem Chemical Supply, California) was dissolved in DMF and treated with NaH (50% dispersion in oil, 0.95 g, 19.8 mmole) for 1 hour. Then 1,3-bromochloropropane (1 ml, 9.9 mmole) was added and the reaction stirred for 16 hours. The DMF was removed in vacuo and the residue dissolved in water, acidified to pH 3, and extracted with ethyl acetate. The ethyl acetate layer was dried with MgSO 4 , filtered and evaporated. Column chromatography (SiO 2 , 97:3:1 CHCl 3 /CH 3 OH/HOAc) yielded 1-1 as a yellow oil. R f =0.3 in 97:3:1 CHCl 3 /CH 3 OH/HOAc ninhydrin stain 1 H NMR (300 MHz, CDCl 3 ) δ7.3 (bs, 5H), 7.03 (d, J=8.3, 2H), 6.8 (d, J=8.3, 2H), 5.2 (d, J=8Hz, 1H), 5.05 (bs, 2H) 4.65 (m, 1H), 4.05 (t, J=5.7 Hz, 2H), 3.73 (t, J=6.3 Hz, 2H), 3.1 (m, 2H), 2.2 (m, 2H). EXAMPLE 2 ##STR10## 2-S-(N-Benzyloxycarbonylamino)-3-[4-(3-t-butylaminopropyloxy)phenyl]propionic acid (1-2) Compound 1-1 (0.4 g, 1.1 mmole) was refluxed in t-butylamine (20 ml) and acetonitrile (20 mL) for three days. The reaction was evaporated to dryness, the residue dissolved in water, and extracted with ether. The aqueous layer was then acidified to pH 4-5 and a precipitate formed. The solid was collected and dried to yield 1-2. R f =0.8 in 9:1 EtOH/NH 4 OH, ninhydrin stain. 1 H NMR (300 MHz, D 2 O+NaOH) δ7.4 (bs, 2H), 7.2 (bs, 4H), 6.85 (d, J=8.55, 2H), 5.2 (d, J=12.8 Hz, 1H), 5.0 (d, J=12.8 Hz, 1H), 4.3 (dd, J=4.0, 9.6 Hz, 1H), 4.0 (bs, 2H), 3.2 (dd, J=4.0, 13.6 Hz, 1H), 2.8 (dd, J=9.6 Hz, 13.6 Hz, 1H), 2.65 (t, J=7.3 Hz, 2H), 1.8 (m, 2H), 1.09 (s, 9H), mass spec (FAB) m/e=429 (m=1) C, H, N analysis C 24 H 32 N 2 O 5 0.65 H 2 O MW=440.244 Calculated C=65.47, H=7.62, N=6.36; Found C=65.52, H=7.54, N=6.27. EXAMPLE 3 ##STR11## 2-S-(N-Benzyloxycarbonylamino)-3-[4-(N,N,2,2-tetramethylpropanediamino)propyloxyphenyl]-propionic acid (1-3) Treatment of compound 1-1 with N,N, 2,2-tetramethyl-1,3-propenediamine by refluxing in acetonitrile for three days, and followed by an aqueous workup provided crude 1-3. This was chromatographed on silica gel eluting with 9:1:1 EtOH/H 2 O/NH 4 OH to provide pure 1-3 (R f =0.37 ninhydrin stain). 1 H NMR (300 MHz, D 2 O) δ7.5 (bs, 3H), 7.4 (bs, 2H), 7.33 (d, J=8.3Hz, 2H), 7.0 (d, J=8.3Hz, 2H), 5.20 (d, J=10Hz, 1H), 5.10 (d, J=10Hz, 1H), 4.25 (m, 1H), 4.25 (t, J=5.6Hz, 2H), 3.4 (t, J=7.8Hz, 2H), 3.4 (s, 2H), 3.25-2.95 (m, 2H), 3.22 (s, 2H), 3.1 (s, 6H), 2.35 (m, 2H), 1.38 (s, 6H). MW=759.28 C, H, N analysis for C 27 H 39 N 2 O 5 2.4 CF 3 CO 2 H; Calcd: C, 50.30; H, 5.50; N, 5.53. Found: C, 50.35; H, 5.43; N, 5.56. EXAMPLE 4 ##STR12## 2-S-(N-Benzyloxycarbonylamino)-3-[4-(3-N-pyrolidinylpropyloxy)phenyl]propionic acid (1-4) Treatment of compound 1-1 with pyrrolidine in CH 3 CN at reflux for three days provided crude 1-4. This was purified by flash chromatography on silica gel eluting with 9:1:1 EtOH/H 2 O/NH 4 OH to give pure 1-4 (R f =0.81, ninhydrin stain). 1 H NMR (300 MH 3 , CDCl 3 ) δ7.3 (bs, 5H), 7.0 (d, J=8.1Hz, 2H), 6.7 (d, J=8.1Hz, 2H), 5.5 (d, J=7.4Hz, 1H), 5.0 (bs, 2H), 4.5 (m, 1H), 3.8 (m, 2H), 3.75 (bs, 1H), 3.4 (m, 2H), 3.18 (t, J=8.5Hz, 2H), 3.1 (bs, 2H), 2.8 (bs, 1H), 2.2-1.8 (m, 6H). C, H, N analysis C 24 H 30 N 2 O 5 •0.25CH 2 Cl 2 ; Calcd: C, 65.05; H, 6.87; N, 6.26. Found: C, 65.28; H, 6.78; N, 6.27. EXAMPLE 5 ##STR13## 2-S-(N-Benzyloxycarbonylamino)-3-[4-(3-N-methyl-N-benzylaminopropyloxyphenyl)propionic acid (1-5) Treatment of 1-1 with N-methyl benzylamine in acetonitrile at reflux for three days afforded crude 1-5. The solvent was removed on a rotary evaporator and the residue was dissolved in water and extracted with 3×75 mL portions of ether. The product separated out an oil which was collected an concentrated to give, after trituration with EtOAc and CH 2 Cl 2 , 1-5 as a foam. 1 H NMR (300 MHz, CDCl 3 /CD 3 OD) δ7.4 (m, 10H), 7.0 (d, J=8.5Hz, 2H), 6.6 (d, J=8.5Hz, 2H), 5.0 (bs, 2H), 4.5 (m, 1H), 4.2 (bs, 2H), 3.88 (t, J=5.3Hz, 2H), 3.1-2.8 (m, 4H), 2.69 (s, 3H), 2.2 (bs, 2H). C, H, N analysis C 28 H 32 N 2 O 5 • 0.8CH 2 Cl 2 0.25 EtOAc; Calcd: C, 63.17; H, 6.33; N, 4.94. Found: C, 63.16; H, 6.40; N, 5.04. MW=548.771 EXAMPLE 6 ##STR14## 2-S-(N-t-Butyloxycarbonylamino)-3-[4-(3-N-t-butylpropyloxy)phenyl]propionic acid (1-6) Treatment of N-BOC-L-tyrosine with sodium hydride in DMF followed by 1,3-bromochloropropane provided the N-BOC analog of 1-1. This was treated with an excess of t-butylamine in refluxing acetonitrile for two days to provide crude 1-6 after aqueous workup and extraction. Pure 1-6 was prepared by preparative reverse phase HPLC. 1 H NMR (300 MHz, CD 3 OD) δ7.17 (d, J=8.5 Hz, 2H), 6.85 (d, J=8.5 Hz, 2H), 4.28 (dd, J=4.8, 9.1 Hz, 1H), 4.1 (t, J=5.9 Hz, 2H), 3.2 (t, J=7.7 Hz, 2H), 3.1 (dd, J=4.8, 13.3 Hz, 1H), 2.8 (dd, J=9.1, 13.3 Hz, 1H), 2.15 (m, 2H), 1.38 (s, 18H). C, H, N analysis C 21 H 34 N 2 O 7 •1.05CF 3 CO 2 H. MW=514.243. Calcd: C, 53.95; H, 6.87; N, 5.45. Found: C, 54.01; H, 6.97; N, 5.51. EXAMPLE 7 ##STR15## 2-S-(N-Benzyloxycarbonylamino)-3-[4-(4-piperazinyl)-butyloxyphenyl]propionic acid (1-7) Treatment of N-CBZ-L-tyrosine with sodium hydride in DMF followed by 1,4-dibromobutane, as described for the preparation of 1-1, provided the corresponding butyl analog. Treatment of this with 1,4-piperazine in refluxing acetonitrile for three days gave crude 1-7 as a precipitate from the reaction mixture. Reverse phase HPLC purification gave pure 1-7. 1 H NMR (300 MH 3 , CD 3 OD) δ7.3 (m, 5H), 7.23 (d, 2H), 6.83 (d, 2H), 5.0 (bs, 2H), 4.35 (dd, 1H), 4.0 (t, 2H), 3.6 (bs, 8H), 3.1 (dd, 1H), 2.85 (dd, 1H), 2.00-1.8 (m, 4H). C, H, N analysis C 26 H 35 N 3 O 5 •1.2H 2 O MW=491.206. Calcd: C, 63.57; H, 7.67; N, 8.56. Found: C, 63.33; H, 7.28; N, 8.55. EXAMPLE 7(a) ##STR16## 2-S-(N-Benzyloxycarbonylamino)-3-[4-(1,1,3,3-tetramethylbutylamino)propyloxyphenyl]pentanoic acid (1-8) Treatment of 1-1 with 1,1,3,3-tetramethylpentylamine, as described for compound 1-2, gave 1-8 as the TFA salt. 1 H NMR (300 MHz, CD 3 OD) δ7.35 (5H, m), 7.18 (2H, d), 6.85 (1H, d), 5.00 (2H, s), 4.35 (1H, dd), 4.10 (2H, t), 3.1 (2H, t), 3.15 (1H, dd), 2.50 (1H, dd), 2.1 (2H, m), 1.70 (2H, s), 1.5 (6H, s), 1.10 (9H, s). Analysis for C 28 H 40 N 2 O 5 •0.9CF 3 CO 2 H; Calcd: C, 60.94; H, 7.02; N, 4.77. Found: C, 60.85; H, 7.01; N, 4.69. EXAMPLE 7(b) ##STR17## 2-S-(N-Benzyloxycarbonyl)-3-[4-(4-methylpiperazin-1-yl)-propyloxyphenyl]propanoic acid (1-9) Treatment of 1-1 with N-methylpiperazine as described for 1-2 gave crude 1-9. This was purified by column chromatography on silica gel eluting with 9:1:1 C 2 H 5 OH/H 2 O/NH 4 OH to give pure 1-9 as the TFA salt. 1 H NMR (300 MHz D 2 O) δ7.5 (3H, m), 7.4 (2H, d), 7.0 (2H, d), 5.18 (1H, d), 5.05 (1H, d), 4.5 (1H, m), 4.2 (2H, t), 3.8 (8H, s), 3.6 (2H, t), 3.3 (1H, m), 3.1 (3H, s), 3.0 (1H, m), 2.4 (2H, m). Analysis for C 25 H 33 N 3 O 5 •2.3CF 3 CO 2 H; Calcd: C, 49.52; H, 4.96; N, 5.85. Found: C, 49.42; H, 4.98; N, 6.01. EXAMPLE 7(c) ##STR18## 2-(N-Benzyloxycarbonylamino)-3-[4-(5-bromopentyloxy)-phenyl]propionic acid (1-10) N-CBZ-L-tyrosine (2.06 g, 5.86 mmole) was treated with NaH (0.58 g, 12.08 mmole) and 1,5-dibromopentane (0.8 ml, 5.87 mmole) as described for 1-1 in Example 1. The crude product was dissolved in methanol and after stirring with silica gel for 0.5 hour, the solvent was removed. This was dry packed and eluted on a flash column with CHCl 3 and then with 97:3:0.3 CHCl 3 /CH 3 OH/HOAc to give pure 1-10. 1 H NMR (300 MHz, CD 3 OD) δ1.50-1.65 (2H, m), 1.63-1.95 (4H, m), 3.10 (2H, m), 3.45 (1H, t), 3.92 (2H, m), 4.40 (1H, m), 6.80 (2H, d), 7.10 (2H, d), 7.28 (5H, m). EXAMPLE 7(d) ##STR19## 2-S-(N-Benzyloxycarbonylamino)-3-[4-(4-piperazin-1-yl)-pentyloxyphenyl]propionic acid (1-11) 1-10 (0.658 g, 1.42 mmole), was dissolved in 30 mL CH 3 CN and 1,4-piperazine (1.22 g, 14.16 mmole) was added. This solution was stirred at room temperature for 4 days. The solvent was then removed and the residue was dry packed on a silica gel column and eluted with 18:1:1 C 2 H 5 OH/H 2 O/NH 4 OH to give pure 1-11 as a white solid. 1 H NMR (300 MHz, CD 3 OD) δ1.52 (4H, m), 1.77 (2H, m), 2.40 (2H, t), 2.59 (4H, m), 2.80-2.94 (1H, m), 3.01-3.12 (5H, m), 3.94 (2H, m), 4.21 (1H, m), 6.76 (2H, d), 7.09 (2H, d). Analysis for C 26 H 35 N 3 O 5 •1.2 H 2 O; Calcd: C, 63.57; H, 7.67; N, 8.56 Found: C, 63.33; H, 7.28; N, 8.55 ##STR20## EXAMPLE 8 ##STR21## 2-S-(N-Benzyloxycarbonylamino)-3-[4-(6-N-t-butyloxycarbonylaminohexyloxy)phenyl]propionic acid (2-1) N-CBZ-L-tyrosine (15.0 g, 0.045 moles) was dissolved in 75 mL DMF and added at 0°-10° C. to a suspension of sodium hydride (2.16 g, 0.09 moles) in 25 mL DMF. The resulting suspension was stirred at 0°-10° C. for 1.0 hour and then 6-(N-t-butyloxycarbonylamino)hexyl bromide (12.6 g, 0.045 moles) in 25 mL DMF was added dropwise at 0°-5° C. and the clear, dark reaction mixture was stirred at room temperature overnight. After solvent removal, the residue was taken up in EtOAc and this was made acidic with 10% KHSO 4 solution. The organic phase was separated, washed with brine, dried (Na 2 SO 4 ) and the solvent removed to give an oil. This was purified by column chromatography on silica gel eluting with 98:2:1 CHCl 3 /CH 3 OH/HOAc to give pure 2-1 as a clear oil. 1 H NMR (300 MHz, CD 3 OD) δ1.45 (15H, m), 1.75 (2H, m), 2.80-3.15 (6H, m), 3.91 (2H, t), 4.38 (1H, m), 4.95 (6H, m), 6.79 (2H, d), 7.10 (2H, d), 7.28 (5H, m). EXAMPLE 9 ##STR22## 2-S-(N-Benzyloxycarbonylamino)-3-[4-(6-aminohexyloxyphenyl)]propionic acid hydrochloride (2-2) Compound 2-1 (51.4 mg, 0.1 mmole) was dissolved in 20 mL EtOAc and cooled to -20° C. under N 2 . HCl gas was bubbled into this solution for 10 minutes as the temperature rose to -5° C. The reaction mixture was stoppered and stirred at 0 to -5° C. for 1 hour. The solvent was then removed on the rotary evaporator and the residue was triturated with ether to give 2-2 as a white solid. R f =0.4 (SiO 2 , 9:1:1 EtOH/NH 4 OH, H 2 O). 1 H NMR (300 MHz, CD 3 OD) δ1.45 (6H, m), 1.73 (4H, m), 2.90 (3H, m), 3.13 (1H, m), 3.95 (2H, m), 4.30 (1H, bs), 6.77 (2H, d), 7.10 (2H, d), 7.32 (4H, m). Analysis for C 23 H 31 N 2 O 5 Cl•0.5 H 2 O; Calcd: C, 60.05; H, 7.01; N, 6.09. Found: C, 60.08; H, 7.06; N, 6.09. EXAMPLE 10 ##STR23## 2-S-(N-Benzyloxycarbonylamino)-3-[4-(7-N-t-butyloxycarbonylaminoheptyloxy)phenyl]propionic acid (2-3) N-CBZ-L-tyrosine (1.27 g, 4.02 mmoles) was alkylated with 7-(N-t-butyloxycarbonylaminoheptyl)bromide as taught in Example 8 for compound 2-1. Crude product was purified by flash chromatography on silica gel eluting with 95:5:0.5 CHCl 3 /CH 3 OH/HOAc to give 2-3 as a clear oil. 1 H NMR (300 MHz, CD 3 OD) δ1.40 (20H, m), 1.66 (2H, m), 2.82 (1H, m), 2.97-3.18 (4H, m), 3.91 (2H, m), 4.19 (1H, m) 5.0 (2H, q), 6.77 (2H, d), 7.10 (2H, d), 7.30 (5H, m). EXAMPLE 11 ##STR24## 2-S-(N-Benzyloxycarbonylamino)-3-[4-(7-aminoheptyloxy)-phenyl]propionic acid hydrochloride (2-4) Compound 2-3 (67.4 mg, 0.127 mmole) was deprotected with HCl gas as described in Example 9 for 2-2 to provide pure 2-4. 1 H NMR (300 MHz, CD 3 OD) δ1.32 (9H, m), 1.60 (4H, m), 2.77 (3H, m), 3.00 (1H, m), 3.18 (2H, m), 3.72 (2H, m), 4.25 (1H, m), 4.90 (2H, q), 6.70 (2H, d), 7.00 (2H, d), 7.18 (5H, m). Analysis for C 24 H 32 N 2 O 5 •0.2EtOH•0.75 H 2 O; Calcd: C, 64.94; H, 7.75; N, 6.21. Found: C, 64.97; H, 7.84; N, 6.22. EXAMPLE 12 ##STR25## 2-S-(N-Benzyloxycarbonylamino)-3-[4-(8-N-t-butyloxycarbonylaminooctyloxy)phenyl]propionic acid (2-5) N-CBZ-L-tyrosine•H 2 O (1.5 g, 4.29 mmole) was dissolved in EtOAc/CH 2 Cl 2 , dried over MgSO 4 , filtered and evaporated. The residue was dissolved in DMF and treated with NaH (50% dispersion in oil, 0.43 g, 8.96 mmole) for 1 hour. N-BOC-8-amino-1-bromooctane (1.33 g, 4.34 mmole) was added and the reaction was stirred for 16 hours. The DMF was removed in vacuo, the residue dissolved in water, acidified to pH 3 and extracted with EtOAc. The EtOAc layers were combined, dried and concentrated. Column chromatography (SiO 2 , 97:3:1 CHCl 3 /MeOH/HOAc) gave 2-5. 1 H NMR (300 MHz, CD 3 OD) δ7.3 (m, 5H), 7.1 (d, 2H), 6.78 (d, 2H), 5.0 (2q, 2H), 4.38 dd, 1H), 3.8 (m, 2H), 3.13 (dd, 1H), 3.0 (t, 2H), 2.85 (dd, 1H), 1.75 (m, 2H), 1.4 (s, 9H), 1.35 (m, 3H), 1.3 (bs, 7H). EXAMPLE 13 ##STR26## 2-S-(N-Benzyloxycarbonylamino)-3-[4-(8-aminooctyloxy)-phenyl]propionic acid (2-6) Compound 2-5 (1.35 g, 2.49 mmole) was dissolved in ethyl acetate and treated with HCl gas at -20° C., purged with N 2 and concentrated to give a white solid which was rinsed with ethyl acetate and dried to give 2-6. 1 H NMR (300 MHz, CD 3 OD) δ7.3 (m, 5H), 7.1 (d, 2H), 6.8 (d, 2H), 5.02, (2q, 2H), 4.35 (dd, 1H), 4.93 (t, 2H), 3.1 (dd, 1H), 2.9 (t, 2H), 2.85 (dd, 1H), 1.75 (m, 2H), 1.65 (m, 2H), 1.5 (m, 2H), 1.4 (bs, 6H). Analysis for C 25 H 34 N 2 O 5 •HCl•0.65H 2 O. MW=490.732. Calcd: C, 61.18; H, 7.45; N, 5.71. Found: C, 61.18; H, 7.45; N, 5.77. EXAMPLE 14 ##STR27## 2-S(Benzyloxycarbonylamino)-3-[4-(5-t-butyloxycarbonylaminopentyloxy)phenyl]-propionic acid (2-7) N-CBZ-L-tyrosine (1.06 g, 3.01 mmole) was alkylated with 5-(N-t-butyloxycarbonylamino)pentyl bromide as described for compound 2-1 in Example 8. Crude product was purified by flash chromatography on silica gel eluting with 97:3:0.5 CHCl 3 /CH 3 OH/HOAc to give pure 2-7. 1 H NMR (300 MHz, CD 3 OD) δ1.42 (9H, S), 1.52 (4H, m), 1.76 (2H, m), 3.05, (3H, m), 3.92 (2H, t), 5.00 (2H, m), 6.79 (2H, d), 7.11 (2H, d), 7.28 (5H, m). EXAMPLE 15 ##STR28## 2-S(N-Benzyloxycarbonylamino)-3-[4-(5-aminopentyloxy)phenyl]propionic acid hydrochloride (2-8) 2-7 was treated with HCl gas as taught in Example 9 for compound 2-2, to provide pure 2-8 as a white powder. 1 H NMR (300 MHz, CD 3 OD) δ1.60 (2H, m), 1.77 (4H, m), 2.90 (3H, m), 3.12, (1H, m), 3.96 (2H, t), 4.37 (1H, m), 5.02 (2H, m), 6.81 (2H, d), 7.12 (2H, d), 7.30 (5H, m). Analysis for C 22 H 29 N 2 O 5 •0.25 H 2 O; Calcd: C, 59.85; H, 6.74; N, 6.35. Found: C, 59.85; H, 6.73; N, 6.32. EXAMPLE 16 ##STR29## 2-(4-N-t-Butyloxycarbonylpiperidin-4-yl)ethanol (2-10) 4-piperidine-2-ethanol (Available from Aldrich) (130 g, 1.0 mole) was dissolved in 700 mL dioxane, cooled to 0 degrees C. and treated with 3N NaOH (336 mL, 1.0 mole), and di-t-butylcarbonate (221.8 g, 1.0 mole). The ice bath was removed and the reaction stirred overnight. The reaction was concentrated, diluted with water and extracted with ether. The ether layers were combined, washed with brine, dried over MgSO 4 , filtered and evaporated to give pure 2-10. R f =0.37 in 1:1 EtOAc/Hexanes, ninhydrin stain 1 H NMR (300 MH 3 , CDCl 3 ) δ4.07 (bs, 2H), 3.7 (bs, 2H), 2.7 (t, J=12.5 Hz, 2H), 1.8-1.6 (m, 6H), 1.51 (s, 9H), 1.1 (ddd, J=4.3, 12.5, 12 Hz, 2H). EXAMPLE 17 ##STR30## Methyl 4-(4-N-t-Butyloxycarbonylpiperidin-4-yl)-but-2-enoate (2-11) Oxalyl chloride (55.8 mL, 0.64 mole) was dissolved in 1 L CH 2 Cl 2 and cooled to -78° C. under N 2 . DMSO (54.2 mL, 0.76 mole) was added dropwise. After gas evolution had ceased, 2-10 (102.5 g, 0.45 mole) dissolved in 200 mL CH 2 Cl 2 was added over 20 minutes. After stirring an additional 20 minutes, triethylamine (213 mL, 1.53 mole) was added dropwise and the cold bath removed. After 1 and 1/2 hours TLC showed starting material gone. Carbomethoxytriphenylphosphorane (179 g, 0.536 mole) was added and the reaction stirred overnight. The solution was diluted with 300 mL Et 2 O, extracted once with 800 mL H 2 O, twice with 300 mL 10% KHSO 4 solution, then once with 300 mL brine. The organic layer was dried over MgSO 4 , filtered and evaporated. Column chromatography (SiO 2 , 5% EtOAc/Hexanes) yielded pure 2-11. 300 MHz, 1 H NMR (300 MH 3 , CDCl 3 ) δ6.9 (ddd J=15.6, 7,6, 7.6 Hz, 1H), 5.8 (d, J=15.6 Hz, 1H), 4.0 (bs, 2H), 3.7 (s, 3H), 2.6 (t, J=12.6 Hz, 2H, 2.1 (t, J=7.4 Hz, 2H), 1.7-1.4 (m, 3H), 1.4 (s, 9H), 1.1 (m, 2H). EXAMPLE 18 ##STR31## 4-(4-N-t-Butyloxycarbonylpiperidin-4-yl)butyl bromide (2-12) Compound 2-11 (36.2 g, 0.128 mole), was dissolved in 500 mL EtOAc. 10% Palladium on carbon (10 g) was added as a slurry in EtOAc and the reaction was placed under H 2 (in a balloon) overnight. The reaction was filtered through Solka-Floc, the cake washed with EtOAc and the ethyl acetate evaporated to give 4-(4-N-t-butyloxycarbonylpiperidin-4-yl)butanoate. TLC R f =0.69 in 30% EtOAc/Hexanes. 1 H NMR (300 MH 3 , CDCl 3 ) δ4.0 (bs, 2H), 3.6 (s, 3H), 2.60 (t, J=12.3 Hz, 2H), 2.20 (t, J=7.4, 2H), 1.6 (m, 4H), 1.40 (s, 9H), 1.40 (m, 1H), 1.20 (m, 2H), 1.0 (m, 2H). The butanoate ester (45.3 g, 0.159 mole) was dissolved in CH 3 OH and treated with 1N NaOH (500 mL, 0.5 mole) overnight. The solvent was removed in vacuo, water was added and the solution washed with ether, then acidified with 10% KHSO 4 solution. The aqueous layer was washed with ether, the ether layers were combined, washed with brine and dried over MgSO 4 and concentrated to give the corresponding acid as a clear oil. 1 H NMR (300 MH 3 , CDCl 3 ) δ4.0 (bs, 2H), 2.6 (m, 2H), 2.25 (m, 2H), 1.6 (bs, 4H, 1.4 (s, 9H), 1.3-0.9 (9H). This acid (20.4 g, 0.077 moles) was treated with borane (BH 3 /THF, 235 mL, 235 mmole) in THF at 0° C. for 1 hour. NaOH (1N, 250 mL) was added dropwise and the solution stirred overnight. The reaction was concentrated to remove THF, extracted with ether, the ether extracts were combined, dried over MgSO 4 , filtered and evaporated to give the corresponding alcohol as a colorless oil. R f =0.7 in 2:1 ethyl acetate/hexanes. 1 H NMR (300 MH 3 , CDCl 3 ) δ4.1 (bs, 2H), 3.6 (t, 2H), 2.65 (t, 2H), 2.1 (bs, 1H), 1.65 (bs, 2H), 1.55 (m, 2H), 1.4 (s, 9H), 1.35 (m, 3H), 1.25 (m, 2H), 1.1 (m, 2H). This alcohol (19.7 g, 76.5 mmole) was dissolved in THF and treated with triphenylphosphine (23.1 g, 88 mmol) and cooled to 0 degrees C. Carbon tetrabromide (29.8 g, 89.9 mmol) was added in one portion, the cold bath was removed and the reaction stirred overnight. Additional triphenyl phosphine (11.71 g) and carbon tetrabromide (14.9 g) was added to drive the reaction to completion. The mixture was filtered and the liquid was diluted with ether and filtered again. After solvent removal the resulting liquid was adsorbed onto SiO 2 and chromatographed with 5% EtOAc/Hexanes to yield 2-12 as a clear colorless oil (20.7 g, 85% yield). R f =0.6 in 1:4 ethyl acetate/hexanes 1 H NMR (300 MH 3 , CDCl 3 ) δ4.1 (bs, 2H), 3.4 (t, 2H), 2.65 (t, 2H), 1.85 (m, 2H), 1.65 (bd, 2H), 1.4 (s, 9H), 1.35 (m, 2H), 1.3 (m, 3H), 1.1 (m, 2H). EXAMPLE 19 ##STR32## 2-S-(N-Benzyloxycarbonylamino)-3-[4-(4-N-t-butyloxycarbonylpiperidin-4-ylbutyloxy) phenyl]-propionic acid (2-13) N-CBZ-L-tyrosine was alkylated with 2-12 as taught for compound 2-5 in Example 12 to provide 2-13 in 87% yield. R f =0.15 in 97:3:1 CHCl 3 /CH 3 OH/HOAc, iodine stain. 1 H NMR (300 MH 3 , CDCl 3 ) δ7.2 (d, J=7.5 Hz, 2H), 7.1 (d, J=7.5 Hz, 2H), 7.0 (d, J=7.3 Hz, 2H), 6.8 (d, J=7.3 Hz, 2H), 5.2 (d, J=7.9 Hz, 1H), 5.1 (s, 2H), 4.6 (m, 1H), 4.01 (bd, 2H), 3.92 (t, J=6 Hz, 2H), 3.67 (m, 2H), 2.65 (bt, 7H), 1.75-1.4 (m, 7H), 1.45 (s, 9H), 1.3 (m, 2H), 1.1 (m, 2H). EXAMPLE 20 ##STR33## 2-S-(N-Benzyloxycarbonylamino)-3-[4-(4-piperidin-4-ylbutyloxy propionic acid (2-14) Compound 2-13 was deprotected at taught for compound 2-2 in Example 9. The solvent was removed on the rotary evaporator and the residue was dissolved in water and extracted with ethyl acetate. The water layer was concentrated to dryness, evaporated and the residue was chromatographed (SiO 2 , 9:1:1 EtOH/H 2 O/NH 4 OH). A small portion was then purified further by HPLC and isolated as the TFA salt. 1 H NMR (300 MH 3 , CDCl 3 ) δ7.3 (m, 5H), 7.1 (d, 2H), 6.8 (d, 2H), 5.0 (q, 2H), 2.93 (t, 2H), 2.85 (dd, 1H), 1.92 (bd, 2H), 1.75 (m, 2H), 1.6-1.45 (m, 3H), 1.35 (m, 4H). Mass Spec. (FAB) m/e=455 (m+1). EXAMPLE 21 ##STR34## 2-S-Amino-3-[4-(6-N-t-butyloxycarbonylaminohexyloxy)-phenyl]propionic acid (2-1a) A solution of compound 2-1 (0.52 g, 1.0 mmole) in 20 mL of 4:1 ethanol/HOAc was hydrogenated under balloon pressure for 8 hours. The catalyst was filtered off and the solvent removed on the rotary evaporator to give a residue that was triturated with 30 mL ether to provide 2-1a. 1 H NMR (300 MHz, CD 3 OD) δ1.40 (9H, m), 1.75 (2H, m), 2.90-3.05 (3H, m), 3.10-3.23 (3H, m), 3.70 (1H, m), 3.96 (3H, t), 6.88 (2H, d), 7.20 (2H, d). EXAMPLE 22 ##STR35## 2-S-(Phenylcarbonylamino)-3[4-(6-N-t-butyloxycarbonylaminohexyloxy)phenyl] propionic acid (2-15) 0.152 g (0.4 mmole) of compound 2-1a was added to a solution of 1 N NaOH (0.4 ml) in 10 mL H 2 O and this was stirred at 0°-5° C. for 10 minutes as most of the solid dissolved. To this vigorously stirred suspension was added benzoyl chloride (0.062 g, 0.44 mmole) followed by solid sodium bicarbonate (0.037 g, 0.44 mmol) and the resulting mixture was stirred at 0°-5° C. for 1 hour. The reaction mixture was then diluted with 30 mL H 2 O and acidified to pH 2-3 with 10% KHSO 4 solution. This was extracted with 3×50 mL EtOAc and the combined organic extract was washed with 30 mL of H 2 O, 30 mL of brine and dried (Na 2 SO 4 ). Solvent removal provided a viscous residue that was purified by flash chromatography on silica gel eluting with chloroform(95)-methanol(5) to give 2-15 as a viscous residue. 1 H NMR (300 MHz, CDCl 3 ) δ1.40 (9H, m), 1.75 (2H, bs), 3.20 (m, 4H), 3.92 (2H, m), 5.03 (2H, m), 6.79 (2H, d), 7.10 (2H, d), 7.45 (3H, m), 7.72 (2H, m). EXAMPLE 23 ##STR36## 2-S-Phenylcarbonylamino-3-[4-(6-aminohexyloxy) phenyl]propionic acid hydrochloride (2-16) 0.28 g (2.0 mmole) of compound 2-15 was dissolved in 20 mL of EtOAc and this was cooled to -15° C. and HCl gas was bubbled into the solution for 10 minutes. The resulting mixture was stoppered and stirred at 0° C. for 1.5 hours at which point all starting material was consumed. The solvent was then removed on the rotary evaporator to afford a white, foam-like residue. This was stirred with 30 mL ether for 1 hour and the resulting solid was collected by filtration to provide pure 2-16 as a white solid. 1 H NMR (300 MHz, CD 3 OD), δ1.50 (3H, m), 1.70 (2H, m), 1.78 (2H, m), 2.90 (2H, t), 3.21 (4H, m), 3.94 (2H, t), 6.80 (2H, d), 7.19 (2H, d), 7.42 (2H, m), 7.50 (1H, m), 7.72 (2H, d). Analysis for C 22 H 38 N 2 O 4 .HCl.0.75 H 2 O; Calc.: C=60.82, H=6.90, N=6.45. Found: C=60.89, H=6.67, N=6.35. EXAMPLE 24 ##STR37## 2-S-Phenethylcarbonylamino-3[4-(6-N-t-butyloxycarbonylaminohexyloxy) phenyl]propanoic acid (2-17) To a solution of 1.2 mL 1 N NaOH in 15 mL H 2 O cooled to 0-5 degrees C. and stirred was added 0.457 g (1.2 mmole) of compound 2-14 and the resulting mixture was stirred for 10 minutes during which time most of the solid dissolved. To this vigorously stirred suspension was then added 3-phenylpropanoyl chloride (0.223 g, 1.32 mmole) followed by solid sodium carbonate (0.111 g, 1.32 mmole). The resulting white mixture was stirred vigorously at 0°-5° C. for 1.5 hours. The reaction mixture was then diluted with 40 mL H 2 O and this was acidified to pH 2-3 with a 10% KHSO 4 solution. The resulting aqueous phase was then extracted with 4×50 mL portions of EtOAc, and the combined organic phase was washed with 50 mL H 2 O, 50 mL brine and dried (Na 2 SO 4 ). Solvent removal gave a viscous solid that was purified by flash chromatography on silica gel, eluting with chloroform (95)-methanol(5) to give pure 2-17 as a clear viscous gum. 1 H NMR (300 MHz, CDCl 3 ) δ1.40 (9H, m), 1.72 (2H, bs), 2.50 (2H, m), 3.02 (6H, m), 3.91 (2H, m), 6.72 (2H, d), 6.88 (2H, m), 7.20 (3H, m), 7.29 (2H, m). EXAMPLE 25 ##STR38## 2-S-(Phenethylcarbonylamino-3-[4-(6-aminohexyloxy)phenyl]propanoic acid hydrochloride (2-18) A solution of compound 2-17 (0.3 g, 3.0 mmole) in 15 mL EtOAc was cooled to -15° C. and HCl gas was bubbled in for 10 minutes. The stoppered reaction mixture was then stirred for 2 hours at 0° C. at which time all 2-17 was consumed. The solvent was then removed on the rotary evaporator and the resulting foam was triturated with 40 mL ether at room temperature for 1.0 hour to give pure 2-18 as a white solid. 1 H NMR (300 MHz, CD 3 OD) δ1.48 (3H, m), 1.67 (2H, m), 1.80 (2H, m), 2.46 (2H, m), 2.80 (3H, m), 2.90 (2H, m), 3.30 (3H, m), 3.95 (2H, t), 6.79 (2H, d), 7.06 (2H, d), 7.15 (3H, m), 7.22 (2H, m). Analysis for C 24 H 32 N 2 O 4 .HCl.H 2 O; Calc.: C=61.72, H=7.55, N=6.00. Found: C=61.97, H=7.11, N=5.96. EXAMPLE 26 ##STR39## 2-S-(2-Benzyloxycarbonyl)phenylacetylamino-3[4-(6-N-t-butyloxycarbonylaminohexyloxy) phenyl]propionic acid (2-10) To a cold solution of 1.8 mL of 1 N NaOH in 15 mL H 2 O was added 0.685 g (1.8 mmole) of compound 2-1a with stirring to give, after 10 minutes, a clear solution. Then, 2-benzyloxycarbonylphenylacetyl chloride (0.577 g, 2.0 mmole) was added followed by sodium bicarbonate (0.168 g, 2.0 mmole) and the resulting mixture was stirred at 0°-5° C. for 1.0 hour. The reaction mixture was diluted with water, acidified to pH 2-3 with 10% KHSO 4 solution and extracted with 4×500 mL portions of EtOAc. The combined organic extracts were washed with brine, dried (Na 2 SO 4 ) and the solvent was removed to give a viscous amber residue. This was purified by column chromatography on silica gel, eluting with CHCl 3 (98)-methanol (2) to give pure 2-19 as an oil. 1 H NMR (300 MHz, CDCl 3 ) δ1.45 (9H, 6s), 1.75 (2H, 6s), 3.07 (4H, m), 3.89 (2H, bs), 4.57 (2H, bs), 5.15 (2H, m), 6.69 (2H, d), 6.88 (2H, d), 7.30 (5H, m). EXAMPLE 27 ##STR40## 2-S-(2-Carboxyphenylacetylamino)-3-[4-(6-aminohexyloxy)phenyl]propionic acid hydrochloride (2-20) Compound 2-19 (0.34 g, 0.55 mmole) was dissolved in 25 mL absolute ethanol and after adding 100 mg 10% Pd/C the suspension was hydrogenated under balloon pressure. Then, the catalyst was filtered off and the solvent removed on the rotary evaporator to give 2-S-(2-Carboxyphenylacetylamino)-3-[4-(6-N-t-butyloxycarbonylaminohexyloxy)phenyl]-propionic acid. 1 H NMR (300 MHz, CD 3 OD) δ1.47 (12H, m), 1.78 (2H, m), 3.06 (3H, m), 3.32 (4H, m), 3.92 (2H, m), 4.60 (2H, m), 6.72 (2H, d), 6.96, (2H, d), 7.30 (5H, m). This acid was dissolved in 25 mL EtOAc and treated with HCl gas as described for compound 2-2 in Example 9. Solvent removal provided a residue that was purified by flash chromatography on silica gel eluting with 9:1:1 ethanol/H 2 O/NH 4 OH to give pure 2-20. 1 H NMR (300 MHz, D 2 O) d 1.55 (H, m), 1.90 (2H, m), 2.83-3.09 (4H, m), 3.28 (1H, m), 4.15 (2H, m), 6.88-7.45 (9H, m). Analysis for C 24 H 30 N 2 O 6 •1.5 H 2 O•0.25 NH 3 ; Calc.: C=60.84, H=7.18, N=6.65. Found: C=60.48, H=6.81, N=6.99. EXAMPLE 28 ##STR41## 2-S-(Phenacylamino)-3-[4-(6-N-t-butyloxy carbonylaminooxy)phenyl]propionic acid (2-21) Compound 2-1a (0.685 g, 1.8 mmole) was acylated with phenacyl chloride as described for compound 2-19 in Example 26. The crude product was purified by flash chromatography on silica gel eluting with 95:5:0.5 CHCl 3 /CH 3 OH/HOAc to give pure 2-21 as a viscous oil. 1 H NMR (300 MHz, CD 3 OD) δ1.45 (12H, m), 1.78 (2H, m), 2.88 (1H, m), 3.10 (3H, m), 3.30 (1H, m), 3.48 (2H, m), 3.92 (2H, m), 4.61 (1H, m), 6.74 (2H, d), 7.02 (2H, d), 7.12 (2H, m) 7.22 (3H, m). EXAMPLE 29 ##STR42## 2-S-(Phenylacylamino)-3-[4-(6-aminohexyloxy) phenyl]-propionic acid (2-22) Compound 2-21 (0.35 g) was dissolved in 25 mL EtOAc and this solution was treated with HCl gas as described for compound 2-16 in Example 23 to give pure 2-22 as a white solid. 1 H NMR (300 MHz, CD 3 OD) δ1.50 (6H, m), 1.65 (2H, m), 2.20 (2H, m), 2.88 (3H, m), 3.12 (1H, m), 3.30 (2H, m), 3.47 (2H, m), 3.94 (2H, m), 4.61 (1H, m), 6.75 (2H, d), 7.02 (2H, d), 7.13 (2H, d), 7.30 (3H, m). Analysis for C 23 H 30 N 2 O 4 .HCl.H 2 O; Calc.: C=60.98, H=7.34, N=6.19. Found: C=61.29, H=6.92, N=6.12. EXAMPLE 30 ##STR43## 2-S-[(2-Benzyloxycarbonyl-3-phenylpropionylamino]-3-[4-(6-N-t-butyloxycarbonylaminohexyloxy)phenyl]propionic acid (2-23) Compound 2-1a (0.685 g, 1.8 mmole) was acylated with 2-benzyloxycarbonyl-3-phenylpropionyl chloride as described for compound 2-19 in Example 26. The crude product was purified by flash chromatography on silica gel eluting with 98:2:1 CHCl 3 /CH 3 OH/HOAc to give pure 2-23 as a viscous oil. 1 H NMR (300 MHz, CD 3 OD) δ1.40 (16H, m), 1.61 (2H, m), 3.03 (8H, m), 3.30 (6H, m), 3.71 (1H, m), 3.86 (2H, m), 4.60 (1H, m), 5.02 (2H, m), 6.70 (2H, d), 6.86, (1H, d), 7.02 (1H, 3), 7.22 (5H, m). EXAMPLE 31 ##STR44## 2-S-(2-Carboxy-3-phenylpropionylamino)-3-[4-(6-aminohexyloxy)phenyl]propionic acid (2-24) Compound 2-23 (0.49 g, 0.76 mmole) was dissolved in 25 mL ethanol and after the addition of 100 mg 10% Pd/C hydrogenated at balloon pressure overnight. Solvent removal provided 2-S-(2-carboxy-3-phenylpropionylamino)-3-[4-(6-N-t-butyloxycarbonylaminooxy)phenyl]propionic acid as a vixcous residue. 1 H NMR (300 MHz, CD 3 OD) δ1.42 (10H, m), 1.75 (2H, m), 2.80-3.15 (5H, m), 3.30 (1H, m), 3.90 (2H, m), 4.58 (2H, m), 6.68-6.85 (4H, m), 7.06-7.27 (5H, m). This acid (0.32 g) was treated with HCl gas as described above for compound 2-12 to give after solvent removal a crude product that was purified by flash chromatography on silica gel eluting with 90:5:5 CHCl 3 /CH 3 OH/HOAc to provide the diastereomeric products 2-24a and 2-24b. 2-24a had 1 H NMR (300 MHz, D 2 O) δ1.58 (4H, m), 1.83 (4H, m), 2.95 (2H, m), 3.08 (3H, m), 3.20 (1H, m), 3.51 (1H, m), 4.18 (2H, m), 4.53 (1H, m), 4.95 (2H, g), 6.92 (4H, m), 7.43 (5H, m). 2-24b had 1 H NMR (400 MHz, D 2 O) δ1.40 (4H, m), 1.62 (2H, m), 1.73 (2H, m) 2.90 (6H, m), 3.31 (1H, m), 4.17 (2H, m), 4.32 (1H, m), 6.93 (2H, d), 7.07 (2H, d), 7.15 (2H, d), 7.26 (3H, m). EXAMPLE 31(a) ##STR45## 2-S-(Hexanoylamino)-3-[4-(6-N-t-butyloxycarbonylaminohexyloxy)phenyl]propionic acid (2-25) (2-1a) (0.685 g, 1.8 mmole) was treated with hexanoyl chloride (0.38 g, 2.0 mmole) as described for 2-15 to provide crude 2-25. This was purified by flash chromatography on silica gel eluting with 95:5:1 CHCl 3 /CH 3 OH/HOAc to give pure 2-25 as an oil. 1 H NMR (300 MHz, CDCl 3 ) δ0.89 (3H, t), 1.20-1.65 (21H, m), 1.75 (2H, m), 2.19 (2H, t), 3.11 (4H, m), 3.92 (2H, m), 4.83 (1H, m), 6.80 (2H, d), 7.05 (2H, d). EXAMPLE 31(b) ##STR46## 2-S-(Hexanoylamino)-3-[4-(6-aminohexyloxy) phenyl]propionic acid hydrochloride (2-26) 2-25 (0.35 g, 0.75 mmole) was dissolved in 30 mL EtOAc and treated with HCl as described for compound 2-2 to give a foam-like solid that was triturated with 50 mL of ether for 1 hour at room temperature. This gave pure 2-26 as a white solid. 1 H NMR (300 MHz, CD 3 OD) δ0.85 (3H, t), 1.20 (4H, m), 1.48 (6H, m), 1.68 (2H, m), 1.77 (2H, m), 2.14 (2H, m), 4.61 (1H, m), 6.80 (2H, d), 7.13 (2H, m). Analysis for C 21 H 34 N 2 O 4 •HCl•0.5 H 2 O; Calc: C=59.49, H=8.56, N=6.61. Found: C=59.32, H=8.48, N=6.55. EXAMPLE 31(c) ##STR47## 2-S-(2-Napthanoylamino)-3-[4-(6-N-t-butyloxycarbonylaminooxy)phenyl]propionic acid (2-27) 2-1a (0.685 g, 1.8 mmole) was treated with 2-napthanoyl chloride (0.409 g, 2.0 mmole) as described for 2-15 to provide crude 2-27. This was purified by flash chromatography on silica gel eluting with 95:4:1 CHCl 3 /CH 3 OH/HOAc to give pure 2-27 as a white solid. 1 H NMR (300 MHz, CD 3 OD) δ1.45 (16H, m), 1.70 (2H, m), 2.88 (1H, m), 3.08 (3H, m), 3.57-3.80 (4H, m), 4.62 (1H, m), 6.54 (2H, d), 6.92 (2H, d), 7.25 (1H, d), 7.42 (2H, m), 7.61 (1H, bs), 7.77 (3H, m). EXAMPLE 31(d) ##STR48## 2-S-(Naphthanoylamino)-3-[4-(6-aminohexyloxy)phenyl]propionic acid (2-28) 2-27 (0.14 g, 0.31 mmole) was dissolved in 25 mL EtOAc and treated with HCl gas as described for 2-2. Crude product was purified by flash chromatography on silica gel eluting with 10:1:1 C 2 H 5 OH/H 2 O/NH 4 OH to give pure 2-28 as a white solid. 1 H NMR (300 MHz, CD 3 OD), δ1.42 (5H, m), 1.71 (2H, m), 2.63 (2H, m), 2.86 (1H, m), 3.07 (2H, m), 3.30 (3H, m), 3.55-3.75 (4H, m), 4.47 (1H, m), 6.43 (2H, d), 6.82 (2H, d), 7.30 (1H, dd), 7.45 (2H, m), 7.64 (1H, bs), 7.80 (3H, m). Analysis for C 27 H 32 N 2 O 4 •0.5 H 2 O; Calc.: C=70.87, H=7.27, N=6.12. Found: C=70.93, H=7.04, N=6.11. EXAMPLE 31(e) ##STR49## 2-S-(2-Butanoylamino)-3-[4-(6-N-t-butyloxycarbonylaminohexyloxy)phenyl]propionic acid (2-29) 2-1a (0.685 g, 1.8 mmole) was acylated with butanoyl chloride as described for 2-15 to give crude 2-29. This was purified by flash chromatography eluting with 95:4:1 CHCl 3 /CH 3 OH/HOAc to provide pure 2-29 as an oil. 1 H NMR (300 MHz, CD 3 OD) δ0.73 (3H, t), 1.32-1.60 (16H, m), 1.73 (2H, m), 2.12 (2H, m), 2.87 (1H, m), 3.03 (2H, t), 3.12 (1H, m), 3.92 (2H, t), 4.61 (1H, m), 6.80 (2H, d), 7.12 (2H, d). EXAMPLE 31(f) ##STR50## 2-S-(Butanoylamino)-3-[4-(6-aminohexyloxy)phenyl]propionic acid (2-30) 2-29 (0.05 g, 1.0 mmole) was dissolved in 25 mL ethyl acetate and treated with HCl gas as described for 2-2. Crude reaction product was triturated with 25 mL ether to give pure 2-30 as a white solid. 1 H NMR (300 MHz, CD 3 OD) δ0.72 (3H, t), 1.45-1.60(6H, m), 1.70 (2H, m), 1.79 (2H, m), 2.12 (2H, m), 2.80-2.95 (3H, m), 3.14 (1H, dd), 3.30 (1H, m), 3.95 (2H, t), 4.40 (1H, m), 6.80 (2H, d), 7.13 (2H, d). Analysis for C 19 H 30 N 2 O 4 •HCl•H 2 O; Calc.: C=56.35, H=8.21, N=6.92. Found: C=56.70, H=8.12, N=6.91. EXAMPLE 31(g) ##STR51## 2-S-(Heptanoylamino)-3-[4-(6-t-N-butyloxycarbonylaminooxy)phenyl]propionic acid (2-31) 2-1a (0.685 g, 1.8 mmole) was acylated with heptanoyl chloride as described for 2-15. Crude product was purified by flash chromatography on silica gel eluting with 96:3:1 CHCl 3 /CH 3 OH/HOAc to give pure 2-31 as an oil. 1 H NMR (300 MHz, CD 3 OD) δ0.78 (3H, t), 1.22 (6H, m), 1.32-1.55 (16H, m), 1.73 (2H, m), 2.13 (2H, m), 2.85 (1H, m), 3.02 (2H, t), 3.15 (1H, m), 4.91 (2H, t), 4.61 (1H, m), 6.81 (2H, d), 7.12 (2H, d). EXAMPLE 31(h) ##STR52## 2-S-(Heptanoylamino)-3-[4-(6-aminohexyloxy)phenyl]propionic acid hydrochloride (2-32) 2-31 (0.070 g) was dissolved in 30 mL EtOAc and treated with HCl gas as described for 2-2. Crude reaction product was triturated with 30 mL ether to provide pure 2-32 as a white solid. 1 H NMR (300 MHz, CD 3 OD) δ0.88 (3H, t), 1.22 (6H, m), 1.47 (6H, m), 1.68 (2H, m), 1.78 (2H, m), 2.13 (2H, t), 2.80-2.95 (3H, m), 3.14 (1H, m), 3.30 (1H, m), 3.94 (2H, m), 4.61 (1H, m), 6.80 (2H, d), 7.13 (2H, d). Analysis for C 22 H 36 N 2 O 4 •HCl•0.75 H 2 O; Calc.: C=59.71, H=8.77, N=6.33. Found: C=59.76, H=8.40, N=6.25. EXAMPLE 31(i) ##STR53## 2-(S)-(5-Phenylpentanoylamino)-3-[4-(6-N-t-butyloxycarbonylaminohexyloxy)phenyl]propionic acid (2-33) 2-1a (0.685 g, 1.8 mmole) was acylated with 5-phenylpentanoyl chloride as described for 2-15. Crude product was purified by flash chromatography on silica gel eluting with 96:3:1 CHCl 3 /CH 3 OH/HOAc to give pure 2-33 (0.49 g) as a clear oil. 1 H NMR (300 MHz, CD 3 OD) δ1.32-1.60 (1H, m), 1.73 (2H, m), 2.18 (2H, m), 2.53 (2H, m), 2.80-2.90 (1H, m), 3.02 (2H, t), 3.04 (1H, m), 4.62 (1H, m), 6.78 (2H, d), 7.08-7.28 (7H, m). EXAMPLE 31(j) ##STR54## 2-S-(5-Phenylpentanoylamino)-3-[4-(6-amino-hexyloxy)phenyl]propionic acid hydrochloride (2-34) 2-33 (0.49 g) was dissolved in 30 mL ethyl acetate and treated with HCl gas as described for 2-2. Crude product was triturated with 50 mL ether to give pure 2-34 as a white solid. 1 H NMR (300 MHz, CD 3 OD) δ1.40-1.58 (8H, m), 1.62-1.70 (2H, m), 1.80 (2H, m), 2.19 (2H, m), 2.55 (2H, m), 2.80-2.95 (3H, m), 3.15 (1H, m), 3.30 (1H, m), 3.90 (2H, t), 4.62 (1H, m), 6.88 (2H, d), 7.08-7.27 (7H, m). Analysis for C 26 H 36 N 2 O 4 •HCl•H 2 O; Calc.: C=64.24, H=7.88, N=5.76. Found: C=64.53, H=7.84, N=5.71. ##STR55## EXAMPLE 32 ##STR56## Methyl 2-S-(N-Benzyloxycarbonylamino)-3-[4-(6-N-t-butyloxycarbonylaminohexyl)oxyphenyl]propionate (3-1) Compound 2-1 (10.0 g, 19.43 mmole) in 75 mL DMF was treated with cesium carbonate (3.16 g, 9.72 mmole) with stirring at room temperature for 1.9 hours. Then, methyl iodide (2.76 g, 19.43 mmole) was added dropwise and the reaction mixture was stirred overnight at ambient temperature. The solvent was removed at high vaccum (30° C.) and the residue was taken up in 300 mL EtOAc and washed with 2×40 mL protions of saturated NaHCO 3 solution and brine and dried (Na 2 SO 4 ). Solvent removal provided 3-1 as a clear oil. 1 H NMR (300 MHz, CDCl 3 ) δ1.25-1.53 (16H, m), 1.76 (2H, m), 2.96-3.17 (4H, m), 3.71 (3H, s), 3.90 (2H, t), 4.61 (1H, m). 5.10 (2H, m), 5.19 (1H, m), 6.88 (2H, d), 6.98 (2H, d), 7.32 (5H, m). EXAMPLE 33 ##STR57## Methyl 2-S-Amino-3-[4-(6-t-butyloxycarbonylaminohexyloxy)phenyl]propionate (3-2) Compound 3-1 (8.0 g, 15.1 mmole) was dissolved in 150 mL absolute ethanol and 1.0 g 10% Pd/C was added. This suspension was hydrogenated in a Parr apparatus (50 psi) for 3.5 hours. The catalyst (-SOUTH-)filtered off and the solvent removed on the rotary evaporator to give pure 3-2 as a clear oil. R f =0.4 on SiO 2 with 95:5 CHCl 3 /CH 3 OH. 1H NMR (300 MHz, CDCl 3 ) δ1.30-1.55 (16H, m), 1.70 (2H, m), 2.80 (1H, m), 3.00-3.17 (3H, m), 3.71 (3H, s), 3.93 (2H, t), 6.82 (2H, d), 7.09 (2H, d). EXAMPLE 34 ##STR58## Methyl 2-S-[(5-t-Butyloxycarbonylamino) pentanoylamino]3-[4-(6-t-butyloxycarbonylaminohexyloxy)phenyl]propionate (3-3) To a solution of 5-(N-t-butyloxycarbonylamino)pentanoic acid (0.293 g, 1.35 mmole) and N-methylmorpholine (0.187 g, 1.35 mmole) in 10 mL EtOAc at 0°-5° C. was added i-butylchloroformate (0.184 g, 1.35 mmole) via syringe and the resulting white suspension was stirred for 0.5 hours. Then, 3-2 (0.5 g, 1.27 mmole) dissolved in 10 mL EtOAc was added dropwise and the reaction mixture was stirred at 0° C. for 2.0 hours. The reaction mixture was diluted with 25 mL water/ 40 mL EtOAc and the organic phase was separated, washed with water, 10% KHSO 4 , water, saturated NaHCO 3 , brine and dried (Na 2 SO 4 ). Solvent removal gave an oil that was purified by flash chromatography on silica gel eluting with 2% CH 3 OH/CHCl 3 (R f =0.35) to give pure 3-3 as a clear oil. 1 H NMR (300 MHz, CDCl 3 ) δ1.35-1.55 (26H, m) 1.62 (2H, m), 1.68 (2H, m), 2.20 (2H, t), 3.0-3.16 (6H, m), 3.33 (3H, s), 3.92 (2H, t), 4.83 9(H, m), 6.80 (2H, d), 6.99 (2H, m). EXAMPLE 35 ##STR59## 2-S-(5-Aminopentanoyl)amino-3-[4-(6-aminohexyloxy)phenyl)]propionic acid dihydrochloride (3-4) 3-3 (0.68 g, 1.14 mmole) was dissolved in 30 mL THF(1)/MeOH(1)/H 2 O(1), LiOH•H 2 O (0.137 g, 5.73 mmole) was added and the reaction mixture stirred at room temperature overnight. The solvent was then removed and the residue was taken up in 75 mL H 2 O and acidified to pH 2-3 with 10% KHSO 4 solution. This was extracted with EtOAc and the combined organic extracts were washed with brine and dried (Na 2 SO 4 ). Solvent removal gave 2-S-(5-N-t-butyloxycarbonylaminopentyl)amino-3-[4-(6-N-t-butyloxycarbonylaminohexyl)oxyphenyl]-propionic acid. 1 H NMR (300 MHz, CDCl 3 ) δ1.40-0.155 (22H, m). 1.60 (2H, m), 1.73 (2H, m), 2.20 (2H, m), 3.10 (4H, m), 3.90 (2H, m), 4.60 (1H, m), 4.72 (1H, m), 4.83 (1H, m), 6.78 (2H, d), 7.05 (2H, d). This acid was dissolved in EtOAc and was treated with HCl gas as described for 2-2. The crude hydroscopic white solid was triturated with a solution of 10 mL EtOAc/50 mL Et 2 O to give pure 3-4 as a white solid. 1 H NMR (300 MHz, CD 3 OD) δ1.42-1.85 (14H, m), 2.23 (2H, m), 2.90 (6H, m), 3.14 (1H, dd), 3.30 (1H, m), 3.97 (2H, t), 4.60 (1H, m), 6.82 (2H, d), 7.13 (2H, d). Analysis for C 20 H 33 N 3 O 4 •2HCl•3H 2 O; Calc.: C=47.43, H=8.16, N=8.30. Found: C=47.87, H=7.49, N=7.90. EXAMPLE 36 ##STR60## Methyl 2-S-[(4-Carbomethoxybutanoyl)amino]-3-[4-(N-t-butoxyloxycarbonyaminohexyloxy)phenyl]propionate (3-5) To a solution of 3-2 (0.5 g, 1.27 mmole), 4-carbomethoxybutanoic acid (0.213 g, 1.5 mmole) and 1 drop of triethylamine in 20 mL CH 3 CN was added BOP reagent (0.66 g, 1.5 mmole) and the resulting clear solution was stirred overnight at room temperature. The solvent was removed on the rotary evaporator and the residue was taken up in EtOAc and this was washed with H 2 O, 10% KHSO 4 , H 2 O, saturated NaHCO 3 , brine and dried (Na 2 SO 4 ). Solvent removal provided a residue that was purified by flash chromatography on silica gel eluting with 1% CH 3 OH/CHCl 3 to give pure 3-5 as a clear oil. 1 H NMR (300 MHz, CDCl 3 ), δ1.35-1.55 (14H, m), 1.75 (3H, m), 1.94 (2H, m), 2.26 (2H, t), 2.35 (2H, t), 2.98-3.16 (4H, m), 3.67 (3H, s), 3.73 (3H, s), 3.91 (2H, t), 4.82 (1H, m), 6.80 (2H, d), 6.95 (2H, d). EXAMPLE 37 ##STR61## 2-S-(4-Carboxybutanoylamino)-3-[4-(6-aminohexyloxy)phenyl]propionic acid (3-6) 3-5 (0.11 g, 0.21 mmole) was treated with LiOH (0.025 g, 1.05 mmole) as described for compound 3-4 to give the desired diacid. 1 H NMR (300 MHz, CD 3 OD) δ1.30-1.55 (16H, m) 1.70-1.82 (4H, m), 2.20 (4H, m), 2.85 (1H, m), 3.03 (2H, m), 3.13 (1H, dd), 3.30 (1H, m), 3.92 (2H, m), 4.62 (1H, m), 6.81 (2H, d), 7.12 (2H, d). This diacid (0.105 g) was dissolved in 30 mL EtOAc and treated with HCl gas as described for compound 2-2. The resulting solid was purified by flash chromatography on silica gel eluting with 90:8:8 ethanol/NH 4 OH/H 2 O to provide pure 3-6 as a white solid. 1 H NMR (300 MHz, CD 3 OD) δ1.42 (2H, m), 1.50 (2H, m), 1.63 (2H, m), 1.76 (4H, m), 2.17 (4H, m), 2.85 (3H, m), 3.16 (1H, m), 4.0 (2H, t), 4.48 (1H, m), 6.78 (2H, d), 7.12 (2H, d). Analysis for C 20 H 30 N 2 O 6 •1.2 H 2 O; Calc.: C=57.73, H=7.85, N=6.73. Found: C=57.66, H=7.21, N=6.83. EXAMPLE 38 ##STR62## Methyl 2-S-[(3-Carboethoxypropanoyl)amino)]-3-[4-(6-N-t-butyloxycarbonylaminohexyloxy)phenyl]-propionate (3-7) 3-2 (0.562 g, 1.42 mmole) was dissolved in 15 mL EtOAc and treated with NaHCO 3 , (0.36 g, 4.27 mmole) and 3-carboethoxypropanoyl chloride (0.235 g, 1.42 mmole) with stirring overnight. The reaction mixture was diluted with 150 mL EtOAc and the organic phase was washed with H 2 O, brine and dried (Na 2 SO 4 ). Solvent removal gave a residue that was purified by flash chromatography on silica gel eluting with 98:2 CHCl 3 /CH 3 OH to give pure 3-7. 1 H NMR (300 MHz, CDCl 3 ) δ1.26 (3H, t), 1.35-1.61 (16H, m), 1.76 (2H, m), 2.48 (2H, m), 2.63 (2H, m), 3.05 (2H, m), 3.11 (2H, m), 3.72 (3H, s), 3.92 (2H, t), 4.13 (2H, q), 4.82 (2H, m), 6.80 (2H, d), 7.00 (2H, d). EXAMPLE 39 ##STR63## 2-S-[(3-Carboxypropanoyl)amino]-3-[4-(6-aminohexyloxy)phenyl]propionic acid hydrochloride (3-8) 3-7 (0.58 g, 1.11 mmole) was treated with LiOH as described for 3-3 to give 2-S-[(carboxypropanoyl)amino]-3-[4-(6-N-t-butyloxycarbonylaminohexyloxyphenyl]propionic acid as a foam. 1 H NMR (300 MHz, CD 3 OD) δ1.32-1.58 (16H, m), 1.77 (2H, m), 2.40 (4H, m), 2.89 (1H, m), 3.0-3.16 (3H, m), 3.33 (1H, m), 3.90 (2H, t), 4.42 (1H, m), 6.78 (2H, d), 7.11 (2H, d). This acid (0.435 g) was treated with HCl gas in EtOAc (30 mL) as described for 2-2 to give a foam that was triturated with EtOAc to give pure 3-8 as a white solid. 1 H NMR (300 MHz, CD 3 OD) δ1.4-1.6 (4H, m), 1.76 (2H, m), 2.46 (4H, m), 2.92 (3H, m), 3.14 (1H, m), 3.30 (1H, m), 3.96 (2H, m), 4.60 (1H, m), 6.81 (2H, d), 7.14 (2H, d). Analysis for C 19 H 28 N 2 O 5 •HCl•0.5H 2 O; Calc.: C=53.58, H=7.10, N=6.58. Found: C=53.18, H=6.93, N=6.27. EXAMPLE 40 ##STR64## Methyl 2-S-(Acetylamino)-3-[4-(6-N-t-butyloxycarbonylaminohexyloxy)phenyl]propionate (3-9) 3-2 (0.562 g, 1.42 mmole) was treated with acetyl chloride (0.112 g, 4.27 mmole) as described for 3-7 to give a yellow oil. This was purified by flash chromatography on silica gel eluting with 98:2 CHCl 3 /CH 3 OH to give pure 3-9 as a clear oil. 1 H NMR (300 MHz, CDCl 3 ) δ1.30-1.56 (14H, m), 1.78 (2H, m), 2.00 (3H, s), 3.05-3.16 (4H, m), 3.73 (3H, s), 3.92 (2H, t), 4.84 (1H, m), 6.80 (2H, m), 6.98 (2H, d). EXAMPLE 41 ##STR65## 2-S-(Acetylamino)-3-[4-(6-aminohexyloxy)phenyl]propionic acid hydrochloride (3-10) 3-9 (0.58 g, 1.33 mmole) was treated with LiOH (0.16 g, 6.64 mmole) as described for 3-3 to give 2-S(acetylamino)-3-[4-(6-N-t-butyloxycarbonylaminohexyloxy)phenyl]propionic acid as a white solid. 1 H NMR (300 MHz, CD 3 OD) δ1.35-1.53 (16H, m), 1.75 (2H, m), 1.90 (3H, s), 2.86 (1H, m) 3.00-3.15 (3H, m), 3.30 (1H, m), 3.93 (2H, t), 4.59 (1H, m), 6.82 (2H, d), 7.12 (2H, d). This compound (0.485 g) was dissolved in 30 mL EtOAc and treated with HCl gas as described for 2-2 to give a residue that was triturated with EtOAc to provide pure 3-10 (0.4 g) as a white solid. 1 H NMR (300 MHz, CD 3 OD) δ1.42-1.60 (4H, m), 1.66 (2H, m), 1.70 (2H, m), 1.90 (3H, s), 2.82 (1H, m), 2.92 (2H, m), 3.12 (1H, dd), 3.30 (1H, m), 3.95 (2H, t), 4.60 (1H, m), 6.82 (2H, d), 7.13 (2H, d). Analysis for C 17 H 26 N 2 O 4 •HCl•H 2 O; Calc.: C=54.17, H=7.76, N=7.43. Found: C=54.30, H=7.71, N=7.09. ##STR66## EXAMPLE 42 ##STR67## 2-S-(N-t-Butyloxycarbonylamino)-3-[4-(4-hydroxybut-1-ynyl)phenyl]propionic acid (4-2) N-BOC-4-iodo-L-phenylalanine (4-1) (Bachem) (1.0 g, 2.55 mmole) was dissolved in diethylamine under N 2 and treated with 3-butyne-1-ol (0.23 mL, 3.06 mmole), Pd[P(C 6 H 5 ) 3 ] 2 Cl 2 (0.089 g, 0.127 mmole) and CuI (0.012 g, 0.064 mmole). After 3 hours the solvent was evaporated, the residue dissolved in water (pH=11) and extracted with ethyl acetate. The water layer was then acidified to pH 3, extracted with ethyl acetate. This organic extract was dried and evaporated to give crude 4-2. R f =0.47 in 97/3/1 CHCl 3 /CH 3 OH/HOAc, ninhydrin stain. 1 H NMR (300 MHz, CDCl 3 ) δ7.35 (2H, d), 7.1 (2H, d), 6.4 (1H, broad) 5.0 (1H, d), 4.6 (1H, m), 3.8 (2H, t), 3.1 (2H, m), 2.65 (2H, t), 1.4 (9H, s). EXAMPLE 43 ##STR68## 2-S-(N-t-Butyloxycarbonylamino)-3-[4-(4-hydroxybutyl)phenyl]propionic acid (4-3) 4-2 (0.40 g, 1.2 mmole) was dissolved in an ethanol/water solution (25 mL) and was treated with 10% Pd/C (0.1 g) and H 2 on a Parr apparatus. After 2 hours the solution was filtered and evaporated. Column chromatography on silica gel (94:5:1 CHCl 3 /CH 3 OH/HOAc) yielded 4-3. R f =0.57 in 97:3:1 CHCl 3 /CH 3 OH/HOAc ninhydrin stain. 1 H NMR (300 MHz, CDCl 3 ) δ7.1 (s, 4H), 4.95 (1H, m), 4.9 (1H, broad), 4.55 (1H, m), 3.65 (2H, t), 3.1 (2H, m), 1.6 (4H, m), 1.4 (9H, s). EXAMPLE 44 ##STR69## Methyl 2-S-(N-t-Butyloxycarbonylamino)-3-[4-(4-tosyloxybutyl)phenyl]propionate (4-4) 4-3 (0.285 g, 0.85 mmole) was dissolved in CH 2 Cl 2 (10 mL) cooled to 0°, and treated with CH 2 N 2 solution. After 10 minutes the reaction was quenched with MgSO 4 , filtered and evaporated to provide ester used in the next reaction. R f =0.5 in 92:8:1 CHCl 3 /CH 3 OH/HOAc, ninhydrin stain. 1 H NMR (300 MHz, CDCl 3 ) δ7.05 (d, J=7.8 Hz, 2H), 7.0 (d, J=7.8 Hz, 2H), 5.0 (1H, m), 4.55 (1H, m), 3.69 (3H, s), 3.6 (2H, J=6.2 Hz, t), 3.0 (2H, m), 2.6 (2H, J=7.5 Hz, t), 1.7 (4H, m), 1.4 (9H, s). This ester was dissolved in 10 mL CH 2 Cl 2 and added at 78° C. to a solution prepared by treating p-toluenesulfonyl chloride (0.14 g, 0.67 mmole) in CH 2 Cl 2 at -78° with pyridine (0.1 ml, 1.35 mmole) for 10 minutes. The reaction was allowed to warm to room temperature over 1.0 hour and then water was added. The organic layer was separated, dried, and evaporated. Column chromatography on silica gel eluting with 97:3:1 CHCl 3 /CH 3 OH/HOAc gave 4-4. R f =0.85 97:3:1 CHCl 3 /CH 3 OH/HOAc. 1 H NMR (300 MHz CDCl 3 ) δ7.88 (2H, J=7.2 Hz, d), 7.74 (2H, J=7.2 Hz, d), 7.38 (2H, J=Hz, d), 7.30 (2H, J=8 Hz, d), 5.0 (1H, m), 4.5 (1H, m), 4.0 (2H, J=5.3 Hz, t), 3.67 (3H, s), 3.0 (2H, m), 2.5 (2H, t), 2.0 (3H, s), 1.6 (4H, m), 1.4 (9H, s). EXAMPLE 45 ##STR70## 2-S-(N-t-Butyloxycarbonylamino)-3-[4-(4-t-butylaminobutyl)phenyl]propionic acid (4-5) 4-4 (0.26 g, 0.48 mmoles) was dissolved in t-butylamine (5 mL) and this solution was refluxed for 2 days. The reaction was filtered and the excess t-butylamine removed at high vacuum (30° C.). The residue was purified by flash chromatography on silica gel eluting with 98:2 CHCl 3 (saturated with NH 3 )/CH 3 OH to give methyl 2-S-(N-t-butyloxycarbonylamino)-3-[4-(4-t-butylaminobutyl)phenyl]propionate as an oil, 1.6 (4H, m), 1.40 (9H, S). 1 H NMR (300 MHz, CDCl 3 ) δ7.05 (2H, d), 7.0 (2H, d), 4.95 (1H, d), 4.55 (1H, m), 3.7 (3H, s), 3.0 (2H, m), 2.55 (2H, d). This ester (0.10 g, 2.7 mmole) was dissolved in 1:1:1 THF/CH 3 OH/H 2 O (10 mL) and LiOH•H 2 O (0.033 g, 1.38 mmole) was added at room temperature. After stirring for 2 hours the solvent was removed and the residue chromatographed on silica gel eluting with 9:1:1 C 2 H 5 OH/H 2 O/NH 4 OH to give pure 4-5. 1 H NMR (300 MHz, D 2 O) δ7.35 (4H, s), 4.25 (1H, dd), 3.2 (1H, m), 3.1 (2H, t), 2.9 (1H, m), 2.8 (2H, t), 1.8 (4H, m), 1.4 (18H, s). Analysis for C 22 H 36 N 2 O 4 •1.0 CF 3 CO 2 H Calc: C=56.90, H=7.36, N=5.53 Found: C=56.73, H=7.51, N=5.58. ##STR71## EXAMPLE 46 ##STR72## 2-S-Amino-3-[4-(4-N-t-butyloxycarbonyl piperidin-4-yl)butyloxyphenyl]propionic acid (5-1) 2-13 (2.0 g) was dissolved in 100 mL EtOH, and 0.2 g 10% Pd/C was charged. This suspension was hydrogenated at balloon pressure overnight. Solvent removal provided 5-1 as a white solid. 1 H NMR (300 MHz, CD 3 OD), δ0.97-1.12 (2H, m), 1.20-1.54 (14H, m), 1.72 (4H, m), 2.71 (2H, m), 2.90-3.00 (1H, m), 3.22 (1H, dd), 3.30 (1H, m), 3.71 (1H, m), 3.95-4.10 (4H, m), 6.88 (2H, d), 7.21 (2H, d). EXAMPLE 47 ##STR73## 2-S-(Pentanoylamino)-3-[4-(4-N-t-butyloxycarbonylpiperidin-4-yl)butyloxyphenyl]propanoic acid (5-2) 5-1 (1.05 g, 2.5 mmole) was added to a cold solution of 1 N NaOH (2.5 mL) in 20 mL H 2 O and stirred at 0°-10° C. for 5 minutes to give a clear solution. Then, pentanoyl chloride (0.332 g, 2.75 mmole) was added dropwise followed by NaHCO 3 (0.231 g, 2.75 mmole) and the resulting mixture was stirred vigorously at 0°-10° C. for 1 hours. The reaction mixture was diluted with H 2 O (75 mL), acidified to pH 2-3 with 10% KHSO 4 and extracted with EtOAc. This extract was filtered, washed with brine, dried (Na 2 SO 4 ) and the solvent removed to give an oil. This was purified by flash chromatography on silica gel eluting with 97:3:1 CHCl 3 /CH 3 OH/HOAc to give pure 5-2 as a clear oil. 1 H NMR (300 MHz, CD 3 OD) δ0.90 (3H, t), 1.20-1.62 (16H, m), 1.72 (2H, m), 2.14 (2H, m), 2.30 (8H, m), 2.65-2.90 (4H, m), 3.30 (1H, m), 3.93 (2H, m), 4.61 (1H, m), 6.81 (2H, d), 7.12 (2H, d). EXAMPLE 48 ##STR74## 2-S-(Pentanoylamino)-3-[4-(4-piperidin-4-ylbutyloxy) phenyl]propionic acid hydrochloride (5-3) 5-2 (0.449 g), was dissolved in 30 mL EtOAc and treated with HCl gas at -10° C. as described for 2-2. The resulting solid was triturated with 40 mL Et 2 O to give pure 5-3 as a white solid. 1 H NMR (300 MHz, CD 3 OD) δ0.85 (3H, t), 1.19 (2H, m), 1.30-1.65 (9H, m), 1.73 (2H, m), 1.95 (2H, m), 2.15 (2H, m), 2.80-3.02 (3H, m), 3.14 (1H, dd), 3.30-3.40 (3H, m), 3.95 (2H, t), 4.61 (1H, m), 6.82 (2H, d), 7.13 (2H, d). Analysis for C 23 H 36 N 2 O 4 •HCl•0.75 H 2 O; Calc.: C=60.77, H=8.54, N=6.16. Found: C=60.97, H=8.39, N=6.06. EXAMPLE 49 ##STR75## 2-S-(Hexanoylamino)-3-[4-(4-N-t-butyloxycarbonylpiperidin-4-yl)butyloxyphenyl]propionic acid (5-4) 5-1 (0.41 g) was treated with hexanoyl chloride (0.21 mL, 1.50 mmole) as described for 5-2. Crude product was purified by flash chromatography on silica gel eluting with 97:3:1 CHCl 3 /CH 3 OH/HOAc to give pure 5-4. 1 H NMR (300 MHz, CD 3 OD) δ0.85 (3H, t), 0.97-1.35 (8H, M), 1.37-1.53 (12H, m), 1.60-1.80 (4H, m), 2.13 (2H, t), 2.80 (2H, m), 2.85 (1H, m), 3.12 (1H, dd) 3.90 (2H, t), 4.04 (2H, d), 4.62 (1H, m), 6.80 (2H, d), 7.12 (2H, d). EXAMPLE 50 ##STR76## 2-S-(Hexanoylamino)-3-[4-(4-piperidin-4-ylbutyloxy)phenyl]propionic acid (5-5) 5-4 (0.199 g) was dissolved in 25 mL EtOAc and treated with HCl gas as described for compound 2-2 to provide pure 5-5 (48 mg). 1 H NMR (300 MHz, CD 3 OD) δ0.84 (3H, t), 1.08-1.20 (4H, m), 1.35 (4H, m), 1.52 (4H, m), 1.77 (2H, m), 1.92 (2H, d), 2.16 (2H, t), 2.80-3.-2 (3H, m), 3.15 (1H, dd), 3.40-3.52 (2H, m), 3.92 (2H, t), 4.61 (1H, m), 6.81 (2H, d), 7.13 (2H, d). Analysis for C 26 H 39 N 2 O 6 F 3 •0.55 H 2 O•0.30 TFA; Calc.: C=55.39, H=7.06, N=4.86. Found: C=55.38, H=7.03, N=4.85. Sample alternative protecting groups that can be used in the preparation of the present invention include benzyl ester, cyclohexyl ester, 4-nitrobenzyl ester, t-butyl ester, 4-pyridylmethyl ester, benzyloxycarbonyl, isonicotinyloxycarbonyl, O-chlorobenzyloxycarbonyl, p-nitrobenzyloxycarbonyl, p-methoxybenzyloxycarbonyl, t-butoxycarbonyl, t-amyloxycarbonyl, isobornyloxycarbonyl, adamantyloxycarbonyl, 2-(4-biphenyl)-2-propyloxycarbonyl and 9-fluorenylmethoxycarbonyl. In addition to those compounds specifically exemplified above, additional compounds of the present invention are set forth in tabular form below. These compounds are synthesized by use of the synthetic routes and methods described in the above Schemes and Examples and variations thereof well known to those of ordinary skill in the art, and not requiring undue experimentation. All variables listed in the Tables below are with reference to the following generic structure: ##STR77## __________________________________________________________________________n Y R.sup.1 R.sup.2 R.sup.3 R.sup.4 R.sup.5__________________________________________________________________________1 CH.sub.2 H C.sub.4 H.sub.9 H t-Bu H2 O CH(CH.sub.3).sub.2 H 2-CH.sub.3 i-Pr C.sub.2 H.sub.53 SO.sub.2 CH.sub.3 CH.sub.2C(CH.sub.3).sub.2CH(CH.sub.3).sub.2 3-F C.sub.2 H.sub.5 CH.sub.34 NHCO C.sub.2 H.sub.5 CH.sub.2 Ph H CH.sub.3 H5 CONH H H H C.sub.4 H.sub.9 H6 CH.sub.2 CH.sub.2 NH.sub.2 CH.sub.3 H C.sub.3 H.sub.7 i-Pr5 O H 2-CO.sub.2 H t-Bu H1 CH.sub.3 ##STR78## t-Bu 3-CF.sub.3 CH.sub.2 tBu H2 SO.sub.2 H (CH.sub.2).sub.2 CO.sub.2 H 2-CH.sub.2 CO.sub.2 H CH.sub.2 CH(CH.sub.3).sub.2 C.sub.2 H.sub.53 NHCO CH.sub.2 CH.sub.2 OCH.sub.3 C.sub.2 H.sub.5 3-OH C.sub.2 H.sub.5 H4 CONH H (CH.sub.2).sub.3 Ph 2-OH CH.sub.2 Ph H__________________________________________________________________________ The test procedures employed to measure the anti-osteoclast activity of the compounds of the present invention are described below. EXAMPLE 51 When osteoclasts engage in bone resorption, they will literally cause the formation of pits in the surface of bone that they are acting upon. Therefore, when testing compounds for their ability to inhibit osteoclasts, it is useful to measure the ability of osteoclasts to excavate these resorption pits when the inhibiting compound is present. Consecutive cross sections (4.4×4.4×0.2 mm) of bovine femur were cut from the diaphysis with a low-speed diamond saw (Isomet, Buehler, Ltd., Lake Bluff, Ill.) by the method of Arnett and Dempter. Endocrinology 120: 602-608. Prior to incubation with osteoclasts, slices were rehydrated in 0.1 ml complete medium 199 in a 48-well plate (Costar, Cambridge, Mass.) overnight in the presence of twice the desired dose of compound being tested. Osteoclasts were isolated from the long bones of 1 to 3-day-old rats (Sprague-Dawley) by adaptations of methods used by Chambers, et al. J. Cell Sci. 66: 383-399. Femora, tibiae, and humeri were split and minced with scalpel blades into 2-5 ml Medium 199 (GIBCO, New York). The resulting suspension was gently pipetted (60 times with a wide-bore pipet and then aliquoted onto petri dishes (Costar) or bone slices (0.1 ml per slice). Cells were allowed to settle for 30-40 minutes at 37° C. in moist CO 2 -air before gentle washing and reincubation in undiluted incubation medium. Osteoclast yields varied from 300 to 1400 per rat and typically comprised 1% or less of the total cell population. Osteoclasts were counted at the day of isolation and after 1 day of incubation by phase-constrast microscopy (Nikon Diaphot). Total attached cells were counted 50-70 h after isolation with a Coulter counter (model ZM, Coulter Electronics, Inc., Hialeah, Fla.). Cell counts of controls varied from 3.352×10 4 to 2.322×10 5 per well. Counting mononuclear cells at the time of isolation was not practical because of matrix and cell debris that could not be completely eliminated. Bone slices exposed to osteoclasts for 20 h after isolation were processed for staining by ultrasonication (twofold, 15 s, Branson) in 0.25M ammonium hydroxide before fixation (20 minutes) in 2.5% glutaraldehyde, 0.1M cacodylate, pH 7.4 (EM Supplies, Fort Washington, Pa.). Samples were dehydrated in ethanol (40, 70, and 100%; 5 minutes), air dried for 2 h, and then stained for 4 minutes with filtered 1% toluidine blue and 1% borax (Sigma, St. Louis, Mo.). Samples used to count osteoclasts were processed as earlier without ultrasonication in ammonium hydroxide. Samples processed for scanning electron microscopy were not air dried but infiltrated for 40 minutes with 1:1 ethanol-Peldri II (Ted Pella, Inc., Redding, Calif.). After incubation in 100% Peldri II, solidified samples were exacuated overnight to sublimate the Peldri II. Slices were rotary shadowed with gold (DV-502A, Denton Vacuum, Cherry Hill, N.J.) and then examined on a JEOL JSM 840 at 3 kV accelerating voltage. The morphology and motility of living osteoclasts were analyzed by recording phase-contrast images (Nikon, N.Y.) in real time onto 3/4 inch videotapes with a u-matic VCR (Model VO 5800H, Sony). A fluorescence microscope (Microphot, Nikon) was adapted for reflected light microscopy by inserting a λ/4 plate between cross polarizers in the epi mode. Fluorescence objectives of long working distance with adjustable correction collars (10×, 20×, Nikon) were fitted with rotatable λ/4 plates (Polaroid Corp., Massachusetts) mounted as the front element. Correction collars were necessary 20× objectives and higher to correct for the presence of the λ/4 plate and the absence of a coverslip. Coverslips were not used to eliminate stray reflections below the λ/4 plate. Immersion oil (Nikon) was added between the objective front lens and λ/4 plate to minimize reflections at this interface. Oil was not placed between objective and specimen. Bone slices were scanned for resorption pits by rotating the λ/4 plate 0°-45° with respect to the plane of polarization in epi-tungsten illumination. Alternatively, Hg illumination (HBO 100w, Nikon) was used with the λ/4 plate fixed at 45° while intermittently viewing stained images by transmission brightfield microscopy with an NCB 10 filter (Nikon). Quantitation of resorbed areas of bone slices examined by bright-field, RLM, and SEM was achieved through digital image processing (Magiscan 2A, Joyce Loebl, New York) of video images (Newvicon or SIT, Dage-MTI, Inc. Michigan City, Ind.) fed through a NTSC/PAL digital standards converter (CEL P156, James Grunder and Assoc., Inc., Mission, Kans.). Osteoclasts were processed for immunofluorescence by briefly rinsing coverslips in buffer S (60 mM Pipes, pH 6.9; 25 mM Hepes; 10 mM EGTA; and 2 mM MgCl 2 ) at 37° C. and then fixing for 2 minutes in buffer S+10% formaldehyde, pH 7.0. Cells were permeabilized in buffer S+0.5% Triton X-100 and then rinsed. Specimens were incubated (30 minutes) in appropriate antibody or rhodamine-phalloidine (Molecular probes, Eugene, Oreg.) followed by fluorescein goat antirabbit antibody (Cappel). The bone slice assay is used to examine the effect of the compound of interest on the activity of isolated osteoclasts from rat long bones. The number of resorption pits formed by osteoclasts after 1 day on consecutive cross sections of bovine femur was first compared to control samples by the method of Arnett and Dempster, Endocrinology 120:602-608, and then plotted as a function of concentration of the compound of interest. This is shown at FIG. 1. The appropriateness of extrapolating data from this assay to utility and use in mammalian (including himan) disease states is supported by the teaching found in Sato, M., et al., Journal of Bone and Mineral Research, Vol. 5, No. 1, 1990. That article teaches that certain bisphosphonates have been used clinically and appear to be effective in the treatment of Paget's disease, hypercalcemia of malignancy, osteolytic lesions produced by bone metastases, and bone loss due to immobilization or sex hormone deficiency. These same bisphosphonates are then tested in the resorption pit assay described above to confirm a correlation between their known utility and positive performance in the assay. While the invention has been described and illustrated in reference to certain preferred embodiments thereof, those skilled in the art will appreciate that various changes, modifications and substitutions can be made therein without departing from the spirit and scope of the invention. For example, effective dosages other than the preferred doses as set forth hereinabove may be applicable as a consequence of variations in the responsiveness of the mammal being treated for severity of bone disorders caused by resorption, or for other indications for the compounds of the invention indicated above. Likewise, the specific pharmacological responses observed may vary according to and depending upon the particular active compound selected or whether there are present pharmaceutical carriers, as well as the type of formulation and mode of administration employed, and such expected variations or differences in the results are contemplated in accordance with the objects and practices of the present invention. It is intended, therefore, that the invention be limited only by the scope of the claims which follow and that such claims be interpreted as broadly as is reasonable.

Compounds of the general formula ##STR1## and the pharmaceutically acceptable salts thereof wherein n is an integer of from 0 to 6; Y is CH 2 , O, SO 2 , --CONH--, --NHCO--, or ##STR2## R 1 and R 2 are independently hydrogen, C 1-8 alkyl, heterocyclyl C 0-4 alkyl, aryl C 0-4 alkyl, amino C 1-4 alkyl, C 1-4 alkylamino C 1-4 alkyl, or C 3-8 cycloalkyl wherein R 1 and R 2 may be unsubstituted or substituted with one or more groups chosen from R 3 , where R 3 is hydrogen, C 1-6 alkyl, hydroxy C 0-4 alkyl, carboxy C 0-4 alkyl, C 1-4 alkyloxy C 0-4 alkyl, heterocyclyl C 0-4 alkyl, aryl C 0-4 alkyl, halogen, or CF 3 ; R 4 is C 1-6 alkyl, heterocyclyl C 0-4 alkyl, or aryl C 0-4 alkyl; R 5 is hydrogen, C 1-6 alkyl, aryl C 0-3 alkyl, or C 1-6 alkylcarbonyloxymethyl are used in a method of treating osteoporosis by inhibiting the bone resorption activity of osteoclasts.

RELATED APPLICATIONS [0001] This application claims priority to co-pending U.S. Provisional Application No. 61/295,492, filed Jan. 15, 2010, and U.S. Provisional Application No. 61/378,160, filed Aug. 30, 2010. The contents of those applications are incorporated by reference. STATEMENT OF GOVERNMENT RIGHTS [0002] This invention was made with government support under CHE-0910824 awarded by the National Science Foundation. The government has certain rights in the invention. INCORPORATION BY REFERENCE [0003] All patents, patent applications and publications cited herein are hereby incorporated by reference in their entirety in order to more fully describe the state of the art as known to those skilled therein as of the date of the invention described herein. BACKGROUND [0004] The subject matter is directed to systems and methods for determining the size of a molecule, or, more generally, the distribution of sizes of an ensemble of molecules. [0005] Gel electrophoresis is the most commonly used technique for measuring distributions of molecular sizes. In its usual application to proteins, the proteins are denatured so the electrophoretic mobility measures the molecular length, and thereby the approximate molecular weight. Native gel electrophoresis can also be applied to biomolecules in their functional conformation, though the interpretation of mobilities in native gels is often ambiguous. Gel electrophoresis cannot be applied to large or weakly associating molecular complexes. Additionally, gel electrophoresis typically requires several hours to run, requires large amounts of sample, and consumes ˜100 mL of reagents. [0006] The sizes of particles larger than ˜10 nm diameter can be determined by dynamic light scattering (DLS). All particles scatter light, so dust or impurities confound or interfere with DLS measurements, and DLS can only be applied to the major component in a heterogeneous mixture. Furthermore, the inverse Laplace transform used in interpretation of DLS is subject to noise, so DLS measurements are often imprecise. [0007] Fluorescence correlation spectroscopy (FCS) measures the size of fluorescent species in solution by measuring the distribution of residence times in a focused laser spot. FCS works best for small molecules, with hydrodynamic radii of less than 20 nm. As with DLS, FCS cannot easily distinguish between individual particles and fluorescent aggregates. FCS provides only a very coarse measure of molecular size, and is not well suited to measuring heterogeneous size distributions. SUMMARY [0008] A simple system that measures the size and/or size distributions of imageable molecules in solution is provided. The present system and method provide means to determine the size of a molecule, or more generally, the size distribution of a population of molecules. [0009] In one aspect, a system for detecting the size of a molecule is provided. The system includes a sample measurement surface having a curved cover plate positioned tangent to a planar surface, e.g., there is a single point or line of contact, and the curved cover plate has a surface that varies in a predetermined and understood manner from the point of contact to a radially displaced position relative to the point of contact. The system also includes an imaging system such as an inverted fluorescent microscope. The system is capable of detecting molecules in solution, with molecular diameters in the size range of ˜2-1000 nm. The imaging system is capable of detecting molecules, e.g., either by absorption, by fluorescence or other technique. The transparent material can be wedged shaped or curvilinear. By way of example, it can be a convex, biconvex, plano-convex lens, or concave convex lens where the curvature of the surface is well-defined. [0010] In one aspect, a method for detecting the size of a molecule is provided. The method includes applying a test liquid containing molecules to be measured to the sample measurement surface. Measuring the location of the fluorescence from the point of contact, wherein the location of fluorescence is an indication of the molecular size. Similarly, other properties of the sample, absorbance, etc. could be measured with a light source below the sample measurement surface to determine onset of molecular exclusion. [0011] The radius of curvature of the transparent material is known. The distance from the (center) point of contact to the observed fluorescence is measured and the distance (or spacing) of the curved surface to the planar surface can then be calculated. This distance correlates with the size of the molecule or collection of molecules. The phenomenon of excluding particles from regions under the curved surface that are smaller than the molecular diameter is referred to as “nanoscale confinement.” [0012] The system for detecting the size of a molecule can operate with low analyte amounts, e.g., ˜10 μL of a ˜1 nM solution of analyte, acquires the data in ˜1 minute, works in the presence of a high concentration of non-fluorescent background, and is simple to construct and operate. [0013] The methodology can be used to determine the sizes of freely diffusing molecules with diameters ranging from 2 nm to 1000 nm by imaging their areal density as a function of the nanoscale confinement. For example, the method and device can be used to detect the molecular size of biomolecules such as proteins, micelles and DNA. It can also be used to detect the molecular size of polymers, in particular polymer beads. The methodology is suited to measuring the size of a homogeneous sample population as well as the size distribution of a heterogeneous sample population. [0014] A simple method for imaging single molecules in free solution is disclosed. The system confines molecules in a nanoscale wedge-shaped gap formed between a curved surface and a planar surface. The sub-wavelength confinement leads to up to 20-fold greater rejection of background fluorescence than is achieved with total internal reflection fluorescence (TIRF) imaging, and approximately 10,000-fold longer per-molecule observation time than is achieved with confocal detection. The system provides information relating to the nanoscale optical and mechanical properties of single molecules, without relying on nanofabrication or nanopositioning equipment. [0015] The system for detecting size of a molecule includes a sample measurement surface having a convex surface positioned tangent to a planar surface, coupled with an imaging system such an inverted fluorescent microscope. In one or more embodiments, the convex surface comprises a lens and the system is referred to as a convex lens-induced confinement system (CLIC). In one or more embodiments, the system comprises a flow cell having two substantially planar surfaces, one of which can be deflected to form a convex surface, and the system is referred to as a flow cell-convex lens-induced confinement system (FC-CLIC). [0016] In one aspect, a method for detecting size of a molecule, includes applying a liquid sample containing molecules to be measured to a sample measurement surface; contacting the sample measurement surface with a curved surface positioned tangent to the sample measurement surface at a point or line of contact, said curved surface having a surface that varies in a predetermined and understood manner from the point or line of contact to a displaced position relative to the point or line of contact; subjecting the sample to imaging to identify a region where sample is present; and determining the location of the sample presence from the point of contact outward, wherein the location of the sample is an indication of molecular size. [0017] In one or more embodiments, the imaging detects fluorescence, or the imaging detects light absorbance. [0018] In any of the preceding embodiments, the curved surface includes a convex lens, and for example, the convex surface is selected from the group consisting of convex, biconvex, plano-convex, and concave convex lenses, or the curved surface comprises a cylindrical lens. [0019] In any of the preceding embodiments, the curved surface is obtained by deflecting a flexible sheet disposed above the sample measurement surface into contact with the sample measurement surface. [0020] In any of the preceding embodiments, the method further includes correlating the location of the fluorescence with a distance of the lens surface to the planar surface, said distance representing a molecular dimension of the molecules. [0021] In any of the preceding embodiments, molecule size is determined, or molecule size distribution is determined, or molecular aspect ratio is determined. [0022] In any of the preceding embodiments, fluorescent imaging provides a gradual transition from a dark region to a bright fluorescence region. [0023] In any of the preceding embodiments, molecular aspect ratio is determined. [0024] In any of the preceding embodiments, the molecular size ranges from about 2 nm to about 1000 nm. [0025] In any of the preceding embodiments, the sample measurement surface comprises a flow cell having an upper and a lower surface for receiving a sample to measured, and the convex surface is provided by deflecting the upper surface of the flow cell downward to the lower surface of the flow cell to create the contact point. [0026] In any of the preceding embodiments, the method further includes coating the convex surface and/or the sample measurement surface with a non-stick coating. [0027] In any of the preceding embodiments, the molecule is a biomolecule, for example, proteins, micelles or DNA, or a polymer molecule, for example, polymer beads. [0028] In any of the preceding embodiments, the sample measurement surface and/or the curved surface comprises surface features, and for example, the surface features are selected from the group of dimples and posts. [0029] In another aspect, a system for detecting size of a molecule, includes a sample measurement zone having a convex surface positioned tangent to a planar surface, coupled with an inverted fluorescent microscope positioned to detect the presence of a molecule of interest in the sample measurement zone. [0030] In another aspect, a system for detecting size of a molecule, includes a sample measurement zone having a convex surface positioned tangent to a planar surface, coupled with an imaging device capable of detecting the presence of a molecule of interest present in the sample measurement zone. [0031] In any of the preceding embodiments, the imaging device is capable of detecting light absorbance or fluorescence. [0032] In any of the preceding embodiments, the molecule of interest is a biomolecule, for example, proteins, micelles or DNA, or a polymer molecule, for example, polymer beads. [0033] In any of the preceding embodiments, comprising a translation stage for positioning the convex surface in the x-, y-, and z-directions. [0034] In any of the preceding embodiments, the convex surface comprises a convex lens, and for example, the convex surface is selected from the group consisting of convex, biconvex, plano-convex, and concave convex lenses. [0035] In any of the preceding embodiments, the lens is coupled with a counterweight to reduce the resting force of the lens on the planar surface. [0036] In any of the preceding embodiments, the convex surface is coated with an anti-stick coating. [0037] In any of the preceding embodiments, the sample measurement zone comprises a flow cell for receiving a sample to measured, said flow cell comprising upper and lower sheet spaced apart from one another a distance defined by side walls. [0038] In any of the preceding embodiments, the system further includes a deflector, positioned above the flow cell, for reversibly deflecting the upper surface of the flow cell into contact with the lower surface of the flow cell to form the convex surface of the sample measurement zone. [0039] In any of the preceding embodiments, the system further includes a translation stage for positioning the convex surface in and out of deformation contact with the flow cell. [0040] In any of the preceding embodiments, the width of the flow cell varies along its length. [0041] In any of the preceding embodiments, the system further includes imaging software or particle tracking software. [0042] In another aspect, a method for detecting size of a molecule, includes applying a liquid sample containing molecules to be measured to a sample measurement zone, the sample measurement zone having a transparent material positioned tangent to a planar surface, said material having a surface that varies in a predetermined manner from the point of contact to a radially displaced position relative to the point of contact; subjecting the sample to fluorescent imaging to identify a region where the fluorescence is observed; and determining the location of the fluorescence relative to the point of contact, wherein the location of the fluorescence is an indication of molecular size. [0043] In any of the preceding embodiments, the transparent material is wedge-shaped. [0044] In any of the preceding embodiments, the transparent material is curvilinear. BRIEF DESCRIPTION OF THE DRAWINGS [0045] Various objects, features, and advantages of the present invention can be more fully appreciated with reference to the following detailed description of the invention when considered in connection with the following drawings, in which like reference numerals identify like elements. The following drawings are for the purpose of illustration only and are not intended to be limiting of the invention, the scope of which is set forth in the claims that follow. [0046] FIG. 1 is a schematic illustration of a convex-lens induced confinement system according to one or more embodiments. [0047] FIG. 2 is a schematic illustration of a convex-lens induced confinement system according to one or more embodiments. [0048] FIGS. 3A and 3B are a schematic illustration demonstrating the determination of molecular size for FIG. 3A , a low aspect molecule and FIG. 3B , a high aspect molecule. [0049] FIG. 4 illustrates normalized fluorescence profiles of solutions (Concentration=1.4 nM) of two lengths of linear DNA, pUC19 (2.7 kbp) (large dot) and φX174 (5.4 kbp) (small dot), and free Alexa 647 dye (Concentration=50 nM). Linear fits to these profiles are performed at large gap heights (0.6 μm<h<2.7 μm). The fluorescence profiles have been normalized to have equal slopes in this region. [0050] FIG. 5 shows the signal-to-background ratio as a function of confinement (displacement form contact point), for CLIC imaging of surface-immobilized fluorescent polystyrene beads immersed in 50 nM Alexa 647 dye. [0051] FIG. 6 shows a CLIC image of surface-tethered DNA oligonucleotides in the presence of 0.2 μM Alexa 647 dye, imaged with a power of 6 mW and exposure time of 0.1 s. A nonlinear contrast scale is applied to permit visualization in the same image of the single molecules at small radius from the point of contact and the background fluorescence at large radius from the point of contact. [0052] FIG. 7 shows a photobleaching timetrace of a single DNA molecule (circled in FIG. 6 ). [0053] FIG. 8 shows CLIC images of free dye (Alexa 647) and surface-tethered DNA oligonucleotides at dye concentrations of 0.2 μM, 1 μM, and C=2 μM, with equal-fluorescence contours indicated. A linear contrast is used. [0054] FIGS. 9A and 9B are schematic illustrations of a flow cell CLIC system according to one or more embodiments in which the convex lens is in a ( FIG. 9A ) raised or ( FIG. 9B ) lowered position. [0055] FIG. 10 is a schematic illustration of a flow cell according to one or more embodiments. [0056] FIG. 11 is a photograph of an exemplary flow cell CLIC system. DETAILED DESCRIPTION [0057] The Convex (or Cylindrical) Lens-Induced Confinement (CLIC) or the flow cell Convex (or Cylindrical) Lens-Induced Confinement system (FC-CLIC) system determines the distribution of molecular sizes by measuring the density profile of molecules confined in a wedge-shaped gap. Molecules are excluded from regions where the height of the gap is less than the diameter of the molecule. Under imaging conditions, a dark region is observed where molecules are excluded due to their size. A fluorescent image centered on the point of contact shows a disk inside of which there is no fluorescence. A bright area is observed outside the disk where molecules are located. Although this method is described using fluorescence as the imaging mode, other imaging or detection techniques can be implemented within the scope of the method. For example, the method can be used with any optical microscopy technique that can be performed in an inverted microscope. Exemplary fluorescence microscopy imaging techniques include epifluorescence, total internal reflection fluorescence (TIRF), confocal, and two-photon microscopy, for example. In addition, the method can be used with differential interference contrast (DIC), dark-field, Raman, and coherent anti-Stokes Raman (CARS) microscopy. [0058] The CLIC or FC-CLIC device provides a direct measure of the diameter of imageable molecules in solution, offering a dynamic range of 2 nm to 3 μm, or 2 nm to 1000 nm, and handling freely diffusing molecules in their native form. Measurements require only 10 μL of solution at an analyte concentration of only 1 nM, and may be performed in less than one minute. [0059] The CLIC or FC-CLIC device employs wedged shaped or curvilinear surface to generate a surface that varies in its distance in a known manner from a planar surface on which it is disposed. In one or more embodiments, the curvilinear surface can be a convex, biconvex, plano-convex lens, or concave convex lens where the curvature of the surface is well-defined. When the lens is placed in contact with a planar surface, it forms a point contact. In other embodiments, the curvilinear surface can be a cylindrical lens. A cylindrical lens is a lens which focuses light which passes through on to a line instead of on to a point, as a spherical lens would. The curved face or faces of a cylindrical lens are sections of a cylinder. When the lens is placed in contact with a planar surface, it forms a line contact. [0060] In one embodiment, the CLIC system includes a plano-convex lens, curved side down, resting on top of a coverslip or other flat, transparent surface. See, e.g., FIG. 3A . Due to the curved nature of the lens surface, it contacts the flat surface at a single point. The region near the point of contact between the lens and the coverslip is imaged using an inverted fluorescence microscope. The lens-coverslip distance varies smoothly from zero at the point of contact, to hundreds of microns at radii far from the point of contact, according to the equation: [0000] h ≈ 1 2  r 2 R , [0061] where r is the distance from the point of contact and R is the radius of curvature of the lens. Near the point of contact, a displacement of tens of microns in the x-y plane leads to a nanometer-scale change in the thickness of the gap. In a typical field of view of 100 μm, with a 100 mm focal length lens (R=4.6 cm), the gap varies from 0 to 27 nanometers. From the radius of the excluded region, r, and the known radius of curvature of the lens, R, one can extract the diameter of the molecules, h. This measurement has an accuracy of ˜2 nm. Locations and measurements of imaged particles can be accomplished using conventional methods. By way of example, three-dimensional particle tracking is described by Peterson et al., in Meas. Sci. Technol. 19 (2008) 115406, which is incorporated in its entirety by reference. Similar relationships are found for the convex surface generated in FC-CLIC, where the convex surface is generated using deflection of a flexible planar surface. [0062] The accuracy of the confinement is determined, in part, by how well the curvature of the lens is known. This curvature can be measured to high accuracy in situ using optical interferometry. The precision of the confinement is a function of the surface roughness of the lens and the coverslip. The surfaces should be relatively smooth. Fused silica optics are commercially available with root mean square (RMS) surface roughness <1 nm. To accurately detect the confinement of molecules in the resulting gap, the sheets should be flat on the length scales of the molecules of interest. Typically, the sheets have a RMS surface roughness less than about 1 nm. Acceptable ranges of surface roughness depend on the size of the molecules to be measured: for a molecule of diameter x, the surface roughness should be less than x/3 or more preferably less than x/5 or most preferably less than x/10. In some embodiments, the surface can be patterned, for example by lithography. Surface features can provide a further level of molecular confinement. For example, a surface can include an array of posts or dimples. The posts constrain the molecules between posts in addition to the constraint based upon the radius of curvature of the convex surface. [0063] In a substantially monodisperse population, molecules will distribute uniformly throughout the liquid sample due to Brownian motion. However, the molecules will be physically excluded from areas under the lens where the gap is less than the molecule dimension. For a uniformly sized population of molecules, there is a fairly abrupt cutoff of fluorescence. See, FIG. 3A . The system determines the distribution of molecular sizes directly by measuring the density profile of molecules confined in a wedge-shaped gap. Simply, molecules are excluded from regions in which the gap height is less than the molecular diameter. In considering an idealized sample of hard spheres, a fluorescent image centered on the point of contact shows a disk inside of which there is no fluorescence ( FIG. 3A ). In a heterogeneous population of real molecules, the cutoff is gradual, and the shape of the cutoff indicates the distribution of molecular sizes. [0064] The CLIC and FC-CLIC systems also allow one to learn about the aspect ratio of anisotropic particles. For rodlike particles, for instance, there is an entropic penalty to enter the region where there is orientational confinement, but the particles are not completely excluded until the confinement is less than the diameter of the rod. FIG. 3B illustrates the various orientations of an aspected particle 300 in the area under the lens a distance away from the central point of contact. By measuring the profile of particle density as a function of confinement, one can extract information about the length and aspect ratio of an asymmetric object. Such a technique is well suited to determine the size and shape of virus particles or amyloid fibrils, for example. [0065] In a heterogeneous population of molecules, molecules of different sizes occupy different locations in the gap. Since molecules are excluded from regions in which the gap height is less than the molecular diameter, larger molecules are excluded at a greater distance from the contact point, Since molecules are expected to randomly distribute throughout the area where the gap height is greater than molecule dimension, the resulting cutoff of fluorescence is gradual, and the shape of the cutoff indicates the distribution of molecular sizes. [0066] The distribution of molecules and their size can be extracted from the pattern of fluorescence intensity using available imaging software. Fluorescence images are loaded into analysis software, bright regions are identified as fluorescent molecules and their spatial density profile is determined. In addition, particle tracking software can be employed to characterize their diffusion. [0067] An apparatus according to one or more embodiments for the determination of molecular size using convex lens induced confinement is shown in FIG. 1 . The apparatus is of a size that permits it to be integrated with conventional imaging instruments such as an inverted fluorescent microscope. FIG. 2 shows a schematic illustration of an exemplary convex lens induced confinement apparatus 100 resting atop a microscope stage. In this particular embodiment, the apparatus is about 4″×5″ in area, although it may take on any size and can be even smaller. [0068] One embodiment of the apparatus is described with reference to FIGS. 1, 3A and 3B . The system employs an imaging microscope, e.g., a fluorescence microscope, including a high numerical aperture objective and an electron-multiplying CCD camera. The convex lens induced confinement apparatus 100 rests atop the microscope stage and includes a planar surface 110 having a sample measurement surface 115 . The surface can include a glass coverslip (not shown) that can be disposed of or replaced after use. The surface is typically transparent to permit imaging of the sample from a light source below the microscope stage. The light source can be a laser, lamp or light emitting diode (LED). The convex lens induced confinement apparatus also includes a convex lens 120 that is positioned with its curved surface facing the planar surface 110 . In some embodiments, the surface of the lens and/or the coverslip can be coated with a non-stick surface coating to reduce adhesion of molecules to the surfaces. When the lens 120 is lowered into contact with the planar surface, it contacts at a single point 125 (shown on FIGS. 3A and 3B ). The lens can include a handle 130 , typically attached to the back (planar) side of the lens, to aid in the positioning of the lens. The positioning handle is attached to an xyz translation stage 140 that provides for positioning capability in x-, y- and z-directions. Handle 130 is mounted to the translation state at pivot 150 that moves the lens in the z-direction. Counterweight 160 can be used to balance the weight of the lens so that the lens rests lightly on the surface of the sample measurement surface and does not distort the surface. [0069] Another version of the CLIC apparatus is illustrated in FIGS. 9A and 9B , which is referred to as Flow Cell CLIC (FC-CLIC). As in the system shown in FIG. 1 , the Flow Cell CLIC apparatus includes an imaging microscope 900 with similar features. The Flow Cell CLIC system also includes a convex lens 910 that can be raised and lowered into contact with the top surface of the flow cell 950 . As with CLIC, Flow Cell CLIC (FC-CLIC) confines molecules to a nanoscale gap. In CLIC, the gap is formed between the surfaces of a lens 120 and coverslip 125 (See, e.g., FIG. 3A ). In FC-CLIC, the sample is inserted between two initially planar sheets of transparent material 930 , 940 , e.g., glass or fused silica, which make up the top and bottom surfaces of a flow cell, respectively. The top surface should be flexible, e.g. by using a thin glass sheet. The lens or other rounded object 910 presses down upon the top sheet 930 of the flow cell, causing it to bow downward until it makes contact with the bottom sheet 940 at a single point 945 . See, FIG. 9B . Molecules are imaged in the annular wedge-shaped gap surrounding the point of contact, as is described above. The convex surface can be raised or lowered onto the flow cell from a support 960 . Support 960 includes a lever 968 that can be pivotable, e.g. from hinge 965 , to lower and raise the convex surface 910 , which is attached to a lower surface of lever 968 . The hinge permits the lens surface to be moved out of the way for ease of access to the sample. [0070] Adjustments to the lens position can be made on a fine-pitch screw 980 that is integrated into the aluminum lever and which conveys the motion to a small convex lens 910 , which pushes down on the top coverslip. This arrangement provides highly precise and reproducible formation of a nanoscale gap. By using a transparent lens to apply pressure to the top coverslip, optical access to both sides of the flow cell is maintained. This access is useful for illuminating the sample from both sides. The lens is optionally made of an elastomeric material such as poly(dimethyl siloxane), so that it does not scratch the flow cell at the point of contact. [0071] The present design could be augmented by addition of a motorized positioner to apply pressure to the top coverslip. The positioner can have x, y, z-axis mobility for precise location of the convex surface. The positioner can be manually controlled or automated. [0072] An exemplary flow cell is illustrated in FIG. 10 . The flow cell is made up of two sheets of material 1000 and 1010 , which serve as the top and bottom surfaces of the flow cell, respectively. The sheets are transparent, e.g., transparent to the light used to analyze the sample, and the top surface is flexible, e.g., capable of bending or being displaced from the resting position indicated in FIG. 9A and the displaced position indicated in FIG. 9B . The sheets can be made from glass or fused silica. In some instances the sheets can be made of plastics, so long as they have the required transparency. For fluorescence measurements, it is desirable for the sheet material to have low autofluorescence. In addition, the sheets should be relatively smooth. In order to accurately detect the confinement of molecules in the resulting gap, the sheets should be flat on the length scales of the molecules of interest. Ideally, the sheets have a RMS surface roughness <1 nm, although for applications with larger molecules RMS surface roughness as large as 10 nm is acceptable. In some embodiments, the surface can be patterned, for example by lithography. Surface features can provide a further level of molecular confinement. For example, a surface can include an array of posts or dimples. The posts constrain the molecules between posts in addition to the constraint based upon the radius of curvature of the convex surface. [0073] The flow cell includes side walls 1020 that define a spacing or gap 1030 between the upper and lower sheets 1000 , 1010 . The initial gap can range from a few microns, e.g., about 5 μm to about 500 μm. The amount of fluid needed for the space is therefore small and typically is about 10 μL. The side walls can be made of any suitable spacer or adhesive that provides the desired gap dimensions. By way of example, the side walls can double sided tape, polymer or plastic stripes, or glue or other adhesive, e.g., an epoxy adhesive. The flow cell is significantly larger than the test area, and has typical dimensions of 100 μm (vertical) by 7-12 mm (horizontal) (but can be smaller or larger than this). Because the test surface (typically on the order of 150 μm) is so much smaller than the overall flow cell and surface substantially centrally located, its distance from the side walls and the material selection for the side walls is not critical. The side walls are shown only on the long lengths of the flow cell; however, the flow cell can include front and rear walls of the flow cell as well. [0074] Liquid is introduced into the flow cell at a suitable aperture. The apertures can include slots 1040 , 1050 at the front and rear sides of the flow cell, as illustrated in FIG. 10 . The slots can make up a full length of the flow cell or a portion thereof. In other embodiments, the apertures may be provided along the length of the side walls. In one or more embodiments, the side walls, front and rear walls are sealed, and apertures are provided in the upper and/or lower sheets of the flow cell. [0075] In one exemplary embodiment, the flow cell channel is constructed using two parallel strips of double-sticky tape, sandwiched between two coverslips. Fluid flows through the gap between the pieces of tape, which has typical dimensions of 100 μm (vertical) by 7-12 mm (horizontal) by 25 mm (length). The width, height and length of the channel determine the volume of the cell, as well as the radius of curvature of the top coverslip at the point of contact. Furthermore, the lateral edges of the flow cell could be constructed of a more durable material than double-sided tape. An exemplary FC-CLIC is shown in FIG. 11 . [0076] In instances where a flowable adhesive is used, a consistent spacing of the desired gap dimension can be obtained by inserting a plastic sheet of the desired gap dimension between the upper and lower sheets of the flow cell. The plastic insert is smaller than the flow cell sheets so that the flow cell sheets extend beyond it on both lengths to define an open channel. The adhesive is applied in the channel and allowed to dry or at least to obtain sufficient mechanical strength to maintain the spacing between the two sheets, at which point the plastic insert can be removed. [0077] The curvature of the flow cell during use is determined by various factors, such as the gap dimension and the width of the flow cell channel. For example, a vertical large gap will result in a steeper curvature (e.g. smaller radius of curvature), all other things equal. Similarly, increasing the width of the flow cell channel will reduce curvature (e.g., increase the radius of curvature). The point of contact can be varied to avoid locations in the flow cell where the glass surface has become contaminated, for example, by the sticking of test molecules to the glass surface. If the width of the flow cell channel varies along the length of the flow cell, e.g., by arranging that its walls are not parallel to one another but instead oriented at an angle, then by translating the lens along the length of the flow cell, one can vary the radius of curvature of the gap geometry. The actual geometry of the surface can be calculated, either prior to testing or in real time (in situ). [0078] FC-CLIC offers several advantageous features. FC-CLIC is simple to set up and operate. The flow cell at the heart of the device is widely used in many biology labs, so the design will be familiar to prospective users. [0079] The volume of the sample is small and can be 10-fold smaller sample volume than in CLIC (ca, 10 μL for FC-CLIC vs. ca. 100 μL for CLIC). The small sample volume is possible due to reduced evaporative losses because the flow cell is a mostly closed system. As the liquids evaporate and the solution concentrates, properties and characteristics of the molecules can change. In CLIC, the sample size is selected to be sufficiently large that evaporative losses are minimal. In FC-CLIC, there is no such constraint. In addition, the closed cell set up of the flow cell reduces exposure of the sample to ambient gases, particularly oxygen. [0080] Simple chemical functionalization of top and bottom confining surfaces is readily available. It may be desirable to functionalize the sample holder surface to enhance or inhibit sample binding to the sample holder or the convex surface. In other embodiments, it may be desirable to monitor the interaction between the molecules of interest in solution and functionalized molecules on the sample holder surface. While it is possible to functionalize either the lower coverslip surface or the convex surface used in CLIC systems, the functionalization of the glass or fused silica used as coverslips is well known and easy. [0081] The samples can be easily exchanged after measurement by lateral flow of fluid through the flow cell. This ability permits rapid and simple testing for serial measurements. Also, the flow cell configuration is compatible with lithographic processing on the confining surfaces. The flat surfaces of the flow cell are easier to pattern than the permanently curved surface of, for example, a convex lens. [0082] The use of the flow cell in conjunction with a movable lens provides a simple procedure for moving the point of contact between top and bottom confining surfaces. As noted above, the geometry of the confining surface can be readily controlled and easily varied by moving the contact point of the lens with the flow cell. Contacting the flow cell in two different points results in two different surfaces. Due to the scale of the flow cell relative to the field of view in the imaging device, movements result in small well-defined changes. The geometry of the confining surface can be measured in situ or calculated prior to testing using conventional interferometry measurements or measurements of the fluorescence intensity profile of a homogeneous solution of a small fluorescent molecule. [0083] The use of a flow cell to contain the sample fluid instead of a convex surface such as a lens opens up a wider and more versatile list of materials to use for the confining surfaces. Lenses are made up of a limited number of materials, but cover slips are made of a wide variety of materials, such as mica, plastics and sapphire, that are not commonly used for lenses. The wide range of material compositions for the confining surfaces in a FC-CLIC system provides greater flexibility and versatility in the testing environment. In addition, the materials used to prepare the flow cell are inexpensive. A sample chamber can be composed entirely of disposable parts, eliminating the need for meticulous cleaning between experiments. [0084] In the operation of the CLIC or FC-CLIC device, a sample to be measured is applied to the sample measurement surface, before or after the convex lens is moved into contact with the surface. The lens may be lowered to the surface before or after the sample is applied. In some embodiments, the lens is moved into contact with the surface before the sample liquid is applied and the sample is drawn into the gap defined by the test surface and the lens by wicking or capillary action. In other embodiments, the lens is raised, the sample liquid is applied and the lens is gently lowered onto the cover slip. As noted above, the lens-coverslip distance (“gap”) varies smoothly from zero at the point of contact, to hundreds of microns at radii far from the point of contact. The molecules can only occupy space where the gap is equal to or greater than their diameter, that is, the molecule is excluded from those areas under the lens where the gap is less than the molecular size. Measurement of the distance of the onset of fluorescence from the center point, coupled with information regarding the curvature of the lens surface provides a measurement of the molecular size. [0085] The CLIC and FC-CLIC systems can also be used to characterize the molecular size distributions of mixtures of molecules of a few sizes by analyzing the first- and second-derivatives of the total fluorescence intensity with respect to radius from the point of contact. These profiles can exhibit a ‘kink’, or distinguishable feature, at the radius of exclusion corresponding to each constituent molecule in the mixture. In addition, by employing particle tracking software, one may determine the distribution of diffusion coefficients of molecules as a function of gap height as a diagnostic of molecular mixtures. For example, in characterizing a mixture of large and small molecules, one would detect a higher fraction of molecules with low diffusion coefficients further from the contact point than in the case of a homogeneous sample of small molecules. [0086] In some embodiments, the analyte is fluorescent or fluorescently labeled. The molecules can be inherently fluorescent, or they can be modified with a fluorescent tag. By way of example, the analyte can be covalently labeled with a fluorescent dye such as Alexa Fluor dyes. For protein analytes, the protein can be fused with a green fluorescent protein marker ( Nat Methods 2 (12): 905-9). In most instances, the size of the label is not expected to interfere with the measurement. In other embodiments, a protein-specific fluorescent antibody can be used. In this instance, the molecular size of a particular protein could be determined without the need to purify the sample. In other embodiments, the samples can be inherently fluorescent, as for example proteins are under short wave ultraviolet irradiation. In such instances, additional measures can be taken such as using ‘fluorescent-free’ materials in the construction of the device to prevent high background fluorescence. [0087] The CLIC and FC-CLIC systems can be used to measure the distribution or sizes of molecules of about 10 nm to about 1000 nm, such as DNA ranging from ˜2,000-48,000 bp, 200 nm lipid vesicles, and polystyrene spheres with diameters ranging from 20-200 nm. The method can also be used with smaller particles, such as individual protein molecules, fluorescent micelles, and short DNA oligonucleotides. The CLIC and FC-CLIC systems can operate over a range of analyte concentrations, e.g. 10 pM-10 μM Low liquid volumes also may be employed (1-100 μL). [0088] While measurements of molecular size are likely to have the greatest impact as a medical diagnostic, the CLIC and FC-CLIC system also enable several new types of single-molecule measurements that may interest researchers. These measurements include a) fluorescence measurements on single immobilized molecules in the presence of a high background concentration of freely diffusing fluorescent molecules; and b) long-time observation of single freely diffusing fluorescent molecules. In both cases, the thin confinement provided by the CLIC and FC-CLIC systems create the optical conditions for higher quality single-molecule imaging than was previously possible. [0089] The CLIC system has been used to characterize the size of a range of fluorescently labeled molecules. FIG. 4 delineates the fluorescence signal, measured as a function of gap height, for ensembles of linear DNA molecules, and free dye (Alexa 647). To a first approximation, the molecules can be treated as hard spheres, valid for h>>d hs . The molecular diameter, d hs , can be determined from the x-intercept of the linear fit to the fluorescence profile in this region. For linear DNA samples of φX174 and pUC 19, r hs =0.19±0.02 μm and 0.15±0.03 μm respectively. These estimates were in good agreement with literature-inferred radii of gyration, r gyr =0.20 μm and 0.13 μm respectively. [0090] For sufficiently large molecules and negligible surface interactions, r hs provides an accurate measure of molecular size. In situations where surface interactions dominate, such as when the salt concentration is sufficiently low that the Debye length is non-negligible, molecules can be repelled from or attracted to the surface, altering the observed R excl , the radius of exclusion for the molecules of interest. Such contributions to R excl due to electrostatic interactions can be calibrated a priori and taken into account in calculating r hs . Alternatively, by coating the surface with a neutral monolayer such as polyethylene glycol (PEG), attractive interactions may be suppressed. [0091] In one embodiment, the device and method can be used to measure the distribution of sizes and shapes of amyloid fibrils. The aggregation of amyloids and their structural traits are associated with the development of neurodegenerative diseases. Since this device and method can be used to characterize the change in size and shape of samples of amyloid fibrils as the diseases progress, it can serve as an important medical diagnostic tool. [0092] A standard working criteria for single-molecule detection is for the detection volume to be occupied by less than one fluorophore on average. Therefore, decreasing the detection volume enables single-molecule detection at higher background fluorophore concentration. Near the lens contact point, the detection volume is smaller in depth than that of either confocal or TIRF imaging and is of comparable extent within the imaging plane. Single immobilized molecules can therefore be detected against a higher background concentration of fluorophores by CLIC or FC-CLIC than by TIRF or confocal microscopy. Details and comparison of CLIC, FC-CLIC and conventional imaging systems is found in Table 1. The improved rejection of background was demonstrated by comparing images taken with CLIC to images taken with TIRF. Singly labeled DNA oligonucleotides were used as a model system. The sample was immobilized on a coverslip and imaged in the presence of a variable concentration of free dye. [0093] Through-the-objective TIRF illuminates a thin sheet of solution adjacent to the coverslip-solution interface. The detection volume is approximately V det =π 2 h TIRF , where ˜λ/2 NA is the radius of a diffraction-limited spot, and h TIRF ˜/2π is the evanescent decay length. □ In a typical setup with illumination at λ=633 nm and an objective with numerical aperture NA=1.45, =218 nm and h TIRF =101 nm. Single-molecule detection via TIRF is possible only when the fluorescent background concentration C max TIRF <180 nM . The single-molecule concentration limit for CLIC is [0000] C max CLIC = h TIRF h CLIC  C max TIRF . [0094] The improved rejection of background under CLIC imaging is shown in FIG. 5 . Single immobilized fluorophores were imaged against a background of up to 4 μM of free dye, 20-fold higher than C max TIRF . FIG. 5 shows the signal-to-background ratio as a function of confinement, for CLIC imaging of surface-immobilized fluorescent polystyrene beads immersed in 50 nM Alexa 647. Probe illumination corresponds to λ=633 nm, and P=120 μW. Under TIRF illumination conditions the background becomes independent of h CLIC when h CLIC >h TIRF . FIG. 6 shows a CLIC image of surface-tethered DNA oligonucleotides in the presence of 0.2 μM Alexa 647 at P=6 mW. A nonlinear contrast scale was applied to permit visualization in the same image of the single molecules at small r and the background fluorescence at large r. FIG. 7 shows a photobleaching timetrace of a single molecule (circled in FIG. 6 ), and a timetrace of the fluorescence from a point where there was no immobilized molecule. FIG. 8 are CLIC images of free dye (Alexa 647) at concentrations of 0.2 μM, 1 μM, and C=2 μM, with equal-fluorescence contours indicated. At 2 μM Alexa 647, single oligos molecules may be detected within a disk of radius r=21 μm, corresponding to h CLIC =5 nm, in good agreement with the expected detection limit. [0095] Comparison of the imaging characteristics of the CLIC method as compared to conventional methods is shown in the table. [0000] TABLE 1 Dimensions of Max # of molecules imaging volume concentration of Observation time observed Imaging modality L × W × H (μm) single molecules (D = 100 μm 2 /s) simultaneously TIRF 100 × 100 × 0.1 180 nM 500 μs (vertical) hundreds Confocal π × 0.3 2 × 1 50 nM 200 μs (in-plane) 1 Zero-mode waveguides .04 × .04 × .02 50 μM 2 μs (vertical) Thousands; 1 per waveguide ABEL trap 3 × 3 × 0.8 200 pM 2 s (photobleaching) 1 Convex Lens-Induced 100 × 100 × 4 μM 25 s (in-plane) hundreds Confinement (CLIC) 0.005 [0096] The foregoing illustrates one specific embodiment of this invention. Other modifications and variations of the invention will be readily apparent to those of skill in the art in view of the teaching presented herein. The foregoing is intended as an illustration, but not a limitation, upon the practice of the invention. It is the following claims, including all equivalents, which define the scope of the invention.

A curved surface is placed tangent to a slide and displaces a sample liquid from the point or line of contact outward. Imaging indicates a region where fluorescence is observed, and the location of the fluorescence indicates the molecular size, The radius of curvature of the lens is known, the distance from the (center) point of contact of the observed fluorescence is measured with a microscope and the distance of the lens surface to the slide's surface can then be calculated. This distance represents the size of the molecule or ensemble of molecules emitting. Similarly, absorbance, etc. could be measured with a light source below the slide.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to generating documents using a computer application, and in particular to inserting a data object like a mathematical formula or special characters like Greek characters into a computer-generated document as for example a text document. 2. Description of Related Art Computer word processing applications typically are used to generate a document, referred to as a computer-generated document, that may contain text data, tables, diagrams, etc. and often mathematical formulae or special characters like Greek characters. Mathematical formulae and special characters are particularly important for documents like scientific articles and the like. Similarly, HTML Web page generators generate a document that is effectively a text-based document. For creating a mathematical formula within a text document 100 (FIG. 1 ), so called formula editors were used. Typically, the formula editor was opened from within the computer word processing application by clicking on a menu bar icon, or alternatively using a menu. The formula editor contained a large number of displayed key fields and list boxes representing different elements of mathematical formulae like brackets, integrals, fraction bars, matrices, so forth. For inserting special characters, like for example the Greek character Σ, it was necessary to enter a list box containing the special characters. The user created the desired formula 101 using these keys and list boxes. After having completed the formula, the user returned to the original document and pasted the formula as an imported object into the document. If the user recognized an error in the formula, the user again opened the formula editor, corrected the error, and returned to the original document. Using a formula editor, it was possible to create nearly every desired mathematical formula; however, the operation was complicated and time consuming in particular for simple formulae like simple fractions or square roots, which appeared frequently in a text document. Editing of the formula always required entering the formula editor and subsequently returning into the original document. To simplify the entry of formulas, some formula editors permitted the use of script like phrases that the formula editor converted to the corresponding mathematical expression. However, while this assisted in entering a formula in some situations by minimizing the use of key fields and list boxes, the general problem of having to utilize the formula editor persisted. In an attempt to minimize some of the entry and exit issues, it was known to select an insert option from a menu bar of an application and the formula editor capability was opened so that the user could insert and edit a formula without leaving the application, only the menus and the object bars were changed. After the formula editor capability was used to enter the data object, double clicking on the embedded object launched the formula editor capability so that the formula could be edited. Again, this was done without leaving the application. SUMMARY OF THE INVENTION According to the principles of this invention, inserting or editing a data object like a mathematical formula or special character in a computer-generated document is facilitated and sped up in comparison to the prior art methods that required use of a formula editor. A method of inserting a data object into a computer-generated document includes inputting instruction symbols representing the data object into the document in the form of text characters, selecting the document portion containing instruction symbols, and converting the instruction symbols contained in the selected document portion into a data object represented by the instruction symbols. With the present invention it is possible to input the data object, which may be a mathematical formula or a Greek, Chinese, Korean, Cyrillic, Arabic, Hebrew, or Japanese character, or any other character or symbol, and which can be represented by certain instruction symbols, into the document using standard characters, which are also used for creating a text document. The user does not need to leave the document and can input the instruction symbols in the same way as the text characters, for example by typing on a keyboard. If the selected document portion contains characters, which are not part of an instruction these characters remain unchanged during the converting operation. Those unchanged characters may be variables like a, b, or x in a mathematical formula. In one embodiment, the converted data object is inserted into the document at the position of the selected document portion. The inserted data object is formatted depending on a surrounding content, for example, the same as the format of text in the same line. The inserted data object is automatically stored with the document in this embodiment. The inserted data object is reconvertible into the original document portion for editing purposes. The document portion including the instruction symbols may be input by means of speech decoding. In this case, the present invention is particularly advantageous since the instruction symbols (in contrast to the mathematical symbol itself) may be expressed orally. One embodiment of the invention allows fast and easy generation and editing of a data object like a mathematical formula or special characters. This is particularly useful for simple and short data objects and for data objects, which the user needs frequently and for which the user easily memorizes the instruction symbols representing these data objects. For inserting the object, the user needs not to enter a special tool like a formula editor and then return to the original document. Another advantage of the present invention is that it allows the input of the data objects by speech decoding since the instruction symbols can be expressed orally. Another embodiment of the invention provides a computer program for inserting, on a computer, a data object into a document, comprising inserting instruction symbols representing the data object in the form of text characters into the document, selecting a document portion containing instruction symbols, and converting the instruction symbols contained in the selected document portion into the data object represented by the instruction symbols. Program code may be embodied in any form of a computer program product. A computer program product comprises a medium configured to store or transport computer readable code, or in which computer readable code may be embedded. Some example of computer program products are CD-ROM discs, ROM cards, floppy discs, magnetic tapes, computer hard drives, servers on a network and signals transmitted over a network representing computer readable program code. According to a still further embodiment, the present invention provides a software tool providing instructions for inserting a data object into a computer-generated document by inserting instruction symbols inputted in the form of text characters and representing the data object into the document, converting instruction symbols contained in a selected document portion into the data object represented by the instruction symbols, inserting the converted data object into the document, and providing signals for displaying the document including the converted data object. According to another embodiment, the present invention provides a computer-generated document including a data object generated by a conversion of instruction symbols inputted in the form of text characters, wherein the data object is reconvertible into the instruction symbols. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic representation of a prior art document containing a mathematical formula. FIG. 2A is an example of a text document containing instruction symbols representing a data object according to the present invention. FIG. 2B is a schematic representation of the text document shown in FIG. 2A after conversion of a data object. FIG. 2C is a process flow diagram for the method of the present invention. FIG. 3A is a schematic illustration of a computer system to which the present invention may be applied. FIG. 3B is a schematic illustration of a client-server computer system in which the present invention may be transferred and/or downloaded. DETAILED DESCRIPTION According to the principles of this invention, a user enters a formula in a computer-generated document by simply typing in text representing the formula and selecting this text. In response to the selection of the text representing the formula, the text representing the formula is automatically converted to a mathematical formula and inserted in the computer-generated document as a data object. Consequently, with this invention, a user generating a document on a computer no longer has to continually open a formula editor to enter a formula. Rather, the user simply continues to input text information in the same form as the rest of the document including text that describes the formula. Similarly, a user can type in text representing a special character, e.g., a Greek, Chinese, Korean, Cyrillic, Arabic, Hebrew, or Japanese character, or any other character or symbol, and use the method of this invention to automatically convert the text representing the special character to a data object that is inserted in the computer-generated document. According to the principles of this invention, in a text-based formula generation method 205 , a user inputs text in an input text operation 221 ( FIG. 2C ) into a computer-generated document 200 A (FIG. 2 A), which is displayed on a display screen 210 by an application 319 ( FIG. 3A ) executing on a computer processor 312 C. In operation 221 , ( FIG. 2C ) the user inputs the text using, for example, a keyboard in input units 320 C ( FIG. 3A ) of a computer system 300 C, which is representative of a computer system input device. The text, however, can be input using another suitable input technique and/or input device, e.g. voice recognition processing or the like. Input text operation 221 transfers to formula check operation 222 . If the user does not want to input a formula, formula check operation 222 returns to input text operation 221 . Conversely, if the user wants to input a formula into document 200 A, formula check operation 222 , which is carried out by the user, transfers to input instruction operation 223 . In input instruction operation 223 , the user inputs the formula using text instruction symbols via one of input units 320 C. For example, as illustrated in FIG. 2A , the user inputs the text portion “x equal sqrt a over b”, which includes the text instruction symbols, equal, sqrt, and over. The user is not required to change modes of input, and is not required to access a formula editor and type the formula into the editor, but rather the user simply continues inputting characters in a conventional fashion. After completing the text input for the desired formula in input instruction operation 223 , the user selects the text formula instruction in select instruction 224 . In this embodiment, the user first highlights text formula instruction 212 and then moves cursor 211 to an equation icon 213 . With cursor 211 on equation icon 213 and with text formula instruction 212 highlighted, the user clicks a mouse button to complete select instruction operation 224 . In more general terms, select instruction operation 224 identifies a text formula instruction 212 for a generate formula method 230 . Operations 221 to 224 form a text formula instruction generation and identification method 220 . In generate formula method 230 , formula check operation 231 determines whether the user selected a text formula instruction. In this embodiment, check operation 231 determines whether the user clicked on equation icon 213 . If the user selected a text formula instruction, check operation 231 transfers to convert instruction operation 233 and otherwise to continue operation 232 . In one embodiment, check operation 231 is part of an event handler of application 319 , and if the event is not a text formula instruction selection input, event handling continues in continue operation 232 and the application continues as in the prior art. However, if a text formula instruction selection input event occurred, processing transfers to convert instruction operation 233 . Convert instruction operation 233 cuts the selected text formula instruction and pastes the selected text formula instruction into a call to a formula editor that can process the text formula instruction. For example, a prior art formula editor is modified to receive a text formula instruction and output a data object that is a corresponding formula. The modified formula editor executes in the background and the user is unaware of its existence. Upon the modified formula editor returning a data object, which in this example is a mathematical formula x = a b · , combinations of characters in the text formula instruction, which do not represent text instruction symbols, like the variables x, a and b in this example, remain unchanged. Hence, the creation of a formula containing variables is possible. Upon return of the mathematical formula, i.e., the data object, processing transfers from convert instruction operation 233 to insert formula operation 234 . In insert formula operation 234 , the data object, i.e., formula 214 , is inserted in document 200 B at the location from which the text formula instruction sequence was cut, and is displayed on display unit 210 . Preferably, the formula is formatted like the surrounding text so that the visual appearance of text document 200 B containing the formula is optimized. However, in one embodiment, the user can include text instructions to format any part, or all of the formula in a specific format, which may be different from the format of the surrounding text. Following insert formula operation 234 , document complete check operation 235 determines whether the user has entered an instruction to indicate the document is complete. If a document complete instruction has been issued, the finished document is saved. Preferably, the inserted data object is stored together with the text document in a memory, e.g., memory 311 B, which is this case is located in a file server 300 B. If the document is not complete, check operation 235 returns to input text operation 221 . Those of skill in the art will appreciate that the method of this invention can be multithreaded. For example, one thread permits the user to continue entering additional text, while another thread executes the text formula instruction. Also, as illustrated in FIGS. 2A and 2B , the content of a text document 200 A, may include in addition to the text data also other data like diagrams, graphics or tables. The text document also may be, for example, an HTML- or XML-document. In addition, the present invention is not restricted to text documents. Hence, according to the principles of this invention, if a user wishes to input a special data object like a formula into the text document, the user enters the formula in the form of a text formula instruction that includes text instruction symbols and variables. For example, the formula a b is represented by “a over b”. Here, the characters “a” and “b” represent variables and “over” is a text instruction symbol representing a fraction bar. Other examples of text formula instructions are “sqrt a” for √{square root over (a)}, “3 ind 1” for 3 1 and “int (a,b) Omega dt” for ∫ a b ⁢ Ω ⁢ ⅆ t . From the last example, it is obvious that the present invention is also very useful for inserting special characters like Greek characters into a text document. “pi” may represent the Greek character π, “alpha” may represent α or “lambda” may represent λ. It is also possible to distinguish between small and capital letters, “Lambda” may for example represent Λ. It is immediately apparent that typing the instruction symbols is in many cases much easier and faster than using a special program like a formula editor or a list box for Greek symbols. The same can apply to other special characters like Chinese, Korean, Cyrillic, Arabic, Hebrew, or Japanese characters, or any other character or symbol characters. In another embodiment, a character, e.g., a percent sign, is used before the name of the character to assist in distinguishing between when the user wants the text word, and when the user wants the Greek or other symbol. Table 1 lists a number of different formula symbols that can be generated in using a text formula instruction. Notice that in each instance, the text formula instruction utilizes only characters that are found on a conventional computer keyboard. The last column in a row of Table 1 gives a simple example of a text instruction for a formula that utilizes the symbol presented in the first column of the row. In the last column, a, b, x, y, and z are used as variables. The text instruction symbol is in a bold font. TABLE 1 Symbol Presented Example of in text formula Formula Type Description instruction + Unary Plus Sign +a operator − Unary Minus Sign −a operator ± Unary Plus Minus Sign plusminus a operator ∓ Unary Minus Plus Sign minusplus a operator Unary Logical neg a operator negation | | Unary Absolute value abs a operator/ function ! Unary Factorial fact a operator/ function √ Unary Square root sqrt a operator/ function n √ Unary n-th root nroot n a -- operator/ where n is the function desired nth root of a Unary User-defined uoper % theta x operator operator = Binary Equal a = b operator/ relation ≠ Binary Not equal a neq b, or operator/ a <> b relation + Binary Addition a + b operator ⊕ Binary Add symbol in a oplus b operator circle − Binary Substraction a − b operator ⊖ Binary Subtract symbol a ominus b operator in circle * Binary Multiply a * b operator • Binary Dot product a cdot b operator ⊙ Binary Dot product in a odot b operator a circle × Binary Multiplication a times b operator Binary Multiply symbol a otimes b operator in circle / Binary Division a / b operator / Binary Slash for a slash b operator quotient set slash c between two characters / Binary Slash between a wideslash b operator two characters, of which the left character is superscript, and the right is subsript \ Binary Back Slash a widebslash b operator between two characters, of which the right character is superscript, and the left subscript Binary Slash in circle a odivide b operator ÷ Binary Division a div b operator a Binary Division/ a over b b operator Fraction Binary Logical AND a and b, or operator a & b Binary Logical Or a or b, or operator a | b ∘ Binary Concatenate a circ b operator | Binary Divides 5 divides 30 operator Binary Does not Divide 7 ndivides 30 operator > Binary Greater than a gt b, or operator/ a > b Relation < Binary Less than a le b, or operator/ a < b Relation ≧ Binary Greater than or a gt b, or operator/ equal to a >= b Relation Binary Greater than- a gtslant b operator/ equal to Relation Binary Much greater a gg b, or operator/ than a >> b Relation ≦ Binary Less than or a le b, or operator/ equal to a <= b Relation Binary Less than-equal a leslant b operator/ to Relation Binary Much less than a 11 b, or operator/ a << b Relation Binary Is defined as/ a def b operator/ by definition Relation equal to ≡ Binary Is equivalent/ a equiv b operator/ congruent to Relation ≈ Binary Is a approx b operator/ approximately Relation ˜ Binary Is similar to a sim b operator/ Relation ≅ Binary Is similar or a simeq b operator/ equal to Relation ∝ Binary Is proportional a prop b operator/ to Relation ⊥ Binary Is orthogonal a ortho b operator/ to Relation ∥ Binary Is parallel to a parallel b operator/ Relation Binary Correspondence a transl b operator/ symbol image of Relation Binary Correspondence a transr b operator/ symbol original Relation of ∈ Binary Is contained in a in b operator/ Set operator ∉ Binary Is not a notin b operator/ contained in Set operator ⊂ Binary Subset a subset b operator/ Set operator Binary Subset or equal a subseteq b operator/ to Set operator Binary Not subset to a nsubset b operator/ Set operator Binary Not subset or a nsubseteq b operator/ equal to Set operator ⊃ Binary Superset a supset b operator/ Set operator Binary Superset or a supseteq b operator/ equal to Set operator Binary Not superset to a nsupset b operator/ Set operator Binary Not superset or a nsupseteq b operator/ equal to Set operator Binary Contains a owns b, or operator/ a ni b Set operator ∪ Binary Union of Sets a union b operator/ Set operator ∩ Binary Intersection of a intersection operator/ Sets b Set operator \ Binary Difference a setminus b, operator/ between Sets or Set operator a bslash b X n Binary x with index n x sub n operator X n Binary n-th power of x x sup n operator → Binary Toward a toward b operator/ Relation Binary User defined x boper % theta opeator binary operator y --used to insert greek character theta Σ Operator Sum Sum x sub i Π Operator Product prod x sub i Operator Coproduct coprod x sub I lim Operator Limit lim x toward infinity lim inf Operator Limit inferior liminf lim sup Operator Limit superior limsup Operator/ Physics hbar Physics Constant Operator/ Physics lambdabar Physics Constant ∃ Operator/ Existential a exists b Logic quantifier, there is at least one ∀ Operator/ Universal a forall b Logic quantifier, for all Operator/ Arrow with a drarrow b Logic double line to the left Operator/ Arrow with a drarrow b Logic double line to the right Operator Arrow with a dlrarrow b Logic double line to the left and to the right ↑ Operator Up arrow a uparrow b ↓ Operator Down arrow a downarrow b ← Operator Left arrow a leftarrow b → Operator Right arrow a rightarrow b ∫ Operator Integral in xdx ∫∫ Operator Double Integral iint f (x,y) dxdy ∫∫∫ Operator Triple Integral iiint f (x,y,z) dxdydz Operator Curve integral lint Operator Double curve llint integral Operator Triple curve lllint integral Operator User defined oper % union operator from {i = 1} to n x_{i} Operator Range from . . . from {i = 1} to to n Operator Lower limit of from {i = 1} an operator Operator Upper limit of to n an operator sin() Function Sine sin x cos() Function Cosine cos x tan() Function Tangent tan x cot() Function Cotangent cot x arcsin() Function Arcsine arcsin x arccos() Function Arccosine arccos x arctan() Function Arctangent arctan x arccot() Function Arccotangent arccot x sinh() Function Hyperbolic sine sinh x cosh() Function Hyperbolic cosh x cosine tanh() Function Hyperbolic tanh x tanget coth() Function Hyperbolic coth x cotangent arsinh() Function Area hyperbolic arsinh x sine arcosh() Function Area hyperbolic arcosh x cosine artanh() Function Area hyperbolic artanh x tanget arcoth() Function Area hyperbolic arcoth x cotangent exp() Function General exp x exponential function ln Function Natural ln x logarithm log Function Logarithm log x base 10 e □ Function Natural func ^{x} exponential function IN Mathematical Natural number setn a symbol Mathematical Integer setz a symbol Mathematical Rational number setq a symbol Mathematical Real number setr a symbol Mathematical Complex number setc a symbol Mathematical Cardinal number aleph a symbol Mathematical back epsilon backepsilon symbol Ø Mathematical Empty set emptyset symbol Mathematical Real part of a re a symbol complex number Mathematical Imaginary part im a symbol of a complex number ∞ Mathematical Infinity infinity, symbol or infty ∇ Mathematical Nabla vector nabla x symbol ∂ Mathematical Partial partial x symbol differentiation or set margin Mathematical p function wp symbol ... Other symbol Three dots dotsaxis vertically in the symbol center Other symbol Three dots dotsup, diagonally from or lower left to dotsdiag upper right Other symbol Three dots dotsdown diagonally from upper right to lower left ... Other symbol Three dots dotslow horizontally below Other symbol Three dots dotsvert vertical □ Other symbol Placeholder <?> () Bracket with Normal round (a over b) grouping left and right oplus c function brackets [] Bracket with Normal left and [a over b] grouping right square oplus c function brackets Bracket with Left and right icibracket . . . grouping double square rdbracket function brackets {} Bracket with Left and right ibrace . . . grouping curly brackets, rbrace function set bracket ︷ Bracket with Scalable curly . . . grouping set bracket on overbrace function top . . . ︸ Bracket with Scalable curly . . . grouping set bracket underbrace function below . . . <> Bracket with Left and right langle . . . grouping pointed rangle function brackets <|> Bracket with Left and right langle . . . grouping pointed mline . . . function operator rangle brackets <|> Bracket with Scalable left left langle grouping and right . . . mline function pointed . . . right operator rangle brackets | | Bracket with Left and right lline . . . grouping vertical lines rline function ∥ ∥ Bracket with Left and right ldline . . . grouping double lines rdline function └ ┘ Bracket with Left and right lfloor . . . grouping lines with rfloor function lower edges ┌ ┐ Bracket with Left and right lceil . . . grouping lines with rceil function upper edges Bracket with Automatic grouping sizing of function brackets by putting left and right (left . . . right . . . ) up front, e.g., left(a over b right) or left lceil . . . right lceil. This way round, square, double square, single, double, single, curley, pointed, and operator brackets can be changed. ( Bracket, round left \( also bracket widowed, without grouping function ) Bracket, Normal round \) also right bracket widowed, without grouping function [ Bracket, Normal left \[ also square bracket widowed, without grouping function ] Bracket, Normal right \] also square bracket widowed, without grouping function { Bracket, Left curly \lbrace, also bracket or, widowed, \{ without grouping function } Bracket, Right curly \lbrace, also bracket or, widowed, \} without grouping function < Bracket, Left pointed \langle also bracket widowed, without grouping function > Bracket, Right pointed \rangle also brackets widowed, without grouping function |... Bracket, Left vertical \lline also line widowed, without grouping function ...| Bracket, Right vertical \rline also line widowed, without grouping function ∥... Bracket, Left double \ldline also line widowed, without grouping function ...∥ Bracket, Right double \rdline also lines widowed, without grouping function └ Bracket, Left line with \lfloor also lower edge widowed, without grouping function ┘ Bracket, Right line with \rfloor also lower edge widowed, without grouping function ┌ Bracket, Left line with \lceil also upper edge widowed, without grouping function ┐ Bracket, Right line with \rceil also upper edge widowed, without grouping function □ □ Indexes and Right index _, or exponents (su sub, or b-and rsub superscript) □ □ Indexes and Right exponent ^, or exponents (su sup, or b-and rsup superscript) □ □ Indexes and Left index lsub exponents(su b-and superscript) □ □ Indexes and Left exponent lsup exponents (su b-and superscript)   Indexes and Exponent csup exponents(su directly above b-and a character superscript)   Indexes and Index directly csub exponents (su below a b-and character superscript) Formatting Horizontal alignl, or alignment -- alignc, or left, center, alignr right Formatting Space/Blank ˜ Formatting Small space/   small blank Formatting Newline newline □ Formatting Binom binom □ □ Formatting Stack stack{x#y#z} □ □ □□ Formatting Matrix matrix{a#b##c#d} □□ ’ Attribute Accent to the acute a with fixed right above a character character width — Attribute Horizontal bar bar a with fixed above a character character width Attribute Upside down breve a with fixed roof above a character character width Attribute Upside down check with fixed roof character width ° Attribute Circle above a circle a with fixed character character width . Attribute Dot above a dot a with fixed character character width .. Attribute Two dots above ddot a with fixed a character character width ... Attribute Three dots dddot a with fixed above a character character width ‘ Attribute Accent to the grave a with fixed left above a character character width Attribute Roof above a hat a with fixed character character width ˜ Attribute Tilde above a tilde a with fixed character character width → Attribute Vector arrow vec a with fixed above a character character width Attribute Horizontal bar underline a with below a variable character character width Attribute Horizontal bar overline a with above a variable character character width Attribute Horizontal bar overstrike a with through a variable character character width → Attribute Wide vector widevec a with arrow, adjusts variable to the character character size width ˜ Attribute Wide tilde, widetilde with adjusts to the variable character size character width Attribute Wide roof, widehat with adjusts to the variable character size character width Font Italics ital attributes Font Remove italics nitalic attributes Font Bold bold attributes Font Remove bold nbold attributes Font Phantom phantom attributes character Font Command to font sans a attributes change characters; first the font name (sans, serif, or attributes fixed) is entered, then the characters to be changed are entered. Font Command to size *2 font attributes change the font sans a size; first the size is entered, then the characters to be changed are entered; for the entered sizes arguments following the pattern n, +n, −n *n or /n can be indicated; size +n and −n are changed in points(pt); a percentage change to e.g. 17% must be entered as *1.17 Font The command to color green attributes change the abc character color; first color green the color name (blank, white, cyna, magenta, red, blue, green and yellow) is entered, then the characters to be changed are entered. In addition to easy generation of a formula, the present invention includes an easy way to edit a data object like a mathematical formula. The object is entered by, e.g., a mouse click, on the object, and then is reconverted into the text formula instruction containing the text instruction symbols. The user edits the object by editing the text formula instruction, selects the edited text formula instruction again, and converts the same again into a data object, as described above. The editing operation can thus be carried out easily without entering a special tool like a formula editor. Further, those of skill in the art will appreciate that while memory 311 C is illustrated as one unit that can include both volatile memory and non-volatile memory, in most computer systems, memory 311 C is implemented as a plurality of memory units. In more general terms, method 205 is stored in a computer readable medium, and when method 205 is loaded from the computer readable medium into a memory of a device, the device is configured to be a special purpose machine that executes method 205 . Alternatively, the application used to execute method 220 , e.g., application 319 , may be stored in one computer readable medium, and method 230 stored in another computer readable medium. Also, herein, a computer program product comprises a medium configured to store or transport computer readable code for method 205 , method 220 , and/or method 230 or in which computer readable code for method 205 , method 220 , and/or method 230 is stored. Some examples of computer program products are CD-ROM discs, ROM cards, floppy discs, magnetic tapes, computer hard drives, servers on a network and signals transmitted over a network representing computer readable program code. As illustrated in FIG. 3A , this storage medium may belong to computer system 300 C itself. However, the storage medium also may be removed from computer system 300 C. For example, method 205 may be stored in either memory 311 A or 311 B that is physically located in a location different from processor 312 C. The only requirement is that processor 312 C is coupled to memory. This could be accomplished in a client-server system, e.g. system 300 C is the client and system 300 B is the server, or alternatively via a connection to another computer via modems and analog lines, or digital interfaces and a digital carrier line. For example, memory 311 C could be in a World Wide Web portal, while the display unit and processor are in a personal digital assistant (PDA), or a wireless telephone, for example, system 300 A. Conversely, the display unit and at least one of the input devices could be in a client computer, a wireless telephone, or a PDA, while the memory and processor are part of a server computer on a wide area network, a local area network, or the Internet. In this paragraph, method 205 that includes the application used to perform method 220 , as well as method 230 was considered. However, those of skill in the art will appreciate that a similar description can be made for only method 220 and for only method 230 . Accordingly, this description and that which follows is not repeated for each of the possible combinations and permutations for using and storing methods 220 and 230 . More specifically, computer system 300 C, in one embodiment, can be a portable computer, a workstation, a two-way pager, a cellular telephone, a digital wireless telephone, a personal digital assistant, a server computer, an Internet appliance, or any other device that includes the components shown and that can execute method 205 . Similarly, in another embodiment, computer system 300 C can be comprised of multiple different computers, wireless devices, cellular telephones, digital telephones, two-way pagers, or personal digital assistants, server computers, or any desired combination of these devices that are interconnected to perform, method 205 as described herein. See, for example, FIG. 3 A. Accordingly, a computer memory refers to a volatile memory, a non-volatile memory, or a combination of the two in any one of these devices. Similarly, a computer input unit and a display unit refers to the features providing the required functionality to input the information described herein, and to display the information described herein, respectively, in any one of the aforementioned or equivalent devices. In view of this disclosure, method 230 and method 220 can be implemented in a wide variety of computer system configurations. In addition, method 205 could be stored as different modules in memories of different devices. For example, method 205 could initially be stored in a server computer, and then as necessary, a module of method 205 could be transferred to a client device and executed on the client device. Consequently, part of method 205 would be executed on the server processor, and another part of method 205 would be executed on the client device. In view of this disclosure, those of skill in the art can implement the invention of a wide-variety of physical hardware configurations using an operating system and computer programming language of interest to the user. In yet another embodiment illustrated in FIG. 3B , method 205 is stored in memory 311 B of system 300 B. Stored method 205 is transferred, over network 315 to memory 311 C in system 300 C. In this embodiment, network interfaces 330 B and 330 C can be analog modems, digital modems, or a network interface card. If modems are used, network 315 includes a communications network, and method 205 is downloaded via the communications network. While the invention has been particularly shown with reference to a preferred embodiment thereof, it will be understood by those skilled in the art that various other changes in the form and details may be made therein without departing from the spirit and scope of the invention.

For inserting a data object as for example a mathematical formula or special characters like Greek characters into a text document, instruction symbols representing the data object are inputted in the form of text characters into the text document. A text portion containing instruction symbols is selected, and the instruction symbols contained in the selected text portion are converted into a data object represented by the instruction symbols. The invention allows rapid input of data objects into the text document, in particular simple mathematical formulae or single special characters without entering a formula editor or the like.

CROSS REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application No. 60/356,605, filed Feb. 13, 2002 which is hereby incorporated by reference in its entirety. The present application is related to co-pending applications Ser. No. 10/326,440 filed concurrently, Ser. No. 10/325,382 filed concurrently, Ser. No. 10/324,976 filed concurrently, and Ser. No. 10/325,192 filed concurrently. FIELD OF THE INVENTION The present invention relates to chip data security generally and, more particularly, to a use of electronically erasable programmable read-only memory for storage of security objects in a secure system. BACKGROUND OF THE INVENTION Digital video Set-Top Box (STB) security is an evolving process. As pirating knowledge increases, the amount of security designed into the STBs is increased to avoid illegal access to descrambling technology. Smart cards are currently being used to provide security for decryption codes. Additional security measures could be introduced to help protect the rest of the box. SUMMARY OF THE INVENTION The present invention concerns a circuit generally comprising a first memory, a second memory and a processor. The first memory may store an instruction to read an updated security value of at least three security values. The second memory may store (i) the updated security value and (ii) information related to security of the circuit. The processor may be configured to (i) execute the instruction while a register stores a highest security value of the security values, (ii) copy the information from the second memory to a third memory in response to the update security value being greater than a current security value of the security values stored in the third memory and (iii) ignore the information in the second memory in response to the updated security value being no greater than the current security value. The objects, features and advantages of the present invention include providing a circuit, method and/or architecture that may provide (i) secured and One-Time Programmable (OTP) memory, (ii) internal boot read-only memory (ROM), (iii) authentication and disable of an Extended Joint Test Action Group (EJTAG) debug interface, (iv) exception vector intercept, and/or (v) cache lockout. BRIEF DESCRIPTION OF THE DRAWINGS These and other objects, features and advantages of the present invention will be apparent from the following detailed description and the appended claims and drawings in which: FIG. 1 is a partial block diagram of a circuit in accordance with a preferred embodiment of the present invention; FIG. 2 is a flow diagram of a process of transitioning between security modes; FIG. 3 is a flow diagram of a process for configuring a one-time programmable memory in the field; FIG. 4 is a flow diagram of a process to initialize EJTAG security flags; FIGS. 5A–D are block diagrams of several example registers; FIG. 6 is a block diagram of a portion of a scan chain; FIG. 7 is a block diagram illustrating a firmware sequence to exit a boot ROM module; FIG. 8 is a table of a security supervisor module protection process; and FIG. 9 is a block diagram of an example mechanism by which pins may be protected. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1 , a partial block diagram of a circuit or system 100 is shown in accordance with a preferred embodiment of the present invention. The partial block diagram is not generally meant to be a completely accurate depiction of the present invention's architecture, but rather a high-level functional overview of the modules that impact the security features. The circuit 100 generally comprises a circuit or component 102 , a memory 104 , a circuit 106 , and a bus 108 . An interface 110 may be provided in the circuit 100 for general purpose serial communications. An interface 112 may be provided in the circuit 100 for debug testing. The component 102 may be implemented as a single-chip or a multiple-chip source decoder for digital video and/or audio signals. The component 102 may provide the interfaces 110 and 112 to the circuit 100 . An interface 116 may be provided in the component 102 to couple to the bus 108 . The memory 104 may be implemented as an electrically erasable programmable read-only memory (EEPROM). In one embodiment, the memory 104 may be implemented as a FLASH memory. The memory 104 may be coupled to the bus 108 for access by the component 102 and the circuit 106 . The circuit 106 may be implemented as an external bus master on the bus 108 . The bus 108 may be configured as an external bus (e.g., E-Bus) connecting the component 102 to the other external circuits and/or external memory blocks. Various standards and protocol may be implemented for the bus 108 to meet the criteria of a particular application. The interface 110 may be implemented as a universal asynchronous receiver/transmitter (UART) interface. The interface 112 may be implemented as a Joint Test Action Group (JTAG) architecture interface or an EJTAG interface. The JTAG interface is generally defined in The Institute of Electrical and Electronics Engineering (IEEE) Standard 1149.1-2001, titled “IEEE Standard Test Access Port and Boundary-Scan Architecture”, published by the IEEE, New York, N.Y., hereby incorporated by reference in its entirety. The EJTAG interface is generally defined in the “EJTAG Specification”, Revision 2.61, September 2001, published by MIPS Technologies, Inc., Mountain View, Calif., hereby incorporated by reference in its entirety. The component 102 generally comprises a circuit or chip 120 and a memory or chip 122 . The component 102 may be configured to perform a source decoding for digital video and/or audio signals. The memory 122 may be configured as a one-time programmable (OTP) memory module. The OTP memory module 122 may store security related information for the decoder circuit 120 . In one embodiment, the decoder circuit 120 and the OTP memory module 122 may be fabricated on the same chip. The decoder circuit 120 generally comprises a circuit 124 and a circuit 126 connected by an internal bus (e.g., I-Bus) 128 . The circuit 124 may be implemented as a core processor circuit. The core processor circuit 124 may be a customer-owned tooling (COT) die or chip. The circuit 126 may be implemented as an input/output (I/O) circuit. The I/O circuit 126 may couple the I-Bus 128 to the OTP memory module 122 . The I/O circuit 126 is generally fabricated on the same chip as the core processor circuit 124 . The core processor circuit 124 generally comprises a circuit or block 130 , a circuit or block 132 , a circuit or block 134 , a circuit or block 136 , a multiplexer 138 , a multiplexer 142 , a circuit or block 144 , a circuit or block 146 , a circuit or block 148 , a bus 150 and a bus 152 . The circuit 130 may be implemented as an on-chip memory (OCM) module. The circuit 132 may be implemented as a processor module. In one embodiment, the processor module 132 may be a reduced instruction set computer (RISC) processor module. The circuit 134 may be implemented as an EJTAG enable module. The circuit 136 may be configured as a security supervisor block or module for the bus 152 . The circuit 144 may be implemented as a basic bus and cache controller (BBCC) interface module. The circuit 146 may be configured as a security flags block or module. The circuit 148 may be implemented as an external bus controller (EBC) module. The bus 150 may be implemented as a core bus (e.g., C-Bus). The bus 152 may be implemented as a system or basic bus (e.g., B-Bus). The I/O circuit 126 may include a circuit or block 160 . The circuit 160 may be implemented as an enable module for communicating with the OTP memory module 122 . The OCM module 130 generally comprises a memory 162 , a circuit or block 164 , a circuit or block 166 and a circuit or block 168 . The memory 162 may be implemented as a read-only memory (ROM) module. In one embodiment, the ROM module 162 may be configured as a bootstrap ROM or boot ROM for short. The boot ROM module 162 may store a code 163 containing instructions. The circuit 164 may be implemented as a tamper detect module. The circuit 166 may be implemented as a precise exit logic module. The circuit 168 may be implemented as an address decode module for decoding addresses on the C-Bus 150 intended for the boot ROM module 162 . The circuit 132 generally comprises a circuit or block 172 , a circuit or block 174 , a circuit or block 176 and a circuit or block 178 . The circuit 172 may be implemented as a UART module. The circuit 174 may be implemented as a Central Processor Unit (CPU) module. The circuit 176 may be implemented as a debug port module or a Test Access Port (TAP) module. The debug port module 176 may be compliant with the EJTAG specification and/or the JTAG specification. Other debug specifications may be implemented to meet the criteria of a particular application. The circuit 178 may be implemented as a basic bus and cache controller (BBCC) module. The circuit 136 generally comprises a circuit 170 . The circuit 170 may be configured as a source/target detector module. The source/target detector module 170 may detect a master (source) and a target address of each transaction of the B-Bus 152 . The system 100 may have multiple security modes or states. In one embodiment, the system 100 may have a Secure Disabled (SEC — DIS) mode, a Secure Application (SEC — APP) mode and a Secure Privileged (SEC — PRIV) mode. Other states and/or modes may be implemented to meet the criteria of a particular application. The Secure Disable mode may be active or asserted when code executed from the boot ROM module 162 determines that security features may not be enforced, and therefore disables the protection. By definition, the CPU module 174 may no longer be executing from the boot ROM module 162 while in the Secure Disable mode. The Secure Disabled mode is generally used for a component 102 that have not yet had the OTP memory module 122 programmed and may include other uses. The Secure Disable mode may be a lowest of the security modes. The Secure Application mode is generally asserted or active when the boot ROM determines that security in some form may be useful, including application software (code or firmware) execution. All or some security measures may be active in the Secure Application mode. By definition, the CPU module 174 may no longer be executing from boot ROM module 162 while in the Secure Application mode. The Secure Application mode may be an intermediate level security mode. The Secure Privileged mode may be asserted or active while the CPU module 174 is still executing from boot ROM module 162 . While in the Secure Privileged mode, the processor module 132 may access the OTP memory module 122 and/or the FLASH memory 104 . The Secure Privileged mode may be a highest or tightest of the security modes. Referring to FIG. 2 , a flow diagram of a process of transitioning between the security modes is shown. Operations expected to be performed in each security mode are generally indicated within a box labeled with the mode name. Transitions between boxes may represent instruction execution leaving the boot ROM module 162 . The Secure Privileged mode is generally indicated by box 180 . The Secure Application mode is generally indicated by box 182 . The Secure Disable mode is generally indicated by box 184 . The process generally begins with the processor module 132 bootstrapping to the boot ROM module 162 (e.g., block 186 ). Instructions in the boot ROM module 162 may then be used to set up a driver for an interface between the I/O circuit 126 and the OTP memory module 122 (e.g., block 188 ). If the OTP memory module 122 has been initialized (e.g., the YES branch of decision block 190 ), one or more instructions stored in the boot ROM module 162 may be executed to perform a security initialization (e.g., block 192 ). Initialization of the OTP memory 122 may be determined by a state of a programmable flag stored within the OTP memory 122 . If initialized, the OTP memory 122 may be configured for use by the system 100 . The security initialization may begin to transition the system 100 from the Secure Privileged mode to the Secure Application mode. A jump instruction stored in the boot ROM module 162 may then cause the processor module 132 to execute a jump to a boot vector in the FLASH memory 104 (e.g., block 194 ). Once the system 100 has transitioned to the Secure Application mode, an application software may be executed from the FLASH memory 104 (e.g., block 196 ). If the OTP memory module 122 is not initialized (e.g., the NO branch of decision block 190 ), one or more instructions stored in the boot ROM module 162 may initiate a transition of the system 100 from the Secure Privileged mode to the Secure Disabled mode. A jump instruction stored in the boot ROM module 162 may be executed to jump to a boot vector in the FLASH memory 104 (e.g., block 198 ). Once the system 100 has transitioned to the Secure Disabled mode, application software may execute from the FLASH memory 104 (e.g., block 200 ). The application software executed in the Secure Disabled mode may be the same or a different application software as the application software executed in the Secure Application mode. Before the core processor circuit 124 is mounted in a package or housing (not shown) with the OTP module 122 , the core processor circuit 124 may not be able to function as a secure part. In particular, until the core processor circuit 124 detects a programmed OTP module 122 , the core processor circuit 124 may leave the Secure Privileged mode to the Secure Disabled mode. While in the Secure Disabled mode, decryption operations may be disabled. In order to implement a feature that (i) a system identification (ID) and (ii) security flags may be programmable only once and not visible outside the packaged part, the component 102 may use the OTP memory 122 for storing security related items. The OTP memory 122 may be designed as a bit-serially-accessed nonvolatile, fused-region memory attached to the I/O circuit 126 and packaged together with the decoder circuit 120 die in a multi-chip package. Access to the OTP memory 122 may be defined according the rules summarized in Table I as follows: TABLE I Mode Access to OTP Memory Secure Disabled Read/Write Secure Application None Secure Privileged Read/Write Referring to FIG. 3 , a flow diagram of a process for configuring the OTP memory module 122 in the field is shown. During normal operation of the system 100 , a service being decrypted may provide a new security upgrade. The security upgrade generally sets security flag registers on-chip that may increase, but not decrease, security settings. The new security register settings may be written into the security flags module 146 by the application software and may not be effective until a next system reset. The decrypted service may also provide a new code release for storage in the FLASH memory 104 that contains one or more new security features or objects to be permanently burned into the OTP memory module 122 . The system 100 may be reboot (e.g., block 210 ) once the new security features have been loaded into the FLASH memory 104 . Upon reboot, the boot ROM code may read a location 211 ( FIG. 1 ) in the FLASH memory 104 containing the security flag upgrades. The upgrade flags may then be read from the FLASH memory 104 (e.g., block 218 ). If the updated flags indicate a same or lower security level than what is already stored in the OTP memory 122 (e.g., the NO branch of decision block 220 ), the configuration process may be halted. Therefore, attempts to decrease security levels may be ignored. If the upgrade flags stored in the FLASH memory 104 have higher security settings than what is currently stored in the OTP memory 122 (e.g., the YES branch of decision block 220 ), the upgrade information or data 221 ( FIG. 1 ) stored in the FLASH memory 104 may be copied into the OTP memory 122 (e.g., block 222 ) by the boot ROM code. Upon a subsequent reboot, the security flag registers within the component 102 may be set according to the new values read from the OTP memory 122 . Other flags not modified by the update through the FLASH memory 104 may be read from the OTP memory 122 to the appropriate registers. The boot ROM module 122 may be accessed upon initialization in a secure component 102 . The boot ROM module 122 may be accessible only at boot and may become inaccessible after the boot code has verified a secure installation. In one embodiment, the boot ROM module 122 may be implemented as 16 KB ROM. Other memory sizes may be implemented to meet a design criteria of a particular application. The boot ROM module 122 may reside exclusively in an uncacheable address space of the processor 132 . The uncacheablity of the boot ROM module 122 generally facilitates ease of design and integration. There may be no performance implications to the processor 132 as the boot ROM module 122 may be designed to provide access times similar to cache accesses, providing a high-performing boot sequence for various computationally intensive activities. In addition, a normal boot vector for an existing CPU module 174 as well as the bootstrap exception vectors and debug exception vectors may all reside within the uncacheable address space. The contents of the boot ROM module 162 may not be visible external to the component 102 , nor determinable from external to the component 102 . Access to the boot ROM module 162 may be governed by the rules summarized in Table II as follows: TABLE II Mode Execute from Boot ROM Secure Disabled No Secure Application No Secure Privileged Yes The component 102 may have three levels of security for EJTAG. A Baseline level of security may be defined as having no security available and access may be unrestricted at all times when asserted. An Authentication level of security may (i) allow access to all EJTAG features and (ii) the EJTAG debug port module 176 may undergo a challenge/response-based authentication via the UART port 110 . Firmware may be used to implement the authentication protocols via the UART interface 110 . The authentication protocols may be implemented by firmware, code or software. A Locked level of security may disable the EJTAG probe interface 112 without any authentication. The EJTAG security levels and the associated features may be summarized in Table III as follows: TABLE III EJTAG Security Features Disable EJTAG MODE Mode Enabled TAP Secure Disable Baseline All No Secure Baseline All No Application Secure Authenticate All No Application Secure Locked Instruction Yes Application based only Secure Privileged N/A Instruction Yes based only Referring to FIG. 4 , a flow diagram of a process to initialize the EJTAG security flags is shown. The EJTAG functionality may be disabled upon bootstrapping to the boot ROM memory 162 (e.g., block 278 ) The boot ROM code 163 may, after setting up the I/O circuit driver for the OTP memory 122 , read the security flag values for the EJTAG enables from the OTP memory 122 (e.g., block 280 ). If an EJTAG enable is allowed (e.g., the BASELINE branch of decision block 282 ), the EJTAG probe may be enabled when leaving the boot ROM module 162 (e.g., block 284 ). If an EJTAG enable is allowed via authentication (e.g., the AUTHENTICATE branch of decision block 282 ), the boot ROM code 163 may execute a challenge portion of the EJTAG authentication procedure, if programmed in the boot ROM module 162 (e.g., block 286 ). After the challenge portion, a response portion of the EJTAG authentication procedure may be performed (e.g., block 287 ). Upon successful authentication (e.g., the YES branch of decision block 288 ), the EJTAG probe may be enabled when leaving the boot ROM module 162 (e.g., block 284 ). Otherwise (e.g., the NO branch of decision block 288 ), the EJTAG probe may be disabled when leaving the boot ROM module 162 (e.g., block 290 ). If an EJTAG enable is disallowed (e.g., the LOCKED branch of decision block 282 ), the EJTAG probe may be disabled by the boot ROM code (e.g., block 290 ). Disabling the EJTAG probe may include masking an input signal (e.g., TDI)(e.g., block 291 ). The boot ROM module 162 may contain a routine at a debug exception vector that may cause a jump-to-self to lock the system 100 . Assertion of the debug exception vector may be caused by an attempt to gain control of the system 100 illegitimately. In order to ensure security in the system 100 , the exception vectors enabled during the execution of the boot ROM code should be able to detect abuse of normal and debug exception mechanisms and the exception vectors should be thwarted. Therefore breaking into the system 100 in a privileged state and determining the contents of various sensitive memory locations may be difficult to impossible. All intercepted exceptions should essentially jump-to-self in order to lock the system 100 from illegal access. Interception of the exceptions is generally a firmware issue using no specialized hardware. The cache RAMs for the CPU module 174 may not be accessible functionally via external pins. Software may place the cache memories into a software test mode, allowing the software to read the contents of the cache. However, when the cache is used in security features, the CPU module 174 is generally under control of the boot ROM firmware and is impervious to outside control. The boot ROM firmware may be written to ensure that the cache contents may not be read later by clearing the caches before exiting the Secure Privileged mode. The security mode flags in the security flags module 146 generally indicate the current security levels present in the device. In addition, a register may be provided in the security flags module 146 that holds a Set Top Box ID for application visibility. The security flag bits may be manipulated using writes to a register in the I-Bus space. A notation of “Write X only” generally indicates that an attempt to write a value other than that X may be ignored. Referring to FIGS. 5A–D , block diagrams of several example registers are shown. A register in FIG. 5A may be referred to as a Security Resource Control (SRC) register 292 . In one embodiment, the SRC register 292 may be located at an I-Bus 128 address of 0xBE060000 (hexadecimal). The SRC register 292 generally contains the register bits that control operations of the security modules in the component 102 . Several security flags within the SRC register 292 may be implemented as four-bit values. The four-bit values may prevent over-clocking or power supply manipulations from allowing the less secure states to be entered without software control. The least secure state (meaning the software has more rights) may be a single value of many possible values. All other states may be “more” secure. The SRC register 292 generally comprises a flag 294 , a flag 300 , a flag 302 , a flag 306 and a flag 308 . The flags 294 and 302 may be reserved (R) flags. The flag 300 may operate as an EJTAG Disable (EDIS) flag. The flag 306 may operate as a Debug (DGB) flag. The flag 308 may operate as a Security mode (SEC) flag. While the flag SEC is set to 8′hAA, the component 102 may be set to the Secure Disabled mode. While the flag SEC is set to 8′h55, the component 102 may be set to the Secure Privileged mode. While the flag SEC is set to anything else, the component 102 may be set to the Secure Application mode. For ease of understanding, the value of 8′hAA may be referred to as “SEC — DIS”, 8′h55 may be referred to as “SEC — PRIV” and all other values may be referred to as “SEC — APP”, unless a particular value is specified precisely. The boot ROM firmware may modify the flag SEC bits to disable all secure resource protection. Modifying the flag SEC bits may disable all on-chip security. The boot ROM firmware may modify the flag SEC bits to indicate that the boot ROM firmware has completed execution. Completing execution from the boot ROM module 162 generally disables all future attempts to access the boot ROM module 162 . Any future accesses to the boot ROM module 162 address space may be mapped to the B-Bus 152 and FLASH memory 104 . A summary of access by the various sources on the B-Bus 152 based upon the flag SEC bits may be shown in Table IV as follows: TABLE IV Read Mode Source Privilege Write Privilege Secure Disabled All All Write SEC — DIS only Secure All All Write SEC — DIS only Application Secure Privileged CPU All Write SEC — APP, SEC — DIS only Secure Privileged Non-CPU None None The values of SEC[7:0] and the associated security mode definitions, are generally shown in Table V as follows: TABLE V SEC [7:0] Definition 8 ′hAA Secure Disabled 8 ′h00-54, 8 ′h56-A9, 8 ′hAB-FF Secure Application 8 ′h55 Secure Privileged The flag DGB is generally a single read-only bit. The flag DGB may be used by the boot ROM code to determine if an access to the debug exception vector within the boot ROM module 162 should be handled. Attempts to write to the flag DGB are generally unsuccessful. Access to the flag DGB may be summarized in Table VI as follows: TABLE VI Mode Source Read Privilege Write Privilege Secure Disabled All All None Secure Application All All None Secure Privileged Non CPU Restricted Restricted The flag EDIS may be implemented as a four-bit value. The meaning of the flag EDIS[3:0] is generally summarized below in Table VII as follows: TABLE VII EDIS [3:0] Definition 4 ′hA EJTAG Probe Enabled All others EJTAG Probe Disabled For ease of understanding, the value of 4′hA may be referred to as “EJ — EN” and all others as “EJ — DIS”, unless a particular value is specified precisely. The boot ROM firmware may modify the flag EDIS bits to EJ — EN in order to enable all of the EJTAG functionality. Application software may modify the flag EDIS bits to increase EJTAG security (e.g., disable EJTAG functionality) but may not be able to clear the flag EDIS. Reset values for the flag EDIS may be summarized in Table VIII as follows: TABLE VIII DGB EDIS [3:0] Rest to: 0 EJ — DIS (e.g., 4 ′hF) 1 EJ — EN Access to the flag EDIS may be summarized in Table IX as follows: TABLE IX MODE Source Read Privilege Write Privilege Secure Disabled All All Write EJ — EN only Secure Application All All Write EJ — DIS only Secure Privileged Cpu All All Secure Privileged Non-CPU None None The fields R may be tied to the logical zero value. The fields R are generally read as zero and may not be writable. The application software should write the R bits to logical zero to preserve functionality in future revisions of the hardware. Referring to FIG. 5B , a block diagram of a vendor register 310 is shown. The vendor register 310 generally comprises a flag 312 and a flag 316 . The vendor register 310 may be located at an address of 0xBE060004 (hexadecimal) in the B-Bus 152 address space. Each bit of the flags 312 and 316 may be set to the logical zero value at reset. Therefore, a default vendor register 310 may contain the value 0x0fffffff (hexadecimal). The flag 316 may contain reserved (R) bits. The flag 312 may be implemented as a single-bit EJTAG Authentication (EA) bit. While the EA bit has the logical zero value, the EJTAG Authentication may be disabled. While the EA bit has the logical one value, the EJTAG Authentication may be enabled. The boot ROM firmware may modify the EA bit to enable or disable the EJTAG authentication. The application software may not write the EA bit. The EA bit may have a reset value of 1′b0. Access to the flag EA may be summarized in Table X as follows: TABLE X MODE Source Read Privilege Write Privilege Secure Disabled All All All Secure Application All All None Secure Privileged CPU All All Secure Privileged Non-CPU None None Referring to FIG. 5C , a block diagram of a Set Top Box ID High register 322 is shown. The Set Top Box ID High register 322 generally comprises a 32-bit field 324 . The field 324 may be designated as a high word (e.g., STBID — HIGH) of an overall set top box identification value. The Set Top Box ID High register 322 generally has an address of 0xBE060008 (hexadecimal) in the B-Bus 152 address space. Access to the Set Top Box ID High register 322 may be granted to the CPU module 174 while executing from the boot ROM module 162 , read-only to the CPU module 174 while not executing from the boot ROM module 162 , and no access for non-CPU masters while in the Secure Privileged mode. The field STBID — HIGH may have a reset value of 0xffffffff (hexadecimal). The field STBID — HIGH may be set at boot by the CPU module 174 by reading the STB ID value from the OTP memory 122 . No other master, including the CPU module 174 while in Secure Application or Secure Disabled mode, may write to the STBID — HIGH field. Referring to FIG. 5D , a block diagram of a Set Top Box ID LOW register 326 is shown. The Set Top Box ID LOW register 326 generally comprises a 32-bit field 328 . The field 328 may be designated as a high word (e.g., STBID — LOW) of the overall set top box identification value. The Set Top Box ID LOW register 326 generally has an address of 0xBE6000C (hexadecimal) in the B-Bus 152 address space. Access to the Set Top Box ID LOW register 326 may be granted to the CPU module 174 while executing from the boot ROM module 162 , read-only to the CPU module 174 while not executing from the boot ROM module 162 , and no access for non-CPU masters while in the Secure Privileged mode. The field STBID — LOW may have a reset value of 0xffffffff (hexadecimal). The field STBID — LOW may be set at boot by the CPU module 174 by reading the STB ID value from the OTP memory 122 . No other master, including the CPU module 174 while in Secure Application or Secure Disabled mode, may write to the STBID — LOW field. In order to prevent other modules from having to decode the various four-bit values for each multi-bit security flag, the security flags module 146 may decode the values into a set of signals that indicate the security levels. Two signals may be decoded for the SEC[7:0] field. A signal (e.g., SECURE — PRIVILEGED — MODE) may indicate that the Secure Privileged mode is active. A signal (e.g., SECURE — APPLICATION — MODE) may indicate that the Secure Application mode is active. In the event that the component 102 is in Secure Disabled mode, both of the signals SECURE — PRIVILEGED — MODE and SECURE — APPLICATION — MODE may be inactive. Referring to FIG. 6 , a block diagram of a portion of a scan chain 330 is shown. The scan chain 330 may be routed through the security related registers of the security flag module 146 , and/or in other modules. An example single bit of a security related register may be indicated by a flip-flop 332 . The scan chain 330 may be disabled for the flip-flop 322 while a signal (e.g., SCAN — ENABLE) is deasserted. A flip-flop 334 may provide temporary storage of a value (e.g., DOUT) loaded from the flip-flop 332 into the scan chain 330 , or from an upstream flip-flop (not shown) in the scan chain 330 , based upon a signal (e.g., SHIFT). The flip-flop 334 may generate and transmit a data signal (e.g., TDO) to a downstream flip-flop (not shown) in the scan chain 330 . A multiplexer 338 may allow the scan chain 330 to (i) bypass or disable the flip-flop 332 and (ii) sample the flip-flop 332 . During a wafer probe test, the component 102 to be placed into scan mode and the signal SCAN — ENABLE may be asserted by the security flags module 146 . During package testing of the secure part 102 , the scan chain 330 may bypass the flip-flop 332 by holding the signal SCAN — ENABLE inactive in the logical zero state. While the signal SCAN — ENABLE is in the logical one state, the contents of the flip-flop 332 (e.g., the signal DOUT) may be visible on the scan chain 330 . Logic (e.g., the X input of the flip-flop 332 may be a Set input or a Clear input) may be implemented to tie off the values to the security related registers (e.g., flip-flop 332 ) to predetermined secure states while a signal (e.g., SCAN — MODE) is active. The logic may prohibit registers upstream from controlling, via functional paths and a scan “evaluate” phase, the contents of the security related registers. The logic may set the values SRC[SEC]=SEC — APP and SRC[EDIS]=EJ — DIS if the scan mode is indicated and a functional clock (e.g., LOAD) is toggled. The logic may prohibit use of the scan chain 330 indirectly from placing the part 102 into a looser security state, such as the Secure Disabled state. Functional testing of the security related registers is generally not feasible prior to programming the OTP memory 122 . In the Secure Disabled mode, the values that the security related registers may take is limited. However, once the OTP memory 122 has been programmed, the CPU module 174 may leave the Secure Privileged mode and transition to the Secure Application mode instead. In the Secure Application mode, the security related bits may be much more testable. Some of the security registers may not read/write in the Secure Application mode, but if the part 102 is functioning correctly, the functional test software should be able to read back the contents that were programmed into the OTP memory 122 from the security registers. A unique test program per chip may be used to read the security values from the OTP memory 122 . The unique test programs may be performed at the customer's location at which the parts 102 have been programmed. Verification of the security register may not be complex as the unique test program that configures the part 102 may already know the unique chip information (e.g., chip ID, etc.) in order to test the design correctly. The on-site testing may filter the remaining test escapes leaving the component manufacturer as a result of the secure scan chain. The OCM module 130 is generally responsible for providing both the boot ROM module 162 and the precise boot ROM execution termination logic module 166 tightly coupled to a pipeline of the CPU module 174 , to prevent windows of insecure operation. The OCM module 130 may sit exclusively in the uncacheable address range of the C-Bus 150 . Although the RISC processor 132 memory map may allow the OCM module 130 to sit in a cacheable address range as well, the choice of the uncacheable address range generally eliminates a possibility that the secure code may be cached. The OCM module 130 generally sits on the CPU system C-Bus 150 . The C-Bus 150 may support the OCM module 150 via a simple interface. An address may be brought out of the processor 132 that the decode module 168 may decode and claim before the address reaches the CPU caches and the B-Bus 152 . Although running uncached, accesses to the boot ROM module 162 memory space may be very fast as the OCM module 130 may have an access time allowing zero wait-state accesses, duplicating the performance of cached code. Following a hardware reset, the CPU module 174 may boot from the boot ROM module 162 . The boot operation is generally controlled by the SRC[SEC] bits. If the SRC[SEC] bits are equivalent to SEC — PRIV, the CPU module 174 may boot from and execute from the internal boot ROM module 162 . If the SRC[SEC] bits are equivalent to SEC — DIS, the CPU module 174 may boot from and/or execute from the FLASH memory 104 . If the SRC[SEC] bits are equivalent to SEC — APP, the CPU module 174 may execute from the FLASH memory 104 . Software 163 running from the boot ROM module 162 may have privileged status as a Secure Privileged mode device, with full access to the entire address map of the component 102 . Control of the privileged access is generally provided by the security supervisor hardware module 136 . The security supervisor module 136 may identify if an instruction being executed is from the boot ROM module 162 , and if so, enable read and write access to all protected address regions. The exit from the boot ROM module 162 may be precise. With only a single secure memory region, such as the boot ROM module 162 , clearing one or more bits enabling execution from the boot ROM module 162 and executing a jump to the normal boot vector in the FLASH memory 104 may be difficult. Furthermore, the pipeline in the CPU module 174 , write buffering, and indeterminate latencies on the B-Bus and I-Bus interfaces may increase the difficulty of a proper exit in executing from the boot ROM module 162 . As such, the OCM module 130 may implement a very precise method that determines when the bits have been set to switch the system from Secure Privileged mode (e.g., executing from the boot ROM module 162 ) to the Secure Application mode. The precise boot ROM exit logic module 166 may mimic the CPU pipeline to determine when to exit. A store to the SRC register 292 with an intent to change the SEC[7:0] field from SEC — PRIV to SEC — APP or SEC — DIS, and to configure any other bits for operation outside the boot ROM module 162 , may be observed by the precise boot ROM exit logic module 166 . The precise boot ROM exit logic module 166 may indicate that the bits in the SRC register 292 may be changed at a precise time, in accordance with the CPU pipeline, to the bits in the SRC register 292 actually sitting on the I-Bus. Referring to FIG. 7 , a block diagram illustrating the firmware sequence to exit the boot ROM module 162 is shown. The precise boot ROM exit logic module 166 may register the updated SRC value at the end of the X2 execute stage (e.g., at time 340 ) of the CPU module pipeline 341 . The updated SRC values may be sent to an I-Bus addressable register (e.g., in the security supervisor module 136 ) and written at the end of the WB write-back stage of the CPU instruction (e.g., at time 342 ). The write at time 342 to the SRC register 292 may also pass through a write buffer (not shown) and may eventually occur again while in the Secure Application mode or Secure Disabled mode. The second write to the SRC register 292 may have a possible, but unlikely and harmless effect of decreasing security levels that an application software had just set at normal boot time (e.g., the application software may have raised a security state from what was programmed in the OTP memory 122 .) Since the OTP memory 122 may be the ultimate source of controlled security, the second write to the SRC register 292 is generally a don't-care scenario. Other security related registers may be updated in other ways to help ensure precise exit from the boot ROM module 162 . The tamper protection module 164 may detect that the CPU module 174 has vectored from the boot ROM module 162 while still executing in the Secure Privileged mode. Vectoring from the boot ROM module 162 prematurely may potentially be caused by over-clocking or power-glitching the part 102 . Over-clocking or power-glitching the part 102 may cause the CPU module 174 to fetch an instruction that is not targeted to the on-chip boot ROM module 162 while in Secure Privileged mode. In the event that the tamper detect module 164 detects an improper vector, the tamper detect module 164 may immediately transition the part 102 into the Secure Application mode by changing the value in the flag SEC. The OCM module 130 may be surrounded by a scan wrapper 131 to be used for scan test of the memory within. The precise exit logic module 166 may be part of the disable-able scan chain(s) 173 of the core processor circuit 144 . Other test architectures for the OCM module 130 may be implemented to meet the criteria of a particular application. Referring to FIG. 8 , a table of a security supervisor module 136 protection process is shown. For the purposes of the table shown in FIG. 8 , “Other” masters encompass an E-Bus 108 external master (e.g., master circuit 106 ) and the CPU module 174 , where appropriate. Notes in the table may be as follows: (1) The registers that may be written as defined in the security flags module 146 . (2) Registers typically may only be written, if at all, to indicate a higher security level. The security supervisor module 136 may be a conceptual block that implements a fixed protection scheme for the address map of the component 102 . The source/target detector module 170 within the security supervisor module 136 generally uses the following information to determine the source of an access that is being supervised: (i) identification of the master that is accessing the B-Bus 152 and (ii) the absolute address of the current instruction executing in the CPU module 174 . The master may be one of the CPU core module 174 or the E-Bus controller module 148 . The security supervisor module 136 may use the address to which the transaction is going to determine the destination of the access and then rule on the validity of the transaction based on the table shown in FIG. 8 . In order to ensure security, the comparison addresses should be fixed such that there may be no programmability of the address comparison values. Because of the CPU pipeline, there is generally a latency between the CPU module 174 fetching an instruction from an address and the execution of that instruction. To ensure synchronization of both indications that the CPU module 174 is initiating a B-Bus 152 transaction and is executing from a specific area in memory, a few non-operation instructions may be placed after a load instruction or a store instruction that falls near a jump or branch that may cause the CPU module 174 to leave the privileged area. Otherwise, the load or store indications might fail to be synchronized. However, as long as the boot ROM module 162 is exited properly, the lack of synchronization should not be a concern. However, branching outside of the boot ROM module 162 while still in Security Privileged mode may present a security issue. When the source/target detector module 170 detects an improper transaction on the B-Bus 152 , the security supervisor module 136 may subvert the B-Bus 152 transaction. For a read transaction, a receive command signal from the source to the target may be forced inactive by the security supervisor module 136 through the multiplexer 138 to prevent the target from seeing the read. A ready signal from the target to the source (or master) may be forced active by the security supervisor module 136 through the multiplexer 142 to prevent the master from hanging waiting for a response. The security supervisor module 136 generally returns a predetermined value (e.g., 0x00000000) as data to the master. The master may consider the predetermined data as a valid return. For a write transaction, the transmit command signal from the master to the target may be forced inactive by the security supervisor module 136 through the multiplexer 138 to prevent the target from seeing the write. A ready signal from the target to the master may be forced active by the security supervisor module 136 through the multiplexer 142 to prevent the master from hanging waiting for a response. The security supervisor module 136 may not provide known data on a write, as the write may not take place. The EJTAG enable module 134 may mask a data input signal (e.g., TDI) to an interface 175 of the EJTAG debug port module 176 on a scan chain 177 in the RISC processor 132 . Masking the signal TDI may allow a TAP state machine within the EJTAG debug port module 176 to change states, but may lock the instruction type to BYPASS. Allowing the TAP state machine to operate generally permits an on-chip JTAG controller to work properly. EJTAG security levels of Baseline, Authenticate or Locked, corresponding to a high value of logical one on a signal generated by the security flags module 146 , and decoded from the SRC[EDIS] bits to be active when SRC[EDIS] is equivalent to EJ — DIS, may mask the signal TDI and render the EJTAG port useless. The CPU module 174 may reset to a state in which interrupts are disabled. The CPU reset state may be implemented so that interrupts may not take control of the component 102 before the boot ROM code 163 has a chance to set one or more predetermined bits to handle the interrupts. The enable circuit 160 may prevent use of the interface between the I/O circuit 126 and the OTP memory 122 while in the Secure Application mode. Disabling the interface may be done at a top level of the decoder circuit 120 . A buffer (not shown) within the enable circuit 160 driving a clock into the OTP memory 122 may have the data input driven to a logical one such that the clock may never be driven. A similar data input to a buffer (not shown) in the enable circuit 160 driving a write protect (WP) pin on the OTP memory 122 may also be driven to a logical one such that the write protect pin is never driven. Disabling the interface to the OTP memory 122 may be performed if the signal SCAN — MODE is active (e.g., the signal that may be active the entire time that scan testing is performed). Disabling the interface to the OTP memory 122 may prevent the use of a boundary scan chain from getting access to the contents of the OTP memory 122 . Referring to FIG. 9 , a block diagram of an example mechanism 374 by which pins may be protected is shown. The mechanism or circuit 374 generally comprises a multiplexer 376 , a logic gate 378 , a buffer 380 , a logic gate 382 , a multiplexer 384 , a logic gate 386 and a buffer 388 . The buffer 380 may be connected to and drive a bonding pad or pin 390 . The buffer 388 may be connected to and drive a bonding pad or pin 392 . A signal (e.g., S 1 ) may be received by the gate 378 . The signals SECURE — APPLICATION — MODE and SCAN — MODE may the logically OR'd together by the logic gate 382 . The signals generated by the multiplexer 376 and the OR gate 382 may be logically OR'd by the logic gate 378 , amplified by the buffer 380 , and driven onto the pad 390 . Therefore, while either or both of the signals SECURE — APPLICATION — MODE and SCAN — MODE are in the logical one state, the pad 390 may be forced to and held at the logical one state. A signal (e.g., S 2 ) may be logically OR'd with the signal SCAN — MODE. A result signal generated by the OR gate 386 may be amplified by the buffer 388 and driven onto the pad 392 . Therefore, while the signal SCAN — MODE is in the logical one state, the pad 392 may be forced to and held at the logical one state. The signals S 1 and S 2 may also be isolated from the boundary scan chain to prevent illegal control of the OTP memory 122 . The signals S 1 and S 2 may be removed from the chain by tying off the inputs such that the boundary scan chain may not influence the respective values. Furthermore, the boundary scan chain may bypass the chain contribution of the signals S 1 and S 2 to the next pins downstream such that the boundary scan chain is unbroken. Pins for the external bus controller block 148 to the FLASH memory 104 may be on the boundary scan chain. Having the external bus controller block 148 to FLASH memory 104 interface in the boundary scan chain generally allows for proper testing of the manufactured component 102 . As a result of the JTAG boundary scan chain: 1. Product testing generally uses two different sets of JTAG vectors. 2. Two different Boundary Scan Debug Layer (BSDL) files may be generated. 3. The Multi-Chip Module (MCM) pins in the JTAG boundary scan chain may not longer be tristated once bonded. 4. Leakage measurements of the MCM pins may no longer be possible. 5. Levels on the MCM pins may no longer be measurable. Several features of the present invention may include, but are not limited to: (i) a security flags block that may implement registers containing on-chip values used to control the security operation, (ii) an on-chip memory module that may provide a ROM for a one-time-only boot execution, (iii) a security supervisor that may govern access to various on-chip secure resources based on legal source/destination combinations, (iv) an EJTAG enable module to control when the EJTAG Probe may be enabled, (v) a CPU with interrupts immediately disabled on reset and (vi) a special core processor circuit boundary scan chain. The various signals of the present invention are generally “on” (e.g., a digital HIGH, or 1) or “off” (e.g., a digital LOW, or 0). However, the particular polarities of the on (e.g., asserted) and off (e.g., de-asserted) states of the signals may be adjusted (e.g., reversed) accordingly to meet the design criteria of a particular implementation. Additionally, inverters may be added to change a particular polarity of the signals. As used herein, the term “simultaneously” is meant to describe events that share some common time period but the term is not meant to be limited to events that begin at the same point in time, end at the same point in time, or have the same duration. While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the invention.

A circuit generally comprising a first memory, a second memory and a processor is disclosed. The first memory may store an instruction to read an updated security value of at least three security values. The second memory may store (i) the updated security value and (ii) information related to security of the circuit. The processor may be configured to (i) execute the instruction while a register stores a highest security value of the security values, (ii) copy the information from the second memory to a third memory in response to the update security value being greater than a current security value of the security values stored in the third memory and (iii) ignore the information in the second memory in response to the updated security value being no greater than the current security value.

FIELD OF THE INVENTION [0001] The present invention pertains to intelligent long-distance constant-voltage feeding method and system, and in particular relates to long-distance constant-voltage feeding method and system with wake-up function. BACKGROUND OF THE INVENTION [0002] An ordinary line telephone system feeds power to terminal devices remotely through twisted pair lines. Actually, most telecommunication terminal devices obtain power supply required for normal operation from the local side at a telecom agency through twisted pair lines. The device that feeds power from the local side is referred to as power supply device, while the device that receive long-distance feeding at the terminal side is referred to as a powered device. Feeding from the local side can improve the availability of the telecommunication system, and is a design objective for remote telecommunication devices. [0003] The implementation block diagram of long-distance power supply in an ordinary telephone system is shown in FIG. 1 . The feeding system that feeds power from the local side to a remote device comprises an local side battery, a power supply and monitoring module ( 12 ), transformers ( 14 and 15 ), a twisted pair lines ( 3 ), a switch hook (K), a rectifier bridge and voltage regulator module ( 22 ), and necessary interconnecting circuits between the modules. The power supply and monitoring module ( 12 ) in the power supply device ( 1 ) at the local side generates feeding voltage from input DC voltage (V A ), and the feeding voltage is applied to local side ports (T-R) of the twisted pair telephone lines via the transformers ( 14 and 15 ). Here, the transformers ( 14 and 15 ) are equivalent to low-pass filter inductors for DC power feeding, and have no influence on the power of the feeding power source. According to GB-T15279 standard, in on-hook state, the switch hook (K) of telephone ( 2 ) is in OFF state, the leak current of the telephone shall be lower than 25 μA, and the feeding voltage of the power supply device ( 1 ) at the local side shall be 48 VDC; in off-hook state, the switch hook (K) is in closed state, and the DC resistance of the telephone must be lower than 350Ω; when the power supply and monitoring module ( 12 ) determines that the telephone is in off-hook state by detecting the feeding current, on one hand, it will send the off-hook state via a port (W) to other modules at the local side for further treatment, on the other hand, it will adjust the feeding output voltage to about 10V. When a power supply and monitoring module ( 12 ) at the local side that supports long-distance billing indication function has information to transmit, according to the indication of the feeding control port (J) it will initiate billing function by swapping the polarity of feeding voltage, i.e., exchanging the positive/negative polarity of the feeding voltage outputted via the ports (T-R). [0004] To inform a called subscriber of an incoming call, a ringing current generator module ( 13 ) is arranged in the device ( 1 ) at the local side, and a prompting module ( 23 ) is arranged in the telephone ( 2 ). When the switch hook is in OFF state, the equivalent impedance of the prompting module ( 23 ) of telephone ( 2 ) shall be greater than 3KΩ. In prompt state, the ringing current generator module ( 13 ) at the local side generates alternating voltage of about 90V, 25 Hz, which is outputted via the transformers ( 14 and 15 ) to the ports (T-R) at the local side. The ringing current generator module ( 13 ) generates ringing current voltage in an intermittent manner, i.e., working for 1 second, and pausing for 4 seconds. In the 1 second period when the ringing current generator module ( 13 ) outputs ringing current voltage, the feeding voltage output and the feeding current detection function of the power supply and monitoring module ( 12 ) are paused; in the 4 seconds period when the ringing current generator module ( 13 ) stops ringing current voltage output, the feeding voltage output and the feeding current detection function of the power supply and monitoring module ( 12 ) are enabled. [0005] After the Caller Identification (CID) technique is launched, the telephone shall display the incoming call number to the subscriber, before the subscriber lifts off the hook. To meet that demand, the feeding system at the local side can tolerate higher drain current of the terminal device instead of concluding a judgment that the subscriber has lifted off the hook. [0006] The new xDSL technique is the developing trend of telecommunication systems in the future. Most xDSL remote devices have high power consumption, and usually the power of a complete device exceeds 2 W. However, conventional telephone feeding systems can only provide feeding power not higher than 0.8 W, which can not meet the demand of xDSL remote devices for normal operation. [0007] In addition, the old-fashioned ringing current approach will not survive, because it results in high power consumption and high cost, and the music rings provided by most telephones are more favorable. The ringing current function at local side should be canceled to optimize the design of feeding system at local side. [0008] It is known to all that the convenience and reliability of remote telecommunication devices largely depends on the feeding technique at the telecommunication local side. Remote telecommunication devices (e.g., telephone) can operate normally without local power supply, and therefore are not affected by power outage or power supply failure of the local electric network. If local power supply must be used because the power fed from the telecommunication local side is too low, the improvement of convenience and reliability of remote telecommunication devices will be limited. Therefore, various long-distance power supply specifications and techniques have been developed, such as IEEE 802.3af PoE (Power over Ethernet) standard and many patents related with long-distance power supply. [0009] Wherein, the IEEE 802.3af PoE standard provides a method for transmitting power source from the power supply equipment (PSE) to powered devices (PDs) through Ethernet cables. Electric power is supplied over Ethernet through three steps: (1) first, the PSE transmits 2.8V to 10V testing voltage, to detect whether the corresponding port of cable has valid common mode resistance and characteristic capacitance. If 19KΩ to 26.5KΩ common mode resistance exists and the capacitance of the port is lower than 150 pF, it indicates there is a PD that supports PoE; if the common mode resistance is smaller than 15KΩ or greater than 33KΩ or the capacitance of the port is greater than 100, it indicates there is no PD that supports PoE; (2) next, the PSE applies 15 to 20V testing voltage to the PD through an Ethernet cable, and the power level of the PD is determined by measuring the current. In that standard, according to required power PDs are classified into five levels, and are deemed as requiring Class 0 power level by default; (3) finally, the PSE applies 48V DC voltage with specified polarity to the PD through the Ethernet cable, and provides power not higher than 15.4 W. [0010] According to IEEE standard, the Ethernet PSE can multiplex two twisted pair lines ( 3 , 4 ) that are used for transceiving data ( 10 S, 10 R, 20 R, 20 S) to provide long-distance feeding FIG. 2( a ), or use two twisted pair lines that are usually spare to provide long-distance feeding FIG. 2( b ). [0011] In the case that the power is fed over Ethernet by multiplexing the twisted pair lines that are used for transceiving data ( FIG. 2( a )), the positive terminal of DC power output from the PSE at the local side ( 1 A) is connected to the center tap at cable side of Ethernet transmitting isolation transformers ( 16 , 17 ), and the negative terminal of DC power output is connected to the center tap at cable side of Ethernet receiving isolation transformers ( 26 , 27 ). Therefore, when electric power is supplied, the output at the center tap at cable side of the Ethernet transmitting isolation transformer of the PD at terminal ( 2 A) is supplied by the negative feeding terminal, while the output at the center tap at cable side of the Ethernet receiving isolation transformer is supplied by the positive feeding terminal. [0012] In the case that the power is fed over Ethernet by using two spare twisted pair lines FIG. 2( b ), the positive terminal of DC power output from the PSE at the local side ( 1 B) is connected to the pin 4 and 5 of the RJ45, and the negative terminal of DC power output is connected to the pin 7 and 8 of the RJ145 at the same time. Therefore, when electric power is supplied, the output at the pin 4 and 5 of Ethernet RJ45 interface of the PD at terminal ( 2 B) is supplied by the positive feeding terminal, while the output at the pin 7 and 8 of Ethernet R345 interface is supplied by the negative feeding terminal. [0013] PoE is not suitable for long-range telecommunication applications, because the coverage radius of Ethernet is less than 100 meters. [0014] The issued patent 200510068309.5 puts forward a scheme that utilizes signal twisted pair lines and supervisory signal twisted pair lines to supply power to the terminal power supply modules. Wherein, a control module is arranged at the local side, a monitoring module is arranged at the remote side, and two supervisory signal twisted pair lines are arranged specially to transmit supervisory and interactive control signals provided by the PD, so as to attain the purpose of improving the maintainability of the terminal power supply module by monitoring the terminal power supply module. [0015] It is seen that there is no wake-up mechanism that can wake up the power supply module of a terminal which requires long-distance power supplying and is in sleep mode in a simple and clear way with the various existing long-distance constant-voltage power supply techniques; whereas, in future constant-voltage feeding systems, it is expected to achieve a more flexible wake-up mechanism on the basis of implementation of long-distance power supplying, so as to conveniently wake up a terminal power supply module that requires long-distance power supplying and is in sleep mode and drive the power supply module to enter into normal power supply state at any time as required, so as to provide required operating voltage to household electric appliances or other public electric devices. DISCLOSURE OF THE INVENTION Technical Problem [0016] To explain the object of the present invention in summary, herein some aspects, advantages, and novel characteristics of the present invention are described. It should be understood that not all these aspects, advantages, and characteristics have to be included in any specific embodiment. [0017] The object of the present invention is to provide long-distance constant-voltage feeding method and system, in particular to a long-distance constant-voltage feeding method and system with wake-up function. Technical Solution [0018] The long-distance constant-voltage feeding method with wake-up function provided in the present invention comprises an intelligent power supply module, a terminal power supply module, and a feeding line that connects the intelligent power supply module and terminal power supply module, wherein: [0019] the intelligent power supply module can provide constant-voltage feeding to the terminal power supply module continuously, and can change the polarity of feeding voltage in accordance with predefined rules when the terminal power supply module is to be waken up remotely from sleep mode; [0020] the intelligent power supply module monitors the active state of the terminal power supply module constantly, and outputs the monitored active state of the terminal power supply module to other modules at the local side; [0021] the terminal power supply module is in sleep mode initially and consumes lower feeding current, and will consume higher feeding current and begin to provide normal operating voltage to the locally connected electric device after it is waken up and enters into normal power supply state. [0022] Preferably, the terminal power supply module comprises a voltage polarity monitoring module. [0023] Preferably, the voltage polarity monitoring module decides whether to wake up the remote terminal power supply module from sleep mode into normal power supply state according to the polarity of feeding voltage from the local side. [0024] Preferably, the voltage polarity monitoring module can further decide whether to wake up the terminal power supply module from sleep mode into normal power supply state according to the parameter of polarity change of feeding voltage from the local side. [0025] A long-distance constant-voltage feeding system with wake-up function, comprising an intelligent power supply module, a terminal power supply module, and a feeder line that connects the intelligent power supply module and the terminal power supply module, wherein: [0026] the intelligent power supply module comprises a power supply module that can provide constant-voltage feeding to the terminal power supply module constantly, a voltage polarity control module that will change the polarity of outputted feeding voltage in accordance with predefined rules when the terminal power supply module is to be waken up remotely from sleep mode, and a current detection module that monitors the active state of the terminal power supply module constantly and outputs the monitored active state of the terminal power supply module to other modules at the local side; [0027] the terminal power supply module is in sleep mode initially and consumes lower feeding current, and will consume higher feeding current and begin to provide normal operating voltage to the locally connected electric device after it is waken up and enters into normal power supply state. [0028] The terminal power supply module comprises a voltage polarity monitoring module and a stabilized voltage supply module. [0029] The voltage polarity monitoring module can decide whether to activate the stabilized voltage supply module into normal operating state according to the parameter of polarity change of feeding voltage from the local side. [0030] The stabilized voltage supply module is in standby state initially, and will enter into normal operating state after it is activated; in addition, the stabilized voltage supply module consumes very low current in standby state, and provides normal operating voltage to the connected electric device and consumes higher current when it is in normal operating state. Beneficial Effects [0031] 1. Flexible Feeding [0032] With the conventional long-distance feeding scheme for telephones, owing to the limitation of the signal processing module, the feeding at the local side will be lowered by about 10V when the device at the local side detects the remote device is in normal operating state; as a result, the feeding power from the local side to the distal end is severely limited. With the long-distance feeding method disclosed in the present invention, a pair of transformers are added at the local side and the distal end respectively, so that the communication signals and DC feeding arc separated from each other timely and effectively, or the communication signals and DC feeding are fed through different lines; thus, the feeding from the local side is not limited by the signal processing module and the long-distance feeding voltage will not be lowered. In addition, with the feeding method disclosed in the present invention, positive voltage and negative voltage can be fed from the local side as required, and therefore the feeding method is very flexible. [0033] 2. High Feeding Power [0034] With the existing feeding method for telephones in the prior art, the maximum power can not be higher than 800 mW. The present invention employs a constant-voltage feeding method, which allows the feeding current to increase when the electric device is in off-hook operating state; therefore, the feeding power is greatly increased and can be higher than 4 W; thus, the present invention can be used to feed power to remote communication devices or other electric devices. [0035] 3. Simple and Easy-to-Implement Feeding Circuit [0036] The present invention employs constant-voltage feeding, and does not require voltage adjustment between on-hook state and off-hook state; therefore, the ringing current generator module at the local side can be shielded, and the feeding circuit is simple and easy to implement. [0037] 4. Lowered Requirement for Voltage Withstand Process [0038] With the improved solution of the present invention, the ringing current generator module that generates voltage as high as 90V AC in the conventional feeding system for telephones is completely omitted, the maximum operating voltage of the entire system is decreased to 48V DC, and the requirement for safety protection against electric leakage and electric shock and requirement for voltage withstand process of the system are greatly lowered; therefore, the system can be applied more widely and the integration level of the system can be further improved. BRIEF DESCRIPTION OF THE DRAWINGS [0039] FIG. 1 is a schematic diagram of implementation of interface device at telecommunication local side and subscriber telephones in the background art of the present invention. [0040] FIG. 2 is a schematic diagram of power supply over Ethernet (PoE) in the background art of the present invention. [0041] FIG. 3 is a schematic diagram of system implementation of a point-to-point embodiment of the present invention. [0042] FIG. 4 is a schematic diagram of feeder line connection in a sample system in which a twisted pair line is used as the feeder line [0043] FIG. 5 is a schematic diagram of feeder line connection in which a twisted pair line and a conductive wire are used as the feeder line. [0044] FIG. 6 is a schematic diagram of feeder line connection in which two twisted pair lines are used as the feeder line. [0045] FIG. 7 is a schematic diagram of three implementation schemes of the power supply module 41 in an embodiment of the present invention. [0046] FIG. 8 is a schematic diagram of three implementation schemes of the current detection module 42 in an embodiment of the present invention. [0047] FIG. 9 is a schematic diagram of two implementation schemes of the output voltage polarity control module 43 in an embodiment of the present invention. [0048] FIG. 10 is a schematic diagram of two implementation schemes of the stabilized voltage supply module in an embodiment of the present invention. [0049] FIG. 11 is a schematic diagram of three implementation schemes of the voltage polarity monitoring module in a point-to-point embodiment of the present invention. [0050] FIG. 12 is a schematic diagram of an implementation scheme of the local control circuit in an embodiment of the present invention. [0051] FIG. 13 is a schematic diagram of an implementation scheme of a first point-to-multipoint embodiment that utilizes a voltage polarity monitoring module and multiple regulated power supply modules in combination. [0052] FIG. 14 is a schematic diagram of system implementation of a second point-to-multipoint embodiment of the present invention. [0053] FIG. 15 is a schematic diagram of an implementation scheme of the terminal power supply module in electric device in the second point-to-multipoint embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS [0054] Hereunder the embodiments of the present invention will be described. To simplify the description of these embodiments, not all characteristics of the actual implementation scheme are described here. It shall be understood that some other specific decisions for a specific application may have to be made in the development process of any actual implementation scheme, so as to meet the constraint conditions related with specific system and service. For those having ordinary skills in the art who can benefit from the content disclosed here, these complex and time-consuming decisions are only common tasks in design, manufacturing, and production. [0055] In the description of specific implementation schemes, to match different actual application scenarios, the implementation schemes will be categorized into two categories. One category covers point-to-point long-distance. constant-voltage feeding method and system with wake-up function, and the other category covers point-to-multipoint long-distance constant-voltage feeding method and system with wake-up function. [0056] First, the specific implementation scheme of point-to-point long-distance constant-voltage feeding method and system with wake-up function will be described hereunder. [0057] The core method of point-to-point long-distance constant-voltage feeding scheme with wake-up function is: arranging an intelligent power supply module at the local side, arranging a terminal power supply module at the terminal, and connecting the intelligent power supply module and terminal power supply module through a feeder line. [0058] The terminal power supply module is in sleep mode initially and consumes very low feeding current; after it is waken up remotely or locally, it will enter into normal power supply state and begin to provide operating voltage required for normal operation to a electric device connected to it or multiple electric devices connected in parallel with it, and will consume higher current fed through the feeder line. [0059] The intelligent power supply module provides constant-voltage feeding with determined polarity to the terminal power supply module in normal state; it will change the polarity of the outputted feeding voltage when the terminal power supply module is to be waken up remotely from sleep mode, and will monitor the magnitude of feeding current in the feeder line constantly; if it finds the feeding current is lower than a specified threshold, it will judge that the terminal power supply module is in sleep mode; if it finds the feeding current is higher than the specified threshold, it will judge that the terminal power supply module is in normal power supply state; in addition, it decides whether to output the monitored sleep mode/normal power supply state of the terminal power supply module to other modules at the local side according to the actual demand. [0060] The implementation method for the intelligent power supply module to wake up the terminal power supply module remotely into normal power supply state in normal state is: arranging a control circuit at the local side in the intelligent power supply module, wherein, the control circuit is designed to invert the polarity of the outputted feeding voltage as a wake-up signal in accordance with predefined rules when the terminal power supply module is to be waken up as instructed by control instructions of other modules at the local side; and arranging a voltage polarity monitoring module in the terminal power supply module to identify the wake-up signal and activate a stabilized voltage supply module belonging to the terminal power supply module into normal operating state and thereby activate the entire terminal power supply module into normal power supply state according to a monitored wake-up signal. [0061] The method for waking up the terminal power supply module into normal power supply state locally can be implemented with a simple local switching circuit or a simple local control circuit. [0062] Hereunder the long-distance constant-voltage feeding method with wake-up function in the present invention will be further described with the specific implementation circuit of a point-to-point long-distance constant-voltage feeding system with wake-up function. [0063] The point-to-point long-distance constant-voltage feeding system with wake-up function comprises an intelligent power supply module 4 , a terminal power supply module 5 , and a feeder line 6 that connects the intelligent power supply module 4 and terminal power supply module 5 , as shown in FIG. 3 . [0064] The connection of intelligent power supply module 4 and terminal power supply module 5 to the feeder line 6 can be a direct connection as shown in FIG. 3 , or a coupled connection via an intermediate apparatus. As shown in FIGS. 4 , 5 , and 6 , the intelligent power supply module 4 at the local side and the terminal power supply module 5 are couple-connected to the feeder line via transformers in different ways. [0065] The feeder line for connecting the intelligent power supply module 4 and the terminal power supply module 5 can be a conductive cable in a variety of forms. [0066] The simplest implementation of the feeder line 6 is two parallel conductive wires, as shown in FIG. 3 . FIGS. 4 , 5 , and 6 show different implementation methods of the feeder line 6 respectively, i.e., a twisted pair line 6 A; a twisted pair line 6 B 1 and a conductive wire 6 B 2 ; and two twisted pair lines 6 C 1 and 6 C 2 . For low-frequency equivalent circuits, the implementation schemes of the feeder line in the embodiments are equivalent to that shown in FIG. 3 in terms of circuitry, owing to the fact that the coupling transformers in the described connection methods are equivalent to serially connected resistors and the twisted pair line is equivalent to a single straight wire for the transmission of wake-up signal and power supply state signal. [0067] The intelligent power supply module 4 feeds constant-voltage feeding with determined polarity to the terminal power supply module in normal state, and will change the polarity of outputted feeding voltage in accordance with predefined rules and feed the power to the terminal power supply module 5 through the feeder line 6 when the terminal power supply module 5 is to be waken up. In addition, the intelligent power supply module 4 at the local side can detect the current output to the feeder line 6 , and will judge that the terminal power supply module 5 has already been waken up and has entered into normal power supply state when the current in the feeder line exceeds the specified threshold. [0068] The intelligent power supply module 4 can be a separate device, or can he a part of other devices, similar to the power supply and monitoring module 12 in the power supply equipment at local side for ordinary analog telephones. [0069] To implement the long-distance constant-voltage feeding method with wake-up function, the intelligent power supply module 4 at the local side in this embodiment comprises: an input power supply port VB, a control port G, a remote state output port S, a feeder line output port 61 , a power supply module 41 , a current detection module 42 , and an output voltage polarity control module 43 . [0070] The power supply module 41 obtains electric energy from the input power supply port VB, transforms the voltage, and outputs the power at constant voltage to other modules in the intelligent power supply module 4 . [0071] If the power supply port VB supplies AC power, an implementation scheme of the power supply module 41 comprising an AC/DC voltage converter module 4111 and a voltage regulator module 4112 , as illustrated by the power supply module 411 shown in FIG. 7( a ). Wherein, the AC/DC voltage converter module 4111 can employ a proven chip available in the market according to the actual demand, such as the SA series TYPE models of AC/DC converter chips from Guangzhou Aipu Electron Technology Co., Ltd, which can work at input voltage of 85 VAC to 256 VAC and provide output voltage of 2 VDC to 48 VDC. Likewise, the voltage regulator module ( 4112 ) can employ a proven chip available in the market according to the actual demand, such as the SRD_(M)P — 3S series from Mornsun Guangzhou Science &Technology Co., Ltd., which can work within input voltage range from 5V to 80V and provide output voltage of 5V to 24V; or, the new high-power voltage regulator module developed by VICOR company (USA) with “zero-current switching” technology, which can work within input voltage range from 10V to 400V and provide output voltage of 2V to 48V and even up to output voltage of 95V. [0072] For a system that is powered steadily with battery, the power supply module can even be the modules 412 and 413 connected through simple straight wires shown in FIGS. 7( b ) and 7 ( c ). [0073] The current monitoring module 42 can be an ammeter, or the current detection circuit 421 shown in FIG. 8( a ), or the current detection circuit 422 shown in FIG. 8( b ), or the current detection module 423 shown in FIG. 8( c ), wherein, the proven commercial chip LT2940 in the current detection module 423 can accomplish both current detection and power detection when the input voltage is within a range of 4V to 80V. If the current detection module 42 detects the feeding current is lower than a specified threshold, it will judge that the terminal power supply module 5 at the distal end is in sleep mode; if detects the feeding current is higher than the specified threshold, it will judge that the terminal power supply module 5 is in normal power supply state; in addition, the current detection module 42 outputs the monitored sleep mode/normal power supply state of the terminal power supply module via the long-distance state output port S. [0074] The voltage polarity control module 43 will control the power supply module 41 to output long-distance feeding voltage with specified polarity as a wake-up signal to the feeder line output port 61 in accordance with the instruction of the control port G when the terminal power supply module 5 is to be waken up. The two implementation schemes are shown as K 1 in the voltage polarity control module 431 in FIG. 9( a ) and K 2 in the voltage polarity control module 432 in FIG. 9( b ); or feeding voltage output with determined polarity can be implemented with a relay, or feeding voltage output with specific polarity can be implemented with a full-bridge drive circuit with a proven chip available in the market, such as LMD18245 from National Semiconductor Corporation (USA), UBA2036 from NXP Semiconductors (the Netherlands), and A3959 from Allegro Corporation; all of these chips can utilize the control signal inputted via the control port G to control the polarity of outputted feeding voltage conveniently. See the recommended reference designs in the related manuals of the chips for the specific circuits. [0075] The terminal power supply module 5 is in sleep mode initially, and will enter into normal power supply state and begin to provide normal operating voltage to the local electric device, and feed back its power supply state signal to the intelligent power supply module 4 through feeder line 6 , after it is waken up. [0076] The terminal power supply module 5 has very low leak current in sleep mode; once it is waken up and enters into normal power supply state, the current flow in the feeder line will increase sharply; therefore, the current in the feeder line can be used as a power supply state signal. When the current in the feeder line is lower than a specific threshold, the terminal power supply module 5 can be deemed as in sleep mode; when the current in the feeder line is higher than the specific threshold, the terminal power supply module 5 can be deemed as already in normal power supply state. [0077] The terminal power supply module 5 provides constant normal operating voltage to the electric device at the terminal when it is in normal power supply state. In this embodiment, the terminal power supply module 5 comprises: a feeder line port 62 , a voltage polarity monitoring module 53 , a stabilized voltage supply module 51 , and a local power output port V. [0078] The stabilized voltage supply module 51 is in standby state initially and consumes very low drain current, and thereby the terminal power supply module is in sleep mode; when the stabilized voltage supply module 51 is activated into normal operating state and begins to provide normal operating voltage to the connected electric device, the consumed feeding current will increase sharply, and thereby the terminal power supply module will enter into normal power supply state. [0079] The stabilized voltage supply module 51 can be in two forms: a voltage-regulating IC chip with an Enabled control terminal, or a stabilized voltage supply without Enabled control terminal. [0080] In the case a voltage-regulating IC chip with an Enabled control terminal is used, the stabilized voltage supply module in a preferred embodiment comprises three branch circuits: a filter circuit (C 1 , L 1 , L 2 , and C 2 ) connected to an input port (IN), an integrated stable voltage circuit (LM2575HV, L 3 and D 1 ), and a filter circuit (C 3 ) connected to an output port (OUT), as illustrated by the regulated power supply module 511 in FIG. 10( a ). When the stabilized voltage supply module 511 receives an Active Low control signal outputted from the voltage polarity monitoring module 53 , it will obtain electric energy from the feeder line, transform the voltage, and output constant voltage, so as to provide constant DC voltage to the local electric device. The stabilized voltage supply module 51 can be implemented with a proven chip available in the market, such as μA78S40 from Motorola, TNY268 from POWER, and NCP3063 from ON Semiconductor, etc., besides LM2575HV from National Semiconductor Corporation (USA). See the description and recommended reference designs in the related manuals of the chips for the specific circuits. [0081] The stabilized voltage supply module 511 in a preferred embodiment employs a voltage-regulating IC chip LM2575HV with an Enabled control terminal. More DC stabilized voltage supplies that are more typical may have no Enabled control terminal. In these cases, the stabilized voltage supply module 512 shown in FIG. 10( b ) can be used. When long-distance feeding input exists at the input terminal of the stabilized voltage supply 512 , the voltage is regulated and steady DC voltage is outputted from the output port (VOUT) for normal operation of the local electric device. The voltage 5121 can employ any proven commercial stabilized voltage supply module that is suitable for the embodiment. [0082] Since a function of polarity inversion of long-distance feeding voltage is required, the stabilized voltage supply module shall be connected in series with a rectifier module in front of its input terminal, to ensure the input power polarity required for normal operation of the DC regulated power supply module. [0083] The voltage polarity monitoring module 53 can monitor the polarity of feeding voltage at the local side, and can control the stabilized voltage supply module 51 to receive long-distance feeding electric energy and enter into normal operating state and thereby wake up the entire terminal power supply module into normal power supply state to start outputting steady constant-voltage feeding to the local electric device when the monitored feeding voltage polarity is a wake-up signal. [0084] In the case that the stabilized voltage supply module 51 is a stabilized voltage supply module without Enabled control terminal, an implementation scheme of the voltage polarity monitoring module 53 can comprise a unidirectional (or bidirectional) thyristor D 5 and a circuit that provides control signals to the thyristor, as shown in FIG. 11( a ). Implementation of this wake-up procedures are as follows: [0085] Set the polarity of voltage output of the intelligent power supply module 4 in normal state to polarity that causes cut-off of the diodes D 2 , D 3 , and D 4 ; in that state, the thyristor is in cut-off state, and therefore the stabilized voltage supply module has very low drain current input and is in standby state; as a result, the entire terminal power supply module 5 consumes very low feeding current and is in sleep mode; [0086] When the intelligent power supply module 4 is to wake up the terminal power supply module 5 in sleep mode remotely in normal state, the equipment at the local side will control the intelligent power supply module with a control signal inputted via the control port G to output voltage with polarity that will cause the diode D 2 to enter into ON state, so as to provide control triggering voltage to the thyristor D 5 by means of the divided voltage on R 1 and R 2 ; as a result, long-distance feeding voltage will be rectified by the rectifier bridge and fed to the input terminal of the stabilized voltage supply module, and the stabilized voltage supply module 51 will be activated into normal operating state, and thereby the entire terminal power supply module 5 will be waken up into normal power supply state and begin to provide operating voltage to the local electric device. Now, the terminal power supply module consumes higher feeding current. When the feeding current exceeds the specified threshold, the intelligent power supply module will judge that the terminal power supply module has entered into normal power supply state and output the state to other modules at the local side via the remote state output port S; [0087] When the terminal power supply module in sleep mode is to be waken up locally, a control triggering voltage signal can be provided to a bidirectional thyristor through a local control circuit (C), so that the diode D 4 gates on and triggers the thyristor D 5 into ON state, and thereby the terminal power supply module is waken up locally into normal power supply state; now, the terminal power supply module consumes higher feeding current; when the feeding current exceeds the specified threshold, the intelligent power supply module at the local will judge that the terminal power supply module is in normal power supply state, and output the state to other modules at the local side via the remote state output port S. [0088] The embodiment shown in FIG. 11( a ) further comprises a resistor for current limiting protection, which should be considered in the actual application. The actual protection circuit can be more complex. The description here is only illustrative, and does not constitute any limitation to the form of the protection circuit. [0089] An implementation scheme of the local control circuit is shown in FIG. 12 . The illustrative scheme employs a battery and a switch, and the control voltage signal for switching on the thyristor can be generated by closing the switch manually. [0090] In the case that the stabilized voltage supply module 51 is a stabilized voltage supply module without Enabled control terminal, another implementation scheme of the voltage polarity monitoring module 53 comprises a voltage polarity monitoring and prompting circuit 5321 and a switch fork K 1 , as shown in FIG. 11( b 1 ), wherein, an implementation scheme of the voltage polarity monitoring and prompting circuit 5321 comprises a diode, a resistor, and a buzzer 5323 in series, as shown in FIG. 11( b 2 ). Implementation of this wake-up procedures are as follows: [0091] Set the polarity of voltage output of the intelligent power supply module 4 in normal state to polarity that causes cut-off of the diode in the voltage polarity monitoring and prompting circuit 5322 ; in that state, the switch hook is in OFF state, and therefore the stabilized voltage supply module does not consume current and is in standby state; as a result, the entire terminal power supply module 5 consumes lower feeding current and is in sleep mode; [0092] When the intelligent power supply module is to wake up the terminal power supply module in sleep mode remotely in normal state, the equipment at the local side will control the intelligent power supply module with a control signal inputted via the control port G to output voltage with polarity that will cause the diode in the voltage polarity monitoring and prompting circuit 5322 to enter into ON state, so that feeding voltage will be applied to the buzzer, and the buzzer will give off a singing or music, to prompt the operator to close the switch hook K 1 , so as to feed the feeding voltage to the input terminal of the rectifier bridge; the feeding voltage will be rectified by the rectifier bridge, and fed with correct polarity to the input terminal of the stabilized voltage supply module to activate the stabilized voltage supply module into normal operating state, and thereby the entire terminal power supply module will be waken up into normal power supply state and begin to provide normal operating voltage to the local electric device; now, the terminal power supply module consumes higher feeding current; when the feeding current exceeds the specified threshold, the power supply module at the local side will judge that the terminal power supply module has entered into normal power supply state, and output the state to other modules at the local side via the remote state output port S; at the same time, the intelligent power supply module at the local side will change the polarity of feeding voltage again under control of the control port G to cut off the diode and thereby stop the buzzer. Owing to the existence of the rectifier module, the normal operating state of the stabilized voltage supply module after the rectifier module will not be affected; [0093] When the terminal power supply module is to be waken up locally, the operator can close the switch hook so as to wake up the terminal power supply module into normal power supply state, and therefore the terminal power supply module will begin to provide normal operating voltage to the local electric device; now, the terminal power supply module consumes higher feeding current; when the feeding current exceeds the specified threshold, the intelligent power supply module at the local side will judge that the terminal power supply module is in normal power supply state, and output the state to other modules at the local side via the remote state output port S. [0094] The voltage polarity monitoring and prompting circuit 5321 can be implemented with a light emitting diode (LED), i.e., when the terminal power supply module is in sleep mode, the LED is in OFF state; when polarity change of feeding voltage is detected, the LED will light up to prompt the operator to close the switch hook K 1 , so as to wake up the terminal power supply module into normal power supply state; now, the terminal power supply module consumes higher feeding current; when the feeding current exceeds the specific threshold, the intelligent power supply module at the local side will judge that the terminal power supply module is in normal power supply state, and output the state to other modules at the local side via the remote state output port S, and change the polarity of feeding voltage again via the control port G so as to switch off the LED. Owing to the existence of the rectifier module, the normal operating state of the stabilized voltage supply module after the rectifier module will not be affected. [0095] If the stabilized voltage supply module is a stabilized voltage supply module with an Enabled control terminal, the voltage polarity monitoring module 53 will decide whether to provide an Enabled control signal to the stabilized voltage supply module with Enabled terminal so as to activate the stabilized voltage supply module into normal operating state, on the basis of the monitored polarity of feeding voltage. [0096] In that case, an implementation scheme of the voltage polarity monitoring module 53 comprises diodes and resistors simply, as illustrated by the voltage polarity monitoring module 533 in FIG. 11( c 1 ). Implementation of this wake-up procedures are as follows: [0097] Set the polarity of voltage output of the intelligent power supply module in normal state to polarity that causes cut-off of the diodes D 6 , D 7 , and D 8 ; in that state, the Enabled terminal of the regulated power supply module is inactive, and therefore the stabilized voltage supply module consumes very low drain current and is in standby state; as a result, the entire terminal power supply module 5 consumes lower feeding current and is in sleep mode; [0098] When the intelligent power supply module is to wake up the terminal power supply module in sleep mode remotely in normal state, the equipment at the local side will control the intelligent power supply module with an control signal inputted via the control port G to output voltage with polarity that causes the diode D 6 , D 7 , and D 8 to enter into ON state, so that a high-level Enabled signal is provided to the stabilized voltage supply module with an Enabled terminal that is normally in active state under positive voltage by means of the divided voltage on R 3 and R 4 ; as a result, the stabilized voltage supply module will be activated to accept long-distance feeding voltage and enter into normal operating state, and output to the local electric device via the local power output port V. Now, the entire terminal power supply module consumes higher feeding current, and therefore enters into normal power supply state; [0099] When the terminal power supply module is to be waken up locally and directly, an Enable signal can be provided to the stabilized voltage supply module 51 through a local control circuit. An implementation scheme of the local control circuit employs a battery and a switch, as shown in FIG. 12 ; the Enable signal can he generated by closing the switch manually, and thereby the voltage stabilizer module will be activated into normal operating state and thereby wake up the entire terminal power supply module into normal power supply state; then, the terminal power supply module will begin to provide operating voltage to the local electric device; now, the terminal power supply module consumes higher feeding current; when the feeding current exceeds the specified threshold, the intelligent power supply module will judge that the terminal power supply module is in normal power supply state, and will output the state to other modules at the local side via the remote state output port S. [0100] In that case, another implementation scheme of the voltage polarity monitoring module 53 employs a simple combined circuit constituted by diodes, resistors (R 5 , R 6 , R 7 ), and a field effect tube (FET), as shown in FIG. 11( c 2 ) by voltage polarity monitoring module 534 . Implementation of the wake-up procedures are as follows: [0101] Set the voltage output of the intelligent power supply module in normal state to voltage that causes cut-off of the diode D 9 ; in that state, the FET is in OFF state, the output through the resistor R 5 is at high level, the Enabled terminal of the stabilized voltage supply module is inactive, and therefore the stabilized voltage supply module consumes very low drain current and is in standby state; as a result, the entire terminal power supply module 5 consumes lower feeding current and is in sleep mode; [0102] When the intelligent power supply module is to wake up the terminal power supply module in sleep mode remotely in normal state, the equipment at the local side will control the intelligent power supply module with a control signal inputted via the control port G to output the polarity that causes the diode D 9 to enter into ON state, so that a low-level Enabled signal will be provided to the corresponding stabilized voltage supply module with an Enabled terminal; as a result, the stabilized voltage supply module will be activated to accept long-distance feeding voltage and enter into normal operating state, and output to the local electric device via the local power output port V after voltage regulation; now, the entire terminal power supply module consumes higher feeding current, and therefore enters into normal power supply state; [0103] When the terminal power supply module is to be waken up locally and directly, an Enabled signal can be provided to the stabilized voltage supply module 51 through a local control circuit. An implementation scheme of the local control circuit employs a battery and a switch, as shown in FIG. 12 ; the Enabled signal can be generated easily by closing the switch manually, and thereby the voltage stabilizer module will be activated into normal operating state and thereby wake up the entire terminal power supply module into normal power supply state; then, the terminal power supply module will begin to provide normal operating voltage to the local electric device; now, the terminal power supply module consumes higher feeding current; when the feeding current exceeds the specified threshold, the intelligent power supply module a the local side will judge that the terminal power supply module is in normal power supply state, and will output the state to other modules at the local side via the remote state output port S. [0104] In the point-to-point system described above, the terminal power supply module can be hooked with one electric device, or hooked in parallel with multiple electric devices. characterized in that, when the terminal power supply module is waken up into normal power supply state, all the electric devices hooked in parallel with the output terminal of the terminal power supply module can obtain operating voltage required for normal operation. [0105] Hereunder embodiments of two point-to-multipoint long-distance constant voltage feeding methods and systems with wake-up function will be described. [0106] The core method of a first embodiment is: arranging an intelligent power supply module at the local side, arranging a terminal power supply module at the terminal, and connecting the intelligent power supply module and the terminal power supply module through a feeder line. [0107] The terminal power supply module has multichannel stabilized voltage supply output modules connected in parallel, and each stabilized voltage supply output module is in standby state initially; when a stabilized voltage supply output module is waken up remotely or locally into normal power supply state, it will begin to provide operating voltage required for normal operation to a electric device connected to it or multiple electric devices connected in parallel; now, the consumed current in the feeder line will increase accordingly. [0108] The intelligent power supply module feeds constant-voltage feeding with determined polarity to the terminal power supply module in normal state; when a stabilized voltage supply output module in standby state in the terminal power supply module is to be waken up remotely in normal state, the polarity of outputted feeding voltage will be changed in accordance with predefined rules, and the feeding current in the feeder line will be monitored constantly; if the intelligent power supply module finds the feeding current increases by a specified value, it will judge that a stabilized voltage supply output module in standby state in the terminal power supply module has entered into normal power supply state; if the intelligent power supply module finds the feeding current decreases by a specified value, it will judge that a stabilized voltage supply output module in the terminal power supply module has entered into standby state; in addition, the intelligent power supply module will output the monitored standby state/normal power supply state of the stabilized voltage supply output module in the terminal power supply module to other modules at the local side. [0109] The implementation method for the intelligent power supply module remotely in normal state to wake up a stabilized voltage supply output module in standby state in the terminal power supply module into normal power supply state is: arranging a voltage polarity control circuit in the intelligent power supply module, wherein, the voltage polarity control circuit will invert the polarity of outputted feeding voltage as a wake-up signal for waking up a stabilized voltage supply output module in standby state in the terminal power supply module, as instructed by the control instructions of other modules at the local side, when the stabilized voltage supply output module in standby state is to be waken up; arranging a voltage polarity monitoring module in the terminal power supply module, wherein, the voltage polarity monitoring module will activate the stabilized voltage supply output module from standby state into normal power supply state, when it detects the corresponding wake-up signal. [0110] The implementation method for waking up a stabilized voltage supply output module in standby state in the terminal power supply module into normal power supply state locally is: providing a local control circuit to each stabilized voltage supply output module, so as to wake up the stabilized voltage supply output module into normal power supply state when the stabilized voltage supply output module is to be waken up locally. [0111] Hereunder the methods described above will be detailed in an example of the implementation circuit of a point-to-multipoint long-distance constant-voltage feeding system with wake-up function. [0112] The point-to-multipoint long-distance constant-voltage feeding system with wake-up function comprises an intelligent power supply module 4 , a terminal power supply module 5 , and a feeder line 6 that connects the intelligent power supply module 4 and the terminal power supply module 5 , as shown in FIG. 3 . The connection of intelligent power supply module 4 and terminal power supply module 5 through the feeder line 6 and the implementation of the intelligent power supply module 4 are the same as those in the point-to-point scheme, and will not he detailed further here. However, the implementation of the terminal power supply module is different to that in the point-to-point scheme. Hereunder an implementation scheme of the terminal power supply module 5 will be introduced. [0113] The terminal power supply module 5 has a voltage polarity monitoring module 53 and a stabilized voltage supply module 51 . [0114] An implementation scheme of the stabilized voltage supply module 51 comprises a rectifier bridge, diodes, stabilized voltage supply output modules with an Enabled control terminal ( 5131 , 5132 , . . . , 513 N), local power output ports (V 1 , V 2 , . . . , VN), and local control ports (C 1 , C 2 , . . . , CN), as illustrated by the module 513 in FIG. 13 . [0115] The input terminals of the stabilized voltage supply output modules with an Enable control terminal ( 5131 , 5132 , . . . , 513 N) are directly connected to the input terminal of the feeder line via the rectifier bridge, and the Enabled terminal of each stabilized voltage supply output module with an Enabled control terminal is in inactive state initially, i.e., the stabilized voltage supply output modules with an Enabled control terminal are in standby state initially, consume very low drain current, and output zero output voltage; when the Enabled control terminal of a certain stabilized voltage supply output module with an Enabled control terminal changes to active state, the stabilized voltage supply output module with an Enabled control terminal will output rated operating voltage, enter into normal power supply state, and provide normal operating voltage to the connected local electric device. [0116] An implementation scheme of the voltage polarity monitoring module 53 comprises a voltage polarity change parameter recording and processing module 5351 and a voltage polarity change sensing circuit constituted by diodes (D 10 , D 11 , D 12 ) and resistors (R 8 and R 9 ), as illustrated by the module 535 in FIG. 13 . The voltage polarity change parameter recording and processing module 5351 can have one input terminal and multiple output terminals, wherein, the input terminal is connected to the output terminal of the voltage polarity change sensing circuit, and each output terminal is connected to the control terminal of a stabilized voltage supply output module with an Enabled control terminal; when the voltage polarity change parameter recording and processing module 5351 receives a different voltage polarity change parameter from the voltage polarity change sensing circuit, it will output an Enabled control signal required for waking up the stabilized voltage supply output module with an Enabled control terminal to the corresponding output terminal. The required function of the voltage polarity change parameter recording and processing module 5351 can be implemented by simply programming the input/output terminals of a single-chip microcomputer or other information processing module. Implementation of this wake-up procedures are as follows: [0117] Set the intelligent power supply module 4 to output feeding voltage with determined polarity in normal state; when a stabilized voltage supply output module with an Enabled control terminal in standby state in the terminal power supply module is to be waken up in normal state, the intelligent power supply module 4 will change the polarity of outputted feeding voltage in accordance with predefined and monitor the magnitude of feeding current in the feeder line constantly; if the intelligent power supply module 4 finds the feeding current has increased by a specified value, it will judge that a power output module with an Enabled control terminal in the terminal power supply module has entered into normal power supply state; if the intelligent power supply module 4 finds the feeding current has decreased by the specified value, it will judge that an power output module with an Enabled control terminal in the terminal power supply module has entered into standby state; in addition, the intelligent power supply module 4 will output the monitored standby state/normal power supply state of the power output module with an Enabled control terminal in the terminal power supply module to other modules at the local side; [0118] When the intelligent power supply module 4 in normal state is to remotely wake up a stabilized voltage supply module with an Enabled control terminal in standby state in the terminal power supply module 513 into normal power supply state, it will invert the polarity of the outputted feeding voltage as a wake-up signal for waking up the stabilized voltage supply output module with an Enabled control terminal in accordance with predefined rules with the control signal inputted via the port G, so that the voltage polarity monitoring module 535 in the terminal power supply module can activate the stabilized voltage supply output module with an Enabled control terminal in standby state connected to its corresponding output terminal into normal power supply state according to the monitored wake-up signal, and thereby the stabilized voltage supply output module with an Enabled control terminal will provide normal operating voltage to the connected local electric device; in that state, the consumed current in the feeder line will increase by a specific value; [0119] When a stabilized voltage supply output module with an Enabled control terminal is to he directly waken up locally into normal power supply state, an Enabled signal can be provided from the local control port controlled by the corresponding local control circuit to activate the stabilized voltage supply output module with an Enabled control terminal into normal power supply state. An implementation scheme of the local control circuit is shown in FIG. 12 . [0120] The core method of a second embodiment is: arranging an intelligent power supply module at the local side, adding a power supply module in each electric device connected in parallel at the terminal to form a terminal power supply module, and connecting the intelligent power supply module and the terminal power supply module through a feeder line. [0121] The power supply module for each electric device in the terminal power supply module is in sleep mode initially; when the power supply module for certain electric device is waken up remotely or locally, it will enter into normal power supply state, and begin to provide operating voltage required for normal operation to other functional modules in the electric device; now, the consumed current in the feeder line will increase by a specific value. [0122] The intelligent power supply module feeds constant-voltage feeding with determined polarity to the terminal power supply module in normal state; when the power supply module for certain electric device in standby state in the terminal power supply module is to be waken up remotely in normal state, the polarity of outputted feeding voltage will be changed in accordance with predefined rules, and the feeding current in the feeder line will be monitored constantly; if the intelligent power supply module finds the feeding current increases by a specified value, it will judge that the power supply module for certain electric device in the terminal power supply module has entered into normal power supply state; if the intelligent power supply module finds the feeding current decreases by a specified value, it will judge that the power supply module for certain electric device in the terminal power supply module has entered into sleep mode; in addition, the intelligent power supply module will output the monitored sleep mode/normal power supply state of the power supply module for the electric device in the terminal power supply module to other modules at the local side. [0123] The implementation method for the intelligent power supply module in normal state to remotely activate the power supply module for a specified electric device from sleep mode into normal power supply state is: arranging a voltage polarity control circuit in the intelligent power supply module, wherein, the voltage polarity control circuit can invert the polarity of outputted feeding voltage as a wake-up signal for waking up the power supply module of the electric device in sleep mode when the power supply module for the specified electric device in sleep mode is to be waken up into normal power supply state as instructed by the control instructions of other modules at the local side; arranging a voltage polarity monitoring module in the power supply module of electric device to identify the corresponding wake-up signal and according to the monitored wake-up signal, enabling the stabilized voltage supply module with an Enabled control terminal in the power supply module for the electric device so as to activate the stabilized voltage supply module into normal operating slate, and thereby wake up the power supply module for the electric device from sleep mode to normal power supply state; thus, the power supply module will begin to provide normal operating voltage to other functional modules in the electric device; now, the consumed current in the feeder line will increase by a specific value. It is important to note: a wake-up signal with specific characteristics can only be used to wake up a specific power supply module, i.e., each power supply module can only identify a specific wake-up signal for waking up it. [0124] The implementation method for locally waking up the power supply module for certain electric device in sleep mode into normal power supply state is: providing a local control circuit for the stabilized voltage supply module with an Enabled control terminal in the power supply module for the electric device, and activating the stabilized voltage supply module into normal operating state, and thereby waking up the power supply module into normal power supply state to provide normal operating voltage to other functional modules in the electric device, when the power supply module for the electric device is to be waken up from sleep mode locally; now, the consumed current in the feeder line will increase by a specific value. [0125] Hereunder the methods described above will be detailed in an example of the implementation circuit of a point-to-multipoint long-distance constant-voltage feeding system with wake-up function. [0126] The point-to-multipoint long-distance constant-voltage feeding system with wake-up function comprises: an intelligent power supply module 4 , a terminal power supply module 7 constituted by multiple power supply modules ( 71 , 72 , . . . , 7 N) for electric devices at distal end, and a feeder line 6 for connecting the intelligent power supply module 4 and the terminal power supply module 7 , as shown in FIG. 14 . The connection method of intelligent power supply module 4 at the local side and terminal power supply module 7 to the feeder line 6 and the implementation method of the intelligent power supply module 4 are the same as those in the point-to-point scheme, and will not be detailed further here. However, the implementation of the terminal power supply module is different to that in the point-to-point scheme. Hereunder a specific implementation scheme of the terminal power supply module will be introduced. [0127] An implementation scheme of the terminal power supply module 7 comprises power supply modules ( 71 , 72 , . . . , 7 N) connected in parallel for multiple electric devices, as indicated by the terminal power supply module 7 FIG. 14 . [0128] The power supply modules ( 71 , 72 , . . . , 7 N) for the electric devices are in sleep mode initially; they will enter into normal power supply state and begin to provide normal operating voltage to other functional modules in the electric devices and feed back the power supply state signal thereof to the intelligent power supply module 4 through the feeder line 6 , after they are waken up. [0129] The power supply modules ( 71 , 72 , . . . , 7 N) for the electric devices have very low leak current in sleep mode respectively; once a power supply module is waken up into normal power supply state, the current in the feeder line will increase by a specific value. [0130] An implementation scheme of the power supply modules ( 71 , 72 , . . . , 7 N) for the electric devices in this embodiment comprises a voltage polarity change sensing circuit constituted by diodes (D 13 , D 14 , and D 15 ) and resistors (R 10 and R 11 ), a voltage polarity change parameter recording and processing module 7111 , and a stabilized voltage supply module 7112 with an Enabled control terminal, as indicated by the power supply module 711 for electric device in FIG. 15 . [0131] The voltage polarity change parameter recording and processing module 7111 can have one input terminal and one output terminal, and the input terminal is connected to the output terminal of the voltage polarity change sensing circuit, and the output terminal is connected to the control terminal of the stabilized voltage supply module with an Enabled; when the voltage polarity change parameter recording and processing module 7111 receives a specific voltage polarity change parameter from the voltage polarity change sensing circuit, it will treat the voltage polarity change parameter and output from its output terminal an Enabled control signal required for activating the regulated power supply module with an Enabled control terminal connected to it. The required function of the voltage polarity change parameter recording and processing module 7111 can be implemented by simply programming the input/output terminals of a single-chip microcomputer or other information processing module Implementation of this wake-up procedures are as follows: [0132] Set the intelligent power supply module 4 to output feeding voltage with determined polarity in normal state; when the power supply module in sleep mode for a specified electric device is to be waken up remotely, the intelligent power supply module 4 will invert the polarity of the outputted feeding voltage as a wake-up signal for waking up the power supply module in sleep mode for the electric device in accordance with predefined rules with a control signal inputted via the port G, and monitor the magnitude of the feeding current in the feeder line constantly; if the intelligent power supply module 4 finds the feeding current has increased by a specific value, it will judge that the power supply module for the electric device has enter into normal power supply state; if the intelligent power supply module 4 finds the feeding current has decreased by a specific value, it will judge that the power supply module for the electric device has enter into sleep mode; in addition, the intelligent power supply module 4 will output the monitored sleep mode/normal power supply state of the power supply module for the electric device to other modules at the local side; [0133] When the intelligent power supply module 4 in normal state is to remotely wake up the power supply module of a specified electric device into normal power supply state, the equipment at the local side will control the intelligent power supply module 4 with an control signal inputted via the control port G to invert the polarity of outputted feeding voltage as a wake-up signal for waking up the power supply module for the electric device on the basis of predefined rules; the voltage polarity change parameter recording and processing module 7111 in the power supply module for the electric device will record the voltage polarity change parameter and identify the wake-up signal by means of the voltage polarity change sensing circuit, treat the voltage polarity change parameter, and output an Enabled control signal to the stabilized voltage supply module thereafter to activate the stabilized voltage supply module into normal operating state, and thereby wake up the power supply module for the electric device from sleep mode into normal power supply state; thus, the power supply module will begin to provide normal operating voltage to other functional modules in the electric device; now, the consumed current in the feeder line will increase by a specific value; [0134] If the power supply module for a specific electric device is to be directly waken up locally into normal power supply state, a local control circuit can be arranged in the stabilized voltage supply module in the power supply module for the electric device to provide an Enabled signal, so as to activate the power supply module into normal power supply state. An implementation scheme of the local control circuit can be implemented by the circuit shown in FIG. 12 . [0135] It is noted that the description in this document is only illustrative, and shall not be deemed as constituting any limitation to the present invention. The protected scope of the present invention shall be confined by the claims only.

Disclosed are a wired long-distance constant-voltage electricity-feeding method with a wake-up function and a system. A smart electricity supply module of a central electricity supply device generates a feed voltage from a central electricity source, and feeds the voltage to a terminal electricity source module through a feed line. Said smart electricity supply module can continuously provide electricity at a constant voltage to the terminal electricity source module and can change feed voltage polarity according to set rules when the terminal electricity module in sleep-mode must be remotely waken up. A voltage polarity monitoring module of said terminal electricity source module can determine, by monitoring the polarity of the voltage of the centrally fed electricity, whether to wake up the terminal electricity source module from sleep-mode to enter a normal electricity-supplying mode. The electrical feed circuit and the wake-up function are easy to implement, and provide a versatile power feed and high energy efficiency while reducing withstand-voltage process requirements.

BACKGROUND [0001] The present invention relates to a spill return nozzle particularly suitable for use in gas cooling. [0002] In gas cooling, atomization of water is utilized to cool a current of hot gases inside a duct or a specific cooling tower. The evaporating water removes a large quantity of heat from the gas, lowering the temperature of gases to the required value. [0003] In order to obtain adequate cooling of the gas it is important for water atomization to be very fine; the dimensions of the water droplets must be optimized and controlled in dimension so that they can evaporate completely and rapidly. [0004] It is very important for the water to be totally atomized so that it can evaporate completely and no droplets of water remain in liquid state in the plant, as these droplets could cause damage to components of the plant downstream or cause dangerous scaling. [0005] To obtain the required water atomization, two types of nozzle known from the state of the art are currently used. [0006] A first type of nozzle currently known comprises nozzles using compressed air and water. In this type of nozzle, water and compressed air are injected together into the nozzle and the jet of high pressure air helps to atomize the water very finely. However, these prior art nozzles require very bulky and powerful compressors, which therefore consume large quantities of energy. The compressors used to operate this type of nozzle have powers which, as a function of the size of the plant, can even reach 250-300 kW. [0007] A second type of prior art nozzle used for gas cooling comprises spill return nozzles, which differ from the previous type in that they only use water at a pressure of 30-50 bar. [0008] For operation of this second type of spill return nozzle, pumps from 50-75 kW are used, with a considerable saving of power compared to compressed air nozzles. [0009] Therefore, with respect to compressed air atomizer nozzles, spill return nozzles offer a great saving of energy, as they do not require compressors with such high powers, which also translates into a saving in terms of maintenance and installation costs. [0010] These spill return nozzles guarantee a finely atomized jet, self-regulating the flow rate of water to the effective requirements of the plant, on the basis of the variations in temperature and the volume of gas to be cooled. A temperature sensitive regulation valve, installed on the return duct, regulates the flow rate of the nozzle in a manner directly proportional to the temperature without modifying the pressure of the liquid upstream of the nozzle. [0011] However, spill return nozzles also present some drawbacks. [0012] A first drawback is the dimensions of the droplets obtainable, which are on average larger compared to compressed air atomizer nozzles, a larger dimension of the droplets translating into lower gas cooling efficiency and higher evaporation times. [0013] Secondly, the lower cooling efficiency is also due to lower heat exchange associated with the low droplet-gas relative velocity and with poor penetration of the jet, as the air pressure of the atomizer nozzles guarantees longer ranges due to the higher velocity of the water particles delivered from the nozzle. [0014] Moreover, further disadvantages that affect prior art spill return nozzles are represented by the spraying angle, which is particularly wide and is not constant when the regulation thereof of varied. [0015] Yet another disadvantage that affects prior art spill return nozzles lies in the fact that the jet emitted by the nozzle is of the hollow conical type, and this limits the efficiency of this nozzle. OBJECTS AND SUMMARY OF THE NEW INVENTION [0016] The main aim of the present invention is therefore to provide a spill return nozzle that allows the drawbacks affecting prior art nozzles to be overcome. [0017] Within this aim, an object of the present invention is to provide a spill return nozzle that combines simplicity and low cost in terms of set up and use of spill return nozzles with greater efficiency in terms of atomization and thus of heat exchange of the nozzles using pneumatic atomization. [0018] A further object of the present invention is to provide a spill return nozzle with an output jet optimized in shape, distribution and dimension of the water particles. [0019] Another object is to accelerate the water droplets in order to improve penetration of the spray in the gas current so as to optimize water distribution and heat exchange. [0020] Yet another object of the present invention is to provide a spill return nozzle having an output jet composed of a full cone rather than a hollow cone. [0021] A further object of the present invention is to provide a spill return nozzle with an output jet having a smaller spray angle compared to that of prior art spill return nozzles and which is constant in the entire regulation range. [0022] This aim and these and other objects, which will be more apparent below from the detailed description of a preferred embodiment of the present invention, are achieved by a nozzle for the atomization of liquid, particularly for the atomization of water for use in gas cooling, of the type comprising an axial duct for discharge of the flow of liquid, characterized in that it also comprises an external annular sleeve coaxial to said duct for the flow of liquid and suitable for a flow of pressurized air to pass through. BRIEF DESCRIPTION OF THE DRAWINGS [0023] Further characteristics and advantages of the present invention will be more apparent from the following detailed description, provided by way of non-limiting example, of a preferred embodiment shown in the accompanying figures, wherein: [0024] FIG. 1 shows a longitudinal sectional view of the nozzle according to the present invention; [0025] FIG. 2 schematically shows a detail of FIG. 1 indicated by the arrow. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0026] According to a preferred embodiment of the nozzle according to the present invention shown in the aforesaid figures, the spill return nozzle according to the present invention comprises a central duct indicated with the reference number 2 . According to what is common to this type of nozzle, the axial duct 2 is in turn divided into an external annular duct 2 a through which the flow of fluid, for example the flow of water, passes, in the direction of the outlet of the nozzle, and an internal axial duct 2 b for return of the fluid from the outlet of the nozzle. As it is known, spill return nozzles are capable of self-regulating the flow delivered from the nozzle as a function of the gas temperature, optimizing the flow rate each time. [0027] The flow delivered from the nozzle, as shown in FIG. 1 , opens outward to adopt a hollow cone configuration 3 typical of this type of nozzle. [0028] The nozzle according to the present invention also presents means suitable to convey a flow of air toward the outlet of the nozzle. [0029] With particular reference to FIG. 1 , said means suitable to convey the flow of air toward the outlet of the nozzle can advantageously comprise a substantially hollow cylindrical element 4 that surrounds said axial ducts 2 a , 2 b for the flow of liquid so as to create a liner between the external wall of said annular duct 2 a and the internal wall of said hollow cylinder 4 . [0030] Viewed in cross section, the profile of said liner can also comprise a first rectilinear section 4 a in which the flow of air runs parallel to the axial direction identified by the axis A of the nozzle, and a final convergent section 4 b suitable to convey the flow of air toward the cone 3 of water delivered from the nozzle, where initial and final are intended with respect to the direction of advance of the flow of air. [0031] Moreover, with particular reference to FIG. 2 , said means suitable to convey the flow of air toward the outlet of the nozzle comprise a perforated baffle 5 . Said perforated baffle 5 will preferably have a circular shape as it must be suitable for insertion into the nozzle body between said hollow cylindrical element 4 and said duct with annular section 2 a . The perforated baffle will preferably comprise a plurality of holes 5 a. [0032] Said perforated baffle 5 substantially forms a centering element for the flow of air delivered to the nozzle from the duct 6 so that said flow is centered and oriented. [0033] The presence of the ring for centering the flow of air optimizes this flow which thus flows in the first rectilinear section 4 a toward the final area of the element 4 where the internal walls converge toward the axis A of the nozzle, substantially forming a final converging section 4 b. [0034] Due to the shape of the internal wall of said hollow element 4 , the flow of air passes through the nozzle in a substantially axial direction until reaching the rectilinear section 4 a , while it is delivered from the nozzle with an axial-centripetal direction, i.e. with a direction converging toward the axis of said nozzle represented by the arrows of FIG. 2 . [0035] According to the above description, the nozzle according to the present invention is capable of combining the advantages of a spill return nozzle, which operates with water alone and thus does not require air compressors that absorb very high power, with the advantages of a pneumatic atomization nozzle in terms of dimensions of the droplets, droplet-gas heat exchange efficiency, optimization of the droplet range, scope of the regulation range and uniformity of the jet. [0036] The nozzle according to the present invention operates with compressed air at very low pressure, indicatively variable from 0.05 to 1 barg. Mixing of air with water takes place outside the spray orifice, and therefore substantially at atmospheric pressure. [0037] Given the extremely modest pressures, contrary to the case of compressed air atomizers, the flow of air required for operation of the nozzle according to the present invention can be obtained without requiring to set up costly and bulky compressors that consume large quantities of energy, with simple fans or blowers being sufficient for the purpose. [0038] The air is delivered to the area in which the droplets are formed, immediately downstream of the outlet orifice where the water atomizes, at high velocity, indicatively from 50 to 350 m/s. As atomization of the water is not performed using air, but as a result of the geometry of the spill return nozzle, the velocity imparted to the air is not lost through impact with the jet of water, and therefore the jet of air delivered from the nozzle has a high velocity. This high velocity of the jet of air contributes toward obtaining a double advantage. [0039] Firstly, the high velocity of the jet of air draws with it the particles of atomized water, which translates into increased penetration of the jet of atomized water in the gas to be cooled. [0040] Secondly, the high velocity of the air improves droplet measurement, reducing the diameter of the droplets, i.e. making water atomization more efficient. [0041] A further advantage obtained by the nozzle according to the present invention consists in reduction of the spray angle, which is also maintained constant during regulation of the flow rate. In fact, as described above, the air delivered from the nozzle has an axial-centripetal direction, i.e. is directed against the cone of atomized water so as to oppose opening of the atomization cone. The effect of the flow of air is also that of driving the finest droplets of the jet of atomized water to the inside of the atomization cone, transforming the hollow cone typical of spill return nozzles into a full cone, further improving the efficiency of this nozzle. [0042] The flow of air of the nozzle according to the present invention can be regulated with specific valves or inverters positioned on the fans or blowers so as to optimize the shape of the jet in each point of operation, and naturally it can also be maintained constant. [0043] As stated previously, the high velocity of the jet of air delivered from the nozzle contributes toward increasing the efficiency of the nozzle when this is used for gas cooling. In fact, the increased droplet-gas relative velocity optimizes heat exchange efficiency, reducing evaporation times of the water particles. [0044] Moreover, an advantage obtained by means of the nozzle according to the present invention lies in the fact that the droplets of smaller dimensions, and therefore having lower inertia, are driven by the jet of air toward the inside of the atomization cone of the water, thereby obtaining a final configuration of the cone delivered from the nozzle characterized by the concentration of fine droplets inside the cone and by droplets of larger dimensions at the external periphery of the cone, which is no longer hollow but full. [0045] This final structure of the atomization cone improves operation of the nozzle in terms of efficiency in the gas cooling action. In fact, the larger droplets which are located at the outside of the atomization cone evaporate in contact with the hottest gas. Instead, the finer droplets, which therefore evaporate more rapidly and easily due to their smaller mass, evaporate subsequently also in contact with cooler gas as it has already been partly cooled by the external droplets of the jet. [0046] It has thus been shown how the spill return nozzle according to the present invention achieves the object and the aims proposed. [0047] In particular, it has been shown how the spill return nozzle according to the present invention allows numerous advantages to be obtained in terms of efficiency of this nozzle and greater efficacy in use in gas cooling. [0048] It has in fact been shown how the spill return nozzle according to the present invention allows an increase in the quality of the jet delivered from the nozzle both in terms of droplet distribution and of cone opening. [0049] Moreover, the nozzle according to the present invention presents improved heat exchange efficiency, both due to the velocity and dimension of the droplets forming the atomization cone, and to the distribution thereof. [0050] A further advantage obtained by the nozzle according to the present invention consists in the possibility of maintaining a constant spray angle due to regulation of the flow rate of compressed air, preventing the atomization cone from interfering with any lances located in the vicinity. [0051] Moreover, the jet of air acts to protect the nozzle from dust and dirt in general, which is kept away from the nozzle due to the jet of air, which creates a kind of protective barrier around the nozzle. [0052] In addition, it has been shown how the nozzle according to the present invention allows all the advantages described above to be achieved with modest energy consumption with respect to prior art atomizer nozzles. [0053] Numerous modifications can be implemented by those skilled in the art without departing from the scope of protection of the present invention. [0054] Therefore, the scope of protection of the claims must not be limited by the illustrations or by the preferred embodiments shown in the description by way of example, but instead the claims must comprise all characteristics of patentable novelty deducible from the present invention, including all those characteristics that would be treated as equivalents by those skilled in the art.

The present invention relates to a spill return nozzle, particularly suitable for use in gas cooling, characterized in that, alongside the ducts for discharge and return of the flow of liquid, it is provided with means suitable to convey a flow of air toward the outlet of the nozzle. With the nozzle according to the present invention it is possible to obtain an output jet with optimized shape and dimensions of the atomized droplets, thereby increasing cooling efficiency in the case of use of the nozzle in gas cooling processes.

TECHNICAL FIELD [0001] The present disclosure relates to a degassing device, and particularly to a degassing device for liquids, especially for blood, which is used in extracorporeal circuits for the treatment of blood. DESCRIPTION OF THE RELATED ART [0002] Degassing devices are used in various treatments of blood, such as blood autotransfusion and cell separation during an operation, such as, for example, cardiopulmonary bypass procedures, but also especially in hemodialysis, hemofiltration, haemodiafiltration or plasmapheresis applications. In all these treatments, blood is withdrawn from a patient, flown through a filter, such as a dialyzer, and returned to the patient. As blood is returned to the patient, it is treated for the removal of particles and especially for the removal of bubbles of gas. [0003] Even if these bubbles of gas are only of very small size, they can cause serious damage to body functions by causing air embolism. Air embolism occurs when bubbles of air become trapped in the circulating blood. An embolus in an artery is travelling in a system of tubes which are getting gradually smaller. Eventually, it will block a small artery, which is serious because the blockage will cut off the blood supply to some area of the body. However, the embolus'effect will depend on the part of the body to which the artery supplies blood. If, for example, the embolism prevents blood supply to the brain, tissues will be starved of oxygen, causing them to die, thus likely resulting in permanent brain damage. If the embolus is in a vein, the tube system widens along the direction of the blood flow so that a small embolus may not do much harm until it passes through the heart, after which it enters an artery. [0004] A machine for hemodialysis, hemofiltration, haemodiafiltration or plasmapheresis applications comprises a peristaltic pump for withdrawing blood from a patient through a so-called “arterial line” connected at one end to the vascular circuit of the patient and at the other end to the inlet of the first compartment of a filter, for pumping blood into the filter, and for returning blood to the patient through a so-called “venous line” connected at one end to the outlet of the first compartment of the filter and at the other end to the vascular circuit of the patient. The treatment machine also usually comprises a first blood pressure sensor for measuring the pressure of blood in the arterial line upstream of the pump, a second blood pressure sensor for measuring the pressure of blood in the arterial line downstream of the pump, a third pressure sensor for measuring the pressure of blood in the venous line, a bubble detector for detecting air bubbles in the venous line and a clamp for closing the venous line, for example when air bubbles are detected by the bubble detector. [0005] An arterial line typically comprises the following components connected together by segments of flexible tubes: a first Luer connector for connection to an arterial canula, an arterial bubble trap, a pump hose for cooperating with the rotor of the peristaltic pump of the treatment machine, and a second Luer connector for connection to the inlet of the first compartment of the filter. [0006] A venous line typically comprises the following components connected together by segments of flexible tubes: a first Luer connector for connection to the outlet of the first compartment of the filter, a venous bubble trap, and a second Luer connector for connection to a venous canula. Usually, the first and third pressure sensors of the machine are connected to the arterial and venous bubble trap respectively, when the treatment machine, the arterial line, the venous line and the filter are assembled in view of a treatment. [0007] In the prior art, devices for separating air bubbles out of medical fluids such as blood have been described. They can often also be used for separating out gases other than air. For that reason, air separators of this kind are also described as degassing devices. [0008] Blood degassing devices must be able to reliably and efficiently separate air bubbles from the blood, and further have to be constructed with respect to the mechanical properties and the flow paths being formed that any damage to the blood components is ruled out. It is further desirable for a low level of blood damage to have smooth surfaces on the material side and a structure of the flow paths which is favourable to the flow, with the result that the adhesion of blood corpuscles to surfaces of the air separator and thus a conglomeration of blood corpuscles is avoided. Also, the residence times of the blood in the air separator should be as short as possible, but without deteriorating the air separation as such. It is further desirable to minimize the fill volume of the degassing device. [0009] A conventional degassing device is basically an elongated container which, when in use, is held vertically. The container has an inlet and an outlet for blood which are arranged not to be adjacent. It generally also comprises, in an upper location, a pressure measuring port for connection to a pressure sensor, an infusion port for infusing a liquid (e.g. a drug or a sterile saline solution) and an injection port for adding or removing air into or from the degassing device so as to adjust the level of blood therein. [0010] In use, such degassing devices contain a volume of blood in a lower part which transiently stagnates therein so as to let gas bubbles and micro bubbles escape by gravity and migrate to an upper part of the container full of air, with the result that a conventional bubble trap therefore always comprises a blood/air interface. [0011] GB 2 063 108 A discloses a degassing device having a vertically arranged chamber with a cylindrical section comprising an end fitting having a conical taper with a venting duct at its top. The fluid to be degassed enters beneath the conical section into the chamber. The inlet connection is disposed in such a manner that the fluid flows tangentially into the chamber in the outer peripheral area. Because the fluid is introduced tangentially, it initially flows in a circular flow path, but with the entire fluid motion through the chamber being superimposed upon it, the fluid flows through the chamber in a helical flow path and emerges again at the bottom end of the chamber out of the tangentially arranged outlet connection. The circular motional components of the fluid flow produce centrifugal forces which build up pressure differences in the fluid so that the air bubbles are forced to the middle of the chamber and rise upwards. The separated air bubbles can then be drawn off through the venting bore at the top end of the chamber. [0012] U.S. Pat. No. 6,053,967 discloses an air separator for liquid containing gas bubbles having an essentially cylinder-shaped chamber through which liquid, such as blood, flows essentially in helical flow paths, with the result that air bubbles are driven in a radial direction relative to the longitudinal axis of the chamber because of pressure differences produced by centrifugal forces. The inlet and outlet of the chamber of the air separator are coaxial relative to each other in the longitudinal axis of the chamber. The known air separator also includes a flow-deflection component which includes a rotation-symmetrical base body element whose outer surface faces inflowing liquid as a first deflection surface, which is geometrically defined by rotation of a curve section about the longitudinal axis of the chamber. The first deflection surface has deflection surface deflector vanes, which are curved in planes perpendicular relative to the longitudinal axis of the chamber, with the result that axially inflowing liquid is deflected so that desired helical flow development is induced. [0013] U.S. Pat. No. 5,849,065 discloses a device for separating gas bubbles out of medical fluids, in particular blood, having a substantially cylindrical chamber, an inlet connection arranged in the longitudinal direction of the chamber, an outlet connection and a flow-guide member attached to the inlet connection and having a plurality of flow channels, which extend in a space curve out of the longitudinal direction of the chamber in a direction running substantially tangential to the inner wall of the chamber. An orifice, which is sealed by a hydrophobic membrane, is provided in the cover part of the chamber. Since the outlet orifices of the flow channels are arranged directly underneath the cover part, the membrane is circumflowed by the inflowing fluid, avoiding the formation of dead zones. The device makes it possible to separate out air bubbles with a substantial degree of reliability, without the danger of the hydrophobic membrane becoming obstructed from contact with the blood. [0014] WO 2005/053772 A1 discloses a degassing device comprising a first chamber having an inlet for a liquid and a second chamber having an opening closed by a hydrophobic membrane and an outlet for discharging the liquid, wherein the first chamber has a downstream portion which partially extends within the second chamber and communicates therewith by a passageway. The second chamber has a downstream portion which extends below the passageway and asymmetrically surrounds the downstream portion of the first chamber. [0015] WO 2005/044340 A1 and WO 2005/044341 A1 both disclose an integrated blood treatment module comprising a degassing device which is connected to the second end-cap of the module. The degassing device comprises a first chamber having a lower inlet for a liquid and a second chamber having an upper opening closed by a hydrophobic membrane and an outlet for discharging the liquid. The connecting structure has at least a first and a second conduits defined therein, wherein the first conduit comprises a first end for connection to a discharge tube from the treatment device and a second end connected to the inlet of the first chamber of the degassing device, and the second conduit comprises a first end connected to the outlet of the second chamber of the degassing device and a second end for connection to a blood return tube to a patient. [0016] The blood conditioning device discloses in U.S. Pat. No. 7,108,785 B1 comprises a helical blood acceleration section which includes a helical flow path for impressing centrifugal forces on the entrained bubbles in the blood to concentrate them towards the centre of the flow path, a bubble pick off tube aligned with the centreline of the acceleration section which collects and recirculates the bubbles to the cardiotomy reservoir upstream of the device during operation, and a blood filtration section to intercept the flow of particles in the blood. [0017] U.S. Pat. No. 6,398,955 B1 discloses a blood filter including a housing with a spiral chamber defined between an inner wall and an outer wall of the housing and a centre chamber defined within the inner wall. The spiral chamber extends in a helix shape to surround the centre chamber. The centre chamber has the air bubble outlet. The spiral passage of the spiral chamber surrounds the centre chamber in the range of 180 degrees to 400 degrees. The degassing device further comprises a filter element which divides the inner space into a space which is in communication with the blood inlet and a second space which is in communication with the blood outlet. SUMMARY [0018] The present disclosure provides a degassing device for separating gas bubbles out of fluids, in particular out of blood. [0019] The proposed degassing device comprises a housing having a liquid inlet, a liquid outlet and a gas bubble outlet, the housing further comprising a spiral wall defining a spiral flow path for the liquid and a hydrophobic membrane placed above the spiral wall and between the spiral wall and the gas bubble outlet, the spiral wall forcing inward flux liquid entering into the housing through the inlet into a spiral flow along the spiral flow path, and causing an upward flow of the gas bubbles towards the hydrophobic membrane. [0020] The degassing device significantly reduces the total volume within the chamber in comparison to the degassing devices known in the art, where air cushions are formed in an upper area. In the present device, no air cushion will form as the bubbles, which are separated from the fluid, are immediately removed from the system through the hydrophobic membrane. In devices in which an air cushion is formed, the inflow must be placed as far away from this upper area in order to stabilize the fluid layer and to avoid renewed introduction of air. This necessitates chambers with a substantial overall height and, as a consequence, the degassing devices will accommodate a relatively large amount of blood. The degassing device according to the present disclosure does not need such height of the chamber, which can in contrast be minimized, thus significantly reducing the blood volume in the degassing device and making the degassing device economic from a material consumption point of view. Such reduced blood volume also minimizes the contact to extracorporeal surfaces, thus reducing the risk of activation of blood components. [0021] As no air cushion or dead zone forms in which air bubbles might accumulate, the degassing device according to the present disclosure avoids the prolonged contact between blood and air and thus reduces the risk of blood clotting. The hydrophobic membrane in the cover part of the degassing device is in direct and complete contact with the fluid. [0022] The blood level in the degassing device is automatically adjusted and limited by the surface of the degassing hydrophobic membrane. As a consequence, no level adjustments are needed during priming as well as during treatment. [0023] The degassing device according to the present disclosure maximizes the advantages which can be gained from the use of a helical or spiral flow within such degassing chamber by means of an extended spiral inside the housing which forces the blood flow into a guided spiral flow. [0024] The proposed degassing device can be used in a system for removing air from a liquid over extended periods of time, without any significant decrease in its effectiveness. This is partly attributable to the fact that the venting membrane is in constant contact with the liquid. In devices wherein the membrane is not permanently contacting the liquid, especially blood, the membrane tends to loose its permeability over time. As the chamber of the degassing device according to the present disclosure is filled with liquid, thus enabling a constant contact of the liquid with the membrane, the degassing device of the present disclosure has a longer life span and requires less monitoring or surveillance by the service personnel. This effect can be even improved by using a specific hydrophobic membrane as described below which can optionally be used as a venting membrane in the degassing device according to the present disclosure. [0025] In the proposed degassing device the blood enters the degassing device tangentially through an inlet which is located at the bottom of the chamber. The flow is forced by a spiral shaped wall inside the degassing device into a spiral flow as shown in FIG. 1 . On the way through the degassing device the air bubbles inside the blood stream have time to rise upwards. To guarantee this upwards movement of the air bubbles, the degassing device is to be placed essentially horizontally, i.e. the spiral wall should be placed essentially vertically. The degassing device is covered by a hydrophobic membrane placed on top of the spiral shaped wall without actually touching the wall of the spiral. Because of the spiral flow gas bubbles cannot stick to the membrane to create gas-bubble-foam underneath the membrane. [0026] According to one aspect, a spacing is provided between the hydrophobic membrane and the upper edge of the spiral wall, allowing the blood to be in full contact with the membrane. Upon introduction into the degassing device through the inlet, the fluid containing air bubbles flows into the spiral. While the fluid, e.g. blood, flows through the spiral chamber, the air bubbles move to the vicinity of the inner top surface of the spiral due to the centrifugal force and buoyancy of the air. As soon as the air bubbles touch the hydrophobic membrane, the air will leave the degassing device through the membrane. The air free blood can leave the degassing device through a hole located in the bottom side of the chamber. Thus, the air bubbles are effectively separated from the blood and will immediately leave the system. The separation is performed with virtually the same effectiveness whether the amount of air bubbles is large or small. [0027] The housing may comprise a cylindrical housing having an inlet and an outlet. In one embodiment, the diameter of the cylinder may be larger than its height. A possible ratio between diameter and height may be from about 2.5:1 to 1:1, or between about 2:1 and 1.75:1, or between about 1.9:1 and 1.8:1. [0028] The outlet may be variously configured. For example, the outlet may comprise a nipple which defines the outlet passage and may be moulded integrally with the body of the chamber. The outlet may project axially down in the centre of the bottom wall of the chamber and is configured to receive the end of a tube. The tube may be made an integral part of the outlet. In this case, the tube may additionally be furnished, at the opposite end which is not connected to the housing, with an integrated male luer. [0029] The inlet may also be variously configured. It is, however, important that the inlet is as close as possible to the bottom wall of the chamber in order to reduce the velocity of the flow beneath the membrane. The inlet may comprise a nipple which defines the inlet passage. In one embodiment, the inlet passage may be horizontal and open through the side wall of the body of the housing in a direction tangential to the side wall. The inlet may be molded integrally with the body of the chamber and configured to receive the end of a tube as shown in FIG. 3 . The tube may be made an integral part of the inlet. In this case, the tube may additionally be furnished, at the opposite end which is not connected to the housing, with an integrated male luer. [0030] The spiral may be an integral part of the body of the housing (the chamber). It is not connected to the outer wall of the chamber, but has its starting point close to the inlet, with a distance of that starting point from the outer wall of the chamber of from about 2 to 5 mm, or about 3 mm. The starting point of the spiral may overlap the inlet in order to avoid that the flow coming from the inlet is split at the entrance of the spiral. [0031] In one embodiment, the spiral wall height is in a range between 17 mm+/−3 mm. The spiral can have 1.6+/−0.3 rotations, or, in other words, can surround the chamber in the range of about 550 degrees +/−108 degrees. The spiral height may be the same over its full length, but it can also be possible to introduce an increasing height from the blood inlet to the blood outlet region. [0032] The spiral housing may have an inner diameter of about 25 to 40 mm, or of about 30 to 35 mm, or about 32 mm. [0033] The distance between the top edge of the spiral wall and the hydrophobic membrane can be in the range of 1.5 mm+/−0.5 mm. A larger or smaller distance generally results in a decrease of the degassing efficiency. [0034] The degassing device is especially effective in removing air from a fluid for fluid flow rates of up to 350 ml/min. Flows below 100 ml/min will result in a decrease in efficiency in removing air from the fluid, even though the degassing device can also be used at lower flow rates. [0035] To improve the efficiency with regard to higher flow rates, the housing can be designed for accommodating a larger fluid volume. In this case, the distance of the hydrophobic membrane from the top edge of the spiral wall should remain the same as described before. Further, the spiral should remain the same in terms of rotations within the chamber. Otherwise, the dimensions can be adapted to an increased size of the degassing device. [0036] The distance between the inner wall of the degassing device and the spiral may be equal to the distance of the outer channel which is generated by the spiral as shown in FIG. 2 . [0037] The housing can be formed from any material which is a sufficiently rigid, impervious material and which can withstand a sterilization treatment usually applied to devices used for extracorporeal circulation circuits, for example a transparent engineering plastic material such as polyurethane, polycarbonate, polystyrene, polymethylmethacrylate or polypropylene. Additionally, all of the surfaces of the housing which contact the liquid should be readily wettable by the liquid. In a possible embodiment, the housing is made from polyurethane. The polyurethane can be a thermoplastic polyurethane (TPU) or it can be a two-component polyurethane which is produced by reacting aromatic di- or polyisocyanate (e.g., MDI or modified MDI) or aliphatic diisocyanate (e.g., HDI or H 12 -MDI) with polyether or polyester polyol. In one embodiment of the invention, the housing is made from a polyurethane which is obtained by reacting modified MDI (Desmodur® PF, Bayer MaterialScience AG) and a castor-oil based polyol (Polycin®, CasChem, Inc.). In another embodiment, the housing is made from polycarbonate. [0038] The housing or the body of the housing can additionally be coated. In a possible embodiment, the housing or the body of the housing is treated with a polyurethane solution, for example a 40 wt.-% solution of a polyurethane produced from modified MDI (Desmodur® PF, Bayer MaterialScience AG) and a castor-oil based polyol (Polycin®, CasChem, Inc.) in methyl isobutyl ketone (MIBK). The housing or body may be treated with such solution by spraying or dipping, followed by drying. Drying may be performed at room temperature. [0039] The degassing device according to one general implementation comprises a protective member or cover for protecting the hydrophobic membrane against external force and for limiting the deformation of the hydrophobic membrane when the pressure of the liquid within the degassing device exceeds a limit. The cover does not touch the upper side of the hydrophobic membrane, but leaves a spacing between its upper side and the membrane. [0040] The cover has a cylindrical configuration and includes, in one embodiment, a generally flat top wall and a downturned, generally cylindrical side wall. FIG. 4A displays an aerial view of the cover; FIG. 4B displays the interior view including the membrane. FIG. 4C shows the housing including the spiral body and the cover. [0041] The cover and the body of the chamber may be joined in any suitable manner. For example, the lower end of the cover side wall may include an annular channel formed in a flange which is configured in such a manner to receive the open upper end of the body of the chamber. The cover and the body may then be joined at the channel, for example by bonding or welding, so that the entire unit is disposed of when the element needs replacement. The cover may also be removably positioned on the chamber for easy replacement when needed. [0042] The material the cover is made from may be the same as the one used for the body of the chamber. The element can have at least one opening which will allow the air which leaves the chamber through the membrane to pass through the element as shown in FIG. 4 . In general, it might be sufficient to have a single opening, such as, for example, in the central part of the cover, which may have a size from about 1 to 3 mm in diameter, even though said diameter is not crucial as long as the air will be able to readily pass through the cover and as long as, at the same time, the cover remains stable enough to fulfill its protective function. However, it is also possible to use a protective element with more openings which may be larger or smaller in diameter. For example, the cover may be constructed to comprise numerous small openings across its surface. [0043] The degassing device according to the present disclosure comprises a hydrophobic membrane which will allow for the air bubbles to directly leave the system. In one embodiment, the membrane may be attached to the underside of the cover by bonding or welding to allow a free flow of gas from the housing. In one embodiment, the membrane may be welded into the cover, and may additionally be fixed at the periphery with a polyurethane cord which is welded onto the weld seam of the membrane. [0044] The membrane may extend over the full diameter of the chamber. However, the membrane may also have a smaller diameter than the housing or cover, respectively, and may, for example, be positioned in the centre of the chamber and cover. In this case, the cover has to be configured in such a manner to allow the adjustment of such a smaller membrane. [0045] Various hydrophobic membranes may be used together with the degassing device of the present disclosure. The hydrophobic membrane can be made from a polypropylene, polyethylene, polyurethane, polymethylpentene or polytetrafluoroethylene. The pore size must be sufficiently small, about 8 μm, e.g. between 0.1 to 8 μm, or between 0.1 to 3 μm to adequately prevent the passage of liquid through the membrane. The membrane may also comprise an additional backing as a support, i.e. it may comprise two different layers. Such hydrophobic membranes may additionally be coated or modified with surfactants, such as, for example, siloxanes of the general type R n H 2-n SiO, wherein n is 1 or 2 and R is a hydrocarbon group having 1 to 18 carbon atoms; polysiloxanes with a monomer unit of the type [—Si(R 1 ) 2 —O—] n —, wherein R 1 hydrocarbon groups and n is a number representing the number of units in the polymer, such as, for example, polydimethylsiloxane; or quaternary ammonium salt derivatives of silicone compounds. One suitable polysiloxane (because of its ready availability and ease of application) is polydimethylsiloxane. However, other silicone resin prepolymers can be used, including polymethylethylsiloxane, polydiethylsiloxane, polydipropylsiloxane, polydihexylsiloxane, polydiphenylsiloxane, polyphenylmethylsiloxane, polydicyclohexylsiloxane, polydicyclopentyl siloxane, polymethylcyclopentylsiloxane, polymethylcyclohexylsiloxane, polydicycloheptyl siloxane, and polydicyclobutyl siloxane. Cyclic siloxane oligomers like octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane or dodecamethylcyclohexasiloxane are other examples of suitable compounds. The membrane may also be coated with a mixture of a polysiloxane and silicon dioxide. It may also comprise as a coating, alone or together with the coatings mentioned before, biologically active substances such as anticoagulants, for example heparin or hirudin. [0046] In one embodiment, the membrane used is a polytetrafluoroethylene membrane, such as, for example a membrane selected from standard GORE™ Medical Membranes, for example MMT-323 (0.2 μm). The membrane may be coated with a mixture of polydimethylsiloxane and silicon dioxide, such as SIMETHICONE or the compound marketed by Dow Corning Corp. under the trade name ANTIFOAM A®. A process for coating polymer surfaces with ANTIFOAM A® is disclosed in U.S. Pat. No. 5,541,167. [0047] In a possible embodiment of the proposed degassing device, the deaeration membrane comprises a porous polytetrafluoroethylene (PTFE) sheet having a thickness of from 0.15 to 0.30 mm, more preferably from 0.20 to 0.25 mm, coated with a composition comprising >60 wt. % polydimethylsiloxane (CAS:63148-62-9), 7-13 wt. % methylated silica (CAS: 67762-90-7), 3-7 wt. % octamethylcyclotetrasiloxane (CAS:556-67-2), 3-7 wt. % decamethylcyclopentasiloxane (CAS: 5541-02-6), 1-5 wt. % dimethylcyclosiloxanes and 1-5 wt. % dodecamethylcyclohexasiloxane (CAS:540-97-6), which can be purchased from Dow Corning Corp. under the trade name Antifoam A®. [0048] The membrane is coated with a defined amount of a defoaming agent. The amount of the defoaming agent present on one face of the membrane may range from 4.25 μg/mm 2 to 10 μg/mm 2 , or even from 4.25 μg/mm 2 to 7.10 μg/mm 2 . In a possible embodiment, only one face of the membrane is coated. [0049] The membrane may exhibit an even or uniform distribution of silicon dioxide (silica) particles throughout the entire coated surface of the membrane, including the inner, middle and outer regions of the membrane. The number of silica particles may be in the range of from 22000 to 32000 particles per mm 2 , or even from 25000 to 30000 particles per mm 2 . [0050] The membrane may have a pore size that is sufficiently small to keep bacteria from passing through the membrane. A desirable mean average pore size is 0.2 μm or smaller. [0051] The membrane can be prepared by coating a porous PTFE membrane with a solution of the defoaming agent by dip-coating the membrane in the solution or spray-coating the solution onto the membrane. For obtaining a uniform coating, it is preferred to spray-coat the solution on the membrane. The person skilled in the art is familiar with methods of spray-coating a solution onto a membrane. In a preferred embodiment, a two-substance nozzle employing air, steam or other inert gases to atomize liquid is used for spray-coating. The pressure of the atomizing gas is preferably greater than 0.3 bar to achieve a large specific surface and uniform distribution. The nozzle orifice preferably ranges from 0.3 to 1 mm. In a preferred embodiment, the nozzle produces a full circular cone with an aperture of from 10° to 40°. The mass flow of the solution, the distance between the nozzle and the membrane to be coated, and the lateral relative velocity of the membrane and the nozzle may be selected to produce a coating comprising from 4.25 μg/mm 2 to 10 μg/mm 2 , or even from 4.25 μg/mm 2 to 7.10 μg/mm 2 of defoaming agent (after removal of solvent present in the solution). In a possible embodiment, a nozzle is used which sprays the solution with a mass flow of about 5-10 ml/min, or 7.5-9 ml/min, or 8-8.5 ml/min onto the membranes which are transported past the nozzle at a velocity of about 175-225 cm/min, or 190-210 cm/min, or even 200 cm/min. [0052] The defoaming agent may be dissolved in an appropriate solvent before using it for coating a membrane. Such a solution may contain the defoaming agent in a concentration of from 0.1 wt.-% to 20 wt.-%, or from 1 wt.-% to 10 wt.-%, or from 3 wt.-% to 8 wt.-%. [0053] The solvent for the defoaming agent used in the present disclosure is not particularly limited, if the polysiloxane compound, the silicon dioxide particles and the solvent are appropriately mixed, and if no significant difficulties are caused by phase separation. However, it is proper to use aliphatic hydrocarbons such as n-pentane, i-pentane, n-hexane, i-hexane, 2,2,4-trimethylpentane, cyclohexane, methylcyclohexane, etc.; aromatic hydrocarbons such as benzene, toluene, xylene, trimethylbenzene, ethylbenzene, methyl ethyl benzene, etc.; alcohols such as methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, secbutanol, t-butanol, 4-methyl-2-pentanol, cyclohexanol, methylcyclohexanol, glycerol; ketones such as methyl ethyl ketone, methyl isobutyl ketone, diethyl ketone, methyl npropyl ketone, methyl n-butyl ketone, cyclohexanone, methylcyclohexanone, acetylacetone, etc.; ethers such as tetrahydrofuran, 2-methyltetrahydrofuran, ethyl ether, npropyl ether, isopropyl ether, diglyme, dioxane, dimethyldioxane, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol monomethyl ether, propylene glycol dimethyl ether, etc.; esters such as diethyl carbonate, methyl acetate, ethyl acetate, ethyl lactate, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, ethylene glycol diacetate, etc.; and amides such as N-methylpyrrolidone, formamide, N-methyl formamide, N-ethyl formamide, N,N-dimethyl acetamide, N,N-dimethyl acetamide, etc. Particularly preferred are aliphatic hydrocarbons such as n-pentane, i-pentane, n-hexane, i-hexane, 2,2,4-trimethylpentane, cyclohexane, methylcyclohexane, etc. N-hexane is especially preferred as a solvent in the context of the present invention. [0054] In a possible embodiment of the spray-coating process, the solution of the defoaming agent is cooled down before application in order to avoid evaporation of the solvent during the spray-coating process. The solution used in the spray-coating process may be cooled down to a temperature of from 0 to 15° C., or from 0 to 10° C., or from 0 to 5° C. [0055] The coated membrane is then dried, e.g. at room temperature, for about 30 minutes to two hours, e.g. for about one hour. However, it is also possible to dry the membranes at elevated temperatures of up to 200° C. to shorten the time that is needed for drying. In case the amount of coating (in weight per mm 2 ) resulting from the first coating procedure is below the desired range, the coating process described above can be repeated on the same membrane. [0056] Further features and embodiments will become apparent from the description and the accompanying drawings. [0057] It will be understood that the features mentioned above and those described hereinafter can be used not only in the combination specified but also in other combinations or on their own, without departing from the scope of the present disclosure. [0058] Various implementations are schematically illustrated in the drawings by means of an embodiment by way of example and are hereinafter explained in detail with reference to the drawings. It is understood that the description is in no way limiting on the scope of the present disclosure and is merely an illustration of a possible embodiment. BRIEF DESCRIPTION OF THE DRAWINGS [0059] FIG. 1 shows an embodiment of the proposed degassing device; [0060] FIG. 2 shows a top view of another embodiment of the proposed degassing device; [0061] FIG. 3 shows a further embodiment of the proposed degassing device with an integrally molded inlet; [0062] FIG. 4 shows still another embodiment of the proposed degassing device; FIG. 4A displays an aerial view of a cover, FIG. 4B displays an interior view including a respective hydrophobic membrane, FIG. 4C shows a housing including a spiral body and the cover; [0063] FIG. 5 shows a dialysis setup including an embodiment of the proposed degassing device; [0064] FIG. 6 shows a setup including a possible embodiment of the proposed degassing device for an in vitro test with bovine blood; [0065] FIG. 7 shows a possible degassing profile of the setup of FIG. 6 ; [0066] FIG. 8 shows another degassing profile of the setup of FIG. 6 ; [0067] FIG. 9 shows a degassing profile of a standard degassing device ( FIG. 9B ) in comparison with a degassing profile of an embodiment of the proposed degassing device ( FIG. 9A ); [0068] FIG. 10 shows a dialysis setup including a further embodiment of the proposed degassing device, the dialysis setup being used for in vivo tests with sheep; [0069] FIG. 11 shows a degassing profile for the dialysis setup of FIG. 10 . DETAILED DESCRIPTION [0070] FIG. 1 shows a possible embodiment of the degassing device as proposed in the present disclosure. As shown in FIG. 1 , a liquid, particularly blood enters the degassing device 10 tangentially through an inlet 11 which is located at a bottom 12 of a chamber 13 of the degassing device 10 . The flow of the entered liquid is forced by a spiral shaped wall 14 inside the degassing device 10 into a spiral flow as shown by an arrow 15 . On the way through the degassing device 10 gas bubbles inside the liquid stream have time to rise upwards as indicated by arrows 16 . To guarantee this upwards movement of the gas bubbles, the degassing device 10 has to be placed essentially horizontally, i.e. the spiral wall 14 must be placed essentially vertically. After having passed the chamber 13 in a spiral flow the gas free liquid stream can leave the degassing device 10 through an opening in the bottom 12 of the chamber 13 as shown by arrow 17 . [0071] FIG. 2 shows a top view of another embodiment of the proposed degassing device. FIG. 2 clearly shows that the distance between an inner wall 18 of the degassing device 10 and a spiral wall 14 inside the degassing device 10 may be equal to the distance of an outer channel 19 which is generated by the spiral wall. [0072] FIG. 3 shows a further possible embodiment of the proposed degassing device with an integrally moulded inlet 11 . The inlet 11 of the degassing device 10 may be variously configured. It is, however, important that the inlet 11 is as close as possible to a bottom wall 12 of a chamber 13 of the degassing device 10 in order to reduce the velocity of the flow beneath a hydrophobic membrane which is to be provided according to the present disclosure. As shown in FIG. 3 , the inlet passage may be horizontal and open through a side wall of the body of the housing in a direction tangential to the side wall. The inlet 11 may further be moulded integrally with the body of the chamber 13 and configured to receive the end of a tube. [0073] FIG. 4 shows a further embodiment of the proposed degassing device. FIG. 4A displays an aerial view of a cover, the cover having a cylindrical configuration and includes, as shown in FIG. 4A , a generally flat top wall and a down turned, generally cylindrical side wall. FIG. 4B displays an interior view including a hydrophobic membrane. FIG. 4C shows a housing of the proposed degassing device including a spiral body and the cover. The cover can have, as shown in FIG. 4 , at least one opening which allows gas which leaves the chamber through the hydrophobic membrane to pass through that opening. In general, it might be sufficient to have a single opening, such as for example in the central part of the cover. [0074] FIG. 5 shows a further possible degassing device which is positioned within a standard dialysis setup on the venous or the arterial side. Such a setup may comprise a pressure sensor 1 , a first air bubble counter 2 , a pump 3 , a degassing device A, a dialyzer 4 , optionally a second degassing device B, a second pressure sensor 5 and a second air bubble counter 6 . [0075] In one embodiment, the degassing device is positioned on the arterial side of the system, i.e. before the dialyzer in order to effectively remove any air which may be present in the system before such air enters the dialyzer ( FIG. 5 , degassing device A). In this setup, the pump should be located before the degassing device as any device located before the degassing device may cause an air-in-blood-alarm. [0076] The setup should further comprise an air bubble counter on the arterial side for detecting air in the system. Optionally, a second degassing device may be located on the venous side after the dialyzer as a safety measure ( FIG. 5 , degassing device B). Such a second degassing device may then remove any remaining air bubbles which have passed or been generated during the passage of the dialyzer. [0077] In another embodiment, the dialysis setup having an arterial degassing device and an optional second venous degassing device comprises an air bubble counter located before the pressure sensor. [0078] In still another embodiment, if a degassing device is mounted in the set which is optimized for a certain flow, such as, for example 350 ml/min or less, it might prove advantageous to reduce the blood flow appropriately. The pump may automatically decrease the blood flow in case of an air-in-blood-alarm to a flow below the optimum of the degassing device. [0079] FIGS. 6 to 11 are described in connection with the following described examples. EXAMPLES [0080] The spiral degassing device according to the present disclosure shows an exceedingly well performance with regard to degassing of a liquid, especially of blood, both in in vitro and in in vivo tests. 1. Removal of Air In Vitro [0081] In an in vitro test with bovine blood (hematocrit between 32 and 40, total protein content: 60-80 g/l) the efficacy of the degassing device according to the present disclosure was tested by injecting air into the corresponding system ( FIG. 6 ). The setup essentially consisted of a circular flow of blood, comprising one litre of blood (bovine blood) at a temperature of 37° C., a pressure manometer, a degassing device according to the present disclosure, a dialyzer (Polyflux® 170 H, Gambro), a drip chamber and the corresponding tubing. Further, the system comprised a first air injection port S 1 and a second air injection port S 2 , with the first air injection port S 1 being located before and the second air injection port S 2 being located after the pressure manometer. The amount or volume of air which left the degassing device was determined by measuring the amount of water which was eliminated from a tube containing water and into which the air coming from the degassing device was introduced. The amount of air introduced into the system via the injection ports can of course be varied. The air injection can be done in a continuous fashion or as a bolus. The flow was adjusted to Q B =300 ml/min, the venous pressure was adjusted to 100 mmHg. [0082] The degassing device used had an inner diameter of 32 mm and a spiral height of 17 mm over the total length of the spiral. The spiral had a rotation of 1.6. The distance of the membrane from the upper rim of the spiral was 1.5 mm. The membrane was a MMT-323 (0.2 μm) PTFE membrane from GORE Medical Membranes, coated with a solution comprising 5% Antifoam A® and 95% of hexane as solvent. [0083] FIG. 7 shows the removal of a bolus of 10 ml, injected at injection port S 1 , i.e. on the arterial side of the system. [0084] The injected air is completely removed from the system, no air remains in the system or the degassing device either as bubbles in the fluid or as an air cushion. The degassing is achieved within a very short period of time, i.e. within seconds. Controls with saline instead of blood showed that there is virtually no difference between the degassing of the liquids, i.e. blood is degassed as good as the significantly less complex saline liquid. [0085] FIG. 8 shows the removal of a continuous injection of 10 ml/min of air at injection port S 1 (arterial side), about 4.5 hours after the test had been started. As can be seen, the air was removed from the system as fast as it was introduced into the system, i.e. with a velocity of 10 ml/min, resulting in a straight slope. This test also shows that the proposed degassing device is able to provide for highly improved degassing efficiency. [0086] For comparison, FIG. 9B shows the degassing profile of a standard degassing device. A bolus of 2 ml was injected at injection port S 1 (arterial side). As can be deduced from the drawing, 1.5 min are needed for removing 1.8 ml of the injected air. The proposed degassing device under the same conditions removes a 2 ml bolus in about 0.5 min ( FIG. 9A ). 2. Removal of Air In Vivo [0087] The same degassing device as described in context of Example 1. above was used also for in vivo tests with sheep, based on a standard dialysis setup including an AK 200 Ultra dialysis machine and a Polyflux® 170 H dialyzer ( FIG. 10 ). The system had again injection ports S 1 to S 4 as shown in FIG. 10 , positioned on the arterial or the venous side of the dialyzer. The system further included two degassing devices according to the present disclosure (see Example 1.) which were positioned before (arterial side) and after (venous side) the dialyzer, respectively. [0088] After the priming of the system the dialysis was performed at a venous pressure of 100 mmHg. The Q B was 300 ml/min. A first air injection (2 ml bolus) was performed 20 min after the start of the priming, a second air injection (2 ml bolus) was performed 65 min after the start. A third air injection (5 ml bolus) was performed after 125 min, a fourth air injection (continuous boli of 1, 2, 5 and 10 ml/min) after 185 min. A fifth and last bolus of 10 ml air was injected after 205 min. [0089] FIG. 11 exemplarily shows the profile for the fourth air injection, including four consecutive continuous injections of 1, 2, 5 and 10 ml/min (4), and the profile for the fifth bolus of 10 ml after almost 3.5 hours (5). The profile on the left displays a control injection directly before the degassing device measuring the air which is removed. [0000] Injection Air detected Injection No. Bolus [ml] Site by ABC [ml] 1 2 S2 0.00 2 2 S2 0.00 3 5 S1 0.02 4  1* S1 0.00 4  2* S1 0.00 4  5* S1 0.00 4 10* S1 0.00 5 10  S1 0.00 *continuous injection [ml/min] [0090] The table above shows the results of the in vivo test in terms of air which could be detected via the air bubble counter (ABC) after a given time after the injection. [0091] Further air injection tests were done in this setup, i.e. injection of air before and after the dialyzer (S 3 and S 4 ), which air was then removed by the degassing device on the venous side. These results were compared to the degassing efficiency in cases where the air injection was done at S 1 and S 2 and removed from the system by the degassing device on the arterial side of the system. [0092] As various changes could be made in the above constructions without departing from the scope of the present disclosure, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not limiting.

A device for degassing gas bubbles out of a liquid comprises a housing having a liquid inlet, a liquid outlet and a gas bubble outlet. The housing includes a spiral wall defining a spiral flow path for the liquid and a hydrophobic membrane above the spiral wall and between the spiral wall and the gas bubble outlet. The spiral wall forces inward liquid entering the housing through the inlet into a spiral flow along the spiral flow path, and causes an upward flow of the gas bubbles toward the hydrophobic membrane. A method for degassing gas bubbles out of a liquid, e.g., blood, e.g., during hemodialysis, hemofiltration and hemodiafiltration, and use of such a degassing device in an extracorporeal circuit for degassing gas bubbles out of liquid, e.g., blood, e.g., during hemodialysis, hemofiltration and hemodiafiltration, are disclosed.

[0001] This application is a Continuation in Part of U.S. patent application Ser No. 09/731,479 filed Dec. 6, 2000, entitled “Fast Dissolving Tablet,” the contents of which are incorporated herein in their entirety to the extent that it is consistent with this invention and application. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The current invention relates to tablets of low hardness but good physical stability, in particular fast dissolving tablets that can be made at very low compression force, yet have acceptable stability, and methods for preparing such tablets. [0004] 2. Description of the Related Art [0005] Several processes are presently available by which a tablet, which dissolves quickly in the mouth, may be formulated. However, various disadvantages are associated with these currently available methods for producing fast dissolving tablets. For example the addition of high levels of disintegrants is disclosed by Cousin et al. (U.S. Pat. No. 5,464,632). Cousin et al. add two disintegrants to the disclosed tablet formulations, for example 16% starch 1500 and 13.3% crossprovidone. The oral-disintegration time of these tablets is 35 seconds to 45 seconds. However, tablets including high levels of disintegrants have a chalky or dry feel when placed in the mouth. [0006] Another process for producing fast dissolving tablets involves freeze drying or lyophilizing solutions or suspensions of an active ingredient and matrix forming excipients. Pehley et al. (U.S. Pat. No. 5,298,261) disclose freeze-drying a slurry or paste comprising an active ingredient and excipients placed in blister packets. Humnbert-Droz et al. (WO 97/36879) disclose vacuum drying, at room temperature or a slightly elevated temperature, a suspension including the active drug, a sugar alcohol, PEG 6000, talc, sweeteners and flavors in preformed blisters. The disadvantages of the freeze drying or vacuum drying methods are time (very slow process), cost of the equipment (not done on conventional tablet manufacturing equipment), and that it is limited to low dose actives. [0007] Fast-dissolving tablets may also be formulated by the inclusion of effervescent coupled compounds. Wehling et al. (U.S. Pat. No. 5,178,878 and WO 91/04757) disclose the addition of an effervescent couple (such as sodium bicarbonate and citric acid) to a tablet. Exposure of the tablet to moisture results in contact and chemical reaction between the effervescent couple which leads to gas production and tablet disintegration. For this reason, tablets which include effervescent pairs are highly sensitive to moisture and have an unpleasant mouthfeel. [0008] Tablets formed by compression under low compression fore also dissolve more rapidly than tablets formed by high compression force. However, tablets produced by these processes have a high degree of friability. Crumbling and breakage of tablets prior to ingestion may lead to uncertainty as to the dosage of active ingredient per tablet. Furthermore, high friability also causes tablet breakage leading to waste during factory handling. [0009] The present invention addresses these and other problems associated with the prior art. The invention provides fast-dissolving tablets of low hardness, low friability and high stability which have the added advantage of cost-effective methods of manufacture and are amenable to established manufacturing and packaging methods. In particular, the fast-dissolving tablets of the invention melt rapidly in the mouth and provide an excellent mouth feel. SUMMARY OF THE INVENTION [0010] The present invention advantageously provides compositions and methods for preparing a fast dissolving tablet of low hardness but good physical stability that can be made at very low compression force. [0011] Thus, the invention provides a tablet comprising a low melting point compound that melts or softens at or below 37° C. a water soluble excipient, and an active ingredient. Preferably, the low melting point compound comprises from about 0.01% to about 20% (wt/wt) of the composition (e.g., 0.01, 0.1, 1, 2.5, 5, 7.5, 10, 12, 14, 16, 18, or 20% (wt/w). Preferably, the tablet has a hardness of about 3 kP or less, more preferably about 2 kP or less, and still mom preferably about 1 kP or less. Preferably, the minimum hardness of the tablet is about 0.1 kP, although lower values, including 0.05 kP, are possible. When established manufacturing and packaging methods are used the low melting point compound preferably comprises about 0.01% to about 2% (wt/wt) of the composition and the tablet hardness is preferably about 1.0 to about 2.0 kP and more preferably between about 1.2 and about 1.5 kP. [0012] The invention further provides a method of producing a tablet composition. The method comprises combining an active agent (also termed “active ingredient” or “active”) with a fast dissolving granulation. The fast dissolving granulation comprises a low melting point compound and a water soluble excipient. Preferably, the low melting point compound is present in an amount that will yield values (i.e., content thereof) of about 0.01% to about 20% (wt/wt) in a final tablet composition (e.g., 0.01, 0.1, 1, 2, 2.5, 5, 7.5, 10, 12, 14, 16, 18, or 20% (wt/wt)). [0013] The accompanying Derailed Description, Examples and Drawings further elaborate the invention and its advantages. BRIEF DESCRIPTION OF THE DRAWINGS [0014] FIG. 1 shows a graph of tablet hardness as a function of compression force for tablets of the invention prepared by a melt granulation process (diamonds), and tablets prepared by direct compression (squares). [0015] FIG. 2 shows a graph of friability as a function of tablet hardness; “Number of Rotations” indicates a number of rotations in a Friabilator which occur before a tablet breaks. Tablets prepared by melt granulation (diamonds) or by direct compression (squares) were evaluated. [0016] FIG. 3 shows a graph of time onset of disintegration (T1) as a function of compression force for tablets of the invention (diamonds) and for tablets formed by direct compression (squares). [0017] FIG. 4 shows a graph of disintegration time (T2) as a function of compression force for tablets of the invention (diamonds) and for tablets formed by direct compression (squares). [0018] FIG. 5 shows a graph of disintegration time as a function of the friability (as measured by the number of rotations in a Friabilator before a first tablet breaks) for tablets of the invention (diamonds) and for tablets formed by direct compression (squares). [0019] FIG. 6 shows a graph of time to dissolve (mean of disintegration time in seconds for 34 samples of a tablet of the invention (MG), two types of tablets formed by direct compression (DC1 and DC2), and a commercial fast dissolving tablet (KIDTAB®). [0020] FIG. 7 shows a graph of grittiness score (adjusted mean determined by least squares from ANOVA). Subjects scored this sensory attribute on a scale of 1 (low grittiness) to a 9 (high grittiness). Tablets were as described for FIG. 6 . [0021] FIG. 8 shows a graph of chalkiness score (adjusted mean determined by least squares from ANOVA). Subjects scored this sensory attribute on a scale of 1 (low chalkiness) to a 9 (high chalkiness). Tablets were described for FIG. 6 . [0022] FIG. 9 shows a graph of overall preference ranking for each product (as described in FIG. 6 ), represented by the percentage of subjects ranking each product 1 st , 2 nd . 3 rd , or 4. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS [0023] The current invention provides fast dissolving tablet formulations that can be formed by compression into a conventional tablet. Tablet friability is lower than conventional fast dissolving tablets prepared by low compression. The fast dissolving tablet has at least one compound (or “component”) which partially or fully melts or softens at or below body temperature and a water soluble excipient. Surprisingly, it has been found that use of the component which partially or fully melts below body temperature in an amount of about 0.01% to about 2.5% w. In the tablet provides for a fast dissolving tablet composition that is conveniently amenable to established tablet manufacturing processes and equipment and to established packaging methods. Amenable to established tablet and manufacturing processes and equipment is taken to mean that the composition (which forms the tablet) may be processed with conventional manufacturing equipment with minimal occurrence of malformed product and/or the need for special equipment maintenance procedures. The low melting point compound may be hydrophilic or hydrophobic. The tablets of the invention may also include an active ingredient and may also include one or more disintegrants, flavors, colorants, sweeteners, souring agents, glidants or lubricants. [0024] The hardness of the tablets is low (less than or equal to about 3 kP), preferably less than or equal to about 2 kP, and more preferably less than or equal to about 1 kP, with a minimum hardness of about 0.1 kP (e.g., 0.05, 0.07, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.3, 1.6, 1.9, 2.0, 2.1, 2.3, 2.5, 2.7, 2.8, or 3.0 kP). In embodiments well suited to established manufacturing and packaging methods, the tablet hardness is preferably about 1.2 to about 1.5 kP. In other embodiments, hardness ranges from about 0.2 to about 1 kP. Attributes such as (1) fast stable dissolution; (2) good tablet mouth feel; and (3) good tablet physical stability are of greater importance than minimum and maximum values of tablet hardness. Nevertheless, the tablets are somewhat pliable, and are less fragile than conventional tablets that have the same crushing strength. The tablets have an excellent mouthfeel resulting from the low melting point component which melts or softens in the mouth to produce a smooth feel and masks the grittiness of insoluble ingredients. Unlike other fast dissolving tablets, the disintegration of this fast dissolving tablet occurs by a combination of melting, disintegration of the tablet matrix, and dissolution of water soluble excipient. Therefore, a dry feels does not occur. Disintegration time is 10 to 30 seconds (e.g., 10, 12, 14, 16, 18, 20, 22, 24, 26, 28 or 30 seconds), depending on the tablet size and amount of insoluble ingredients, e.g., coated active. Even though the tablet contains a low melting point ingredient. It is relatively stable to high temperatures. Heating the tablet above the melting point of its low melting point component will not significantly reduce its physical stability. [0025] The friability of conventional tablets is measured by the percentage weight loss after a typical friability test (rotating 10 tablets in a friability apparatus for 100 rotations). This test is very harsh for conventional fast dissolving tablets and so cannot be used to measure their friability. Fast dissolving tablets made by a prior art method of direct compression at low force crumble after a few rotations in the friability apparatus. Fast dissolving tablets manufactured by the method in the current invention can withstand 20-50 rotations in the friability apparatus before any tablet breaks. After 20 rotations, the friability (% weight lost) is typically less than 1%. [0026] The term “low melting point compound” may include any edible compound which melts or softens at or below 37° C. which is suitable for inclusion in the tablets of the invention. Materials commonly used for manufacturing suppositories usually have a melting point at or just below body temperature and can be used in the invention. The low melting point compound can be hydrophilic or hydrophobic. [0027] Examples of hydrophilic low-melting point compounds include, but are not limited to polyethylene glycol; the preferred mean molecular weight range of polyethylene glycol for use in the tablets of the invention is from about 900 to about 1000. Mixtures of polyethylene glycol with different molecular weights (200, 300, 400, 550, 600, 1450, 3330, 8000 or 10,000) are within the scope of the invention if the mixture melts or softens at or below 37 degrees celsius. [0028] Examples of hydrophobic low-melting point compounds include, but are not limited to low melting point triglycerides, monoglycerides and diglycerides, semisynthetic glyceride (e.g., EUTECOL®, GELUCIRE® (gatteffosse)), hydrogenated oils, hydrogenated oil derivatives or partially hydrogenated oils (e.g., partially hydrogenated palm kernel oil and partially hydrogenated cottonseed oil), fatty acid esters such as myistyl lactate, stearic acid and palmitic acid esters, cocoa butter or its artificial substitutes, palm oil/palm oil butter, and waxes or mixtures of waxes, which melt at 37° C. or below. In preferred embodiments, the hydrogenated oil is Wecobec M. To be effective in the tablet compositions, the low melting point compound must be edible. [0029] Mono-di- and triglycerides are rarely used as pure components. Hydrogenated vegetable oils and solid or semisolid fats are usually mixtures of mono-di and triglycerides. The melting point of the fat or hydrogenated vegetable oil is characteristic of the mixture and not due to a single component Witepsol (brand name by Condea), Supocire (brand name by Gattefosse), and Novata (brand name by Henkel) are commonly used in manufacturing suppositories, because they melt a body temperature. All are mixtures of triglycerides, monoglycerides and diglycerides. [0030] In preferred embodiments, the low melting point compound comprises from about 0.01% to about 20%, by weight, of a tablet composition (e.g. about 0.01, 0.1, 1, 2.5, 5, 7.5, 10, 12, 14, 15, 16, 18 or 20% (wt/wt)). Concentration of low melting point compound in the amount of about 0.01% to about 2% (wt/wt) of the tablet are preferable when established manufacturing and packaging methods are used. The tablets of the present invention also include a water soluble excipient. As used herein, the term “water soluble excipient” refers to a solid material or mixture of materials that is orally ingestible and readily dissolves in water. Examples of water soluble excipients include but are not limited to saccharides, amino acids, and the like. Saccharides are preferred water soluble excipients. Preferably, the saccharide is a mono-, di- or oligosaccharide. Examples of saccharides which may be added to the tablets of the invention may include sorbitol, glucose, dextrose, fructose, maltose and xylitol (all monosaccharides); sucrose, lactose, glucose, galatose and mannitol (all disaccharides). In a specific embodiment, exemplified below, the saccharide is lactose. Preferably, the saccharide is mannitol. Other suitable saccharides are oligosaccharides. Examples of oligosaccharides are dextrates and maltodextrins. Modified saccharides such as sucralose or other artificial sweeteners such as saccharin or aspartame, for example, may be used. Other water soluble excipients may include amino acids such as alanine, arginine, aspartic acid, asparagine, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine and valine. Glycine and lysine are preferred amino acids. [0031] In preferred embodiments, the water soluble excipient comprises from about 25% to about 97.5%, by weight, of a tablet composition. The preferred range is about 40% to about 80%. For example, tablet compositions comprising about 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95 or 97.5%, by weight, of the excipient, e.g. monosaccharide, disaccharide, polysaccharide, modified saccharide, artificial sweetener or mixtures thereof are within the scope of the invention. [0032] As used herein, the term “about” (or “approximately”) means a particular value can have a range acceptable to those of skill in the at given the nature of the value and method by which it is determined. In a specific embodiment, the term means within 50% of a given value, preferably within 20%, more preferably within 10%, and more preferably still within 5%. Active Ingredients [0033] As used herein, the term “active ingredient” or “active agent” refers to one or more compounds that have some pharmacological property. Accordingly, more than one type of active ingredient compound may be added to the tablets of the invention. The tablets of the invention may comprise any active ingredient which may be orally administered to a subject. Tablets including active ingredients in amounts appropriate for the desired pharmacological properties at the dosage administration can be formulated. Any amount of active ingredient that does not significantly affect beneficial tablet features, such as hardness, friability and mouthfeel are within the scope of the invention. Placebo tablets, which lack an “active ingredient” having a known pharmacologic activity, are also within the scope of the invention. An “active ingredient” of a placebo can be the water soluble excipient (i.e., lacking any identifiable “active”), a different water soluble compound, or any non-active compound. [0034] A non-limiting list of acceptable active ingredients may include but is by no means limited to: 1) antipyretic analgesic anti-inflammatory agents such as indomethacin, aspirin, diclofenac sodium, ketoprofen, ibuprofen, mefenamic acid, dexamethasone, dexamethasone sodium sulfate, hydrocortisone, prednisolone, azulene, phenacetin, isopropylantipyrin, acetaminophen, benzydamine hydrochloride, phenylbutazone, flufenamic acid, mefenamic acid, sodium salicylate, choline salicylate, sasapyrine, clofezone or etodolac: 2) antiulcer agents such as ranitidine, sulpiride, cetraxate hydrochloride, gefarnate, irsogladine maleate, cimetidine, lanitidine hydrochloride, famotidine, nizatidine or roxatidine acetate hydrochloride; 3) coronary vasodilators such as Nifedipine, isosorbide dinitrate, diltiazem hydrochloride, trapidil, dipyridamole, dilazep dihydrochloride, methyl 2,6-dimethyl-4-(2-nitrophenyl)-5-(2-oxo-1,3,2-dioxaphosphorinan-2-yl)-1,4-dihydropyridine-3-carboxylate, verapamil, nicardipine, nicardipine hydrochloride or verapamil hydrochloride; 4) peripheral vasodilators such as ifenprodil tartrate, cinepazide maleate, cyclandelate, cinnarizine or pentoxyfyline; 5) oral antibacterial and antifungal agents such as penicillin, ampicillin, amoxicillin, cefalexin, erythromycin ethylsuccinate, bacampicillin hydrochloride, minocycline hydrochloride, chloramphenicol, tetracyline, erythromycin, fluconazole, itraconazole, ketoconazole, miconazole or terbinafine; 6) synthetic antibacterial agents such as nalidixic acid, piromidic acid, pipemidic acid trihydrate, enoxacin, cinoxacin, ofloxacin, norfloxacin, ciprofloxacin hydrochloride, or sulfamethoxazole trimethoprim; 7) antispasmodics such as propantheline bromide, atropine sulfate, oxapium bromide, timepidium bromide, butylscopolamine bromide, rospium chloride, butropium bromide, N-methylscopolamine methylsulfate, or methyloctatropine bromidebutropium bromide; 8) antitussive, anti-asthmatic agents such as theophylline, aminophylline, methylephedrine hydrochloride, procaterol hydrochloride, trimetoquinol hydrochloride, codeine phosphate, sodium cromoglicate, tranilast, dextromethorphane hydrobromide, dimemorfan phosphate, clobutinol hydrochloride, fominoben hydrochloride, benproperine phosphate, tipepidine hibenzate, eprazinone hydrochloride, clofedanol hydrochloride, ephedrine hydrochloride, noscapine, carbetapentane citrate oxeladin tannate, or isoaminile citrate; 9) bronchodilators such as diprophylline, salbutamol sulfate, cloprenaline hydrochloride, formoterol fumarate, orciprenaline sulfate, pirbuterol hydrochloride, hexoprenaline sulfate, bitolterol mesylate, clenbuterol hydrochloride, terbutaline sulfate, mabuterol hydrochloride, fenoterol hydrobromide, or methoxyphenamine hydrochloride: 10) diuretics such as furosemide, acetazolamide, trichlormethiazide, methylclothiazide, hydrochlorothiazide, hydroflumethiazide ethiazide, cyclopenthiazide, spironolactone, triamterene, fluorothiazide, piretanide, mefruside, ethacrygnic acid, azosemide, or clofenamide; 11) muscle relaxants such as chlorphenesin carbamate, tolperison hydrochloride, eperisone hydrochloride, tizanidine hydrochloride, mephenesin, chlorzoxazone, phenprobamate, methocarbamol, chlormezanone, pridinol mesylate, afloqualone, baclofen, or dantrolene sodium: 12) brain metabolism altering drugs such as meclofenoxate hydrochloride; 13) minor tranquilizers such as oxazolam, diazepam, clotiazepam, medazepam, temazepam, fludiazepam, meprobamate, nitrazepam, or chlordiazepoxide; 14) major tranquilizers such as sulpiride, clocapramine hydrochloride, zotepine, chlorpromazinon, haloperidol; 15) β-blockers such as pindolol, propranolol hydrochloride, carteolol hydrochloride, metoprolol tartrate, labetalol hydrochloride, acebutolol hydrochloride, butethanol hydrochloride, alprenolol hydrochloride, arotinolol hydrochloride, oxprenolol hydrochloride, nadolol, bucumolol hydrochloride, indenolol hydrochloride, timolol maleate, befunolol hydrochloride, or bupranolol hydrochloride; 16) antiarrhythinic agents such as procainamide hydrochloride, disopyramide, ajimaline, quinidine sulfate, aprindine hydrochloride, propafenone hydrochloride, or mexiletine hydrochloride; 17) gout suppressants allopurinol, probenecid, colchine, sulfinpyrazone, benzbromarone, or bucolome; 18) anticoagulants such as ticlopidine hydrochloride, dicumarol, or warfarin potassium: 19) antiepileptic agents such as phenyloin, sodium valproate, metharbital, or carbamazepine; 20) antihistamines such as chlorpheniramine maleate, cremastin fumarate, mequitazine, alimenazine tatrate, or cycloheptazine hydrochloride; 21) antiemetics such as difenidol hydrochloride, metoclopramide, domperidone, betahistine mesylate, or trimebutine maleate; 22) hypotensives such as dimethylaminoethyl reserpilinate dihydrochloride, rescinnamine, methyldopa, prazosin hydrochloride, bunazosin hydrochloride, clonidine hydrochloride, budralazine, or urapidin; 23) sympathomimetic agents such as dihydroergotamine mesylate, isoproterenol hydrochloride, or etilefrine hydrochloride; 24) expectorants such as bromhexine hydrochloride, carbocysteine, ethyl cysteine hydrochloride, or methyl cysteine hydrochloride; 25) oral antidiabetic agents such as glibenclamide, tolbutamide, or glymidine sodium; 26) circulatory agents such as ubidecarenone or ATP-2Na; 27) iron preparations such as ferrous sulfate or dried ferrous sulfate; 28) vitamins such as vitamin B1, vitamin B2, vitamin B6, vitamin B12, vitamin C, Vitamin A, vitamin D, vitamin E, vitamin K or folic acid; 29) pollakiuria remedies such as flavoxate hydrochloride, oxybutynin hydrochloride, terodiline hydrochloride, or 4-diethylamino-1,1-dimethyl-2-butynyl (1)-α-cyclohexyl-α-phenylglycolate hydrochloride monohydrate; 30) angiotensin-converting enzyme inhibitors such as enalapril maleate, alacepril, or delapril hydrochloride; 31) anti-viral agents such as trisodium phosphonoformate, didanosine, dideoxycytidine, azido-deoxythymidine, didehydro-deoxythymidine, adefovir, dipivoxil, abacavir, amprenavir, delavirdine, efavirenz, indinavir, lamivudine, nelfinavir, nevirapine, ritonavir, saquinavir or stavudine; 32) high potency analgesics such as codeine, dihydrocodeine, hydrocodone, morphine, dilandid, demoral, fentaryl, pentazocine, oxycodone, pentazocine or propoxyphene: 33) antihistamines such as Brompheniramine maleate; 34) nasal decongestants such as phenylpropanolamine HCl and 35) antacids such as calcium carbonate, calcium hydroxide, magnesium carbonate, magnesium hydroxide, potassium carbonate, potassium bicarbonate, sodium carbonate, and sodium bicarbonate. Active ingredients in the foregoing list may also have beneficial pharmaceutical effects in addition to the one mentioned. Other Tablet Ingredients [0035] The term “tablet” refers to a pharmacological composition in the form of a small, essentially solid pellet of any shape. Tablet shapes may be cylindrical, spherical, rectangular, capsular or irregular. The term “tablet composition” refers to the substances included in a tablet. A “tablet composition constituent” or tablet constituent” refers to a compound or substance which is included in a tablet composition. These can include, but are not limited to the active and any excipients in addition to the low melting point compound and the water soluble excipient(s). An excipient is any ingredient in the tablet except the active. In addition to the low melting point compound excipients may include, for example, binders, disintegrants, flavorants, colorants, glidants, souring agents and sweeteners. [0036] For purposes of the present application, “binder” refers to one or more ingredients added before or during granulation to form granules and/or promote cohesive compacts during compression. A “binder compound” or “binder constituent” is a compound or substance which is included in the binder. Binders of the present invention include, at least, the low melting point compound. [0037] Additionally, and optionally, other substances commonly used in pharmaceutical formulations can be included such as flavors (e.g., strawberry aroma, raspberry aroma, cherry flavor, magnasweet 135, key lime flavor, grape flavor trusil art 5-11815, fruit extracts and prosweet), flavor enhancers and sweeteners (e.g. aspartame, sodium saccharine, sorbitol, glucose, sucrose), souring agents (e.g. citric acid), dyes or colorants. [0038] The tablet may also contain one or more glidant materials which improve the flow of the powder blend and minimize tablet weight variation. Glidants such as silicone dioxide may be used in the present invention. [0039] Additionally, the tablets of the invention may include lubricants (e.g. magnesium stearate) to facilitate ejection of the finished tablet from dies after compression and to prevent tablets from sticking to punch faces and each other. [0040] Any method of forming a tablet of the invention into a desired shape which preserves the essential features thereof is within the scope of the invention. Tablet Formation [0041] A preferred method of forming the tablet compositions of the invention includes preparing a fast dissolving granulation by mixing a low-melting point compound, (preferably a hydrogenated oil, partially hydrogenated oil or hydrogenated oil derivative) and a water soluble excipient, (preferably a saccharide or modified saccharide). The term “fast dissolving granulation” refers to a composition of the low melting point compound and the water soluble excipient prepared for use as a granulation in the manufacture of tablets of the invention. A portion of the fast dissolving granulation may then be added to the remaining ingredients. However, methods of forming the tablets of the invention wherein all tablet constituents are combined simultaneously or wherein any combination of tablet constituents are combined separate from the other constituents are within the scope of the invention. [0042] Granulation end point can be determined visually (visual inspection) or by using a load cell that measures power consumption. Tablet manufacturing and granulation routinely employ both techniques. [0043] The tablet compositions of the invention can be formed by melt granulation which is a preferred method. In particular, the melt granulation can be prepared in a high shear mixer (e.g. high sheer granulation process), low sheer mixer or fluid bed granulator. An example of high shear mixer is Diosna (this is a brand name by Diosna Dierks & Söhne GmbH). Examples of low shear mixers are various tumbling mixers (e.g. twin shell blenders or V-blender). Examples of fluid bed granulators are Glatt and Aeromatic fluid bed granulators. [0044] There are at least three ways of manufacturing the granulation: Melting the low melting point ingredient, then combining (e.g. by spraying) it with the water soluble ingredient(s) (including the water soluble excipient) in the granulator and mixing until granules form. Loading the water soluble excipient in the granulator and spraying the molten low melting point compound on it while mixing. Combining the two (water soluble component (including the water soluble excipient) and low melting point component) and possibly other ingredients and mixing while heating to a temperature around a higher than the melting point of the low melting point component until the granules form. [0048] After the granulation congeals, it may be milled and/or screened. Examples of mills that can be used are CoMill. Stokes Oscillator (these are brand names). Any mills that are commonly used for milling tablet granulations may be used. [0049] Melt extrusion can be used to form the fast dissolving granulation. An example of an extruder that can be used is Nica (a brand name by Niro-Aeromatic). The low melting point compound and the water soluble saccharide (or other excipient) are mixed and heated in a planetary mixer bowl (low shear mixer) that is usually part of the extruder. The soft mass is then fed to the extrusion chamber and forced through small holes or orifices to shape it into thin rods or cylinders. After the extruded material congeals it can be milled or spheronized using standard equipment. In the spheronization step, the extrudate is dumped onto the spinning plate of the spheronizer and broken up into small cylinders with a length equal to their diameter, then rounded by frictional forces (See, International Journal of Pharmaceutics 1995, 116:131-146, especially p. 136). [0050] Spray congealing or prilling can also be used to form the tablet compositions of the invention. Spray congealing includes atomizing molten droplets of compositions which, may include low melting point compound, low melting point compound and selected tablet ingredients, or the entire tablet composition onto a surface. The surface may be an inert mechanical support, a carrier surface or in embodiments in which the spray contain droplets only part of the tablet components a second portion of the tablet composition. Equipment that can be used for spray congealing includes spray driers (e.g., Nero spray drier) and a fluid bed coater/granulation with top spray (e.g., Glatt fluid bed coater/granulator). In preferred embodiments, a fast-dissolve granulation is formed wherein, preferably a water soluble excipient, more preferably a saccharide, is suspended in a molten low melting point ingredient and spray congealed. After spray congealing, the resulting composition is allowed to cool and congeal. Following congealing of the mixture, it is screened or sieved and mixed with remaining tablet constituents. Spray congealing processes wherein fast-dissolve granulations comprising any combination of low melting point compound and other tablet constituents are melted and spray congealed onto other tablet constituents are within the scope of the present invention. Spray congealing processes wherein all tablet constituents, including the low-melting point compound, are mixed, the low melting point compound is melted and the mixture is spray congealed onto a surface are also within the scope of the invention. [0051] After spray congealing, the mixture may be milled and then combined with other tablet constituents. Following formation of the final tablet composition, the composition may be further processed to form a tablet shape. [0052] Mixing and milling of tablet constituents during the preparation of a tablet composition may be accomplished by any method which causes the composition to become mixed to be essentially homogeneous. In preferred embodiments the mixers are high shear mixers such as the Diosna, CoMill or V-Blender. [0053] Once tablet compositions are prepared, they may be formed into various shapes. In preferred embodiments, the tablet compositions are pressed into a shape. This process may comprise placing the tablet composition into a form and applying pressure to the composition so as to cause the composition to assume the shape of the surface of the form with which the composition is in contact. In preferred embodiments, the tablet is compressed into the form at a pressure which will not exceed about 10 kN, preferably less than 8 kN. For example, pressing the tablets at less than 1, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 6, 7, 8, 9 or 10 kN is within the scope of the invention. The tablets of the invention generally have a hardness of about 3 kP or less; preferably the tablets have a hardness of about 2 kP or less and more preferably about 1 kP or less. For compositions subjected to established manufacturing methods hardness of about 1 to about 2.0 is preferred and harness of about 1.2 to about 1.5 is more preferable. In another embodiment, for example, tablets of less than 0.1 kP including tablets of about 0.05, 0.07 kP and tablets of about 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.3, 1.6, 1.9, 2.0, 2.1, 2.3, 2.5, 2.7, 2.8, or 3.0 are within the scope of the invention. Hydraulic presses such as a Carver Press or rotary tablet presses such as the Stokes Versa Press are suitable means by which to compress the tablet compositions of the invention. [0054] Tablets may also be formed by tumbling melt granulation (TMG) essentially as described in Maejima at al. Chemical Pharmacology Bulletin (1997) 45(3): 518-524; which is incorporated herein by reference. Tumbling melt granulation can be used for preparing the melt granulation. It can be done in a tumbling mixer. The molten low melting point compound is sprayed on the crystalline saccharide and powdered saccharide in the blender and are mixed until granules form. In this case, the low melting point ingredient is the binder and the crystalline saccharide is the seed. An alternative method is to combine the unmelted low melting point ingredient, crystalline sugar (e.g., mannitol or lactose) in the tumbling mixer and mix while heating to the melting point of the low melting point binder or higher. The seed should be crystalline or granular water soluble ingredient (saccharide), e.g., granular mannitol, crystalline maltose, crystalline sucrose, or any other sugar. An example of tumbling mixers is the twin-shell blender (V-blender), or any other shape of tumbling mixers. Heating can be achieved by circulating heated air through the chamber of the granulator and by beating the bottom surface of the chamber. As the seed material and the powdered tablet constituents circulate the heated chamber, the low-melting point compound melts and adheres to the seeds. The unmelted, powdered material adheres to the seed-bound, molten low-melting point material. The spherical beads which are formed by this process are then cooled and screen sifted to remove nonadhered powdered material. Example 1 Fast Dissolving Granulation [0055] Compositions of Fast Dissolving Granulations. In these compositions, the water soluble excipient is a saccharide. As described above, the tablets of the invention may be formulated by a method wherein a fast dissolving granulation, comprising a low melting point compound and a water soluble excipient, is mixed separately from other tablet constituents. A portion of the fast dissolving granulation may then be combined with the other tablet constituents. In this example, several specific examples of fast dissolving granulations are set forth. [0000] TABLE 1 Fast dissolving granulation formulations. Fast Dissolving Granulation Low Melting Point Saccharide Composition Compound (amount) (amount) 1 Wecobee M hydrogenated mannitol powder vegetable oil (1 Kg) (5 Kg) 2 Gelucire 33/01 semisynthetic mannitol powder glycerides (200 g) (1 Kg) 3 Wecobee M (150 g) crystalline maltose (100 g) mannitol powder (750 g) 4 polyethylene glycol 900 (100 g) fructose powder (400 g) [0056] Fast dissolving granulations 1 and 2 were prepared by heating the low melting point compound to 50° C. At 50° C., Wecobee M and Gelucire 33/01 become molten. The molten material was gradually added to the mannitol powder in a high shear granulator (Diosna). The granulation was mixed at high speed. When the granulation end point was reached as determined by visual inspection, the granulation was allowed to congeal. The congealed granulation was then milled using a CoMill. [0057] Granulation 3 was granulated by combining melted Wecobee M with the mannitol in a high shear mixer (Robot Coupe) and blending until the granules formed. Granulation 4 was made by combining the melted PEG with fructose powder in a planetary mixer (low shear mixer) and mixing until the granules formed. The granulations were allowed to coot, then were screened. Example 2 Fast Dissolving Ibuprofen Tablets [0058] The following is an example of a fast dissolving tablet wherein the active ingredient is ibuprofen. [0000] Ingredient Amount (mg tablet) Coated ibuprofen (active ingredient) 121.9 (equivalent to 100 mg ibuprofen) Citric acid (souring agent) 11.0 Magnasweet 135 (sweetening agent) 3.9 Aspartame (sweetening agent) 6.5 Cherry flavor (flavoring agent) 7.8 Crosscarmellose sodium (disintegrant) 39.0 Silicone dioxide (glidant flow aid) 1.95 Magnesium stearate (lubricant) 3.25 Fast dissolving granulation 4 457.9 Total 653.2 [0059] Ingredients were screened, then mixed in a V-blender. Tablets were compressed using a hydraulic press (Carver Press) at 600 lb (about 2.7 kN). The tablets had a hardness of 0.2-0.5 kP and disintegrated in less than 15 seconds. [0060] The following is an example of a fast dissolving tablet comprising the active ingredients of many common allergy medications, Phenylpropanolamine HCl and Brompheniramine maleate. [0000] Ingredient Amount (mg/tablet) Phenylpropanolamine HCl (active ingredient) 6.25 Brompheniramine maleate (active ingredient) 1.0 Citric acid (souring agent) 6.0 Magnasweet 135 (sweetening agent) 1.80 Aspartame (sweetening agent) 4.5 Cherry flavor (flavoring agent) 3.60 Corn Starch (anti-adherent) 30.0 Silicone dioxide (glidant flow aid) 3.0 Fast dissolving granulation 4 219.25 Magnesium stearate (lubricant) 2.1 Total 301.5 [0061] Tablets were compressed on a hydraulic press (Carver Press) at approximately 3 kN. Tablet hardness was 0.2-0.5 kP and disintegration time 10 seconds. Example 4 Fast Dissolving Ibuprofen Tablets [0062] The following is an example of a fast dissolving tablet wherein the active ingredient is ibuprofen. [0000] Ingredient Amount (mg/tablet) Coated ibuprofen (active agent) 119.0 Citric Acid (souring agent) 20.0 Magnasweet 135 (sweetening agent) 7.5 Aspartame (sweetening agent) 7.5 Grape flavor Trusil Art 5-11815 (flavoring agent) 5.00 Prosweet (flavor and sweetness enhancer) 5.00 Crosscarmellose sodium (enhancer) 20.0 Corn Starch, NF (anti-adherent) 40.0 Silicone dioxide (Syloid 244) (glidant flow aid) 5.00 Fast dissolving granulation 1 271 Total 500 [0063] Tablets were compressed using a rotary press (Stokes Versa Press) at 3.3-3.5 kN, resulting in a hardness of 0.2-0.9 kP. In vivo disintegration time was 19 seconds (average of 34 subjects). [0064] Sensory Study: [0065] The melt granulation tablets of Example 4 were evaluated for in vivo disintegration time and mouthfeel in an in-house sensory study. The comparator was Kidtab®, an 80 mg acetaminophen fast dissolving tablet prepared by direct compression. Two other ibuprofen fast dissolving tablets prepared by direct compression were also included in the study. The study included 34 subjects. The subjects were asked to record the time for the tablet to completely dissolve in the mouth and give scores for mouthfeel attributes and overall liking of the product. The melt granulation prototype (based on this invention) performed best on disintegration time ( FIG. 6 ) and mouthfeel attributes (least grittiness ( FIG. 7 ) and least chalkiness ( FIG. 8 )) and were ranked best on the overall performance by the panelists. The following table shows the ranking results of the sensory study on disintegration time and mouthfeel attributes: MG is the melt granulation tablet of the invention. DC1 and DC2 are the two direct compression phototypes. [0000] Ranking (1 = best, 4 = worst) Prototype/Product Sensory Attribute DC1 MG Kidtab DC2 Time to dissolve (seconds) 2 1 4 3 Grittiness 4 1 2 3 Chalkiness 3 1 4 2 Overall Preference 4 1 2 3 [0066] The tablets of the invention were ranked the highest (1, best) in all four categories tested (dissolution time, grittiness, chalkiness and overall performance) against DC1, DC2 and KIDTAB. [0067] As illustrated in FIG. 6 , the tablets of the invention exhibited superior fast dissolving characteristics as compared to the direct compression tablets which were also evaluated (DC1, DC2 and KIDTAB), the average time for the tablet of the invention (MG) to dissolve was 19 seconds wherein the time for DC1, DC2 and KIDTAB to dissolve were about 20, 22 and 25 seconds, respectively. The tablets of the invention also exhibited a moothfeel which was superior to the DC1, DC2 and KIDTAB tablets. FIGS. 7 and 8 indicate the 34 individuals who participated in the study perceived a lower level of grittiness and chalkiness associated with the tablets of the invention as compared to the direct compression tablets (DC1, DC2 and KIDTAB). [0068] Overall preference was also scored (least squares mean from ANOVA) on a scale from 1 (most preferred) to 9 (least preferred). As indicated in FIG. 9 , the tablet of the invention scored highest (2.11), followed by the KIDTAB® (2.29), and the two direct compression tablets (DC2-2.52, DC1-3.05). Example 5 Fast Dissolving Ibuprofen Tablets [0069] The following is an example of a fast dissolving tablet wherein the active ingredient is ibuprofen. [0000] Ingredient (mg/tablet) Coated ibuprofen (active agent) 238.0 Citric Acid (souring agent) 17.5 Magnasweet 135 (sweetening agent) 9.75 Aspartame (sweetening agent) 9.75 Key Lime flavor (flavoring agent) 6.50 Vanilla powder (flavoring agent) 0.650 Corn Starch, NF (anti-adherent) 52.0 Silicone dioxide (Syloid 244) (glidant/flow acid) 6.50 Sodium stearyl fumarate (Pruv) (lubricant) 4.88 Fast dissolving granulation 1 304 Total 650 [0070] Tablets were compressed using a rotary tablet press (Stokes Versa Press) at 3 kN, resulting in a hardness of 0.35-0.60 kP. In vive disintegration time was 16 seconds. Example 6 Compressibility and In Vitro Evaluation of Tablets [0071] To compare fast dissolving tablets of the invention with fast dissolving tablets prepared by direct compression, the following two examples were prepared. [0072] Melt Granulation Fast Dissolving Tablet: [0000] Ingredient (mg/tablet) Ibuprofen microcaps 119.0 Citric Acid, anhydrous, fine granular 20.0 Magnasweet 135 7.5 Aspartame (Nutrasweet) 7.5 Cherry Berry flavor 4.25 Sweet AM 2.50 Crosscarmellose sodium 20.0 Corn Starch, NF 40.0 Silicone dioxide (Syloid 244) 5.00 Fast dissolve granulation* 274.25 TOTAL 500 *The granulation is 85.0% Mannitol powder, USP and 15.0% Wecobee M (hydrogenated vegetable oil). The granulation was prepared similar to granulation 1 in Table 1. [0073] Direct Compression Fast Dissolving Tablet. [0000] Ingredient mg/tablet Ibuprofen microcaps 119.0 Citric Acid, anhydrous, fine granular 20.0 Magnasweet 135 7.5 Aspartame (Nutrasweet) 7.5 Sweet AM 2.5 Fruit Punch flavor 3.50 Crosscarmellose sodium 20.0 Corn Starch, NF 40.0 Silicone dioxide (Syloid 244) 5.00 Mg Stearate 3.50 Fast Dissolve granulation 271.5 TOTAL 500 [0074] Melt granulation tablets and direct compression tablets were prepared based on the same formula, except that granular mannitol was used instead of the fast dissolve melt granulation. The compressibility of the two tablet formulations (melt granulation and direct compression) were compared. The two blends were compressed at different compression forces and the resulting tablets were evaluated for hardness and in vitro disintegration time. Tablet hardness (crashing strength) was measured using a high resolution texture analyzer (Stable Microsystems) with an acrylic cylindrical probe. [0075] In vitro disintegration was performed in a texture analyzer. A tablet was held on a net that was then attached to a ¼″ stainless steal ball probe. The disintegration medium was 5 ml of water in a 50 ml beaker. The height of water was barely enough to submerge the tablet, and the water temperature was kept at 37±1° C. The texture analyzer was instructed to apply a small force (20 g) when the tablet hit the bottom of the beaker. The time for disintegration onset and total disintegration time was recorded. [0076] Compressibility: [0077] Fast dissolving tablets in general are soft and need to be blister-packaged directly off the tablet press. The tablets manufactured according to the invention can be compression or wet granulation. For fast dissolving tablets containing a coated active, it is important to compress at the lowest force possible so that the coating will not be ruptured under compression. With the melt granulation approach, tablets that are robust enough to withstand packaging right off the tablet press were obtained using a compression force as low as 2 kN, whereas for a similar direct compression formulation, acceptable tablets could not be obtained at compression forces below 5 kN ( FIG. 1 ). [0078] Hardness and Friability: [0079] Although the melt granulation tablets had a lower hardness compared to direct compression tablets that are compressed at the same force ( FIG. 1 ), the melt granulation tablets were somewhat pliable and less fragile. As illustrated in FIG. 2 , the softest melt granulation prototype, with a hardness of about 0.2 kP, was able to withstand at least 9 rotations in the friabilator (friability apparatus) before any tablet breaks. At 0.5 kP, these tablets survived 20-30 rotations. Direct compression tablets at about 0.45 kP stated breaking after 4 rotations, while the hardest direct compression prototype with about 0.9 kP hardness only survived 12 rotations. In the same friability test, Kidtab® tablets (marketed fast dissolving tablets prepared by direct compression) started breaking after 5-10 rotations. The average hardness of Kidtab tablets was 1.8 kP. Moreover, at the end of the east, the direct compression tablets showed more chipping around the edges than melt granulation prototypes. Direct compression tablets with hardness greater than 1 kP were not fast dissolving (took 1 minute or more to dissolve in the mouth of a subject). [0080] In Vitro Disintegration: [0081] The onset of disintegration was faster for the melt granulation prototypes compared to direct compression prototypes prepared at the same compression force ( FIG. 3 ). Furthermore, the total time for in vitro disintegration was dependent on compression force regardless of the formulation ( FIG. 4 ). We obtained acceptable tablets from the melt granulation processing low compression force. Direct compression tablets could not be obtained at the same compression force. Therefore, for tablets with similar friability, the melt granulation approach produced faster disintegration time ( FIG. 5 ). [0082] The melt granulation was less sensitive to small changes in compression force, whereas for the direct compression formulation, both hardness and onset of disintegration increased sharply with increasing the compression force ( FIGS. 1 and 3 ). Example 7 Example of Melt Granulation Tablets with Higher Hardness [0083] [0000] Ingredient mg/tablet Ibuprofen microcaps (encapsulated ibuprofen) 121.9 Citric Acid, anhydrous, fine granular 11.0 Magnasweet 135 4.0 Aspartame (Nutrasweet) 6.0 Cherry flavor 6.0 Sweet AM 0.5 Crosscarmellose sodium 45.0 Corn Starch, NF 40.0 Silicone dioxide (Syloid 244) 2.50 Fast dissolve granulation 263.1 TOTAL 500 *The granulation is 85.0% Mannitol powder, USP and 15.0% Wecobee M (hydrogenated vegetable oil). [0084] Tablets were compressed on Stokes Versapress. Compression force was not recorded. Tablet hardness was 1.5 kP. The tablets had a friability of less than 1.0% after 50 rotations in the friabilator, i.e. lost less than 1% of their initial weight and so tablet broke. Man in vivo disintegration time was 25.8 seconds (12 subjects were asked to take the tablets and record the tune it takes for the tablet to completely dissolve without chewing). Example 8 Example of Melt Granulation Tablets Amendable to Established Tablet Manufacturing Process and Packaging Methods [0085] [0000] Composition 1 Ingredient mg/tablet Ibuprofen microcaps 238.0 Sucralose 5.6 Citric acid 28.0 Lemon-lime flavor 1.4 Crosscamellose 28.0 Mannitol SD200 315.0 Corn starch 42.0 CabOSil 7.0 Fast Dissolve Granulation* 35.0 [0000] Composition 2 Ingredient mg/tablet Ibuprofen microcaps 238.0 Sucralose 5.6 Citric acid 28.0 Lemon-lime flavor 1.4 Crosscamellose 28.0 Mannitol SD200 280.0 Corn starch 42.0 CabOSil 7.0 Fast Dissolve Granulation* 70.0 [0000] Composition 3 Ingredient mg/tablet Ibuprofen microcaps 238.0 Sucralose 5.6 Citric acid 28.0 Lemon-lime flavor 1.4 Crosscamellose 28.0 Mannitol SD200 297.5 Corn starch 42.0 CabOSil 7.0 Fast Dissolve Granulation* 52.5 Note: The Fast Dissolve Granulation* had 17% Wecobee and 83% mannitol powder, so the three formulations had 0.85%, 1.7% and 1.275% Wecobee. [0086] Compositions 1, 2 and 3 were compressed using a rotary press (Stokes Versa Press) to a hardness range of 0.45-1.4 kP for Composition 1, as hardness of 0.7-1.7 kP for composition 2 and a hardness of 1.8 to 2.2 kP for Composition 3. [0087] The present invention is not to be limited in scope by the specific embodiments described herein. Indeed, various modifications of the invention in addition to those described herein will become apparent to those skilled in the at from the foregoing description and the accompanying figures. Such modifications are intended to fall within the scope of the appended claims. [0088] It is further to be understood that all values are approximate, and are provided for description. [0089] Patents, patent applications, publications, product descriptions, and protocols are cited throughout this application, the disclosures of which are incorporated herein by reference in their entireties for all purposes.

The present invention relates to processes for the preparation of tablets which dissolve rapidly in the mouth and provide an excellent mouthfeel. The tablets of the invention comprise a compound which melts at about 37° C. or lower, have a low hardness, high stability and generally comprise few insoluble disintegrants which may cause a gritty or chalky sensation in the mouth. Convenient and economically feasible processes by which the tablets of the invention may be produced are also provided.

CROSS REFERENCE TO RELATED APPLICATIONS The present application is a continuation of U.S. application Ser. No. 14/328,655, filed on Jul. 10, 2014, which is a continuation of Ser. No. 13/555,124 filed on Jul. 21, 2012, now U.S. Pat. No. 8,781,534 which is a continuation of U.S. application Ser. No. 10/878,666 filed Jun. 28, 2004, which is a continuation of U.S. application Ser. No. 09/597,607 filed Jun. 20, 2000, now U.S. Pat. No. 6,882,859; the disclosures of all the above patents and applications are herein incorporated by reference in their entirety. BACKGROUND OF THE INVENTION Currently the key pad buttons on a cellular telephone/mobile device (CT/MD) pose a limitation in inputting broad based queries. There are only 12 non-control buttons on many CT/MDs. Even where there are more, there are so few that inputting even as little as the letter-number ASCII set is not really practical. For example, in the present art there have been attempts to expand the number of keys, such as treating the numeric keys as numbers unless a code is entered, such as A*#@ or the like, then treating a A2″ as an Aa@, A2-2″ as a Ab@, and A2-2-2″ as a Ac@. Entering A2″ three times to form a Ac@ is both confusing and slow, and such approaches have not been popular. If a mixed string of letters and numbers are desired, the three A2″s may have to be delimited with, for example, A*#@, and the process becomes increasingly more unwieldy. There has been some success in using a computer, especially a computer operating with Afuzzy@ logic, to extract the probable combination of letters in a numeric string, exemplified by an interactive directory for finding the telephone extension number of an employee by Aspelling@ the employee's name on a numeric key pad. This is a satisfactory solution only in limited cases. Numeric reduction of this type has not been generally used except for telephone directories and similar purposes. SUMMARY OF THE INVENTION It is an object of the present invention to provide a scheme by which the limitations of a key pad are overcome and the key pad is enhanced. The scheme uses a local or network server. The protocols for configuring each key to a specific function or variable set of functions are stored in a Server C. The protocols for all keys may be stored on Server C similarly. The menu for any macro function can be stored on this Server C. Server C may be part of a local loop or located on the internet. In an embodiment of the present invention, displays, such as small LCD displays, are mounted on the top of the keys and connected to a matrix addressing system. When a key is reconfigured, such as from an English language AA@ to some Japanese character, the legend displayed on the key with the small display is changed accordingly. In another embodiment of the present invention, the keyboard is displayed in the display window of a computing device, such as a hand held wireless device. The term wireless device includes entertainment/game machines. The screen of the wireless device is touch sensitive, so the user can type on the screen as if it were a standard keyboard. In another embodiment of the present invention, the keyboard is displayed on a separate screen in the position of and replacing the keyboard on a device, such as a hand held wireless device. This screen is touch sensitive, so the user may type on it as if it were a keyboard. In another embodiment of the present invention, the keys on any of the above keyboards, as well as on keyboards of the present invention generally, have a sound output, such as a voice output. In this way visually impaired or persons with similar concerns can listen to what keys are being depressed. Other objects, features and advantages of the present invention will become apparent from the following detailed description when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING The accompanying drawings, being incorporated in and forming a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the present invention: FIG. 1 is an embodiment of the present invention showing a CT/MD with a reconfigurable keyboard communicating with a Central Server C. FIG. 2 is an embodiment of the present invention showing a CT/MD with display devices on the keys for defining the function of the key dynamically. FIG. 3 is an embodiment of the present invention showing a key with a screen or display thereon for containing a legend. FIG. 4 is an embodiment of the present invention showing a wireless device having a screen for containing a keypad which is accessed by a pointer, such as a stylus. FIG. 5 is an embodiment of the present invention showing a wireless device having a microphone for allowing voice entries for language translation. FIG. 6 is an embodiment of the present invention showing how users of the present invention who are physically separated can collaborate in a signing ceremony. DETAILED DESCRIPTION OF THE INVENTION The present invention provides means for more easily and intuitively assigning, for example, key values to a wireless device such as to a key associated with the wireless device. The present invention also provides means for compressing or expanding the keys on an entry system such as a wireless device or wireless computing device to more efficiently provide keys needed for entry or other reasons, such as sound, in a desired space. The present invention uses a Central Server C providing the software routines and other support for realizing the improved input key means for a wireless device or for a wireless computing device. Thus the Server C contains a number of menus for different applications comprising of assigned values for each key function. 1. Individual Key→may take one or more values that are programmable. 2. Full set or subset of keys→may take one or more values that are programmable. 3. The individual or subset or full set of keys→is programmable to perform assigned functions. 4. The above individual or subset or full set of keys in combination may comprise a menu to perform various customizable functions. 5. The identity of each programmed value for a key, set of keys or full set of keys is stored in the Server C. 6. The menus, sub menus and individual key functions are stored in Server C and may be accessed for use by wired or wireless means. They can be dynamically changed as defined by the user=s needs. 7. The user may easily go from one set of functions or menus to another set of functions or menus by selecting an option from the CT/MD. 8. The menus or functions may coexist on the CT/MD. One function or menu may go to the background and one may be in the foreground. One set may be primary and the others secondary or a hierarchy of functions/menus may be maintained, such as with a windowing of templates, where the user may change templates in the same manner as changing windows on a personal computer (PC). 9. Server C manages the delivery of these functions to the CT/MD and also maintains a history. 10. This same process is extendible to pen based inputs where certain figures or icons or strokes may be designated to indicate certain functions or menus that we stored on the Server C and delivered as needed by a command from the CT/MD. 11. This same process is extendible to voice based input commands and output where each voice command or output means a certain function or a menu that is stored in Server C. The voice recognition function in addition may add more functionality to respond to a given voice. The voices may be in different languages. 12. The same process may be extendible to sounds rather than voice; for example, the sound of a bell. In addition the CT/MD may contain electronics and process capability to internally store the various programmable key functions or menus such that different functions and menus may be chosen as the need arises. In addition, the web server may be shrunk into a microchip that can be part of the internal electronics of the CT/MD, in which case a local or network server may or may not be needed. In this event the features described above for programming and describing each key or input/output could be handled by the internal web server independently or in conjunction with a local or network Server C. If a user initiates communication with a particular device, i.e., if a user selects a particular device, the system may understand the context and may change the keypad automatically. Thus the system may perform context-aware keypad changes. This context may be based upon location, the devices communicated with, devices present in its local environment, or other factors FIG. 1 illustrates a wireless system 100 with a CT/MD 102 having a dynamically reconfigurable keypad 104 . Such a keypad 104 provides the ability to define macro keys not included with the standard alphanumeric keypad. In FIG. 1 , a CT/MD 102 which seems standard has display devices mounted on each key 106 , so that the legend appearing on the key 106 is configurable in software such as from Central Server C 108 without requiring external physical changes. FIG. 2 illustrates a wireless device 200 such as a CT/MD having a display 202 and a key pad 204 . The key pad 204 has keys such as key 206 which are assignable as desired in software. The user may choose to reassign a key on the wireless device to represent a particular function. For example, the user could assign a key to serve as a garage door opener. The user may also use this functionality for universal language capability, such as to change an English keypad to serve as a Japanese keypad. The display mounted on the key may be used to change the keypad template, such as by introducing a Japanese character on the key replacing the English letter AA@ or a macro such as “open garage door”. FIG. 3 shows an embodiment of the present invention in the form of a key 300 such as a key that might be found on a multifunction keyboard. In FIG. 3 , the key 300 , such as a key from a multi-function keypad, is composed of a liquid crystal display (LCD) which can be modified with electrical inputs only. In this manner, as new templates are used, the key 300 will immediately reflect these changes. Thus, when a key 300 is reassigned a new name and function, the key=s new name can become apparent to the user as a legend 302 on the key 300 itself. The LCD or similar display need not form a part of the key. A clear button made of, for example, plastic may encase a LCD type display which may or may not be touch sensitive; that is, a touch sensitive LCD. As new templates are loaded, the LCD display is modified to reflect these changes. FIG. 4 shows an embodiment of the present invention with a CT/MD 400 . FIG. 4 shows the CT/MD 400 having a dynamic key pad 402 such as a touch sensitive LCD panel. The CT/MD 400 optionally includes a liquid crystal display (LCD) 404 . If a writing area is present then new templates can be loaded with, for example, selectable icons, and a stylus 406 can be used to choose the various keys. Server Based, Remote Handwriting Recognition. Handwriting recognition may be processing intensive. Wireless devices may not have the processing capability to perform advanced handwriting recognition techniques within a reasonable time. The wireless devices can offload handwriting recognition functions to a central server. The server may then transmit the recognized characters back to the wireless device, such as screen 402 . This could serve also as a signature authentication or finger print authentication mechanism. A scanner could be used to perform finger print authentication. Such authentication could take place remotely on a Central Server C 108 . FIG. 5 illustrates a wireless system 500 which is an embodiment of the present invention. In FIG. 5 , a wireless device 502 transmits an image of the text that has been captured from the writing area 504 . This may be a bit map image or it could be in a standard format that both the wireless device 502 and Central Server C 508 understand. The wireless device 502 establishes a wireless connection with the Central Server C 508 and transmits the image in a standard format. The Server C 508 then performs the processing on the image and converts it into a format of standard recognized characters which the wireless device 502 understands. The server 508 thus takes an image format of the inputted information and converts it into another format of known characters. After this processing is complete the server C 508 can then transmit the converted format back to the wireless device 502 . The server C 508 could also perform language translation on the inputted information. A microphone 506 at the wireless device 502 accepts voice. Voice clips may be transferred to the server 508 and converted to text using voice recognition software at the server 508 . Alternatively, language translation may be performed on the voice file for voice based language translation. After the server 508 has performed these processing steps, voice files or text may be sent back to the wireless device 502 . The system 500 can also be used for user authentication such as with finger print, eye print, or password authentication. Authentication: Additionally, the key pad 400 /stylus 406 interface could be redefined so that a finger print could be taken for image authentication. This image would be used, for example, for user authentication. The software for recognizing a finger print could reside on a network server 508 or on the hand held device 502 . The present invention allows for handwriting recognition and can be used for authentication. The recognition software can be on the network server or on the hand held device. The present invention also allows for the person to speak to a cell phone/hand held device and access remote macros. For example, by stating Aopen garage@. This command could connect to a network server 508 which would then authenticate the voice. Since voice recognition could be burdensome, this operation could be performed on a networked server 508 or on the hand held device 502 . Once the voice has been recognized through voice recognition software, the command will be performed. In FIG. 6 , an embodiment of an input pad such as a touch sensitive screen 600 of another part of the invention allows for collaborating. The present invention allows screens such as screen 600 to be viewed interactively for interacting from separate devices. For example, if three screens such as screens 602 - 1 , 602 - 2 , 602 - 3 are used to sign a document from different places, signatures 602 can be on separate screens 600 and optionally displayed on other screens as well. Each screen can be watched separately, with signing being done in parallel or sequentially on the separate screens. This allows the signatures displayed on screens 602 to be placed on a virtual document 604 for interactive verification. Each signature displayed on screens 602 can have a different trust level. The escrow agent is Server C 508 . The present invention has been described with a number of features and advantages. For example, one embodiment of the present invention provides a keyboard device including a a plurality of configurable keys and a central server where the central server includes means for dynamically configuring a legend on a selected key from the configurable keys, means for detecting an actuation (selection) of the selected key with the legend, and means for associating the actuation of the selected key with the legend on the selected key. The central server could be remote or local to the keyboard device. The keys in the keyboard typically could be LCDs for displaying the respective legends, and desirably are touch sensitive. The keyboard device could be voice based, sound based or macro based, including key, sound or voice. The keyboard device could be wireless, such as a cellular telephone or mobile device. The keyboard device could be non-wireless. The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and it should be understood that many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, to thereby enable others skilled in the art to best utilize the present invention and various embodiments, with various modifications, as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents.

A cellular phone and mobile device is configured with the ability to accept a signature. A user may write a signature on a touch sensitive display of a mobile device using touch or a pen. A user may be further authenticated by using voice or password. Software for recognizing a finger print could reside on a network server or on the hand held device. Handwriting recognition can be used for authentication. The signature may be viewed on a second mobile device in real time. The signature may be synchronized with a server or an Internet device. The system may allow for multiple parties to sign an electronic document using mobile devices and Internet servers.

TECHNICAL FIELD The present invention relates to an inside-door-handle device for a vehicle. BACKGROUND ART Patent Document 1 discloses an inside-door-handle for a vehicle, in which a fixed part of the inside-door-handle to a vehicle inner panel is covered with a cover body and therefore prevented from being exposed to an outside. PRIOR ART DOCUMENT Patent Document Patent Document 1: US 2004/0212200 The inside-door-handle disclosed in Patent Document 1 includes a handle base to which an operation handle is pivotally supported and a cover body which is connected to the handle base and covers a fixed part of the handle base to a door panel. The cover body is mounted to the handle base by resiliently locking a locking leg for a releasing operation formed at a side edge to the handle base. A detaching operation is performed by inserting a tool through a gap appearing on a wall surface of the handle base and a surface of the cover body and unlocking the locking leg for the releasing operation. However, since the tool is required, a workability of the detaching operation becomes poor. SUMMARY OF INVENTION Embodiments of the present invention provide an inside-door-handle device for a vehicle which is capable of improving a detaching operability of a cover body. In accordance with embodiments of the present invention, an inside-door-handle device for a vehicle may include a base part BP and a cover body 3 which is removably connected to the base part BP and which covers a connection section 13 of the base part BP to a door-side in a cover body 3 mounted-position where the cover body 3 is mounted to the base part BP. A swinging space 8 may be provided between the base part BP and the cover body 3 in the mounted position. The cover body 3 may have a locking part 4 , the base part BP may have a locked part 5 and the swinging of the cover body 3 relative to the base part BP may be restricted by a resilient locking of the locking part 4 and the locked part 5 so that the cover body 3 is held in the mounted position. An inclined surface part 6 may be formed on at least one of the locking part 4 and the locked part 5 . A force in an unlocking direction may be generated by the inclined part 6 when the cover body 3 is swung relative to the base part BP by a pushing operation of the cover body 3 and therefore the locking of the locking part 4 and the locked part 5 may be released, so that the cover body 3 can be detached from the base part BP. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a front view showing an inside handle device. FIG. 2( a ) is a sectional view taken along a line 2 A- 2 A in FIG. 1 and FIG. 2( b ) is a sectional view taken along a line 2 B- 2 B in FIG. 1 . FIG. 3 is a front view showing a cover body in a mounted state. FIG. 4( a ) is a rear view of the cover body. FIG. 4( b ) is a view as seen in a direction of an arrow 4 B in FIG. 4( a ). FIG. 4( c ) is a view as seen in a direction of an arrow 4 C- 4 C in FIG. 4( a ). FIG. 5( a ) to FIG. 5( d ) are sectional views taken along a line 5 A- 5 A in FIG. 3 . FIG. 5( a ) shows a mounting operation. FIG. 5( b ) shows a completely mounted state. FIG. 5( c ) shows a state where a side edge of the cover body is pushed down. FIG. 5( d ) shows a state where the locking of the cover body is released. FIGS. 6( a ) and 6 ( b ) are views showing a fixing structure of the inside handle device in which the cover body is mounted to a door trim. FIG. 6( a ) is a view corresponding to FIG. 2( a ). FIG. 6( b ) is a view corresponding to FIG. 2( b ). FIG. 7 is an alternate embodiment corresponding to FIG. 5( c ). DESCRIPTION OF EMBODIMENTS Hereinafter, an exemplary embodiment of the present invention will be described with reference to the drawings. Here, the exemplary embodiment is only an example and not intended to limit the invention. It should be noted that all the features or their combinations described in the exemplary embodiment are not necessarily essential to the invention. As shown in FIGS. 1 to 5( d ), an inside handle device of the exemplary embodiment is formed by connecting an operation handle 1 and a locking lever 9 to a handle base 2 as a base part BP. The operation handle 1 is rotatable around a handle rotation center axis (C 1 ) between an initial rotation position indicated by a solid line in FIG. 2( a ) and an operational rotation position indicated by a dashed line in FIG. 2( a ) and connected to a lock device 11 via a cable device 10 . The cable device 10 is formed by slidably inserting an inner cable 10 b into an outer case 10 a having one end connected to the handle base 2 . As the operation handle 1 is rotationally operated to the operational rotation position, an operating force is transmitted to the lock device 11 via the inner cable 10 connected to the operation handle 1 and therefore a lock state of a door is released. Further, as shown in FIG. 2( b ), the locking lever 9 can be operated to rotate around a lever rotation center axis (C 2 ). As the locking lever 9 is operated to rotate in a clockwise direction by a predetermined angle from the locked rotation position shown, a cancellation part 11 a of the door-lock device 11 is operated via a cable device 12 connected to the locking lever 9 and then the operation of the door-lock device 11 by the operation handle 1 is restricted. As shown in FIGS. 2( a ) to 3 , the inside handle device is fixed to a door panel (not shown) by fixing the handle base 2 to the door panel. The handle base 2 is provided with a through hole 14 through which a fastener 13 used to fix is inserted. In order to cover a head of the fastener 13 , the cover body 3 is mounted to the handle base 2 . The handle base 2 includes a frame part 7 to surround the operation handle 1 and the locking lever 9 as described above. The handle base 2 forms a bottom wall surface excluding a rotational base end of the locking lever 9 and the operation handle 1 in a state where the cover body 3 is mounted thereto. As shown in FIG. 3 , the handle base 2 is provided with a locked part 5 and a lock opening for locking the cover body 3 , a bearing plane 2 a for bearing the cover body 3 and a ridge 15 perpendicular to the handle rotation center of the operation handle 1 . As will be described later, the ridge 15 is intended to provide a swinging center of the cover body 3 and a swinging space 8 of the cover body 3 . The bearing plane 2 a is arranged only at a region where the locked part 5 is provided across the ridge 15 , in order not to interfere with the swinging operation of the cover body 3 . As shown in FIGS. 4( a ) to 4 ( c ), the cover body 3 is formed in a plate shape. One side marginal part of the cover body along the operation handle 1 is provided with two locking protrusions 16 and a marginal part thereof facing these protrusions is provided with one claw-shaped locking part 4 . The cover body 3 is mounted to the handle base 2 by pushing the marginal part of the cover body on which the locking part 4 is formed, as indicated by an arrow “a” in FIG. 5( a ), in a state where the locking protrusions 16 are locked to an upper edge of the locking opening 17 provided at a lower end of the frame part 7 of the handle base 2 . When the pushing operation is performed, an inner wall surface of the frame part 7 of the handle base 2 guides a peripheral edge of the cover body 3 to lead the locking part 4 to the locked part 5 and the locking part 4 led to the locked part 5 is once elastically deformed to avoid the peripheral edge part of the locked part 5 and then returns to an original shape when facing the locked part 5 . In this way, a locked state is achieved. In a mounted state where the locking of the locking part 4 has been completed, the cover body 3 covers the head of the above-described fastener 13 to prevent exposure to the outside, as shown in FIG. 1 . Separation of the inside handle device from this state is performed once by separating the cover body 3 and the above-described ridge 15 is provided in the handle base 2 in order to facilitate the separation. As shown in FIG. 5( b ), the ridge 15 is formed with a height dimension to come into contact with the rear surface of the cover body 3 in a state where the cover body 3 is mounted. The ridge 15 provides the swinging space 8 of the cover body 3 when the locking of the locking part 4 is released. Further, as shown in FIG. 5( b ), the locking part 4 of the cover body 3 is provided with a mounting inclined surface 4 a . During the pushing operation of the cover body 3 , the mounting inclined surface 4 a is brought into contact with the locked part 5 to generate a reaction force directed inward (to opposite edge) to the locking part 4 . The locking part 4 and the locked part 5 are provided with an inclined surface part 6 to generate a component force in an unlocking direction to the locking part 4 when a swinging force is applied in a counter-clockwise direction in FIG. 5( b ). Accordingly, in the exemplary embodiment, when a pushing operation force is applied to a marginal part (the pushing operation part 3 P) on the side where the locking protrusions 16 of the cover body 3 in the mounted state are disposed, a swinging force in a counter-clockwise direction having a contact part with the ridge 15 as a swinging center occurs in the cover body 3 . As described above, the component force in the unlocking direction occurs in the inclined surface part 6 of the locking part 4 by the swinging force. Then, as shown in FIG. 5( c ), the locking part 4 is elastically deflexed and thus the locking of the locking part 4 and the locked part 5 is released. In this way, the cover body 3 can be detached from the handle base 2 , as shown in FIG. 5( d ). The pushing operation force required for releasing the mounting of the cover body 3 is properly determined in consideration of an incline angle of the inclined surface part 6 , rigidity of the locking part 4 and a gap between the ridge 15 and a pushing operation side end edge. Further, the pushing operation force is set to a magnitude such that the locking of the locking part 4 is not released simply by an erroneous operation. Further, as shown in FIGS. 1 and 3 , the pushing operation part 3 P is set at a side where the pushing operation part is covered with the operation handle 1 and is not exposed to the outside in a normal state, so that the detachment of the cover due to a prank is prevented as much as possible. In the foregoing description, the inside handle device has a configuration that the handle base 2 is an interior surface forming member 20 for providing an external surface of a panel body in a mounted region of the operation handle 1 and the head of the fastener 12 for fixing the handle base 2 to the door panel is covered with the cover body 3 mounted to the interior surface forming member 20 . Meanwhile, as shown in FIG. 6 , in a case where a door trim 21 is configured as the interior surface forming member 20 , the cover body is mounted to the door trim 21 . That is, in the structure shown in FIG. 6 , the handle base 2 is covered with the door trim 21 and a design surface in the mounted region of the operation handle 1 is configured by the door trim 21 . Fixing of the inside handle device is performed by fastening both the door trim 21 and the handle base 2 to the panel using the fastener 13 . The locked part 5 , the locking opening 17 and the ridge 15 or the like are formed in the door trim 21 as the interior surface forming member 20 and the cover body 3 is connected to the door trim 21 as the base part BP. Further, although the door trim 21 and the handle base 2 are fastened to the panel by a single fastener 13 in this fixing structure, the fastening between the door trim 21 and the handle base and the fastening between the handle base 2 and the panel may be performed by separate fasteners, respectively. In FIG. 6 , the same or similar components as in the structure of FIGS. 1 to 5( d ) are denoted by the same or similar reference numerals, and a duplicated description thereof will be omitted. According to the exemplary embodiment, the door-inside-handle device includes the base part BP (the handle base 2 , the door trim 21 ) and the cover body 3 which is removably mounted to the base part BP and covers the fixing part of the base part BP to the door panel. The swinging space ( 8 ) is formed between the cover body 3 and the handle base 2 when the cover body 3 is in the mounted position. By locking the locking part 4 formed on a side edge of the cover body 3 and the locked part 5 of the handle base 2 to each other while elastically deforming either or both the locking part 4 and the locked part 5 , the swinging operation is prohibited and the mounted state is maintained. The inclined surface part 6 is formed between the locking part 4 and the locked part 5 and intended to generate a component force in an unlocking direction to the locking part 4 or the locked part 5 by applying a swinging operation force to the cover body 3 . The component force in the unlocking direction occurs in the locking part 4 or the locked part 5 by applying a pushing force directed inward the base part BP to one side edge of the cover body 3 . Accordingly, when the magnitude of the component force by the inclined surface part 6 and the locking force in the locking part 4 and the locked part 5 are properly set, it is possible to detach the cover body 3 simply by providing the pushing operation force to the side edge of the cover body 3 . As a result, a special tool is not required and therefore the detaching operability is improved. The cover body 3 in the mounted state covers substantially the entire base part BP and is formed as an escutcheon to determine a design exterior of the inside handle device. Alternatively, the cover body 3 may be mounted to a bottom wall of the base part BP including the frame part 7 to accommodate the operation handle 1 as the design exterior surface, thereby covering only a region near the fixed part. In addition to providing a special part (for example, the ridge 15 formed in the base part BP or the cover body 3 ) set for forming a swinging center, the swinging center of the cover body 3 in a mounted posture may be configured as a result of the contact state or the like without forming the special part. The locking part 4 may be provided on a marginal part intersecting a swinging center axis, in addition to a marginal part along the swinging center axis. Further, the swinging restriction may be performed only by the locking of the locking part 4 and the locked part 5 or one swinging end may be determined by using a side edge as a contact edge with the base part BP. Further, when the locking part 4 is formed to protrude from the rear surface of the cover body 3 , a locking region between the locking part 4 and the locked part 5 does not appear on the surface and therefore it is possible to improve an outer appearance. Further, when the pushing operation part 3 P of the cover body 3 is disposed at a position where the pushing operation part is covered with the operation handle 1 in an initial rotation position, it is possible to reduce the possibility that the pushing operation part 3 P is erroneously pushed and the cover body 3 is detached. Further, the cover body 3 may be mounted to the handle base 2 or may be mounted to the interior surface forming member 20 (such as the door trim 21 ) which is used for forming the interior (an exterior design surface) of the door body in the mounted position of the operation handle 1 . According to the above-described exemplary embodiment, since a tool is not required in the detaching operation of the cover body, it is possible to improve the detaching operability. DESCRIPTION OF REFERENCE NUMERALS 1 OPERATION HANDLE 2 HANDLE BASE 3 COVER BODY 3 P PUSHING OPERATION PART 4 LOCKING PART 5 LOCKED PART 6 INCLINED SURFACE PART 7 FRAME PART 8 SWINGING SPACE 20 INTERIOR SURFACE FORMING MEMBER 21 DOOR TRIM BP BASE PART

An inside-door-handle device for a vehicle is provided with a base part and a cover. A swinging space is provided between the base part and the cover. The cover has a locking section; the base part has a lock-receiving section. A swing motion of the cover relative to the base part is regulated by the elastic locking between the locking section and the lock-receiving section. If the cover swings relative to the base part due to pushing operation toward the cover, the lock between the locking section and the lock-receiving section is released, and the cover can be separated from the base part.

CLAIM OF PRIORITY [0001] This application a continuation of U.S. patent application Ser. No. 10/337,058, filed Jan. 3, 2003, which is a divisional of U.S. patent application Ser. No. 09/038,494 filed Mar. 10, 1998 (now U.S. Pat. No. 6,525,386). The present application also incorporates the foregoing utility disclosures herein by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] This invention relates to the field of optoelectronics, which includes light emitting components, such as light emitting diodes (LED) and laser diodes, and which also includes light detecting components, such as photodiodes, phototransistors, photodarlingtons and photovoltaic cells. Optoelectronics also includes various devices which incorporate optoelectronic components, such as displays, photosensors, optocouplers, and fiberoptic transmitters and receivers. In particular, this invention relates to lenses to increase the efficiency of optoelectronic emitters and the sensitivity of optoelectronic detectors. [0004] 2. Description of the Related Art [0005] A prior art LED 100 is shown in FIG. 1 and consists of a semiconductor diode element 110 electrically connected to a leadframe 120 and surrounded by an encapsulating material 130 . The diode element 110 is typically mounted to one lead 122 of the leadframe 120 and connected to a second lead 124 of the leadframe 120 by a wire bond 140 . These two leads provide an electrical connection between an external current source and the anode and cathode of the diode element 110 . The external current source supplies power to the diode device 100 that is converted to emitted light by the photoelectric effect, which occurs at the semiconductor junction within the diode element 110 . [0006] Internal inefficiencies within a semiconductor diode result in very low net efficiencies, which is the ratio of emitted light power to input power. Internal inefficiencies arise from a low ratio of minority carriers injected into the diode semiconductor junction to photons generated at the junction; photon loss due to internal reflection at the semiconductor/encapsulant interface; and absorption of photons within the semiconductor material. Because of these low net efficiencies, many LED applications require high input current, resulting in heat dissipation and device degradation problems in order to obtain sufficient light. [0007] As illustrated in FIG. 1 , the encapsulant 130 forms a flat light-transmitting surface 150 . A flat surface is convenient in many applications where the LED is mounted to another surface that is also generally flat or in applications that otherwise cannot accommodate a protruding surface. The inefficiencies described above, however, are compounded by the configuration of the LED encapsulant/air interface. An encapsulant having a flat surface, such as in FIG. 1 , allows photons transmitted by the diode element 110 to have considerable dispersion. A flat encapsulant surface also results in internal reflection at the encapsulant/air interface, further reducing photon transmission and increasing photon absorption within the encapsulant material. [0008] FIG. 2 illustrates a prior art LED 200 having an encapsulant 230 that forms a spherical surface 250 . A spherical or other curved surface gives a larger angle of incidence for photons emitted from the semiconductor diode element 210 , reducing losses due to internal reflection. Further, this surface 250 acts as a lens to reduce the dispersion of generated photons. Unfortunately, a protrusion, such as this curved surface, is difficult to accommodate in many applications. SUMMARY OF THE INVENTION [0009] An optoelectronic device according to the present invention incorporates a lens that increases component performance. For example, the output of an LED utilizing the lens is increased by, in part, reducing internal reflection. Internal reflection results from the differing indices of refraction at the interface between the LED encapsulant and the surrounding air. [0010] As shown in FIG. 3 , when a light ray 310 passes from a media having a higher index of refraction 320 to a media having a lower index of refraction 330 , the ray 310 is refracted away from the normal 340 to the surface 350 . The angle, θ 1 , is customarily referred to as the angle of incidence 370 and the angle θ 2 is customarily referred to as the angle of refraction 380 . As the angle of incidence 370 is increased, the angle of refraction 380 increases at a greater rate, in accordance with Snell's Law: sin θ 2 =(N 1 /N 2 )sin θ 1 , where (N 1 >N 2 ). When the angle of incidence 370 reaches a value such that sin θ 1 =N 2 /N 1 , then sin θ2=1.0 and θ 2 =90°. At this point none of the light is transmitted through the surface 350 , the ray 310 is totally reflected back into the denser medium 320 , as is any ray which makes a greater angle to the normal 340 . The angle at which total reflection occurs: θ c =arcsin N 2 /N 1 is referred to as the critical angle. For an ordinary air-glass surface, where the index of refraction is 1.5, the critical angle is about 42°. For an index of 1.7, the critical angle is near 36°. For an index of 2.0, the critical angle is about 30°. For an index of 4.0, the critical angle is about 14.5°. [0011] An optoelectronic device according to the present invention has an encapsulant that functions as a lens. For emitter applications, the lens reduces internal reflection and dispersion without having a protruding curved surface. Thus, LEDs utilizing the present invention have an improved efficiency compared with prior art flat-surfaced LEDs and similar devices, without the physical interface difficulties of the prior art curved-surface LEDs and similar devices. For detector applications, the lens focuses photons on the active area of the detector, increasing detector sensitivity. This increased detector sensitivity allows a detector having a reduced size, hence a reduced cost, to be used for a given application. [0012] A particularly advantageous application of an optoelectronic device with a non-protruding lens is in pulse oximetry, and in particular, as an emitter in pulse oximetry probes. Pulse oximetry is the noninvasive measurement of the oxygen saturation level of arterial blood. Early detection of low blood oxygen saturation is critical because an insufficient supply of oxygen can result in brain damage and death in a matter of minutes. The use of pulse oximetry in operating rooms and critical care settings is widely accepted. [0013] A pulse oximetry probe is a sensor having a photodiode which detects light projected through a capillary bed by, typically, red and infrared LED emitters. The probe is attached to a finger, for example, and connected to an instrument that measures oxygen saturation by computing the differential absorption of these two light wavelengths after transmission through the finger. The pulse oximetry instrument alternately activates the LED emitters then reads voltages indicating the resulting intensities detected at the photodiode. A ratio of detected intensities is calculated, and an arterial oxygen saturation value is empirically determined based on the ratio obtained: I rd /I ir =Ratio % O 2 Saturation [0014] Typically, a look up table or the like correlates the Ratio to saturation. The use of conventional LEDs within pulse oximetry probes has a number of drawbacks. Pulse oximetry performance is limited by signal-to-noise ratio which, in turn, is improved by high light output emitters. LEDs without lenses, such as illustrated in FIG. 1 , are not optimized to transmit the maximum amount of light into the skin. LEDs with protruding lenses, such as illustrated in FIG. 2 , create increased pressure on the skin, resulting in perfusion necrosis, i.e. a reduction of arterial blood flow, which is the medium to be measured. A solution to this problem in accordance with the present invention is an LED incorporating a non-protruding lens. [0015] One aspect of the present invention is an optoelectronic device that comprises an encapsulant having a surface, a lens portion of the surface, and a filler portion having a generally planar surface. The filler portion is disposed around the lens, and the lens does not extend substantially beyond the plane of the generally planar surface. The optoelectronic device also comprises an optoelectronic element embedded in the encapsulant and operable at at least one wavelength of light. The lens being configured to transmit or receive the at least one wavelength. [0016] Another aspect of the present invention is a mold tool for an optoelectronic device that comprises a first mold piece having a surface that defines a first cavity and an aperture within the first cavity. The mold tool also comprises a second mold piece having a surface which defines a second cavity. The first cavity and second cavity cooperate to form a molding compound into a predetermined shape. The mold tool further comprises an ejector pin having a contoured tip. The pin is movably located within the aperture between a first position retracted within the cavity and a second position extended from the aperture. In the first position, the tip constitutes an integral portion of the first cavity. In the second position, the ejector pin facilitates removal of the compound from the first cavity. The ejector pin tip at least partially defines the predetermined shape. [0017] Another aspect of the present invention is an optoelectronic method comprising the steps of providing a generally planar surface at a predefined distance from an optoelectronic element, defining a light transmissive region of that surface within the critical angle of the optoelectronic element, and contouring the surface within the transmissive region without exceeding the predefined distance. These steps create a non-protruding lens for the optoelectronic element. In one embodiment, the transmissive region has a circular cross-section. The optoelectronic method can comprise the further step of shaping a surrounding region adjacent said transmissive region. [0018] Yet another aspect of the present invention is an optoelectronic device comprising an encapsulant means for embedding an optoelectronic element and a lens means for conveying light between the optoelectronic element and a media surrounding the encapsulant means. In one embodiment, the optoelectronic device further comprises a flat surface means for providing a low-pressure contact surface for the lens means. In that embodiment, the optoelectronic device can further comprise an arcuate surface means for avoiding total internal reflection of light from the flat surface means. In another embodiment, the optoelectronic device further comprises a surrounding surface means for providing a contact surface for the encapsulant from which the lens means does not protrude. BRIEF DESCRIPTION OF THE DRAWINGS [0019] The present invention is described in detail below in connection with the following drawing figures in which: [0020] FIG. 1 is a cross-section view of a prior art LED having an encapsulant with a flat light-transmitting surface; [0021] FIG. 2 is a cross-section view of a prior art LED incorporating a protruding, spherical light-transmitting surface; [0022] FIG. 3 generally illustrates light refraction at a surface between two media having different indices of refraction; [0023] FIG. 4 is a cross-section view of an LED incorporating a single emitter and a flat-surfaced, vertical-side lens according to the present invention; [0024] FIG. 5A is a plan view of an LED incorporating dual-emitters and a flat-element, non-protruding lens; [0025] FIG. 5B is an enlarged view of a portion of FIG. 5A illustrating the critical angle; [0026] FIG. 6 is a plan view of another LED incorporating dual-emitters and a spherical-element, non-protruding LED lens; [0027] FIG. 7A is a plan view of the lower cavity of a production mold tool for encapsulating an optoelectronic element; [0028] FIG. 7B is a plan view of the upper cavity of a production mold tool for encapsulating an optoelectronic element; [0029] FIG. 7C is a cross section view of the upper cavity and the lower cavity of a production mold tool in a closed position; [0030] FIG. 8A is an illustration of a prior art ejector pin for a production mold tool; [0031] FIG. 8B is a cross-section view of a prior art ejector pin tip; [0032] FIG. 9 is a cross-section view of a non-protruding optoelectronic lens being formed in a mold tool with a contoured ejector pin tip according to the present invention; [0033] FIG. 10A is a cross-section view of an ejector pin tip for creating a non-protruding optoelectronic lens featuring a flat surface element; [0034] FIG. 10B is a cross-section view of an ejector pin tip for creating a non-protruding optoelectronic lens featuring a spherical surface element; and [0035] FIG. 10C is a cross-section view of an ejector pin tip for creating a detector cavity. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0036] FIG. 4 illustrates an embodiment of an LED having a non-protruding or minimally protruding lens according to the present invention. The LED 400 consists of at least one semiconductor diode element 410 , which is mounted to one lead of a leadframe 420 and connected to another lead of a leadframe 420 with a bond wire 440 . The diode element 410 , bond wire 440 and portions of the leadframe 420 are surrounded by an encapsulant 430 . A lens 460 is molded into a portion of the encapsulant 430 . The lens 460 has a generally flat, surface portion 462 that is at or below the plane of the surrounding surface portions 434 of the encapsulant 430 . The lens extends radially from the diode element 410 out to the critical angle 464 , at which point total internal reflection of photons emitted from the diode element would occur. Past the critical angle 464 , the lens 460 has a steep side surface portion 466 , which extends below the surface of the surrounding filler portion 434 of the encapsulant 430 to prevent internal reflection. A trough 468 is located between the flat surface portion 462 of the lens 460 and the surface of the surrounding filler portion 434 of the encapsulant 430 . Due to refraction, light rays exiting the side surface portion 466 are bent towards the lens 460 , reducing dispersion as compared to the prior art LED of FIG. 1 . [0037] Manufacturability considerations may limit the lens embodiment described above. If the lens side surface portion 466 is too steep, the LED may be difficult to release from the encapsulant mold. Further, the depth of the trough 468 may restrict the flow of encapsulant during the molding process and may also interfere with the bond wire 440 . Optical considerations also may constrain this embodiment. The sharp transition 465 between the flat surface portion 462 and side surface portion 466 of the lens 460 results in an abrupt directional change of light rays exiting the lens 460 on either side of this transition 465 , which may be problematic in some applications. [0038] FIG. 5A illustrates an embodiment of a non-protruding lens LED for pulse oximetry applications. Pulse oximetry requires transmission of two wavelengths. Thus, this LED 500 utilizes dual semiconductor diode elements, a “red emitter” 512 producing wavelengths in the red portion of the spectrum and an “IR emitter” 514 producing infrared wavelengths. One type of red emitter is an AlGaAs chip available from, among others, Opto Tech Corporation, Hsinchu Science-Based Industrial Park, Taiwan, R.O.C., part number ED-014-UR/3. This part has a peak emission at 660±3 nm and a radiant power of 1.3 mW minimum. One type of IR emitter is a GaAs chip available from, among others, Infratech Corporation, 10440 Miller Road, Dallas, Tex., part number INF905N13H. This part has a peak emission at 905±10 nm and a radiant power of 1.8 mW typical. [0039] The cathode side of the red emitter 512 is mounted to a first lead 522 and the cathode side of the IR emitter is mounted to a second lead 524 . A third lead 528 is unused. A first bond wire 542 connects the anode side of the red emitter 512 to the second lead 524 . A second bond wire 544 connects the anode side of the IR emitter 514 to the first lead 522 . With this configuration, the red emitter 512 and IR emitter 514 are electrically connected in parallel and “back-to-back,” i.e. cathode to anode. In this manner, the red emitter 512 and IR emitter 514 are activated one at a time by alternating the polarity of a voltage applied between the first lead 522 and second lead 524 . [0040] The semiconductor diode elements 512 , 514 , the leads 522 , 524 , 528 and associated bond wires 542 , 544 are all encapsulated after the mounting and bonding process. Encapsulation is accomplished with a transfer mold process as described in detail below. The encapsulant 530 is molded into a standard-sized planar package having a length, L, of 220 mils, a width, W, of 170 mils and a thickness, T, of 70 mils. This forms a light transmitting side 502 and a backside 504 for the LED 500 . One available encapsulant is HYSOL® MG18, which is from The Dexter Corporation, Electronic Materials Division, Industry, Calif. The index of refraction, I R , for MG18 is 1.52. Thus, the critical angle, θ c , is arcsin(1/1.52)=41.1°. Another available encapsulant is NT-300H, which is from Nitto Denko America, Inc., 55 Nicholson Lane, San Jose, Calif. The index of refraction and critical angle for NT-300H is I R =1.564 and θ c =39.7° [0041] A lens is advantageously formed in the encapsulant during the molding process, as further described below. The light transmitting side 502 of the encapsulant 530 contains a contoured region 550 and a flat, filler region 570 . The contoured region 550 is a shaped-surface within a circular cross-section 125 mils in diameter. The flat region 570 is a planar surface that surrounds the contoured region 550 . Within the contoured region 550 are a lens 560 and a trough 552 having a sidewall 554 . The lens 560 has a circular cross-section 563 , a flat surface element 564 , and an arcuate surface element 568 . The flat surface element 564 is a substantially flat, circular portion of the lens 560 having a 30-mil diameter in one embodiment. The arcuate surface element 568 is a curved portion of the lens 560 having a 25-mil radius extending from the edge of the flat surface element 564 to the beginning of the trough 552 in one embodiment. The trough 552 has a depth of 22 mils and a bottom width of 4.2 mils in one embodiment. The sidewall 554 is constructed at an angle of 50° with respect to the flat region 570 . With the lens configuration described above, the flat surface element 564 of the lens 560 is in the same plane as the flat region 570 surrounding the lens. This creates a non-protruding lens surface, which avoids pressure necrosis when the emitter with a lens in accordance with the present invention is used is a sensor. [0042] As depicted in FIG. 5B , if the center of an emitter 512 is assumed to be a point source, the maximum distance, B, along the flat surface element before total internal reflection of light occurs is calculated as follows: A=the distance to the lens surface =thickness of encapsulant top-half−lead thickness−½ emitter thickness=(50−10−4)=36 mil B/A =tan (π·θ c /180°)=0.83, for θ c =39.7°, therefore B=0.83·36≈30 mil Thus, the entirety of the flat surface element 564 , which has a diameter of 30 mil, is within the critical angle of light rays from either the red emitter 512 or the IR emitter 514 , as illustrated in FIG. 5B and by the calculations above. [0043] The red emitter 512 is advantageously mounted only slightly offset with respect to the center of the lens 560 . Although there is no total internal reflection of light from either emitter 512 , 514 at any portion of the flat surface element 564 , internal reflection increases as the incident angle approaches the critical angle. The red emitter 512 has a lower efficiency as compared to the IR emitter 514 , as apparent from the 1.3 mW versus 1.8 mW radiant power, respectively, for the parts described above. The placement of the red emitter 512 near the lens center minimizes losses from internal reflection in the red spectrum to somewhat compensate for the red emitter's lower efficiency. This placement, however, is somewhat at the expense of the IR emitter 514 , which has a higher efficiency and is, accordingly, mounted near the periphery of the lens 560 due to the space constraints imposed by the red emitter 512 placement and the configuration of the leads 522 , 524 and bond wires 542 , 544 . At its location, the IR emitter 514 may incur significant internal reflection at portions of the lens 560 and uncalculated optical effects due to the proximity of the trough 552 and the trough sidewall 554 . [0044] The embodiment illustrated in FIGS. 5 A-B overcomes the limitations of the non-protruding LED lens described with respect to FIG. 4 . The trough 552 is shallow enough to allow encapsulant flow and to avoid bond wires. The sidewall 554 is angled to allow easy release of the part from the molding tool. The arcuate portion 568 provides a smooth transition between the flat surface portion 564 and the trough 552 to reduce corner effects. [0045] FIG. 6 illustrates another preferred embodiment of the LED that incorporates a non-protruding spherical lens. As in the embodiment described with respect to FIGS. 5 A-B, the light transmitting side 502 of the encapsulant 530 contains a contoured region 550 and a flat, filler region 570 . The contoured region 550 and flat region 570 are as described above. Within the contoured region 550 are a lens 660 and a trough 652 having a sidewall 654 . The lens 660 has a spherical surface element 664 having a curved surface with a radius of 50 mils. In this configuration, the trough 652 has a depth of 25 mils and a bottom width of 2.7 mils. The sidewall 654 is constructed at an angle of 56° 35′ with respect to the flat region 570 . With the lens configuration described above, the apex portion of the spherical surface element 664 is in the same plane as the flat region 570 surrounding the lens. As with the lens described with respect to FIGS. 5 A-B, this creates a non-protruding lens surface, which avoids pressure necrosis. One of ordinary skill in the art will recognize that other lens shapes are also feasible within the scope of the current invention, such as a lens with a parabolic surface element. [0046] FIG. 7A depicts top, front and side views of the lower cavity portion 710 of a production transfer mold for encapsulating an LED according to the present invention. An available mold has 200 cavities and is manufactured by Neu Dynamics Corp., 110 Steamwhistle Drive, Ivyland, Pa., part number 97-3239. As shown in FIG. 7A , the lower cavity portion 710 has a cavity 720 for each LED to be molded. Placed into this mold are leadframe strips each containing the components for multiple LEDs. Each cavity has portions 722 to accommodate the three leadframe leads allocated to each LED. Each cavity 720 also has a gate 724 through which encapsulant is injected during the molding process, which is described in detail below. A vent 728 allows excess encapsulant and air to be ejected from the cavity. The depth of each cavity 720 is 50 mils, which, with reference to FIG. 5B , corresponds to the thickness, T u , of the encapsulant upper half. [0047] Each cavity 720 in the lower cavity portion 710 of the mold tool contains an ejector pin 800 . When the mold press is opened, these ejector pins 800 protrude into the cavities 720 , separating the encapsulated leadframes from the mold tool and allowing removal of the encapsulated leadframes. Within each cavity 720 is an aperture 732 that accommodates the ejector pin tip 1000 as described below. The ejector pin 800 for each cavity is installed in a shaft 734 in the body of the lower cavity portion 710 . [0048] FIG. 7B depicts the upper cavity portion 760 of the production transfer mold corresponding to FIG. 7A . As shown in FIG. 7B , the upper cavity portion 760 has a cavity 770 for each LED to be molded. The depth of each cavity 770 is 20 mils, which, with reference to FIG. 5B , corresponds to the thickness, T 1 , of the encapsulant lower half. The production mold, including the lower 710 and upper 760 cavity mold portions are mounted on lower and upper platens, respectively, of a standard production press. An available press is an 83-ton press manufactured by Fujiwa Seiki, model number TEP75-30, available from ESC International, Four Ivybrook Blvd., Ivyland, Pa. [0049] A transfer molding process is utilized to encase the semiconductor diode elements, interconnecting gold bond wire and leadframe within a thermosetting epoxy resin, which is optically transmissive. Further conventional processing results in a completed LED device. Initially, the mold tool is brought to an operating temperature between 140-175° C. The mold tool is brought to an open position. One or more leadframes having multiple leads 522 , 524 , 528 , mounted emitters 512 , 514 and bond wires 542 , 544 are loaded into a carriage so that the emitters 512 , 514 will be face down in the lower mold cavities 720 , which form the light emitting side 502 of the encapsulant 530 . The leadframe carriage is then preheated to 325° F. and loaded into the mold tool. The mold press is closed, exerting maximum pressure on the mold tool. Mold compound pellets, which have been preheated for approximately 25 seconds to the consistency of a marshmallow are then loaded into a mold compound pot. A transfer ram injects the molten encapsulant into each cavity gate 724 at a pressure of between 500-1000 psi, and air and excess encapsulant are ejected through each cavity vent 728 . The mold cycle time is between 2-5 minutes and nominally 3:00 minutes. After transfer molding, the clear molding resin is cured in an oven at 150° C.±10° C. for 2-4 hours. [0050] FIG. 7C shows a side, cross-section view of the upper cavity portion 760 and the lower cavity portion 710 of the mold tool in the closed position. The upper cavity portion 760 is shown attached to the upper mold tool base 780 with bolts 782 . The lower cavity portion 710 is shown attached to the lower mold tool base 740 with bolts 742 . In this closed position, each upper cavity 770 and lower cavity 720 together form a whole cavity 790 that accepts and shapes mold compound to form the LED encapsulant. Also shown is a cavity ejector pin 800 that functions as described above for separating an encapsulated leadframe from the mold tool. In addition, there is a runner ejector pin 744 that functions similarly to the cavity ejector pin 800 to separate an encapsulated leadframe from the mold tool. A runner holddown pin 784 serves to position a leadframe within the mold tool. [0051] FIG. 8A illustrates a conventional ejector pin 800 . The pin 800 has a base 810 , a rod 820 and a tip 830 . FIG. 8B illustrates the flat surface at the tip 830 of a prior art ejector pin 800 . A pin 801 with a contoured tip 1000 according to the present invention, as described below with respect to FIGS. 10 A-B, is installed in the shaft 734 of the lower cavity portion 710 described with reference to FIG. 7A . The rod 820 can freely slide within the shaft 734 such that the tip 1000 is flush with or protrudes into the cavity 720 through the aperture 732 . A separate portion of the mold tool presses against the base 810 to actuate the ejector pin 800 when the press is opened or closed. With the prior art ejector pin 800 , discontinuities between the pin tip 830 and the surrounding tool and the fact that the pin tip 830 is not exactly flush with the surrounding tool result in imperfections on the surface of the mold compound. This undesirable ejector pin mark typically has to be polished off or placed on a portion of the molded part where the mark has no effect. With respect to molding LED devices, the ejector pin mark can distort the optical properties of the LED encapsulant surface. As a result, in a typical LED molding process, ejector pins are placed on the backside or non-emitting surface of the LED. [0052] FIG. 9 illustrates a mold tool that advantageously utilizes the presence of the ejector pin in each mold cavity to shape the mold compound. This is in stark contrast to the prior art, which attempts to minimize the ejector pin effect. With respect to molding an LED, such as that shown in FIG. 6 , the ejector pin 800 is located such that it contacts the light transmitting surface 502 of the LED 600 , rather than the backside surface 504 . The ejector pin 800 is located within a cavity 720 of the lower cavity portion 710 of the mold tool so that it becomes an integral part of the molding process. As illustrated in FIG. 9 , the pin tip 1000 is contoured to form the lens 660 , trough 652 and trough sidewall 654 of the LED 600 . [0053] The ejector pin 801 according to the present invention functions both to remove the molded parts from the tool and impart a contour to the surface of the LED. As shown in FIG. 9 , in the mold tool closed position, the ejector pin 801 provides a shaped surface for molding a lens 660 into the encapsulant 530 . In the mold tool open position, the ejector pin 801 serves the function of separating the encapsulated LED 600 from the mold tool 710 to facilitate removal. [0054] FIG. 10A illustrates an embodiment of a contoured-tip ejector pin according to the present invention. The ejector pin tip 1000 is advantageously shaped to create an LED 500 having a non-protruding lens 560 with a flat surface element 564 corresponding to the illustration of FIG. 5A . The ejector pin tip 1000 of FIG. 10A has an optically ground and polished flat circular surface 1010 of 30 mil diameter which corresponds to the flat surface element 564 of the LED lens 560 . The ejector pin tip 1000 also features a curved portion 1020 of 25 mil radius, R 1 , blending into the flat surface 1010 which is similarly ground into the pin tip 1000 and which corresponds to the arcuate surface element 568 of the LED lens 560 . The pin tip 1000 has a combination of a 50° angle, θ 1 , and a 0.023 inch height, D 1 , taper 1030 ground and optically polished on the outer diameter of the pin tip 1000 which corresponds to the LED encapsulant sidewall 554 . The tip area 1040 between the curved portion 1020 and taper 1030 corresponds to the LED encapsulant trough 552 . [0055] FIG. 10B illustrates another embodiment of a contoured-tip ejector pin according to the present invention. The ejector pin tip 1000 A is advantageously shaped to create an LED 600 having a non-protruding lens 660 with a spherical surface element 664 corresponding to the illustration of FIG. 6 . The ejector pin tip 1000 A of FIG. 10B has an optically ground and polished spherical dome 1060 of 50-mil radius, R 2 , which corresponds to the spherical surface element 664 . The tip 1000 A also has a 56°, 35′ angle, θ 2 , and 0.025 inch height, D 2 , taper 1070 ground and optically polished on the outer diameter of the pin tip 1000 A which corresponds to the encapsulant sidewall 654 . The tip area 1080 between the spherical dome 1060 and taper 1070 corresponds to the encapsulant trough 652 . Neu Dynamics, Ivyland, Pa., is capable of manufacturing ejector pins with contoured tips such as shown in FIGS. 10 A-B. [0056] FIG. 10C illustrates yet another embodiment of a contoured-tip ejector pin according to the present invention. The ejector pin tip 1000 B is advantageously shaped to create a generally cone-shaped chamber in the encapsulant to concentrate or “funnel” energy onto the surface of a detector element embedded in the encapsulant. This creates a one-piece detector device that functions similarly to a photodetector mounted within a separate chamber, as described in U.S. Pat. No. 5,638,818 and assigned to the assignee of the present invention. The tip 1000 B features a taper 1090 that is ground and optically polished on the outer diameter of the pin tip 1000 B and that corresponds to the chamber walls. [0057] The non-protruding optoelectronic lens and associated contoured-tip ejector pins have been disclosed in detail in connection with the various embodiments of the present invention. These embodiments are disclosed by way of examples only and are not to limit the scope of the present invention, which is defined by the claims that follow. One of ordinary skill in the art will appreciate many variations and modifications within the scope of this invention. For example, although the current invention was described above mostly with respect to LED embodiments, the current invention also applies to non-protruding lenses for encapsulated photodiode detectors and to detector cavities.

An optoelectronic component has a lens that is formed in the surface of an encapsulant surrounding a semiconductor diode element. With respect to emitters, the lens reduces internal reflection and reduces dispersion to increase overall efficiency. With respect to detectors, the lens focuses photons on the active area of the detector, increasing detector sensitivity, which allows a detector having a reduced size and reduced cost for a given application. The lens portion of the encapsulant is generally non-protruding from the surrounding portions of the encapsulant reducing contact surface pressure caused by the optoelectronic component. This non-protruding lens is particularly useful in pulse oximetry sensor applications. The lens is advantageously formed with a contoured-tip ejector pin incorporated into the encapsulant transfer mold, and the lens shape facilitates mold release.

BACKGROUND OF THE INVENTION 1. Filed of the Invention This invention relates to an apparatus for making ball-shaped marshmallow products. 2. Description of the Prior Art Individual marshmallows are typically made by forming a marshmallow string and then cutting it into predetermined lengths with a planar, reciprocating cutter, whereby the resultant products have a generally squared or rectangular configuration. Further, when the marshmallows contain a filler material, such as jam, jelly, etc., such filler is liable to become exposed and leak out. The reciprocating operation of the conventional cutter also makes it difficult to achieve high speed operation without causing machine problems, whereby the production rates are generally relatively low. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an improved marshmallow producing apparatus which eliminates the above defects. According to the invention, a roll cutter comprising a pair of rotary cutter drums having scalloped surfaces is used instead of a conventional reciprocating cutter, whereby an elongated marshmallow string extrusion is smoothly and easily cut into predetermined lengths with each individual marshmallow having a rounded or ball-shape. The cutter drums implement a form of squeeze or pinch cutting, whereby any filler material such as jam or jelly is effectively sealed in at the cut ends to thus prevent exposure and leakage. The rounded effect is also implemented by providing reciprocal axial movement between the two cutter drums, whereby each marshmallow is rolled during its temporary presence between facing scallop grooves of the drums. BRIEF DESCRIPTION OF THE DRAWINGS In the drawings: FIG. 1 shows a schematic side view of an apparatus for manufacturing ball-shaped marshmallow products according to this invention, FIG. 2 shows a plan view of FIG. 1, FIG. 3 shows a perspective view of the cutter drums used in the invention, FIG. 4 shows a sectional view of a double tube extrusion nozzle used in the invention, FIG. 5 shows a sectional view illustrating the cutting of a marshmallow extrusion, and FIG. 6 shows a sectional view illustrating the cutting of a filler containing marshmallow extrusion. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1, reference numeral 1 designates a conveyor for feeding an extruded string of marshmallow. The conveyor comprises an endless belt 3 and a pair of spaced rollers 2, 2. An extruder 4 is disposed above the upper surface of the conveyor belt 3, and includes an extrusion nozzle 5 for continuously supplying a string or rod of marshmallow material. To produce a marshmallow containing a filler such as jam or jelly a double tube nozzle 5' must be used, as shown in FIG. 4. The double tube nozzle 5' is constructed so that an inner tube 5a is eccentrically disposed within an outer tube 5b. The space 5c between the tubes supplies a marshmallow covering material a, whereby extrusions of the filler material b from the tube 5a and the covering material a from the space 5c are simultaneously carried out. A pair of powder supply means 6, 6' are disposed adjacent each other on the feed side (x) of the conveyor 1, as shown in FIG. 2. These powder supply means are constructed so that an endless belt 9 is perpendiculary arranged on a pair of rollers 8, 8 disposed in a housing 7, and a plurality of scoop buckets 10 are mounted on the outer periphery of the belt 9 at spaced intervals. The belt 9 is driven through the rollers 8 by a motor or the like, schematically shown at 30. In the powder supply means 6, the internal portion of the upper side of the housing 7 is connected through a chute 11 to a first powder spreading hopper 12 disposed above the conveyor 1 on the feed side (x) thereof. Powder 13 gathered in the bottom of the housing 7 is fed into the first hopper 12 through the chute 11 after it is scooped up by the buckets 10, and is thereafter spread out on the upper surface of the conveyor belt 3. The powder 13 may be confectioners sugar or the like, whose primary purpose is to prevent the individual marshmallows from sticking together. The other powder supply means 6' is connected through a screw conveyor 14 to a second hopper 16 disposed above the discharge side(y) of the conveyer. The conveyor 14 comprises an enclosed feed screw 15 driven by a motor 31. The powder 13 supplied to the screw conveyor 14 is delivered thereby into the second hopper 16, whereafter it is spread out on the upper surface of the conveyor belt 3. A plurality of rotatable guide rollers 17 are horizontally disposed adjacent the discharge end (y) of the conveyor 1, and a roll cutter 18 is positioned just after the guide rollers 17. The roll cutter 18 comprises a pair of cutter drums 20, 20 rotatably journaled on side walls 19 one above the other. The cutter drums 20, 20 have a plurality of wavy scallop grooves 21 on their peripheral surface, which are cut out in parallel in the axial direction. The projecting edges 22 between adjacent grooves constitute sharp cutting edges. The surface of each cutter drum is coated with a layer of teflon to prevent the marshmallow material A from adhering thereto. The grooves 21 and the cutting edges 22 on the upper and lower drums are disposed to face each other. Both cutter drums are synchrounously rotated in opposite directions, and are also reciprocatingly movable in the axial direction by a drive mechanism 24 (known per se) whereby one shaft 23 is relatively axially movable in a back and forth manner with respect to the other shaft 23'. The mechanism 24 may, for example, comprise a rotationally driven crank shaft having a link arm pivotally coupled between the offset portion of the crank shaft and a drum shaft 23 or 23', much in the same manner as the piston rod/crank shaft arrangement in an internal combustion engine. A pressing and transferring means 25 is disposed on the discharge side of the roll cutter 18, and comprises a lower conveyer belt 26 and an upper pressing belt 27 adapted to move up-and-down to slightly flatten the marshmallows. A container 28 for the final products is disposed beneath the conveyor belt 26. Reference numeral 29 designates a powder collecting belt for recovering the powder 13 fallen from the conveyor 1, the guide rollers 17, and the roll cutter 18, and delivering it back to the powder supply means 6, 6'. The motor 30 drives the powder conveyor 1, the powder supply means 6, 6', and the conveyor belt 29. In operation, the conveyor 1, the powder supply means 6, 6', the roll cutter 18, the compressive transfer means 25, and the powder collecting conveyor belt 29 are first driven or started up so that the powder 13 is spread out from the hoppers 12, 16 onto the moving conveyor belt 3. The extruder 4 is then turned on to deliver a string of marshmallow A, either in solid form from a single nozzle or containing a filler material b from a double nozzle, onto the powdered conveyer belt 3, over the guide rollers 17, and into the roll cutter 18. During the transfer from the belt 3 to the cutter 18, the powder 13 spread over the belt prevents the marshmallow string A from adhering thereto. When the string passes under the second hopper 16 additional powder 13 is dispensed over the upper and side surfaces of the string, whereby it does not adhere to the cutter drums 20, 20. The roll cutter 18, whose drums 20, 20 are rotating in opposite directions while reciprocatingly moving along their axes relative to each other, thus separate and shape the string into individual, rounded marshmallow products, as shown in FIGS. 5 and 6. Any filler material (b) is covered at its severed ends with the marshmallow material (a), as shown in FIG. 6, whereby the filler does not leak out even when the marshmallow material is pressed by the cutting edges 22, 22. The eccentric or center-displaced positioning of the filler material (b) enables and enhances this end sealing effect, together with the pinch or squeeze cutting implemented by the scalloped cutter drum surfaces. Since the covering material (a) is somewhat viscous, it is depressed toward the center of the string during cutting, whereby the filler material is not exposed in the final product. Moreover, during the cutting operation the marshmallows are temporarily positioned between a pair of cutter grooves 21, 21, and by reason of the reciprocal axial movement of the drums 20, 20 each marshmallow is rolled between the facing grooves to thus form a ball-shaped product. The severed and formed products are then fed to the conveyor 26 by the continued rotation of the lower cutting drum 20, whereat the ball-shaped marshmallows are slightly flattened by the belt 27 during its up-and-down motion and then drop into the container 28. In the above description the covering material and filler are extruded such that the latter is displaced from the center axis of the former, but the present invention is not necessarily limited to such a feature. Further, only one cutting drum 20 has to be axially reciprocated in order to effect the necessary relative movement between the two drums.

An extruded string of marshmallow material is powdered and conveyed to a pair of scallop surfaced cutter drums which are synchronously rotated in opposite directions and simultaneously axially reciprocated relative to each other, whereby the string is pinch or squeeze severed into individual marshmallows. A rounded form is implemented by each marshmallow being rolled in the tube formed by a pair of facing scallop grooves of the reciprocating drums during its temporary presence therein. If a filler of jam or the like is extruded within the string, the pinch severing tends to sealingly force the relatively viscous marshmallow material over the ends of the filler pocket to thereby prevent the escape and leakage of the filler.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This is a U.S. national stage of application No. PCT/GB2014/050663, filed on 6 Mar. 2014. Priority under 35 U.S.C. §119(a) and 35 U.S.C. §365(b) is claimed from Great Britain Application No. 1304046.4 filed on 6 Mar. 2013, the disclosure of which is also incorporated herein by reference in its entirety. TECHNICAL FIELD [0002] This disclosure relates to methods and apparatuses for producing very high localised energies. It relates particularly, although not exclusively, to generating localised energies high enough to cause nuclear fusion. BACKGROUND [0003] The development of fusion power has been an area of massive investment of time and money for many years. This investment has been largely centred on developing a large scale fusion reactor, at great cost. However, there are other theories that predict much simpler and cheaper mechanisms for creating fusion. Of interest here is the umbrella concept “inertial confinement fusion”, which uses mechanical forces (such as shock waves) to concentrate and focus energy into very small volumes. [0004] Much of the confidence in the potential in alternative methods of inertial confinement fusion comes from observations of a phenomenon called sonoluminescence. This occurs when a liquid containing appropriately sized bubbles is driven with a particular frequency of ultrasound. The pressure wave causes bubbles to expand and then collapse very violently; a process usually referred to as inertial cavitation. The rapid collapse of the bubble leads to non-equilibrium compression that causes the contents to heat up to an extent that they emit light [Gaitan, D. F., Crum, L. A., Church, C. C., and Roy, R. A., Journal of the Acoustical Society of America, 91(6), 3166-3183 June (1992)]. There have been various efforts to intensify this process and one group has claimed to observe fusion [Taleyarkhan, R. P., West, C. D., Cho, J. S., Lahey, R. T., Nigmatulin, R. I., and Block, R. C., Science, 295(5561), 1868-1873 March (2002)]. However, the observed results have not yet been validated or replicated, in spite of substantial effort [Shapira, D. and Saltmarsh, M., Physical Review Letters, 89(10), 104302 September (2002)]. This is not the only proposed mechanism that has led to luminescence from a collapsing bubble; however it is the most documented. Luminescence has also been observed from a bubble collapsed by a strong shock wave [Bourne, N. K. and Field, J. E., Philosophical Transactions of the Royal Society of London Series A - Mathematical Physical and Engineering Sciences, 357(1751), 295-311 February (1999)]. It is this second mechanism, i.e. the collapse of a bubble using a shockwave, to which this invention relates. [0005] It has been proposed in U.S. Pat. No. 7,445,319 to fire spherical drops of water moving at very high speed (˜1 km/s) into a rigid target to generate an intense shock wave. This shock wave can be used to collapse bubbles that have been nucleated and subsequently have expanded inside the droplet. It is inside the collapsed bubble that the above-mentioned patent expects fusion to take place. The mechanism of shockwave generation by high-speed droplet impact on a surface has been studied experimentally and numerically before and is well-documented (including work by one of the present patent inventors, [Haller, K. K., Ventikos, Y., Poulikakos, D., and Monkewitz, P., Journal of Applied Physics, 92(5), 2821-2828 September (2002)]). The present invention differs from U.S. Pat. No. 7,445,319, even though the fundamental physical mechanisms are similar, because it does not utilise a high speed droplet impact. SUMMARY [0006] The present invention aims to provide alternatives to the aforementioned techniques and may also have other applications. When viewed from a first aspect the invention provides a method of producing a localised concentration of energy comprising creating a shockwave propagating through a non-gaseous medium so as to be incident upon a boundary between the non-gaseous medium and a gaseous medium formed by at least one hole in a barrier separating the non-gaseous medium from a gaseous medium, thereby forming a transverse jet on the other side of the hole which is incident upon a target surface comprising a depression which is spaced from the barrier in the gaseous medium. [0007] The invention also extends to an apparatus for producing a localised concentration of energy comprising: [0008] a gaseous medium; [0009] a non-gaseous medium separated from the gaseous medium by a barrier comprising at least one hole therein; [0010] a target surface comprising a depression which is spaced from the barrier in the gaseous medium; and [0011] means for creating at least one shockwave propagating through said non-gaseous medium so as to be incident upon a boundary formed by said hole, thereby forming a transverse jet on the other side of the hole. [0012] It has been shown in WO 2011/138622 that an interaction between a shockwave in a non-gaseous medium and a gaseous medium, for example a shockwave striking a gas bubble within a liquid, can generate a high speed transverse jet of the non-gaseous medium that moves through the gaseous medium, which results in the jet impacting on the leeward side of the bubble. In accordance with the present invention this is developed further. The transverse jet created by the shockwave incident upon the boundary traps a volume or “bubble” of the gaseous medium against the target. This gives rise to an intense concentration of energy within the gas by two mechanisms. The first mechanism is a simple transfer of kinetic energy from the jet into potential energy and subsequently into heat energy as the bubble is compressed while it arrests the motion of the jet. This includes heating by the bow shock moving in front of the jet and heating caused by the rebounding of this bow shock and subsequent interactions of further resulting shocks confined within the bubble. [0013] The second mechanism is the transfer of energy from the converging shockwave generated by the impact between the jet and the surface of the target which propagates from the jet into the adjacent bubble. As the edge of the shockwave propagates towards the trapped volume, it is focussed, forming a contracting circle. When this shockwave eventually focuses down near to a point, it results in extremely high pressures and temperatures in the compressed bubble. The large reduction in density of the medium in which the shockwave is travelling in going from the jet to the bubble means that the shockwave generates very high temperatures in the bubble, particularly as it converges to a point. [0014] The transverse jet created when the shockwave in the non-gaseous medium is incident upon the gaseous medium accelerates from the boundary between the non-gaseous and gaseous media to its high speed at the target surface where it traps and compresses a volume of gas. As the jet continues through the gaseous medium it continues to accelerate as the shockwave converges. Therefore, by providing the spacing of the target surface from the hole in the barrier, i.e. where the transverse jet is first formed at the boundary, the jet has space to accelerate further, such that it reaches a higher speed upon impact on the target surface than without such a spacing. The maximum spacing of the target surface from the hole in the boundary is determined by the point at which the transverse jet starts to be become unstable and therefore breaks down into a spray of droplets. Therefore, the spacing of the target surface from the hole in the barrier could be less than 20 times the diameter of the hole, e.g. less than 10 times the diameter, e.g. less than 5 times, e.g. less than twice the diameter of the hole. In a set of embodiments discussed below in which the boundary surface (i.e. the boundary between the non-gaseous and gaseous media) is curved, the spacing could be less than 10 times the radius of curvature of the boundary surface, e.g. less than 5 times, e.g. less than twice the radius of curvature of the boundary surface. In theory there is no minimum spacing, it is simply required that the barrier and the target surface do not touch. In practice however, the spacing must be sufficient to provide a supply of the gaseous medium and, in a set of embodiments discussed below, slide in a new target surface. This spacing allows more energy from the shockwave to be harnessed into the jet and subsequently the impact on the target surface, therefore increasing the compression and heating of the trapped bubble. This is compared to, for example, an arrangement in which the gaseous medium is directly attached to the target surface as a bubble without the presence of a barrier spaced from the target surface as disclosed in WO 2011/138622. [0015] Thus, depending on a variety of factors, such as the spacing between the barrier and the target surface, it may be possible to improve the speed reached by the jet using the present invention. Furthermore, as will be explained below, the spacing of the barrier from the target surface gives a number of other advantages. Embodiments of the invention may be used to create very high concentrations of energy through the creation of a jet of non-gaseous medium which compresses a volume of gaseous medium against a target surface. Owing to the very high concentrations of energy in the trapped bubble and the adjacent target surface, damage to the target surface will inevitably result. In some embodiments of the invention, for example those in which the target surface includes fuel for nuclear fusion or reactants for a chemical reaction, damage to the target surface is intended. If the invention is to be used for such purposes, in order to obtain a sustainable reaction, repeated impacts at a high repetition rate are desirable. However, it will appreciated that for repeated impacts of the jet onto the target surface, particularly when the target surface is damaged by an impact, the target surface will need to be replaced quickly. The separation of the barrier and the target surface makes this possible, particularly because the target surface is not in contact with any of the non-gaseous medium except when the shockwave is propagating. For example, the target surface could be completely replaced, e.g. the damaged surface slid out and a new surface slid in, or the target surface with a number of different impact sites could be moved along successively to position each impact site relative to the hole in the barrier such that with each repetition, or multiples thereof, of the shockwave in the non-gaseous medium, a new target site on the target surface receives the impact from the transverse jet created. [0016] The separation of the target surface and the barrier allows them to be made from different materials, each suited to their purpose. In order to withstand the pressures created by the shockwave, and possibly multiple shockwaves, in one set of embodiments the barrier is made from a strong material, e.g. high strength steel. The barrier could be reinforced around the perimeter of the hole, as this is where the pressure and energy is likely to be greatest. Conversely, the target surface may not need to have any particular structural strength, as it is not in direct contact with the shockwave other than via the jet. As discussed previously the target surface may be made from, or at least include, a fuel for nuclear fusion or reactants for a chemical reaction. [0017] The separation of the target surface from the non-gaseous medium, i.e. by the barrier, also enables independence of the composition of the non-gaseous medium from the composition of the gaseous medium, e.g. because the non-gaseous medium does not need to be of a composition which allows the gaseous medium to be nucleated within it, but also because different supplies for these two materials can be provided easily either side of the barrier. This independence of the gaseous and non-gaseous materials is particularly advantageous in the chemistry applications of the invention, e.g. sonochemistry and exotic chemistry, where the composition of the materials can be chosen to be suitable to the particular reaction to be investigated. [0018] With the independence of the barrier and the target surface, resulting from their separation, the shape of these two structures, as well as the hole in the barrier, can also be individually tailored. Advantageously the target surface comprises a depression. This can be designed to receive the transverse jet impact such that at least some of the gaseous medium is trapped between the impacting jet and the surface depression, e.g. a bubble of gas is trapped and compressed against the internal surface of the depression by the jet. Depending upon the application for which the apparatus is employed, e.g. nuclear fusion or a chemical reaction, the target surface could be shaped to collect the products from whatever reaction is generated at the surface. For example, the target surface could be arranged at an angle to the horizontal such that the products from the reaction flow down off the surface to a collecting vessel. [0019] The shape of the surface in the depression opposite where the shockwave is incident could be flat so that the jet contacts the surface at a point. In one set of embodiments however the surface depression is arranged such that the initial contact region is a curve which forms a closed loop—e.g. a ring. This increases the ease of trapping a volume of the gaseous medium between the jet tip and the edge of the depression. To achieve this, a section of the target surface has a curvature greater than that of the tip of the jet and this part of the surface is placed such that the jet impacts into it. Upon impacting, a toroidal shockwave is generated whose inner edge propagates towards the base of the depression and towards the trapped portion of gas. Combining this with the ‘piston’ effect of the gas halting the motion of the impacting jet yields extremely strong heating of the trapped gas. For example, for a given strength of shockwave the peak temperatures can be increased by over an order of magnitude by these arrangements as compared to a volume of gas in contact with a planar surface. [0020] The depression could take a number of shapes. In a set of embodiments it tapers in cross-section away from the mouth. The depression could resemble a dish—e.g. being continuously curved. The surface need not be continuously curved however. In a set of embodiments the surface more closely resembles a crack rather than a dish shape. This could be defined by stating that the depth is greater than the width or by the presence of a region of curvature at the tip of the crack greater than the curvature (or maximum curvature) of the portion of the bubble trapped in it. In one set of embodiments the surface comprises a plurality of discrete portions, e.g. with a gradient discontinuity between them. The portions could themselves be partial ellipses, parabolas, and so on, but equally could be straight. A particular set of embodiments of surfaces made from discrete portions could be described as piecewise polynomial. [0021] The target surface need not be limited to having a single depression (e.g. to exploit the jetting phenomenon described above) and thus in one set of embodiments, the target surface comprises a plurality of depressions. [0022] In a particular set of embodiments the transverse jet is arranged to strike an area of surface that has been prepared with a particular roughness, microscopic or macroscopic shape such that many small portions of the gaseous medium are trapped between the jet tip and the target surface, i.e. the many small depressions are small in comparison to the size of the transverse jet tip. [0023] In another set of embodiments plural discrete depressions are provided. Each individual depression may be shaped to encourage energy focusing by causing the transverse jet created at the barrier to trap one or more volumes of gas. That is to say, the surface may be prepared with more than one site where the transverse jet will interact with a shaped section of surface in which a volume of the gaseous medium can be trapped, thus providing scalability. An advantage of employing a plurality of depressions is that a greater proportion of the transverse jet energy may be harnessed. Furthermore, owing to the separation of the barrier from the target surface, no changes need to be made to the nature of the gaseous medium or how it is supplied as this will be spread across the plurality of depressions. [0024] It will be appreciated that plural discrete depressions are particularly suited to a set of embodiments in which more than one hole is provided in the barrier. Preferably each depression corresponds to a hole in the barrier, i.e. so that each transverse jet created impacts in its corresponding depression on the target surface. This allows a greater proportion of the initial shockwave incident upon the barrier to be harnessed. The plurality of holes could all comprise the same shape, which simplifies the manufacture of the barrier, or they could be different shapes, e.g. dependent on their position on the barrier. This could be useful in the embodiments in which the shape of the barrier is optimised to control the formation of the transverse jet, e.g. the shape of the hole may depend on the local shape of the barrier. Furthermore, the holes could be arranged, by the shape of the barrier and/or the shape of the holes, such that multiple transverse jets are directed to a single position on the target surface, e.g. where a depression is located, in order to intensify the compression of the trapped bubble at that point. As such it will be appreciated that this can also be applied to the set of embodiments in which only a single depression on the target surface is provided. [0025] The plurality of depressions in the target surface could be formed in a number of ways. For example, a solid surface could be drilled or otherwise machined to produce depressions or pits. In one set of embodiments, however, the depressions are created by the surface texture of the surface. For example, the surface could be blasted with an abrasive material, etched or otherwise treated to give a desired degree of surface roughness which provides, at the microscopic level, a large number of pits or depressions. [0026] The target surface could be constructed from a solid, as implied in many of the embodiments outlined above, but it could equally well be a liquid. In the case of a solid, any of the proposed materials in U.S. Pat. No. 7,445,319 could be suitable. In the case of a liquid the required surface shape (if required, e.g. in the set of embodiments comprising a depression) could be achieved in a number of ways. For example, the surface of a volume of liquid could be excited with a suitable vibration (e.g. using ultrasound or another method) to generate a wave having the desired shape. Alternatively the desired shape could be achieved through the contact angle between a liquid and a solid surface with appropriately matched wetting properties. Of course, this latter example shows that the surface could comprise a combination of solid and liquid. Where the target surface comprises a liquid it will generally be denser than the non-gaseous medium. [0027] The shape of the barrier can also be shaped to control the formation of the transverse jet. More particularly, by designing the barrier explicitly to receive the high speed jetting formed by the interaction of the incident shockwave with the gaseous medium, as the incident shockwave interacts with the surface of the gaseous medium it forms a transmitted shock and a reflected rarefaction. If the contact is the correct shape, i.e. curving away from the incident shockwave, then this rarefaction will act to focus the flow to a point. This then results in the formation of the high speed transverse jet which can, purely as an example, reach over 2000 ms −1 for a 1 GPa shockwave. When this jet strikes the target surface, a strong shockwave is generated within by the force of the impact in a manner analogous to the high speed droplet impact situation described in U.S. Pat. No. 7,445,319. The barrier could comprise an overall shape to focus the shockwave towards the hole or, in the set of embodiments in which a plurality of holes in the barrier are provided, the barrier could be shaped locally in the vicinity of each hole to control the formation of each transverse jet created. [0028] As well as the shape of the target surface and/or the shape of the barrier being chosen to optimise formation of the transverse jet and the compression of the trapped bubble, the shape of the hole in the barrier can also be chosen to aid the formation of the transverse jet. The hole could comprise one of a number of different shapes, e.g. circular, through the barrier with a constant cross section. However, the cross section could flare or taper through the barrier in the direction of the gaseous medium in order to control formation of the transverse jet and focus or direct it onto the target surface, e.g. towards a depression. In this regard, the region on the target surface upon which the transverse jet is intended to impact, e.g. the depression, does not need to be positioned directly opposite the hole from which the transverse jet originates, the shape of the barrier and/or the hole could be arranged to control this. [0029] The shape of each hole can also be used to control the shape of the boundary between the gaseous and non-gaseous media in the hole. The boundary shape can also be controlled by the relative pressures of the gaseous medium to the non-gaseous medium. As will be appreciated, this is particularly simple to control with the arrangement of the present invention because of the separation between the barrier and the target surface. In one set of embodiments the apparatus comprises means to control the pressure of the gaseous medium. These means, or alternative means, e.g. a gas supply in fluid communication with the gaseous medium, can also be used to replenish the gaseous medium after a shockwave has been applied to the non-gaseous medium. This set of embodiments has the advantage of great control over the contents and size of the gaseous medium generated, as well as allowing the gaseous medium to be replenished quickly, i.e. compared to nucleating a bubble in the non-gaseous medium, enabling the shockwaves to be applied at a high repetition rate, giving another advantage resulting from the separation of the barrier from the target surface. [0030] The shape of the boundary between the non-gaseous and gaseous media could be flat. However in one set of embodiments, alluded to above, the boundary is non-flat, i.e. curved. Preferably the gaseous medium protrudes into the non-gaseous medium through the hole, i.e. the boundary is convex. This convex shape has been found to be particularly advantageous in forming the transverse jet as the rarefaction fan, which is formed when the shockwave is incident upon the boundary, acts to focus the flow of the non-gaseous medium to a point, thereby forming a narrow jet in which energy from across the surface of the boundary is harnessed. This is considered novel and inventive in its own right and thus when viewed from a further aspect the invention provides a method of producing a localised concentration of energy comprising creating a shockwave propagating through a non-gaseous medium so as to be incident upon a convex boundary between the non-gaseous medium and a gaseous medium formed by at least one hole in a barrier separating the non-gaseous medium from a gaseous medium, thereby forming a transverse jet on the other side of the hole which is incident upon a target surface which is spaced from the barrier in the gaseous medium. [0031] The invention also extends to an apparatus for producing a localised concentration of energy comprising: [0032] a gaseous medium; [0033] a non-gaseous medium separated from the gaseous medium by a barrier comprising at least one hole therein which forms a boundary which is convex in the non-gaseous medium; [0034] a target surface which is spaced from the barrier in the gaseous medium; and [0035] means for creating at least one shockwave propagating through said non-gaseous medium so as to be incident upon the boundary formed by said hole, thereby forming a transverse jet on the other side of the hole. [0036] In one set of embodiments the initial shockwave applied to the non-gaseous medium might be arranged to conform to the shape of the boundary between the non-gaseous and gaseous media which could increase the intensity of the transverse jet created is increased. [0037] In one set of embodiments the microstructure or wetting characteristics of the barrier and/or the edge of the hole can be optimised to control the boundary shape. For example the barrier and/or the hole could comprise hydrophobic and/or hydrophilic surfaces or coatings (or materials with affinities and repulsions to types of fluids other than water). Providing a particular microstructure or wetting characteristics of the barrier and/or hole, in combination with the means to replenish the gaseous medium, again can aid rapid formation of the gaseous medium at the boundary to enable a high repetition rate for the shockwaves. For example the perimeter of the hole could comprise a hydrophobic material, outside of which is a hydrophilic material to control the position boundary of the gaseous and non-gaseous media as well as the contact angle of the boundary with the barrier. [0038] In a further set of embodiments the surface tension of the non-gaseous medium can be used to control the boundary shape. In another set of embodiments a standing pressure wave, e.g. a standing ultrasound wave, is applied to the non-gaseous medium to control the boundary shape. This technique can also be used to encourage the reformation of the gaseous medium at the boundary following a shockwave, again enabling a high repetition rate for the shockwaves. [0039] Yet a further technique has been envisaged by the inventors to control the boundary shape and to enable a high repetition rate for the shockwaves. In one set of embodiments the apparatus comprises a membrane which defines the boundary between the gaseous and non-gaseous media, e.g. a pre-manufactured membrane, which defines the boundary shape. The use of a thin membrane in this manner allows a decoupling of the non-gaseous and gaseous materials, allowing any choice of combination of compositions to be made. It also allows the boundary shape to be controlled with a precision not available to other methods. The membrane could be formed from any suitable material, e.g. glass, e.g. plastic, e.g. rubber. [0040] Having a prefabricated membrane allows a non-gaseous medium, e.g. a liquid, to be used more easily as the gaseous medium is trapped on its side of the barrier and therefore cannot float away through the hole or otherwise be disturbed. In a particular set of embodiments the membrane is frangible and is arranged to break upon impact from the shockwave such that it has no influence on the resulting dynamics. In one set of embodiments the prefabricated membrane includes a line or region of weakness, so that upon impact from the shockwave it breaks along the line or in the region of weakness. The line or region of weakness can be arranged so that the position of the breach has an influence on the ensuing flow patterns, for example this could help control the formation and dynamics of the transverse jet. In another set of embodiments the membrane is designed to deform with the collapsing boundary. [0041] In the set of embodiments in which a plurality of holes are provided in the barrier, a separate membrane could be provided to cover each of the holes. However in one set of embodiments the membrane is arranged to cover two or more of the holes in the barrier. This is easier to arrange, particularly when a high repetition rate for multiple shockwaves to be applied to the non-gaseous medium are desired. For example, a new membrane could be slid into the apparatus prior to each application of the shockwave, similar to the arrangement for the target surface as discussed above. Indeed the target surface and membrane could be slid into place simultaneously, e.g. pre-fabricated with the gaseous medium therebetween. [0042] In one set of embodiments the apparatus comprises a plurality of barriers, each barrier comprising at least one hole therein and separating a gaseous medium from a non-gaseous medium. In this way, the energy from the initial shockwave can be intensified with each successive incidence upon a barrier and a non-gaseous medium thereby harnessing a greater amount of the energy from the initial shockwave onto the target surface. Each volume of non-gaseous medium and gaseous medium either side of the barriers need not comprise the same composition. For example in a set of embodiments with two barriers, the shockwave could be applied to a first non-gaseous medium to be incident upon a boundary with first gaseous medium at a hole in the first barrier, and then subsequently incident upon a second non-gaseous medium and then a second boundary with a second gaseous medium at a hole in the second barrier before being incident upon the target surface. [0043] In embodiments in which the general orientation of the barriers is horizontal, the intermediate layers of gaseous medium could simply float above the respective layers of non-gaseous medium. However in one set of embodiments the apparatus comprises a membrane separating the boundary between the non-gaseous and gaseous media away from the boundary, which is particularly advantageous in the embodiments in which the general orientation of the barriers is away from the horizontal, to retain the respective positioning of the non-gaseous and gaseous media. This can be in addition to or instead of a membrane across the holes at the barriers. [0044] The holes in adjacent barriers could be directly aligned with each other in order to direct the transverse jet created at one barrier onto the non-gaseous medium at the corresponding hole in the next barrier. Alternatively the holes could be arranged such that multiple transverse jets from one barrier are directed towards the non-gaseous medium at a single hole in the next barrier, or vice versa, i.e. a single jet to multiple holes. This former alternative can be seen to be particularly advantageous as the multiple converging jets intensify the shockwave incident upon the next non-gaseous layer. Therefore if successive layers of non-gaseous and gaseous material are arranged in this manner, a large amount of energy from the initial shockwave can be harnessed and focussed onto the final gaseous material which is trapped and compressed against the target surface. It will also be appreciated that any of these arrangements can be combined with any number of the embodiments discussed above, e.g. with regard to the shape of the holes, the shape of the barrier, etc, in order to control the formation of the transverse jets and the resultant shockwaves. In particular, the barriers could be shaped to focus the initial and/or resultant shockwaves onto the one or more holes and/or the target surface, e.g. to conform to the shape of the boundary between the gaseous and non-gaseous media at the one or more holes in the subsequent barrier. [0045] Of course, as has already been alluded to, some embodiments may comprise a plurality of volumes of the gaseous medium. However, in addition or instead of these multiple volumes which are each in contact with a respective barrier, the inventors have envisaged a further arrangement in which the initial shockwave can be focussed onto the final target surface. In one set of embodiments the apparatus comprises one or more pockets of fluid within the non-gaseous medium which are positioned relative to the one or more holes in the barrier such that the incidence of the shockwave on the first pocket of fluid concentrates the intensity of the shockwave subsequently incident upon the gaseous medium. Preferably the fluid comprises a gas, e.g. of the same composition as the gaseous medium. [0046] It will be appreciated that the one or more pockets of fluid within the non-gaseous medium (and any layer thereof), as with the multiple layers of non-gaseous and gaseous media, acts to harness a greater proportion of the initial shockwave than is incident upon a single hole in the barrier. The incidence of the shockwave on the pocket of fluid causes a transverse jet to be formed which accelerates across the volume of the pocket and impacts on the leeward side of the pocket. This impact results in an outward moving shockwave which can be over ten times the pressure of the incident shockwave. The pocket of fluid is positioned relative to the one or more holes in the barrier such that this more intense shockwave then interacts with the gaseous medium with a greater pressure than if the initial shockwave had been incident upon it. As with the multiple holes in the barrier for the multiple layers, multiple fluid pockets can be positioned in the non-gaseous medium to generate transverse jets which subsequently impact on the gaseous medium at one or more holes in the barrier. [0047] As well as creating a particular shape for one or more of the target surface, the barrier, the hole in the barrier, and the boundary, in one set of embodiments the micro-structure or wetting characteristics of one or more of the target surface, the barrier and the hole can be optimised to control the speed of the shockwave near the target surface, e.g. to increase the speed near the target surface, thereby changing the shockwave's shape and hence the nature of the interaction between the shockwave and the trapped bubble. As previously discussed, an appropriately shaped boundary between the non-gaseous and gaseous media can be used in this set of embodiments to match the shape of the shockwave to the shape of the boundary, thereby allowing the dynamics of the transverse jet formation to be controlled in order to maximise the temperature and density achieved on compression of the trapped bubble. [0048] The invention described herein provide alternatives to the technique described in U.S. Pat. No. 7,445,319 which may carry their own benefits. The present inventors have recognised that there are significant challenges in the nucleation of a bubble in a droplet fired at high speed into a target, as suggested in U.S. Pat. No. 7,445,319. The timing will have to be very precise for the bubble to be at a favourable moment of its expand-collapse cycle when the shock strikes. The method by which the high speed droplets are created as required by U.S. Pat. No. 7,445,319 and detailed in U.S. Pat. No. 7,380,918 is also complex and expensive. By contrast such complexity and associated expense can be avoided in accordance with at least preferred embodiments of the present invention. Thus, the various aspects of the present invention provide much simpler techniques for compressing a bubble trapped by a jet from a non-gaseous medium, as a shockwave simply needs to be created within the non-gaseous medium. Moreover the theoretical and computer modelling of both techniques carried out by the present inventors suggests that the method in accordance with the present invention can give pressure and temperature intensities which are an order of magnitude greater than the method detailed in U.S. Pat. No. 7,445,319. [0049] The more static framework that can be employed in accordance with the invention to compress a gas bubble using a shockwave allows much greater control (compared to a free bubble) over how the shockwave strikes the gaseous medium and interacts with the trapped bubble. [0050] The initial shockwave could be created in a number of different ways by a number of different devices depending on the pressure required. For example, a shockwave lithotripsy device could be used to generate lower intensity shockwaves or an explosive plane wave generator could be used to provide high intensity shockwaves. Alternatively a gas gun could be used to strike a projectile into a diaphragm or piston in contact with the non-gaseous medium to create the shockwave. In preferred embodiments such an explosive device can create a shockwave pressure of between 0.1 GPa and 50 GPa, and in another preferred embodiment a lithotripsy device could be used to generate shockwave pressures of 100 MPa to 1 GPa. If a shockwave is to be repeatedly applied to the non-gaseous medium, the repetition rate might be greater than 0.1 Hz, e.g. greater than 1 Hz, e.g. greater than 10 Hz, e.g. greater than 100 Hz, e.g. greater than 1 kHz, e.g. 20 kHz. [0051] The term “gaseous medium” and “gas” as used herein should be understood generically and thus not as limited to pure atomic or molecular gases but also to include vapours, suspensions or micro-suspensions of liquids or solids in a gas or any mixture of these. The “non-gaseous medium” should be understood generically and thus could include liquids, non-Newtonian liquids, semi-solid gels, materials that are ostensibly solid until the passage of the shockwave changes their properties, suspensions or micro-suspensions and colloids. Examples include but are not limited to water, oils, solvents such as acetone, hydrogels and organogels. It should be understood that the non-gaseous medium will have a greater density than the gaseous medium. [0052] The non-gaseous medium could be any suitable substance for creating a shockwave in, such as a liquid or a semi-solid gel. The gaseous medium can be provided as described above between the barrier and the target surface. Using a gel or a viscous liquid has the advantage that it is easier to control the detailed shape of the boundary between the gaseous and non-gaseous media at the hole in the barrier, compared to a lower viscosity liquid in which the buoyancy of the non-gaseous medium may overcome the viscosity of the liquid. Furthermore, the non-gaseous and/or gaseous media could comprise additives, e.g. surfactants to control the surface tension, and therefore the shape, of the boundary between the gaseous and non-gaseous media. [0053] In a preferred set of embodiments, the methods described herein are employed to generate nuclear fusion reactions. The fuel for the reaction could be provided by the gaseous medium, the non-gaseous medium, or the fuel could be provided by the target surface itself. Any of the fuels mentioned in U.S. Pat. No. 7,445,319 is suitable for use in the present invention. [0054] The fusion reactions which can be obtained in accordance with certain embodiments of the invention could be used for net energy production (the long term research aim in this field), but the inventors have appreciated that even if the efficiency of the fusion is below that required for net energy production, the reliable fusion which is obtainable in accordance with embodiments of the invention is advantageous for example in the production of tritium which can be used as fuel in other fusion projects and is very expensive to produce using currently existing technologies, e.g. using a nuclear fission reactor. The fusion can also be beneficial in giving a fast and safe neutron source that is cheaper and more compact than conventional alternatives. Those skilled in the art will appreciate that this has many possible applications, e.g. shipping container scanning to name one. [0055] Moreover, it is not essential in accordance with the invention to produce fusion at all. For example, in some embodiments the techniques and apparatus of the present invention may be advantageously employed as a sonochemistry or exotic chemistry reactor which can be used to access extreme and unusual conditions, or simply to produce substantial heating particularly which is localised in its concentration. BRIEF DESCRIPTION OF DRAWINGS [0056] Certain embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: [0057] FIG. 1 shows an embodiment in accordance with the invention; [0058] FIGS. 2 a - 2 c show three successive stages of an interaction of a shockwave with the gaseous medium shown in FIG. 1 ; [0059] FIG. 3 shows a variant of the embodiment of FIG. 1 comprising a membrane; [0060] FIG. 4 shows a variant of the embodiment of FIG. 1 comprising hydrophilic and hydrophobic areas; [0061] FIG. 5 shows a variant of the embodiment of FIG. 1 comprising focussing bubbles; [0062] FIG. 6 shows a variant of the embodiment of FIG. 1 comprising two layers; and [0063] FIG. 7 shows a variant of the embodiment of FIG. 6 comprising two holes in the upper layer. DETAILED DESCRIPTION [0064] FIG. 1 shows schematically an arrangement in accordance with the invention. A solid barrier 2 , for example made from high strength steel or a titanium alloy, is placed between a non-gaseous medium 4 in the form of a hydrogel, for example a mixture of water and gelatine, and a gaseous medium 6 , e.g. a vaporous fuel suitable for taking part in a nuclear fusion reaction. A hole 8 is formed in the barrier 2 , thus allowing a boundary 10 to form at the contact surface between the non-gaseous medium 4 and the gaseous medium 6 . The boundary 10 between the non-gaseous medium 4 and the gaseous medium 6 is defined in the hydrogel as a hemi-spherical surface protruding into the non-gaseous medium 4 . A solid target surface 12 , made from any suitable material, e.g. containing nuclear fuel or reactants, is placed spaced from and parallel to the barrier 2 on the other side of the non-gaseous medium. It will be appreciated that there is no constraint on the material of the target surface needing to withstand a shockwave, giving a large range of possible materials. The target surface 12 comprises a concave, V-shaped, depression 14 opposite the hole 8 in the barrier 2 which is filled with the gaseous medium 6 . The depression 14 could be machined or formed as the result of a crack in the target surface 12 . The size of the apparatus is not essential but a typical dimension of this diagram could be between 0.1 and 1×10 −5 m. [0065] The operation of this embodiment will now be described, with particular reference to the three successive stages shown in FIGS. 2 a - 2 c of a shockwave 16 interacting with the gaseous medium 6 . Initially, a shockwave 16 is created from an explosion, for instance with a pressure of 5 GPa, within the non-gaseous medium 4 . This is represented in FIG. 1 as a line 16 propagating in the direction of the arrow towards the barrier 2 . [0066] First the shockwave 16 strikes the upper part of the boundary 10 , as shown in FIG. 2 a , causing a portion of the shockwave 16 to be reflected as a result of the large change in density from the non-gaseous medium 4 to the gaseous medium 6 . This reflected portion forms a rarefaction fan which propagates away from the gaseous medium 6 and therefore creates a low pressure region between the reflected portion of the shockwave and the gaseous medium 6 at the boundary 10 . [0067] The non-gaseous medium 4 flows into this low pressure region as a transverse jet 13 which than traverses the gaseous medium 6 , as shown in FIG. 2 b . The spacing of the barrier 2 from the target surface 12 allows the jet 13 to accelerate through the gaseous medium 6 until it impacts in the depression 14 on the target surface 12 , trapping a volume 15 of the gaseous medium 6 between the tip of the jet 13 and the tapering depression 14 in the target surface 12 , as shown in FIG. 2 c . The compression of the gaseous fuel inside the trapped volume causes intense local heating which can be sufficient to generate a nuclear fusion reaction. [0068] FIG. 3 shows a variant of the embodiment shown in FIG. 1 , in which the non-gaseous medium 104 is separated from the gaseous medium 106 by a pre-fabricated membrane 110 which is positioned over the hole 108 in the barrier 102 . The pre-fabricated membrane 110 is frangible, i.e. it is designed to break on the impact of the shockwave 116 . Once the pre-fabricated membrane 110 has been broken by the impact of the shockwave 116 , the resultant transverse jet continues to propagate into the gaseous medium 106 , trapping a small volume of the gaseous medium against the target surface 112 in the depression 114 , in the same manner as for the previous embodiment. The pre-fabricated membrane 110 also allows the non-gaseous medium 104 to be made from a liquid as it prevents the gaseous medium 106 from floating up through the hole 108 and escaping. [0069] FIG. 4 shows another variant of the embodiment shown in FIG. 1 , in which the perimeter of the hole 208 in the barrier 202 is coated in a hydrophobic material 218 and outside of this the barrier 202 is coated in a hydrophilic material 220 . The combination and relative positioning of the hydrophobic material 218 and the hydrophilic material 220 allow the boundary 210 between the non-gaseous medium 204 and the gaseous material 206 to be located accurately and with repeatability, e.g. when replenishing the gaseous medium 206 after the application of a shockwave 216 . The coatings of the hydrophobic material 218 and the hydrophilic material 220 also help to shape the boundary 210 , i.e. to make it stand up into its hemi-spherical shape. [0070] FIG. 5 shows a further variant of the embodiment shown in FIG. 1 , in which two pockets of gas 322 are positioned within the non-gaseous medium 304 , symmetrically spaced above and to the side of the hole 308 in the barrier 302 . In operation, the shockwave 316 is first incident upon the upper surface of the two pockets of gas 322 and, in a similar manner to the shockwave interacting with the gaseous medium 306 at the hole 308 as described with reference to the above embodiments, a transverse jet of the non-gaseous medium 304 is formed which travels across the volume of each of the pockets of gas 322 such that it impacts on the leeward surface of each of the pockets of gas 322 . These impacts create a resultant shockwave, which is more intense than the initial shockwave 316 applied to the non-gaseous medium 304 , and which subsequently is incident upon the gaseous medium 306 at the hole 308 in the barrier 302 . This resultant shockwave interacts with the gaseous medium 306 , thus subsequently trapping a volume of the gaseous medium 306 against the target surface 312 in the depression 314 , as described above for the previous embodiments. [0071] FIG. 6 shows yet another variant of the embodiment shown in FIG. 1 , in which a lower barrier 424 is provided below and parallel to the upper barrier 402 . A first layer of non-gaseous medium 404 is provided above the upper barrier 402 with a layer of gaseous medium 406 below, and a second layer of non-gaseous medium 426 is provided above the lower barrier 424 with a layer of gaseous medium 428 below. In operation, the shockwave 416 is first incident upon the boundary 410 between the first layer of non-gaseous medium 404 and the first layer of gaseous medium 406 and, in a similar manner to the shockwave interacting with the gaseous medium 406 at the hole 408 as described with reference to the above embodiments, a transverse jet of the non-gaseous medium 404 is formed which travels across the first layer of gaseous medium 406 such that it impacts on the second layer of non-gaseous medium 426 . This impact creates a resultant shockwave in the second layer of non-gaseous medium 426 , which is more intense than the initial shockwave 416 applied to the first layer of non-gaseous medium 404 , and which subsequently is incident upon a boundary with the second layer of gaseous medium 428 formed by the hole 430 in the lower barrier 424 . The resultant transverse jet passes through the second layer of gaseous medium 428 , thus subsequently trapping a volume of the gaseous medium 428 against the target surface 412 in the depression 414 , as described above for the previous embodiments. [0072] FIG. 7 shows a variant of the embodiment shown in FIG. 6 , in which two holes 508 are provided in the upper barrier 502 symmetrically spaced above and to the side of the hole 530 in the lower barrier 524 . The operation of this embodiment is very similar to the embodiment shown in FIG. 6 , apart from that two resultant transverse jets are created in the first layer of gaseous medium 506 which combine and eventually are incident upon the second layer of gaseous medium 528 , thereby harnessing a greater proportion of the energy from the initial shockwave 516 which is channelled into the final transverse jet which traps a volume of the gaseous medium 528 in the depression 514 in the target surface 512 . [0073] Although specific examples have been given, it will be appreciated that there are a large number of parameters that influence the actual results achieved, for example liquid or gel medium density, ambient pressure and temperature, composition of the gaseous medium and of the non-gaseous medium, impact angle and shape of the shockwave, target surface shape and micro-structure of the target surface, barrier shape, number of barriers and layers of non-gaseous and gaseous media, and the shape of the boundary between the non-gaseous and gaseous media. [0074] In each of the embodiments described above, the diagrams shown are a vertical cross-section through a three-dimensional volume of the gaseous medium and target surface and hence they depict embodiments that are rotationally symmetric. However, this is not essential to the invention. In particular the surface could comprise discrete surface portions in the rotational direction either instead of, or as well as in the vertical cross-section shown. In the latter case the target surface would be multi-facetted. Each facet could give rise to separate but converging shockwaves. [0075] In all of the embodiments described, the apparatus can be used by creating a shockwave in the medium which is incident upon a bubble containing deuterated water vapour. [0076] In numerical modelling of the experiment, the techniques described herein give rise to a peak pressure of ˜20 GPa which is sufficient to cause temperatures inside the collapsed volume of gas in excess of 1×10 6 Kelvin which can be sufficient for a nuclear fusion reaction of the deuterium atoms. In some non-limiting examples the resulting neutrons could be used in other processes, or could be absorbed by a neutron absorber for conversion of the kinetic energy of the neutrons to thermal energy and thus conventional thermodynamic energy generation.

A method of producing a localised concentration of energy includes: creating a shockwave propagating through a non-gaseous medium so as to be incident upon a boundary between the non-gaseous medium and a gaseous medium formed by at least one hole in a barrier separating the non-gaseous medium from a gaseous medium. This forms a transverse jet on the other side of the hole which is incident upon a target surface comprising a depression which is spaced from the barrier in the gaseous medium. An apparatus for producing a localised concentration of energy is also described.

PRIORITY CLAIM [0001] This application constitutes a continuation-in-part of U.S. patent application Ser. No. 12/788,721, entitled “METHODS FOR IDENTIFYING VIDEO SEGMENTS AND DISPLAYING CONTEXTUAL TARGETED CONTENT ON A CONNECTED TELEVISION,” filed May 27, 2010, and issued Nov. 6, 2013 as U.S. Pat. No. 8,595,781, that application being a non-provisional application claiming priority from U.S. Provisional Patent Application No. 61/182,334, entitled “SYSTEM FOR PROCESSING CONTENT INFORMATION IN A TELEVIDEO SIGNAL,” filed May 29, 2009 and being a non-provisional application claiming priority from U.S. Provisional Patent Application No. 61/290,714, entitled “CONTEXTUAL TARGETING BASED ON DATA RECEIVED FROM A TELEVISION SYSTEM,” filed Dec. 29, 2009; this application further constitutes a continuation-in-part of U.S. patent application Ser. No. 12/788,748, entitled “METHODS FOR DISPLAYING CONTEXTUALLY TARGETED CONTENT ON A CONNECTED TELEVISION,” filed May 27, 2010; this application further constitutes a continuation-in-part of U.S. patent application Ser. No. 14/089,003, entitled “______,” filed Nov. 25, 2013; this application further constitutes a continuation-in-part of U.S. patent application Ser. No. ______, entitled “SYSTEMS AND METHODS FOR ADDRESSING A MEDIA DATABASE USING DISTANCE ASSOCIATIVE HASHING,” filed Mar. 17, 2014; this application further constitutes a continuation-in-part of U.S. patent application Ser. No. ______, entitled “SYSTEMS AND METHODS FOR IDENTIFYING VIDEO SEGMENTS FOR DISPLAYING CONTEXTUALLY RELEVANT CONTENT,” filed Mar. 17, 2014; this application further constitutes a continuation-in-part of U.S. patent application Ser. No. ______, entitled “SYSTEMS AND METHODS FOR REAL-TIME TELEVISION AD DETECTION USING AN AUTOMATED CONTENT RECOGNITION DATABASE,” filed Mar. 17, 2014; this application further constitutes a continuation-in-part of U.S. patent application Ser. No. ______, entitled “SYSTEMS AND METHODS FOR ON-SCREEN GRAPHICS DETECTION,” filed Mar. 17, 2014; this application further constitutes a continuation-in-part of U.S. patent application Ser. No. ______, entitled “SYSTEMS AND METHODS FOR MULTI-BROADCAST DIFFERENTIATION,” filed Mar. 17, 2014; and this application further constitutes a non-provisional application of U.S. Provisional Patent Application No. 61/791,578, entitled “SYSTEMS AND METHODS FOR IDENTIFYING VIDEO SEGMENTS BEING DISPLAYED ON REMOTELY LOCATED TELEVISIONS,” filed Mar. 15, 2013. The foregoing applications are either currently co-pending or are applications of which a currently co-pending application is entitled to the benefit of the filing date. FIELD OF THE INVENTION [0002] The present invention relates to the field of digital video displays and various systems and methods for implementing Automatic Content Recognition systems. BACKGROUND [0003] A television display device equipped with significant associated data processing capability, often called a “Smart TV,” can be configured to optimize a viewer's experience through the provision of contextually-relevant material. One example of this might include offering additional background information or special messages associated with the programming or commercial material being displayed at that moment. To accomplish this goal, the processing means within the TV device itself, or an associated device such as a set-top box needs to have real time “awareness” of what programming is being displayed on the TV screen at that moment. [0004] There are currently two primary forms of automatic content recognition in use for enhanced TV experiences. One method is digital watermarking, and the other is content fingerprinting. The digital watermark method requires the broadcast content to be preprocessed so that the watermark data may be hidden within the content signal. That data is then detected by the TV processing means in order to enable identification and synchronization. [0005] Another method of automated content recognition involves using audio or video content fingerprinting to identify the content signal as it is displayed by computing a sequence of content fingerprints and matching them with a database. While it does away with the need to have all content pre-processed, it is more challenging to identify audio or video programming with content fingerprinting, particularly if the system is intended to operate simultaneously across potentially hundreds of television program channels while dealing with a variety of user behavior such as channel changing, pausing or viewing time-shifted content that causes a loss of identification. [0006] Therefore, for video content fingerprint-based ACR, a person skilled in the art might implement a solution requiring computational processing power, both at a centralized server or other computing means as well as within each local display device that is too costly to be commercially reasonable and practical. For example, the ACR system might be programmed to operate continuously on a video frame-by-frame basis in order to identify the program and track the relative time location within each show across a wide time range and for a large database of shows, while simultaneously needing to account for time-shifted content, channel surfing, or the like. [0007] At most any point in time in the US market, there are several hundred program choices offered by most cable TV or satellite providers. In addition, there are over one hundred major television market areas with dozens of local television channels. On a national level, an ACR system must monitor thousands of unique television programs. The need for computational efficiency is clearly required in order for a system to operate reliably and at a commercially reasonable cost. [0008] Despite continuing advances in computing power, automated matching of audio or video content remains a daunting task. Such “brute force” identification implies that the TV display device's processing means is continuously computing fingerprints and sending these fingerprints and other associated content signals to centralized fingerprint database for identification. Such as process would use an excessive amount of the computing resources of a typical smart TV; leaving little else for the other smart TV applications that a user may wish to utilize. [0009] The challenge is even greater on a system level than at the local TV set because the centralized system must have sufficient computing power to handle simultaneous processing demands from potentially millions of TV sets. As noted in the detailed description below, the costs of memory and processing power needed to support each ACR system in the field can soon overwhelm the revenue being generated by each such system. Therefore a method to optimize these systems to make them commercially viable is a still unmet need for the operators of such systems. In addition, it has been found that improvements in the efficiency of these systems, also improves the accuracy of the content matching process. SUMMARY [0010] In some embodiments, an exemplary method related to improving server and client performance in fingerprint ACR systems may include determining one or more values related to transmitting fingerprints associated with a client to an Automated Content Recognition (ACR) system, the one or more values associated with one or more of at least one sampling rate, at least one pattern of sampling, at least one number of samples associated with creating a fingerprint package, or at least one time interval between fingerprint package transmissions; signaling to transmit one or more fingerprint packages associated with the client to the ACR system based at least partially on the one or more values; and adjusting at least one of the one or more values related to transmitting fingerprints associated with the client to the ACR system. [0011] In some embodiments, determining one or more values related to transmitting fingerprints associated with a client to an Automated Content Recognition (ACR) system, the one or more values associated with one or more of at least one sampling rate, at least one pattern of sampling, at least one number of samples associated with creating a fingerprint package, or at least one time interval between fingerprint package transmissions may include determining the one or more values following at least one of a power-on condition, a change of channels, a fast-forward operation, a rewind operation, a pause operation, or a skip operation associated with the client. In some embodiments, determining one or more values related to transmitting fingerprints associated with a client to an Automated Content Recognition (ACR) system, the one or more values associated with one or more of at least one sampling rate, at least one pattern of sampling, at least one number of samples associated with creating a fingerprint package, or at least one time interval between fingerprint package transmissions may include determining the one or more values based at least in part on a channel associated with the client, a video segment associated with the client, a time offset related to a video segment associated with the client, or a time of day. [0012] In some embodiments, adjusting at least one of the one or more values related to transmitting fingerprints associated with the client to the ACR system may include identifying at least one of a channel or a video segment associated with the client based at least partially on one or more transmitted fingerprint packages; determining whether the at least one of the identified channel or the identified video segment is at least one of a channel of interest or a video segment of interest; and adjusting one or more values related to transmitting fingerprints based at least partially on whether the at least one of the identified channel or the identified video segment is at least one of a channel of interest or a video segment of interest. [0013] In some embodiments, adjusting one or more values related to transmitting fingerprints based at least partially on whether the at least one of the identified channel or the identified video segment is at least one of a channel of interest or a video segment of interest may include determining whether the at least one of the identified channel or the identified video segment is at least one of a channel of interest or a video segment of interest and, if the at least one of the identified channel or the identified video segment is at least one of a channel of interest or a video segment of interest, adjusting one or more values related to transmitting fingerprints wherein the adjusted one or more values are operable to transmit fingerprint packages enabling ACR detection sufficiently fast for providing at least some context-sensitive content substantially simultaneously with at least one targeted video. In some embodiments, adjusting one or more values related to transmitting fingerprints based at least partially on whether the at least one of the identified channel or the identified video segment is at least one of a channel of interest or a video segment of interest may include determining whether the at least one of the identified channel or the identified video segment is at least one of a channel of interest or a video segment of interest and, if the at least one of the identified channel or the identified video segment is at least one of a channel of interest or a video segment of interest, adjusting one or more values related to transmitting fingerprints wherein the adjusted one or more values are operable to transmit fingerprint packages enabling ACR detection sufficiently fast for providing at least some context-sensitive content substantially simultaneously with at least one targeted video. [0014] In some embodiments, adjusting one or more values related to transmitting fingerprints based at least partially on whether the at least one of the identified channel or the identified video segment is at least one of a channel of interest or a video segment of interest may include determining whether the at least one of the identified channel or the identified video segment is at least one of a channel of interest or a video segment of interest and, if the at least one of the identified channel or the identified video segment is not at least one of a channel of interest or a video segment of interest, adjusting one or more values related to transmitting fingerprints wherein the adjusted one or more values are operable to transmit fingerprint packages enabling ACR detection sufficiently fast for detecting a channel to which the client is changed within at least one time proximity of the change of channel. [0015] In some embodiments, adjusting one or more values related to transmitting fingerprints based at least partially on whether the at least one of the identified channel or the identified video segment is at least one of a channel of interest or a video segment of interest may include determining whether the at least one of the identified channel or the identified video segment is at least one of a channel of interest or a video segment of interest and, if the at least one of the identified channel or the identified video segment is not at least one of a channel of interest or a video segment of interest, adjusting one or more values related to transmitting fingerprints wherein the adjusted one or more values are operable to at least one of halt or slow transmission of fingerprint packages until a channel change occurs. [0016] In some embodiments, adjusting one or more values related to transmitting fingerprints based at least partially on whether the at least one of the identified channel or the identified video segment is at least one of a channel of interest or a video segment of interest may include determining whether the at least one of the identified channel or the identified video segment is at least one of a channel of interest or a video segment of interest and, if the at least one of the identified channel or the identified video segment is not at least one of a channel of interest or a video segment of interest, adjusting one or more values related to transmitting fingerprints wherein the adjusted one or more values are operable to at least one of halt or slow transmission of fingerprint packages until a trigger time for an expected video segment of interest occurs. [0017] In some embodiments, adjusting one or more values related to transmitting fingerprints based at least partially on whether the at least one of the identified channel or the identified video segment is at least one of a channel of interest or a video segment of interest may include determining whether the at least one of the identified channel or the identified video segment is at least one of a channel of interest or a video segment of interest and, if the at least one of the identified channel or the identified video segment is not at least one of a channel of interest or a video segment of interest, adjusting one or more values related to transmitting fingerprints wherein the adjusted one or more values are operable to at least one of halt or slow transmission of fingerprint packages until a detection of an ad pod occurs. [0018] In some embodiments, adjusting one or more values related to transmitting fingerprints based at least partially on whether the at least one of the identified channel or the identified video segment is at least one of a channel of interest or a video segment of interest may include determining whether the at least one of the identified channel or the identified video segment is at least one of a channel of interest or a video segment of interest and, if the at least one of the identified channel or the identified video segment is not at least one of a channel of interest or a video segment of interest, adjusting one or more values related to transmitting fingerprints wherein the adjusted one or more values are operable to at least one of halt or slow transmission of fingerprint packages until a detection of a video segment of interest is detected by an ingest system associated with the ACR system. [0019] In some embodiments, adjusting at least one of the one or more values related to transmitting fingerprints associated with the client to the ACR system may include making a first identification of at least one of a channel or a video segment associated with the client based at least partially on at least one transmitted fingerprint package; adjusting at least one of the one or more values related to transmitting fingerprints based at least partially on the first identification; receiving at least one additional transmitted fingerprint package at the ACR system in accordance with the adjusted one or more values related to transmitting fingerprints; making a second identification of at least one of a channel or a video segment associated with the client based at least partially on the at least one transmitted fingerprint package and the at least one additional transmitted fingerprint package; and if the second identification is not the same as the first identification, further adjusting at least one of the one or more values related to transmitting fingerprints. In some embodiments, adjusting at least one of the one or more values related to transmitting fingerprints associated with the client to the ACR system may include at least one of reducing a rate at which fingerprint packages are transmitted, increasing an interval between successive fingerprint packages being transmitted, or reducing a number of fingerprints packaged in a fingerprint package. [0020] In some embodiments, adjusting at least one of the one or more values related to transmitting fingerprints associated with the client to the ACR system may include adjusting one or more values related to transmitting fingerprints associated with a client to the ACR system based at least partially on a recognition of one or more monochromic frames associated with the client, the one or more values operable to cause transmission of fingerprints related to the one or more monochromic frames to be skipped. In some embodiments, adjusting at least one of the one or more values related to transmitting fingerprints associated with the client to the ACR system may include determining one or more values related to transmitting fingerprints associated with a client to the ACR system based at least partially on a recognition of a sequence of fade-to-black frames associated with the client, the one or more values operable to cause transmission of fingerprints related to the sequence of fade-to-black frames to be skipped. [0021] In some embodiments, an exemplary method related to improving server and client performance in fingerprint ACR systems may include receiving a first fingerprint package, the first fingerprint package associated with a first timestamp; retrieving at least one first match based at least partially on the received first fingerprint package, the at least one first match associated with a first video segment; receiving a second fingerprint package, the second fingerprint package associated with a second timestamp; retrieving at least one second match based at least partially on the received second fingerprint package, the at least one second match associated with a second video segment; determining a difference in time between the first timestamp and the second timestamp; and establishing a likelihood that at least one of the first match or the second match correctly identifies a video segment associated with a client sending the first and second fingerprint packages based at least partially on the determined difference in time. In some embodiments, establishing a likelihood that at least one of the first match or the second match correctly identifies a video segment associated with a client sending the first and second fingerprint packages based at least partially on the determined difference in time may include establishing a likelihood that at least one of the first match or the second match correctly identifies a video segment associated with a client sending the first and second fingerprint packages based at least partially on the determined difference in time, wherein increased differences in time correlate with increased likelihoods of correct identifications. [0022] In some embodiments, an exemplary method related to improving server and client performance in fingerprint ACR systems may include receiving a first fingerprint package, the first fingerprint package associated with a first timestamp; retrieving at least one first match based at least partially on the received first fingerprint package, the at least one first match associated with a first video segment and a first offset related to the first video segment; receiving a second fingerprint package, the second fingerprint package associated with a second timestamp; retrieving at least one second match based at least partially on the received second fingerprint package, the at least one second match associated with a second video segment and a second offset related to the second video segment; determining a first duration, the first duration indicative of the first timestamp and the second timestamp; determining whether the first video segment and the second video segment are the same and, if the first video segment and the second video segment are the same, at least: determining a second duration, the second duration indicative of the difference in time between the first offset and the second offset; comparing the first duration with the second duration; and establishing a likelihood that at least one of the first match or second match correctly identifies a video segment associated with a client sending the first and second fingerprint packages based at least partially on the comparison of the first duration with the second duration. [0023] In some embodiments, establishing a likelihood that at least one of the first match or second match correctly identifies a video segment associated with a client sending the first and second fingerprint packages based at least partially on the comparison of the first duration with the second duration may include establishing a likelihood that at least one of the first match or second match correctly identifies a video segment associated with a client sending the first and second fingerprint packages based at least partially on the comparison of the first duration with the second duration, wherein smaller differences in the first duration and the second duration correlates with increased likelihoods of correct identification. [0024] In some embodiments, an exemplary computer program product related to improving server and client performance in fingerprint ACR systems may include at least one non-transitory computer-readable medium, and the at least one non-transitory computer-readable medium may include one or more instructions for determining one or more values related to transmitting fingerprints associated with a client to an Automated Content Recognition (ACR) system, the one or more values associated with one or more of at least one sampling rate, at least one pattern of sampling, at least one number of samples associated with creating a fingerprint package, or at least one time interval between fingerprint package transmissions; one or more instructions for signaling to transmit one or more fingerprint packages associated with a client to an ACR system based at least partially on one or more values related to transmitting fingerprints; and one or more instructions for adjusting at least one of one or more values related to transmitting fingerprints associated with the client to the ACR system. [0025] In some embodiments, an exemplary system related to improving server and client performance in fingerprint ACR systems may include circuitry configured for determining one or more values related to transmitting fingerprints associated with a client to an Automated Content Recognition (ACR) system, the one or more values associated with one or more of at least one sampling rate, at least one pattern of sampling, at least one number of samples associated with creating a fingerprint package, or at least one time interval between fingerprint package transmissions; circuitry configured for signaling to transmit one or more fingerprint packages associated with the client to the ACR system based at least partially on one or more values related to transmitting fingerprints; and circuitry configured for adjusting at least one of one or more values related to transmitting fingerprints associated with the client to the ACR system. [0026] In addition to the foregoing, various other methods, systems and/or program product embodiments are set forth and described in the teachings such as the text (e.g., claims, drawings and/or the detailed description) and/or drawings of the present disclosure. [0027] The foregoing is a summary and thus contains, by necessity, simplifications, generalizations and omissions of detail; consequently, those skilled in the art will appreciate that the summary is illustrative only and is NOT intended to be in any way limiting. Other aspects, embodiments, features and advantages of the device and/or processes and/or other subject matter described herein will become apparent in the teachings set forth herein. BRIEF DESCRIPTION OF THE DRAWINGS [0028] Certain embodiments of the present invention are described in detail below with reference to the following drawings: [0029] FIG. 1 is a simplified block diagram of one illustrative embodiment of the system and method of this invention. At a regional media processing center 100 television programming is ingested 101 from various sources. Fingerprints are made and stored in a database 103 . Programming is distributed 105 to a plurality of individual television viewing devices 107 . The client processing means associated with each said device 108 a , 108 b . . . 108 n takes samples of the programming actually being displayed on that TV at any point in time and sends the fingerprints of those samples 106 to the centralized fingerprint matching server 104 to compare against already existing fingerprints in the database 103 . [0030] FIG. 2 is a visual depiction of the system and method of this invention. Samples 202 of the TV raster 201 are taken at a variable rate and periodicity 205 . The average value 203 for each pixel patch and the total 205 comprise a clue 204 which is created with each sample taken. The frequency and pattern of the sampling may be varied 206 , 207 , 208 , according to an algorithm of the invention to reduce computing demands on the ACR database while still supporting the required functionality. [0031] FIG. 3 illustrates an operational flow representing example operations related to improving server and client performance in fingerprint ACR systems. [0032] FIG. 4 illustrates an alternative embodiment of the operational flow of FIG. 3 . [0033] FIG. 5 illustrates an alternative embodiment of the operational flow of FIG. 3 . [0034] FIG. 6 illustrates an alternative embodiment of the operational flow of FIG. 3 . [0035] FIG. 7 illustrates an alternative embodiment of the operational flow of FIG. 3 . [0036] FIG. 8 illustrates an operational flow representing example operations related to improving server and client performance in fingerprint ACR systems. [0037] FIG. 9 illustrates an operational flow representing example operations related to improving server and client performance in fingerprint ACR systems. [0038] FIG. 10 illustrates an exemplary computer program product related to improving server and client performance in fingerprint ACR systems. [0039] FIG. 11 illustrates a system related to improving server and client performance in fingerprint ACR systems. DETAILED DESCRIPTION [0040] One of the most important metrics of an ACR system from a business perspective is how much said system costs to operate in order to support each specific TV processing means associated with it over some specific unit of time, such as a year. ACR systems must monitor a TV viewing device for many hours while it is on and active, however the system only generates revenue for the operator during the time period which that same TV is locally tuned to a show or a commercial during which the system operator has been contracted to serve the specific contextually-targeted content that is being mediated by the ACR system and other subsystems of the invention. [0041] For example, the operator of the system of the invention could have a contract with some hypothetical customer; for example, “Acme Broadcasting,” to provide ACR-mediated contextual content services for some number of its cable channels. In this example, it is assumed there are three such Acme Broadcasting channels. However, to fulfil the contract, the system of the invention would need to monitor every active smart TV viewing means on the cable system or other distribution network, and to monitor them all the time just to catch those instances when any TV on the distribution network happens to be tuned (even momentarily) to one of Acme Broadcasting's channels. [0042] Since those three specific channels of this example represent only a small segment of all TV programming being viewed at any given time on the distribution network that the system of the invention is monitoring as illustrated in FIG. 1 (for this example, assume 10% of all devices) it would clearly be commercially preferable to be able to ration the detection services on the 90% of the distribution system's television viewing means that are not watching those specific three channels at any instant in time. [0043] FIG. 2 illustrates how the algorithm implemented by the system will provide said rationing. From the original patent application, all TV viewing means equipped with appropriate ACR software installed on their internal or associated computing means, use that software to sample the screen at a given rate and then process and package the pixel cues (fingerprints) and send them to the server of the invention at yet another given rate. For the purpose of this example, we assume that the TV's ACR software is sampling the screen at ten times per second and sending the central server means of the invention a package of ten such fingerprints each second. [0044] The server matches the content being viewed on the TV with what is in its database and determines if the TV is tuned to one of the channels of interest. If the result is “no” then the server instructs the application software running in the TV to enter “skip mode” and drop a given number of fingerprints from the number normally sent. For example, the TV application of the invention running on the processing means of each TV set active on the system could be commanded to skip every other data block that would have been sent as shown in 208 . That is, instead of every second it would only send fingerprints every other second. Alternatively, the TV set application could be commanded to send fingerprints for five seconds and then skip the next five seconds as shown in 207 . [0045] While skipping video frames, the server is still able to detect the content being displayed on the television viewing means, but at a lower resolution and therefore potentially with less accuracy. [0046] If the server determines that the TV is indeed displaying a channel of interest, even if at a low level of confidence, it instructs the TV application of the invention to resume sending every second. If, after more fingerprints (cue values) arrive and with this additional data the server system of the invention determines that it was mistaken and in fact the programming being watched is actually not what it expects to see on one of the channels of interest, it will again instruct the TV based application of the invention to resume skipping data transmissions. [0047] This mechanism can also be applied to individual TV shows as well as channels. In this way, cost of operations is reduced by, in effect, rationing the services. For example, assume that at full detection (i.e. every TV sending cue packages every second) it costs the system operator $1.00 per monitored TV viewing device per year to operate the ACR detection system. Further, assume that the three Acme Broadcasting channels, in the previous example, account for 10% of TV viewing. Then, by using a skipping setting of 2:5 (two seconds on followed by five seconds off) the hypothetical operating cost of the service is reduced to: 2/7×$1×90%+$1×10%=$0.36 per TV per year compared to $1.00 per TV per year with the full-resolution scaling of the automated data transmission of this invention. [0048] The system and method of the invention also enables setting timers that cause resolution modes to go up as local clock time at the TV viewing device approaches network or other times when contextually targeted events of the invention are queued in the system. In one embodiment, the new invention will stay in skip frame (low resolution) mode on a channel when an event is not in the context queue. However, when there is an event in said queue expected to occur during a specific show coming up on a given network, the system and method of the invention automatically increases resolution when the show starts. [0049] For example, if the system has detected that a certain TV viewing device utilizing the subject ACR application is tuned to a show on a particular channel, and the system of the invention knows that there is a contextually-targeted event configured to occur during the next hour, then the sampling speed and other resolution metrics may be adjusted in advance. [0050] The same concept should apply for dynamic ad insertion. The system of the invention does not need to operate at the 30 millisecond granularity for the duration of an entire television program of interest but rather this fine granularity of detection is only needed for a couple of seconds prior to a planned insertion point or primary feed restart point. [0051] For lower resolution, the ACR application running in the TV processing means, sends fewer clue points to the server by skipping over frames. If the system is made aware that there is content of interest arriving shortly, the system automatically increases resolution by appropriately modifying sampling rates or other metrics. [0052] On each channel change, the system and method of the invention detects the network and the show in progress. If there are no events during that show that the application of the invention residing in the computing means associated with the specific TV viewing means needs to detect and synchronize to, it will then go into a form of sleep mode until a trigger time for an expected event approaches, or a channel change occurs. An exception to the previous rule might involve directing the application to “wake up” upon the expected arrival of a “pod” of advertising since said ad pod's channel and time slot are known to the system. [0053] Another significant problem with Automatic Content Recognition (ACR) systems, whether audio or video, that can cause loss of efficiency are error rates due to false positives or false negatives where one or more audio or video samples of digital media from an unknown source do not match a reference database of known media when they should, or seem to match samples in the database when they do not. This problem of false negatives or false positives is addressed by the system and method of this invention in several ways including examining if the time stamps on the real time samples and stored references in the database are logically compatible, and if the samples whether new or stored contain enough information to make them unique and usable for identification. For example, samples taken during a “fade to black” sequence would have so little information that they could match no matter what the actual programs were. [0054] A “Confidence Interval” is a metric determined by calculating the difference between the timestamp of the first match the system makes for a given piece of content, and the timestamp of the current match. By way of example, suppose the system matches fingerprints sent to it by the ACR application running on the processing means of the TV viewing device to a certain “TV program A” at a position of 100 seconds subsequent to the start time of said program. [0055] After a period of time, the next fingerprint arrives which matches “TV program A” at a position of 105 seconds from the start of the program. The “confidence interval” is then calculated as the difference between the first and second match positions which in this example is five seconds. [0056] Confidence intervals provide a metric correlated with the relative reliability of the match. High confidence intervals indicated that the matches found are less likely to be false positives. Experimentally, it has been found that confidence intervals that are between one and five seconds in duration are good candidates for an accurate match. In contrast, false positives generally have confidence intervals of less than one second. [0057] The next useful metric is the Ratio of Real-Time to Program-Time. If 100 seconds passes in real time between two matches, and it is known from the matching database that that the two samples match points in the program that differ by 100 seconds when compared to the start of the program, then the match is likely to be correct. [0058] By way of example the system of the invention matches a sample set of pixels of “TV program A” at a position of 100 seconds from the start of said program. Assume that the local time of said match event was 2:20:10 PM EST. Some time passes and the next sample set of pixels arrive for testing. Said sample set matches “TV program A” at a position of 105 seconds from the known start of the show and the current local time of said match event is 2:20:12 PM EST. The “Real-Time Interval” is then calculated as the difference between 2:20:12 and 2:20:10 which is an interval of 2 seconds. [0059] The “Real-Time to Program-Time Ratio” is helpful in maintaining an upper bound on the “Confidence Interval” described earlier. A “Confidence Interval” that is higher than the “Real-Time Interval” is flagged as probably an unreliable match. This is because if actual elapsed time between database “hits” is shorter than the corresponding running time of the TV program under test, then is either the TV device is being “fast-forwarded” through the program, or the system has generated a false positive match. [0060] Another source of computing and other system efficiency is achieved by detecting video fingerprints sampled from monochromic segments or during a fade-to-black sequence. Since such fingerprints contain little or no color information they are not likely to be unique to the programming being monitored and not helpful in identifying it. By eliminating these from the fingerprints transmitted to the centralized matching server means of the system, computing and other system resources are conserved. [0061] This process works as follows. Normally, pixel samples are configured and transmitted by the application running in the processing means of the TV device as three numbers representing the Red, Green, and Blue components of the RGB value. [0062] Prior to such transmission however, An algorithm in the application running in the processing means of the TV viewing device or its associated set-top box performs the following steps: [0063] Sums the standard deviation of each color component of each RGB pixel of a sample set (i.e. sums the standard deviation of the red values plus the standard deviation of the green values plus the standard deviation of the blue values). [0064] Sums the mean value of each color component of each RGB value of said sample pixel set. [0065] If the sum of the standard deviation is below a given threshold and the sum of the mean is below another given threshold then the sample is flagged to be likely to yield a false positive if said sample were to be tested against the reference database. [0066] The above process tests for color uniformity as well as luminance value (brightness). Either condition of color uniformity (for example, a blue screen) or a very dark screen will likely indicate the elevated probability of a false match between said sample and the reference database of the invention. This likelihood of false matching is due to the preponderance of dark video images generated by any television program, such as when a typical television program video fades to black. Similarly, video frames of uniform color, even partially filled are also common in all television programming and provide little or no useful information in identifying unknown video content. [0067] Another source of false positive results in a video matching system is a segment of video that matches very well to some other segment of video that is completely unrelated or to a still frame image. One might refer to said video segment as a “super-matcher.” When encountering such a super-matching segment, the ACR matching system becomes stuck in a loop; detecting said segment over and over again as though that segment of video were itself being broadcast in a loop. [0068] To conserve system resources, the ACR fingerprinting application running in the processor or the TV viewing device utilizes the following algorithm to mitigate this undesirable condition. [0069] Subtract the previously described “Confidence Interval,” from the “Real-Time Interval,” as described above. [0070] If the absolute value of said subtraction is greater than a given threshold, then all of the samples for the duration of said “Confidence Interval” are flagged as being questionable since if a considerable amount of real-time has passed but the video is not progressing forward sufficiently, then the probability of false positive matches increases significantly. [0071] FIG. 3 illustrates an operational flow 300 representing example operations related to on-screen graphics detection. In FIG. 3 and in following figures that include various examples of operational flows, discussion and explanation may be provided with respect to the above-described examples of FIGS. 1 and 2 , and/or with respect to other examples and contexts. However, it should be understood that the operational flows may be executed in a number of other environments and contexts, and/or in modified versions of FIGS. 1 and 2 . Also, although the various operational flows are presented in the sequence(s) illustrated, it should be understood that the various operations may be performed in other orders than those which are illustrated, or may be performed concurrently. [0072] After a start operation, the operational flow 300 moves to operation 302 . Operation 302 depicts determining one or more values related to transmitting fingerprints associated with a client to an Automated Content Recognition (ACR) system, the one or more values associated with one or more of at least one sampling rate, at least one pattern of sampling, at least one number of samples associated with creating a fingerprint package, or at least one time interval between fingerprint package transmissions. For example, as shown in and/or described with respect to FIGS. 1 and 2 . [0073] Then, operation 1304 depicts signaling to transmit one or more fingerprint packages associated with the client to the ACR system based at least partially on the one or more values. For example, as shown in and/or described with respect to FIGS. 1 and 2 . [0074] Then, operation 1306 depicts adjusting at least one of the one or more values related to transmitting fingerprints associated with the client to the ACR system. For example, as shown in and/or described with respect to FIGS. 1 and 2 . [0075] FIG. 3 also illustrates alternative embodiments of the example operational flow 300 . FIG. 3 illustrates an example embodiment where operation 302 may include at least one additional operation. Additional operations may include operation 308 and/or operation 310 . FIG. 3 also illustrates an example embodiment where operation 306 may include at least one additional operation. Additional operations may include operation 312 , operation 314 , and/or operation 316 . [0076] Operation 308 illustrates determining the one or more values following at least one of a power-on condition, a change of channels, a fast-forward operation, a rewind operation, a pause operation, or a skip operation associated with the client. For example, as shown in and/or described with respect to FIGS. 1 and 2 . [0077] Operation 310 illustrates determining the one or more values based at least in part on a channel associated with the client, a video segment associated with the client, a time offset related to a video segment associated with the client, or a time of day. For example, as shown in and/or described with respect to FIGS. 1 and 2 . [0078] Operation 312 illustrates identifying at least one of a channel or a video segment associated with the client based at least partially on one or more transmitted fingerprint packages. For example, as shown in and/or described with respect to FIGS. 1 and 2 . [0079] Operation 314 illustrates determining whether the at least one of the identified channel or the identified video segment is at least one of a channel of interest or a video segment of interest. For example, as shown in and/or described with respect to FIGS. 1 and 2 . [0080] Operation 316 illustrates adjusting one or more values related to transmitting fingerprints based at least partially on whether the at least one of the identified channel or the identified video segment is at least one of a channel of interest or a video segment of interest. For example, as shown in and/or described with respect to FIGS. 1 and 2 . [0081] FIG. 4 illustrates alternative embodiments of the example operational flow 300 of FIG. 3 . FIG. 4 illustrates an example embodiment where operation 316 may include at least one additional operation. Additional operations may include operation 402 , operation 404 , and/or operation 406 . [0082] Operation 402 illustrates determining whether the at least one of the identified channel or the identified video segment is at least one of a channel of interest or a video segment of interest and, if the at least one of the identified channel or the identified video segment is at least one of a channel of interest or a video segment of interest, adjusting one or more values related to transmitting fingerprints wherein the adjusted one or more values are operable to transmit fingerprint packages enabling ACR detection sufficiently fast for providing at least some context-sensitive content substantially simultaneously with at least one targeted video. For example, as shown in and/or described with respect to FIGS. 1 and 2 . [0083] Further, operation 404 illustrates determining whether the at least one of the identified channel or the identified video segment is at least one of a channel of interest or a video segment of interest and, if the at least one of the identified channel or the identified video segment is not at least one of a channel of interest or a video segment of interest, adjusting one or more values related to transmitting fingerprints wherein the adjusted one or more values are operable to transmit fingerprint packages enabling ACR detection sufficiently fast for detecting a channel to which the client is changed within at least one time proximity of the change of channel. For example, as shown in and/or described with respect to FIGS. 1 and 2 . [0084] Further, operation 406 illustrates determining whether the at least one of the identified channel or the identified video segment is at least one of a channel of interest or a video segment of interest and, if the at least one of the identified channel or the identified video segment is not at least one of a channel of interest or a video segment of interest, adjusting one or more values related to transmitting fingerprints wherein the adjusted one or more values are operable to at least one of halt or slow transmission of fingerprint packages until a channel change occurs. For example, as shown in and/or described with respect to FIGS. 1 and 2 . [0085] FIG. 5 illustrates alternative embodiments of the example operational flow 300 of FIG. 3 . FIG. 5 illustrates an example embodiment where operation 316 may include at least one additional operation. Additional operations may include operation 502 , operation 504 , and/or operation 506 . [0086] Operation 502 illustrates determining whether the at least one of the identified channel or the identified video segment is at least one of a channel of interest or a video segment of interest and, if the at least one of the identified channel or the identified video segment is not at least one of a channel of interest or a video segment of interest, adjusting one or more values related to transmitting fingerprints wherein the adjusted one or more values are operable to at least one of halt or slow transmission of fingerprint packages until a trigger time for an expected video segment of interest occurs. For example, as shown in and/or described with respect to FIGS. 1 and 2 . [0087] Further, operation 504 illustrates determining whether the at least one of the identified channel or the identified video segment is at least one of a channel of interest or a video segment of interest and, if the at least one of the identified channel or the identified video segment is not at least one of a channel of interest or a video segment of interest, adjusting one or more values related to transmitting fingerprints wherein the adjusted one or more values are operable to at least one of halt or slow transmission of fingerprint packages until a detection of an ad pod occurs. For example, as shown in and/or described with respect to FIGS. 1 and 2 . [0088] Further, operation 506 illustrates determining whether the at least one of the identified channel or the identified video segment is at least one of a channel of interest or a video segment of interest and, if the at least one of the identified channel or the identified video segment is not at least one of a channel of interest or a video segment of interest, adjusting one or more values related to transmitting fingerprints wherein the adjusted one or more values are operable to at least one of halt or slow transmission of fingerprint packages until a detection of a video segment of interest is detected by an ingest system associated with the ACR system. For example, as shown in and/or described with respect to FIGS. 1 and 2 . [0089] FIG. 6 illustrates alternative embodiments of the example operational flow 300 of FIG. 3 . FIG. 6 illustrates an example embodiment where operation 306 may include at least one additional operation. Additional operations may include operation 602 , operation 604 , operation 606 , operation 608 , and/or operation 610 . [0090] Operation 602 illustrates making a first identification of at least one of a channel or a video segment associated with the client based at least partially on at least one transmitted fingerprint package. For example, as shown in and/or described with respect to FIGS. 1 and 2 . [0091] Further, operation 604 illustrates adjusting at least one of the one or more values related to transmitting fingerprints based at least partially on the first identification. For example, as shown in and/or described with respect to FIGS. 1 and 2 . [0092] Further, operation 606 illustrates receiving at least one additional transmitted fingerprint package at the ACR system in accordance with the adjusted one or more values related to transmitting fingerprints. For example, as shown in and/or described with respect to FIGS. 1 and 2 . [0093] Further, operation 608 illustrates making a second identification of at least one of a channel or a video segment associated with the client based at least partially on the at least one transmitted fingerprint package and the at least one additional transmitted fingerprint package. For example, as shown in and/or described with respect to FIGS. 1 and 2 . [0094] Further, operation 610 illustrates if the second identification is not the same as the first identification, further adjusting at least one of the one or more values related to transmitting fingerprints. For example, as shown in and/or described with respect to FIGS. 1 and 2 . [0095] FIG. 7 illustrates alternative embodiments of the example operational flow 300 of FIG. 3 . FIG. 7 illustrates an example embodiment where operation 307 may include at least one additional operation. Additional operations may include operation 702 , operation 704 , and/or operation 706 . [0096] Operation 702 illustrates at least one of reducing a rate at which fingerprint packages are transmitted, increasing an interval between successive fingerprint packages being transmitted, or reducing a number of fingerprints packaged in a fingerprint package. For example, as shown in and/or described with respect to FIGS. 1 and 2 . [0097] Further, operation 704 illustrates adjusting one or more values related to transmitting fingerprints associated with a client to the ACR system based at least partially on a recognition of one or more monochromic frames associated with the client, the one or more values operable to cause transmission of fingerprints related to the one or more monochromic frames to be skipped. For example, as shown in and/or described with respect to FIGS. 1 and 2 . [0098] Further, operation 706 illustrates determining one or more values related to transmitting fingerprints associated with a client to the ACR system based at least partially on a recognition of a sequence of fade-to-black frames associated with the client, the one or more values operable to cause transmission of fingerprints related to the sequence of fade-to-black frames to be skipped. For example, as shown in and/or described with respect to FIGS. 1 and 2 . [0099] FIG. 8 illustrates an operational flow 800 representing example operations related to on-screen graphics detection. In FIG. 8 and in following figures that include various examples of operational flows, discussion and explanation may be provided with respect to the above-described examples of FIGS. 1 and 2 , and/or with respect to other examples and contexts. However, it should be understood that the operational flows may be executed in a number of other environments and contexts, and/or in modified versions of FIGS. 1 and 2 . Also, although the various operational flows are presented in the sequence(s) illustrated, it should be understood that the various operations may be performed in other orders than those which are illustrated, or may be performed concurrently. [0100] After a start operation, the operational flow 800 moves to operation 802 . Operation 802 depicts receiving a first fingerprint package, the first fingerprint package associated with a first timestamp. For example, as shown in and/or described with respect to FIGS. 1 and 2 . [0101] Then, operation 804 depicts retrieving at least one first match based at least partially on the received first fingerprint package, the at least one first match associated with a first video segment. For example, as shown in and/or described with respect to FIGS. 1 and 2 . [0102] Then, operation 806 depicts receiving a second fingerprint package, the second fingerprint package associated with a second timestamp. For example, as shown in and/or described with respect to FIGS. 1 and 2 . [0103] Then, operation 808 depicts retrieving at least one second match based at least partially on the received second fingerprint package, the at least one second match associated with a second video segment. For example, as shown in and/or described with respect to FIGS. 1 and 2 . [0104] Then, operation 810 depicts determining a difference in time between the first timestamp and the second timestamp. For example, as shown in and/or described with respect to FIGS. 1 and 2 . [0105] Then, operation 812 depicts establishing a likelihood that at least one of the first match or the second match correctly identifies a video segment associated with a client sending the first and second fingerprint packages based at least partially on the determined difference in time. For example, as shown in and/or described with respect to FIGS. 1 and 2 . [0106] FIG. 8 also illustrates alternative embodiments of the example operational flow 800 . FIG. 8 illustrates an example embodiment where operation 812 may include at least one additional operation 814 . [0107] Operation 814 illustrates establishing a likelihood that at least one of the first match or the second match correctly identifies a video segment associated with a client sending the first and second fingerprint packages based at least partially on the determined difference in time, wherein increased differences in time correlate with increased likelihoods of correct identifications. For example, as shown in and/or described with respect to FIGS. 1 and 2 . [0108] FIG. 9 illustrates an operational flow 900 representing example operations related to on-screen graphics detection. In FIG. 9 and in following figures that include various examples of operational flows, discussion and explanation may be provided with respect to the above-described examples of FIGS. 1 and 2 , and/or with respect to other examples and contexts. However, it should be understood that the operational flows may be executed in a number of other environments and contexts, and/or in modified versions of FIGS. 1 and 2 . Also, although the various operational flows are presented in the sequence(s) illustrated, it should be understood that the various operations may be performed in other orders than those which are illustrated, or may be performed concurrently. [0109] After a start operation, the operational flow 900 moves to operation 902 . Operation 902 depicts receiving a first fingerprint package, the first fingerprint package associated with a first timestamp. For example, as shown in and/or described with respect to FIGS. 1 and 2 . [0110] Then, operation 904 depicts retrieving at least one first match based at least partially on the received first fingerprint package, the at least one first match associated with a first video segment and a first offset related to the first video segment. For example, as shown in and/or described with respect to FIGS. 1 and 2 . [0111] Then, operation 906 depicts receiving a second fingerprint package, the second fingerprint package associated with a second timestamp. For example, as shown in and/or described with respect to FIGS. 1 and 2 . [0112] Then, operation 908 depicts retrieving at least one second match based at least partially on the received second fingerprint package, the at least one second match associated with a second video segment and a second offset related to the second video segment. For example, as shown in and/or described with respect to FIGS. 1 and 2 . [0113] Then, operation 910 depicts determining a first duration, the first duration indicative of the first timestamp and the second timestamp. For example, as shown in and/or described with respect to FIGS. 1 and 2 . [0114] Then, operation 912 depicts determining whether the first video segment and the second video segment are the same and, if the first video segment and the second video segment are the same, at least: determining a second duration, the second duration indicative of the difference in time between the first offset and the second offset; comparing the first duration with the second duration; and establishing a likelihood that at least one of the first match or second match correctly identifies a video segment associated with a client sending the first and second fingerprint packages based at least partially on the comparison of the first duration with the second duration. For example, as shown in and/or described with respect to FIGS. 1 and 2 . [0115] FIG. 9 also illustrates alternative embodiments of the example operational flow 900 . FIG. 9 illustrates an example embodiment where operation 912 may include at least one additional operation 914 . [0116] Operation 914 illustrates establishing a likelihood that at least one of the first match or second match correctly identifies a video segment associated with a client sending the first and second fingerprint packages based at least partially on the comparison of the first duration with the second duration, wherein smaller differences in the first duration and the second duration correlates with increased likelihoods of correct identification. For example, as shown in and/or described with respect to FIGS. 1 and 2 . [0117] FIG. 10 illustrates an exemplary computer program product 1000 which may include at least one non-transitory computer-readable medium. Further illustrated in FIG. 10 are instructions 1002 of computer program product 1000 . Instructions 1002 illustrate one or more instructions for determining one or more values related to transmitting fingerprints associated with a client to an Automated Content Recognition (ACR) system, the one or more values associated with one or more of at least one sampling rate, at least one pattern of sampling, at least one number of samples associated with creating a fingerprint package, or at least one time interval between fingerprint package transmissions; one or more instructions for signaling to transmit one or more fingerprint packages associated with a client to an ACR system based at least partially on one or more values related to transmitting fingerprints; and one or more instructions for adjusting at least one of one or more values related to transmitting fingerprints associated with the client to the ACR system. For example, as shown in and/or described with respect to FIGS. 1 through 9 , a computer program product may include one or more instructions encoded on and/or stored by one or more non-transitory computer-readable media. The one or more instructions may, when executed by one or more processing devices, cause the one or more processing devices to perform operations including detecting one or more graphics superimposed over a content rendered on a display of a television; and providing at least some data associated with the detected one or more graphics to at least one content recognition operation configured for at least determining one or more identifiers associated with the content being rendered. The foregoing operations may be similar at least in part and/or be substantially similar to (but are not limited to) corresponding operations disclosed elsewhere herein. [0118] FIG. 11 illustrates an exemplary system 1100 . System 1100 may include circuitry 1102 , circuitry 1104 , and/or circuitry 1106 . [0119] Circuitry 1102 illustrates circuitry configured for determining one or more values related to transmitting fingerprints associated with a client to an Automated Content Recognition (ACR) system, the one or more values associated with one or more of at least one sampling rate, at least one pattern of sampling, at least one number of samples associated with creating a fingerprint package, or at least one time interval between fingerprint package transmissions. For example, as shown in and/or described with respect to FIGS. 1 through 9 , circuitry 1102 may cause operations with an effect similar at least in part and/or substantially similar to (but not limited to) corresponding operations disclosed elsewhere herein. [0120] Then, circuitry 1104 illustrates circuitry configured for signaling to transmit one or more fingerprint packages associated with the client to the ACR system based at least partially on one or more values related to transmitting fingerprints. For example, as shown in and/or described with respect to FIGS. 1 through 9 , circuitry 1104 may cause operations with an effect similar at least in part and/or substantially similar to (but not limited to) corresponding operations disclosed elsewhere herein. [0121] Then, circuitry 1106 illustrates circuitry configured for adjusting at least one of one or more values related to transmitting fingerprints associated with the client to the ACR system. For example, as shown in and/or described with respect to FIGS. 1 through 9 , circuitry 1104 may cause operations with an effect similar at least in part and/or substantially similar to (but not limited to) corresponding operations disclosed elsewhere herein. [0122] The system and methods, flow diagrams, and structure block diagrams described in this specification may be implemented in computer processing systems including program code comprising program instructions that are executable by a computer processing system. Other implementations may also be used. Additionally, the flow diagrams and structure block diagrams herein described describe particular methods and/or corresponding acts in support of steps and corresponding functions in support of disclosed structural means, may also be utilized to implement corresponding software structures and algorithms, and equivalents thereof. [0123] Embodiments of the subject matter described in this specification can be implemented as one or more computer program products, i.e., one or more modules of computer program instructions encoded on a tangible program carrier for execution by, or to control the operation of, data processing apparatus. The computer readable medium can be a machine readable storage device, a machine readable storage substrate, a memory device, or a combination of one or more of them. [0124] A computer program (also known as a program, software, software application, script, or code) can be written in any form of programming language, including compiled or interpreted languages, or declarative or procedural languages, and it can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program does not necessarily correspond to a file in a file system. A program can be stored in a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document), in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files that store one or more modules, sub programs, or portions of code). A computer program can be deployed to be executed on one computer or on multiple computers that are located at one site or distributed across multiple sites and interconnected by a suitable communication network. [0125] The processes and logic flows described in this specification can be performed by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output. The processes and logic flows can also be performed by, and apparatus can also be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit). [0126] The essential elements of a computer are a processor for performing instructions and one or more memory devices for storing instructions and data. Generally, a computer will also include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magneto optical disks, or optical disks. However, a computer need not have such devices. Processors suitable for the execution of a computer program include, by way of example only and without limitation, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer. Generally, a processor will receive instructions and data from a read only memory or a random access memory or both. [0127] To provide for interaction with a user or manager of the system described herein, embodiments of the subject matter described in this specification can be implemented on a computer having a display device, e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor, for displaying information to the user and a keyboard and a pointing device, e.g., a mouse or a trackball, by which the user can provide input to the computer. Other kinds of devices can be used to provide for interaction with a user as well. For example, feedback provided to the user can be any form of sensory feedback, e.g., visual feedback, auditory feedback, or tactile feedback; and input from the user can be received in any form, including acoustic, speech, or tactile input. [0128] Embodiments of the subject matter described in this specification can be implemented in a computing system that includes back end component(s) including one or more data servers, or that includes one or more middleware components such as application servers, or that includes a front end component such as a client computer having a graphical user interface or a Web browser through which a user or administrator can interact with some implementations of the subject matter described is this specification, or any combination of one or more such back end, middleware, or front end components. The components of the system can be interconnected by any form or medium of digital data communication, such as a communication network. The computing system can include clients and servers. A client and server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client server relationship to each other. [0129] While this specification contains many specific implementation details, these should not be construed as limitations on the scope of any invention or of what may be claimed, but rather as descriptions of features that may be specific to particular embodiments of particular inventions. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. [0130] Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination. [0131] Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the embodiments described above should not be understood as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products. [0132] This written description sets forth the best mode of the invention and provides examples to describe the invention and to enable a person of ordinary skill in the art to make and use the invention. This written description does not limit the invention to the precise terms set forth. Thus, while the invention has been described in detail with reference to the examples set forth above, those of ordinary skill in the art may effect alterations, modifications and variations to the examples without departing from the scope of the invention.

A system and method are disclosed that improve the efficiency and performance of an Automatic Content Recognition (ACR) system. Several approaches are described that may be used alone or in combination to reduce total system computational costs related to the manner in which such an ACR means takes samples, called “fingerprints,” of digital content being played by a television display device and transmits said fingerprints to a remote server to be compared to a database of fingerprints from known programming. Methods are described for implementing such system performance enhancement including varying sampling rates and other resolution metrics during the process of creating such fingerprints and transmitting them to the database server. The system and method disclosed also describes how to reduce the probability that, when compared to samples from already-identified programming, such fingerprints are incorrectly identified as being of programming other than that which they are in fact derived from.

CROSS-REFERENCE TO RELATED APPLICATIONS The benefit of U.S. Provisional Patent Application No. 60/003,471 filed on Sep. 8, 1995 and entitled "NONCLASSICAL ANTIFOLATES" is claimed. BACKGROUND OF THE INVENTION Folic acid is used by a number of cells in the course of cell replication. Antifolate compounds mimic folic acid and its derived cofactors, interacting with one or more folate-requiring enzymes. Antifolate compounds inhibit the growth of malignant cells and find use in the treatment of cancer. Known antifolate compounds, such as Lometrexol (U.S. Pat. Nos. 5,008,391), include a glutamic acid portion in the natural or "L" configuration which undergoes polyglutamation upon entry into a cell by the enzyme polyglutamate synthetase (FPGS). The polyglutamated antifolate then can react with other folate-requiring enzymes such as dihydrofolate reductase (DHFR) and glycinamide ribonucleotide formyl transferase (GARFT), the latter being the first of two folate-dependent enzymes in the de novo purine biosynthetic pathway. Inhibition of DEFR and GARFT and other folate-utilizing enzymes eventually leads to inhibition of cell replication. The efficacy of classical antifolates in inhibiting cell replication can decrease with continued use. One possible explanation for this is the fact that malignant cells become resistant toward classical antifolates through impaired polyglutamation reactions. As a polyglutamated antifolate reacts more efficiently with folate-requiring enzymes than a monoglutamated antifolate, this lack of polyglutamation could be sufficient to account for the decline in efficacy. One way of increasing efficacy, in terms of inhibiting cell replication, is to provide an antifolate that does not contain a terminal L-glutamic acid group, thus avoiding the reaction with FPGS. The difficulty in providing such a compound is that in order to be effective in inhibiting cell replication, the compound must still be able to react with other folate requiring enzymes even though it is not polyglutamated. Use of a non-polyglutamatable inhibitor has been suggested as an approach to the design of DHFR inhibitors targeted against FPGS deficient tumors. See Rosowsky et al., J. Med, Chem., (1983), 26, 1719-1724. In addition, several derivatives of folic acid in which the terminal L-glutamate moiety is replaced by L-ornithine have been shown to be effective FPGS inhibitors. Singh, et al., J. Med. Chem., (1992), 35 (11), 2002-6. Non-polyglutamatable GARFT inhibitors also have been described. Rosowsky, et al., J. Med. Chem., (1992), 35 (9), 1578-88. DETAILED DESCRIPTION The present invention pertains to compounds of the formula: ##STR1## in which: Q is --OH or --NH 2 ; A is --CH 2 --, --CH 2 CH 2 --, --O--, or --S--; --Ar-- is a divalent aromatic ring; W is --CO-- or --SO 2 --; and Z is: (A) an α-amino acid group of the formula ##STR2## wherein * designates a chiral center in the L configuration, n has a value of from 0 to 4, and R is: (i) --COJ wherein J is an amino acid linked through the α-amino group, which if chiral, is of the D configuration, (ii) V, wherein V is a tetrazolyl group of the formula ##STR3## where B is hydrogen, C 1 -C 4 alkyl, or C 1 -C 4 hydroxyalkyl, or (iii) --SO 3 H; (B) a tetrazolyl group of the formula ##STR4## wherein n has a value of from 0 to 4 and E is --COOH or V, wherein V is a tetrazolyl group as defined previously and, if n is greater than 0 or E is other than V, the carbon atom designated * is in the L configuration; (C) --NHR 1 , where R 1 is hydrogen, --CH 2 --COOH, or a substituted or unsubstituted C 1 -C 4 alkyl, C 1 -C 4 hydroxyalkyl, cycloalkyl, or polycycloalkyl group; (D) --NR 2 R 3 where R 2 and R 3 are independently C 1 -C 4 alkyl, C 1 -C 4 hydroxyalkyl or COOT, where T is hydrogen or C 1 -C 4 alkyl; (E) ##STR5## where each T is independently as defined previously, n has a value of from 0 to 4, and y has a value of 0 or 1; (F) ##STR6## where n, T and y are as defined previously, provided at least one y is other than zero; (G) ##STR7## where n, T and y are as defined previously, provided at least one y is other than zero; or (H) --NHOH; and the pharmaceutically acceptable salts and esters thereof. The present invention also relates to pharmaceutical compositions containing one or more of the above compounds. The compounds of Formula I are named herein as derivatives of the pyrido 2,3-d!-pyrimidine fused ring system which is numbered as follows: ##STR8## It will be appreciated that the pyrido 2,3-d!pyrimidines of Formula I are the tautomeric equivalent of the corresponding 3-H-4-oxo or 3-H-4-imino structures. For simplicity's sake, the compounds are depicted herein as 4-hydroxy and 4-amino compounds, it being understood the corresponding and tautomeric keto and imino structures, respectively, are fully equivalent; e.g.: ##STR9## The carbon atom in the 6-position of the 5,6,7,8-tetrahydropyrido 2,3-d!pyrimidine ring is a chiral center leading to two isomers. If a further chiral center is present in Z, this will result in two diastereomers. The mixture of isomers can be utilized therapeutically, both serving as substrates for relevant folate enzymes, or can be separated so as to be in a form substantially free of the other; i.e., in a form having an optical purity of >95%. The isomers can be separated mechanically, as by chromatography, or the racemate or mixture of diastereomers can be treated with a chiral acid operable form a salt therewith. The resultant diastereoisomeric salts are then separated through one or more fractional crystallization and thereafter the free base of the cationic moiety of at least one of the separated salts is liberated through treatment with a base and removal of the protecting groups. The liberation of the cation of the salt can be performed as a discrete step before or after the removal of the protecting groups or concomitantly with the removal of such groups under basic hydrolysis. Suitable chiral acids include the individual enantiomers of 10-camphorsulfonic acid, camphoric acid, α-bromocamphoric acid, menthoxyacetic acid, tartaric acid, diacetyltartaric acid, malic acid, pyrrolidine-5-carboxylic acid, and the like. The group-Ar-- is a 5- or 6-membered aromatic ring which optionally can contain up to three N, O, or S heteroatoms such as, for example, 1,4-phenylene, 1,3-phenylene, thiene-2,5-diyl, thiene-2,4-diyl, furan-2,4-diyl, and furan-2,5-diyl. Such divalent aromatic rings optionally can be substituted with from 1 to 4 substituents such as bromo, chloro, fluoro, iodo, hydroxy, or C 1 -C 4 alkyl. "C 1 -C 4 alkyl" includes methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl and tert.-butyl. "Cycloalkyl" refers to C 3 -C 7 cycloalkyl, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl. The term "polycycloalkyl" refers to two or more rings, each independently containing from 3 to 15 carbon atoms which share two or more carbon atoms, such as bicyclo 2.2.1!heptane (e.g., norbornane), bicyclo 2.2.2!octa-2-ene, and tricyclo 2.2.1.0 2 ,6 !heptane (e.g., nortricyclene). "Amino protecting group" refers to substituents on an amino group commonly employed to protect the amino functionality during one or more reactions. Examples include the formyl, trityl, phthalimido, pivaloyl, trichloroacetyl, chloroacetyl, bromoacetyl, iodoacetyl, benzoylmethylsulfonyl, 2-nitrophenylsulfenyl, and diphenylphosphine oxide group. The protecting group employed is not critical provided the group is stable to the condition of subsequent reactions involving other positions and can be removed at the appropriate point without disrupting the remainder of the molecule. Examples of amino protecting groups can be found in J. W. Barton, "Protective Groups in Organic Chemistry", J. G. W. McOmie, Ed., Plenum Press, New York, N.Y., 1973, Chapter 2; and T. W. Greene, P. G. M. Wuts, "Protective Groups in Organic Synthesis-2nd Edition", John Wiley and Sons, New York, N.Y., 1991, Chapter 7. "Carboxylic acid protecting group" similarly refers to derivatives of a carboxylic acid group commonly employed to protect a carboxylic acid group. Examples of such carboxylic acid protecting groups include 4-nitrobenzyl, 4-methoxybenzyl, 3,4-dimethoxybenzyl, 2,4-dimethoxybenzyl, 2,4,6-trimethoxybenzyl, 2,4,6-trimethylbenzyl, pentamethylbenzyl, 3,4-methylenedioxybenzyl, benzhydryl, 4,4'-dimethoxybenzhydryl, 2,2',4,4'-tetramethoxybenzhydryl, methyl, ethyl, propyl, isopropyl, t-butyl, t-amyl, trityl, 4-methoxytrityl, 4,4'-dimethoxytrityl, 4,4',4"-trimethoxy-trityl, 2-phenylprop-2-yl, trimethylsilyl, t-butyldimethylsilyl, phenacyl, 2,2,2-trichloroethyl, β-(trimethylsilyl)ethyl, β-(di-(n-butyl)methylsilyl)ethyl, p-toluenesulfonylethyl, 4-nitrobenzylsulfonylethyl, allyl, cinnamyl, 1-(trimethylsilylmethyl)prop-1-en-3-yl, and like. The protecting group employed again is not critical provided the derivatized carboxylic acid is stable to the conditions of the reactions and can be removed at the appropriate point without disrupting the remainder of the molecule. Examples of such groups are found in Barton, "Protective Groups in Organic Chemistry", supra, Chapter 5, and Greene, "Protective Groups in Organic Synthesis, 2nd Edition", supra, Chapter 5. The compounds of Formula I can form salts with bases and acids. For final usage these are pharmaceutically acceptable salts, although for synthetic steps the salts do not necessarily have to be pharmaceutically acceptable. Examples of salts with acids include the sulfate, pyrosulfate, bisulfate, sulfite, bisulfite, phosphate, monohydrogenphosphate, dihydrogenphosphate, metaphosphate, pyrophosphate, chloride, bromide, iodide, acetate, propionate, decanoate, caprylate, acrylate, formate, isobutyrate, caproate, heptanoate, propiolate, oxalate, malonate, succinate, suberate, sebacate, fumarate, maleate, butyne-1,4-dioate, hexyne-1,6-dioate, benzoate, chlorobenzoate, methylbenzoate, dinitrobenzoate, hydroxybenzoate, methoxybenzoate, phthalate, sulfonate, xylenesulfonate, phenylacetate, phenylpropionate, phenylbutyrate, citrate, lactate, gamma-hydroxybutyrate, glycollate, tartrate, methanesulfonate, propanesulfonate, naphthalene-1-sulfonate, naphthalene-2-sulfonate, mandelate, etc. Preferred pharmaceutically acceptable acid addition salts are those of hydrochloric acid, hydrobromic acid, maleic acid, and methanesulfonic acid. The present invention also pertains to the physiologically acceptable salts of the fore-going compounds with alkali metals, alkaline earth metals, ammonia and organic amines as, for example, salts in which the cations are sodium, potassium, magnesium, calcium, or the protonated amines such as those derived from ethylamine, triethylamine, ethanolamine, diethylaminoethanol, ethylenediamine, piperidine, morpholine, 2-piperidinoethanol, benzylamine, procaine, etc. The compound of the present invention generally can be prepared by coupling an amino compound contributing Z with substituted aromatic acids, e.g., benzoic acid and thienyl carboxylic acid intermediates (W=--CO--) or the corresponding sulfonic acid derivatives in which W is --SO 2 --. These acids are substituted with a 2-amino-4-hydroxy-4,5,6,7-tetrahydropyrido 2,3-d!pyrimidin-6-yl substituent. The coupling reaction is conducted using conventional condensation techniques for forming peptide bonds such as, for example, the use of dicyclohexylcarbodiimide, diphenylchlorophosphonate, or 2-chloro-4,6-dimethoxy-1,3,5-triazine {see, e.g, Kaminski, Synthesis, 917-920 (1987)}, following which any remaining protecting groups are removed. The benzoic acid and thienyl carboxylic acid intermediates carrying a 2-(2-amino-4-hydroxy-4,5,6,7-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl substituent; i.e., A is --CH 2 --, can be prepared for example using the procedures of U.S. Pat. No. 4,818,819, the disclosure of which is incorporated herein by reference. This 6-ethynylpyrido 2,3-d!pyrimidine is allowed to react with a compound of the formula X-Ar-COR 5 in which X is bromo or iodo and R 5 is a carboxy protecting group in the presence of a palladium catalyst. The palladium catalysts are those which have been employed in the reaction of aryl halides and allylic alcohols, as described for example by Melpoler et al., J. Org. Chem., 41 (2), 265 (1976); Chalk et al., J. Org. Chem., 41 (7), 1206 (1976); Arai et al., J. Heterocyclic Chem., 15, 351 (1978); Tamaru et al., Tetrahedron Letters, 10, 919 (1978); and Tetrahedron, 35, 329 (1979); and Sakamoto, Synthesis, (1983) 312. Particularly useful are palladium acetate or a palladium or cuprous halide such as palladium chloride and a cuprous iodide. The reaction generally is conducted in the presence of at least one molar equivalent of a secondary or tertiary amine which acts as an acid acceptor, as for example triethylamine or diethylamine, and under an inert atmosphere, optionally in the presence of an inert polar solvent such as acetonitrile, dimethylformamide, or N-methylpyrrolidinone. Acetonitrile serves as a solvent for the reactants and for the salt formed from the acid acceptor and acid generated. Moderately elevated temperatures, as for example from about 75° to 125° C., preferably from about 75° to 100° C., generally are employed. The coupling reaction with the palladium catalyst is followed by catalytic hydrogenation of the carbon-carbon triple bond and the pyridine ring of the pyrido 2,3-d!pyrimidine ring system. Suitable catalysts for this hydrogenation include platinum oxide or palladium-on-carbon. The hydrogenation reaction generally is run at room temperature for approximately 3 to 4 hours, though up to 24 hours may be required for certain compounds in which --Ar-- is thienediyl. The benzoic acid and thienyl carboxylic acid intermediates carrying a 2-amino-4-hydroxy-4,5,6,7-tetrahydropyrido 2,3-d!pyrimidin-6-ylmethoxy or 2-amino-4-hydroxy-4,5,6,7-tetrahydropyrido 2,3-d!pyrimidin-6-ylmethylthio substituent; ie., A is --O-- or --S--, respectively, can be prepared using the procedures of U.S. Pat. No. 5,159,079, the disclosure of which is incorporated by reference, e.g., allowing a 2-amino-4-hydroxy-6-hydroxymethyl-4,5,6,7-tetrahydropyrido 2,3-d!pyrimidine to react with an ester of benzoic acid or thienyl carboxylic acid which is substituted with hydroxy or mercaptan, optionally in the presence of diethyl azodicarboxylate, to form the corresponding ether or thioether. The benzoic acid and thienyl carboxylic acid intermediates carrying a 3-(2-amino-4-hydroxy-4,5,6,7-tetrahydropyrido 2,3-d!pyrimidin-6-yl)prop-1-yl substituent, i.e., A is --CH 2 CH 2 --, can be prepared using the procedures of U.S. Pat. No. 4,895,946, the disclosure of which is incorporated by reference, e.g., condensing a 2,4-diaminopyrimidin-6-one with an ester of benzoic acid or thienyl carboxylic acid which is substituted with an activated dialdehyde such as a dinitrile. According to the foregoing processes, compounds of Formula I in which Z is hydroxy are obtained. When a compound of Formula I in which Q is amino is desired, a compound in which Q is hydroxy can be treated with 1,2,4-triazole and (4-chlorophenyl)dichlorophosphate and the product of this reaction then treated with concentrated ammoma. Preferred amino acids for J are glycine, D-aspartic acid, D-proline, and D-homocysteic acid. Tetrazolyls include 1H-tetrazol-5-yl, 2H-tetrazol-5-yl, 1-methyltetrazol-5-yl, 1-ethyltetrazol-5-yl, 1-propyltetrazol-5-yl, 2-ethyltetrazol-5-yl, 2-methyltetrazol-5-yl, 2-propyltetrazol-5-yl, 1-hydroxymethyltetrazol-5-yl, 2-hydroxymethyltetrazol-5-yl, 1-butyltetrazol-5-yl, 2-butyltetrazol-5-yl, 1-(2-hydroxyethyl)-tetrazol-5-yl, 1-(1-hydroxyethyl)tetrazol-5-yl, 2-(2-hydroxyethyl)tetrazol-5-yl, 2-(1-hydroxyethyl)tetrazol-5-yl, 1-(1-hydroxypropyl)-tetrazol-5-yl, 2-(1-hydroxypropyl)tetrazol-5-yl, 1-(2-hydroxypropyl)tetrazol-5-yl, 2-(2-hydroxypropyl)-tetrazol-5-yl, 1-(1-hydroxybutyl)tetrazol-5-yl, 2-(1-hydroxybutyl)tetrazol-5-yl, 1-(2-hydroxybutyl)tetrazol-5-yl, and 2-(2-hydroxybutyl)tetrazol-5-yl. A preferred subclass pertains to compound of the formula: ##STR10## in which Ar is phenylene or thienediyl; W is --CO-- or --SO 2 --; Q is hydroxy or amino; (a) R 2 and R 3 when taken together with the nitrogen atom to which they are attached are a pyrrolidino or piperidino group substituted with one or two groups of the formula COOT in which T is hydrogen or alkyl of 1 to 4 carbon atoms, or (b) when taken separately, R 2 is hydrogen and R 3 is: (1) hydroxy, (2) cycloalkyl of 3 to 8 carbon atoms substituted with --COOT in which T is hydrogen or alkyl of 1 to 4 carbon atoms, or ##STR11## in which E is hydrogen, carboxy, or tetrazolyl and if E is other than hydrogen the configuration about the carbon atom designated * is L, n has a value of 0 to 4, and R is (i) --SO 3 H, (ii) glycyl, or (iii) --CO--J in which J is an α-amino acid residue of the D-configuration, or when E is not carboxy, hydroxy or alkoxy of 1 to 4 carbon atoms. Particularly preferred are compounds of Formula II in which Q is hydroxy and W is --CO--. As noted, the compounds of this invention have an effect on one or more enzymes which utilize folic acid, and in particular metabolic derivatives of folic acid, as a substrate. The compounds are particularly effective inhibitors of GARFT enzyme. For example, N-(N-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!thien-2-ylcarbonyl}-L-γ-glutamyl)-D-aspartic acid demonstrates 100% inhibition against growth of 6C3HED lymphosarcoma tumor evaluated in C3H female mice at 100 mg/kg. The compounds can be used, under the supervision of qualified professionals, to inhibit the growth of neoplasms including choriocarcinoma, leukemia, adenocarcinoma of the female breast, epidermid cancers of the head and neck, squamous or small-cell lung cancer, and various lymphosarcomas. The compounds can also be used to treat mycosis fungoides, psoriasis, and arthritis. The compounds can be administered orally but preferably are administered parenterally, alone or in combination with other therapeutic agents including other anti-neoplastic agents, steroids, etc., to an animal in need of treatment. Animals include mammals, reptiles, crustacean, amphibians, fish, and poultry. The principal target recipient are mammals, particularly humans. Parenteral routes of administration include intramuscular, intrathecal, intravenous and intra-arterial. Dosage regimens must be titrated to the particular neoplasm, the condition of the patient, and the response but generally doses will be from about 10 to about 100 mg/day for 5-10 days or single daily administration of 250-500 mg, repeated periodically; e.g., every 14 days. While having a low toxicity as compared to other antimetabolites now in use, a toxic response often can be eliminated by either or both of reducing the daily dosage or administering the compound on alternative days or at longer intervals such as every three days. Oral dosage forms including tablets and capsules, contain from 1 to 100 mg of drug per unit dosage. Isotonic saline solutions containing 1-100 mg/mL can be used for parenteral administration. Accordingly, the present invention also includes pharmaceutical compositions comprising as active ingredient one or more compounds of Formula I associated with at least one pharmaceutically acceptable carrier, diluent or excipient. In preparing compositions containing one or more other compounds of Formula I, the active ingredients are usually mixed with an excipient, diluted by an excipient or enclosed within such a carrier which can be in the form of a capsule or sachet. When the excipient serves as a diluent, it may be a solid, semi-solid or liquid material which acts as a vehicle, carrier or medium for the active ingredient. Thus, the compositions can be in the form of tablets, pills, powders, elixirs, suspensions, emulsions, solutions, syrups, soft and hard gelatin capsules, suppositories, sterile injectable solutions and sterile packaged powders. Examples of suitable excipients include lactose, dextrose, sucrose, sorbitol, mannitol, starch, gum acacia, calcium silicate, microcrystalline cellulose, polyvinylpyrrolidinone, cellulose, water, syrup, and methyl cellulose, the formulations can additionally include lubricating agents such as talc, magnesium stearate and mineral oil, wetting agents, emulsifying and suspending agents, preserving agents such as methyl- and propylhydroxybenzoates, sweetening agents or flavoring agents. The compositions can be formulated so as to provide immediate, sustained or delayed release of the active ingredient after administration to the patient by employing known procedures. The compositions are preferably formulated in a unit dosage form. The term "unit dosage form" refers to physically discrete units suitable as unitary dosages for human subjects and other mammals, each unit containing (i) a predetermined quantity of active material calculated to produce, upon administration in a single or multiple dose regimen, the desired therapeutic effect, in association with (ii) a suitable pharmaceutical excipient. However, it will be understood that the amount of the compound actually administered, and the frequency of administration, will be determined by a physician in light of the relevant circumstances including the relative severity of a disease state, the choice of compound to be administered, the age, weight, and response of the individual patient, and the chosen route of administration. The following examples illustrate specific aspects of the present invention but are not intended to limit the scope thereof in any respect and should not be so construed. EXAMPLE 1 N-(N-{4- 2-(2-Amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!benzoyl}-L-γ-glutamyl)-D-aspartic Acid A. To a solution of 1.79 g (5.31 mmol) of N-carbobenzyloxy-L-glutamic acid α-tert.-butyl ester in 25 mL of methylene chloride in a dried, three-necked, 100 mL round bottom flask cooled in an ice bath was added under nitrogen 0.74 mL (5.3 mmol) of triethylamine. The reaction mixture was stirred at 0° C. for ten minutes and 0.69 mL (5.31 mmol) of isobutyl chloroformate was added. The reaction mixture was stirred for 35 minutes and 1.06 g (5.36 mmol) of D-aspartic acid dimethyl ester hydrochloride was added. An additional 0.75 mL (5.3 mmol) of triethylamine was added and the reaction mixture warmed slowly to room temperature overnight, diluted with 80 mL methylene chloride, and washed sequentially with 5% sodium bicarbonate, 0.5N hydrochloric acid, and brine. The organic layer was dried over sodium sulfate and concentrated in vacuo. The product was then chromatographed on silica gel (55% hexanes/ethyl acetate) to give 1.93 g (75%) of dimethyl N- 4-(benzyloxycarbonylamino)-4-tert.-butoxycarbonylbutanoyl!-D-aspartate as a clear viscous oil. Mass Spectrum (FD+): M+1=481; IR (CHCl 3 , cm -1 )=1029, 1052, 1155, 1227, 1295, 1348, 1370, 1394, 1408, 1440, 1455, 1508, 1675, 1729, 2957, 2983, 3011, 3428; UV (ethanol) λ max =201 (ε=9875); Anal. Calcd. for C 23 H 32 N 2 O 9 : C, 57.48; H, 6.71; N, 5.83. Found: C, 57.14; H, 6.79; N, 5.82. 1 H NMR (300 MHz, CDCl 3 ) δ1.47 (s, 9H), 1.90-1.98 (m, 1H), 2.19-2.37 (m, 3H), 2.83 (dd, J=4.5 Hz and J=17.2 Hz, 1H), 3.04 (dd, J=4.5 Hz and J=17.2 Hz, 1H), 3.70 (s, 3H), 3.76 (s, 3H), 4.27-4.33 (M, 1H), 4.86-4.91 (m, 1H), 5.11 (s, 2H), 5.57 (d, J=7.8 Hz, 1H), 6.81 (d, J=7.7 Hz, 1H), 7.27-7.37 (m, 5H). B. To a solution of 1.92 g (4.0 mmol) of dimethyl N- 4-(benzyloxycarbonylamino)-4-tert.-butoxycarbonylbutanoyl!-D-aspartate in 15 mL of anhydrous methanol was added 0.43 g of 10% Pd/C and the mixture was then stirred under an atmosphere of hydrogen overnight. The catalyst was removed by filtration through a Celite® pad and the filtrate concentrated in vacuo to yield 1.45 g of dimethyl N-(4-amino-4-tert.-butoxycarbonylbutanoyl)-D-aspartate as a thick clear oil. Mass Spectrum (FD+): M+1=347; IR (CHCl 3 , cm -1 )=840, 1048, 1155, 1371, 1396, 1440, 1511, 1602, 1672, 1739, 2980, 3428, 3691; 1 H NMR (30 MHz, CDCl 3 ) δ1.51 (s, 9H), 1.66 (s, 2H), 2.07 (m, 2H), 2.46 (m, 2H), 2.85 (t, J=6.0 Hz, 2H), 3.68 (s, 3H), 3.72 (s, 3H), 3.76 (t, J=6.4 Hz, 1H), 4.78 (t, J=5.7 Hz, 1H), 7.15 (d J=8.0 Hz, 1H). C. To 0.27 g (0.77 mmol) of 4- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!benzoic acid hydrochloride in a three-necked round bottomed flask under an atmosphere of nitrogen were added 4.5 mL of anhydrous dimethylformamide and 0.19 mL (1.72 mmol) of N-methylmorpholine followed by 0.14 g (0.78 mmol) of 2-chloro-4,6-dimethoxy-1,3,5-triazine. The reaction mixture was stirred for 40 minutes and 0.27 g (0.78 mmol) of dimethyl N-(4-amino-4-tert.-butoxycarbonylbutanoyl)-D-aspartate in 1.0 mL of anhydrous dimethylformamide was added. After 2.5 hours, the reaction mixture was diluted with 50% CH 3 OH/CHCl 3 and was concentrated in vacuo and the residue was chromatographed on silica gel with a gradient of 5-7% CH 3 OH/CHCl 3 to yield 0.26 g (54%) of N-(N-{4- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!-benzoyl}-L-γ-glutamyl)-D-aspartic acid 1-tert.-butyl-2,2-dimethyl ester as a white solid. Rf=0.43 (20% CH 3 OH/CHCl 3 ) m.p. 129°-133° C. (foam, dec); Mass Spectrum (FD+): M+1=643; IR (KBr, cm -1 l)=645, 732, 773, 847, 1153, 1220, 1305, 1368, 1393, 1439, 1468, 1481, 1502, 1541, 1645, 1740, 2931, 3350; UV (C 2 H 5 OH): )λ max =224, 279 (ε=28373, 12315); 1 H NMR (300 MHz, DMSO d6 ) δ1.38 (s, 9H), 1.53-1.70 (m, 3 H), 1.77-2.02 (m, 3H), 2.21-2.32 (m, 2H), 2.60-2.80 (m, 5H), 3.15-3.18 (m, 1H), 3.58 (s, 3H), 4.23-4.26 (m, 1H), 4.58-4.63 (m, 1H), 5.92 (s, 2H), 6.26 (s, 1H), 7.27 (d, J=8.1 Hz, 2Hz), 7.77 (d, J=8.1 Hz, 2H), 8.39 (d, J=7.8 Hz, 1H), 8.52 (d, J=7.3 Hz, 1H); 9.69 (s, 1H). D. A solution of 0.116 g (0.18 mmol) of N-(N-{4- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!-benzoyl}-L-γ-glutamyl)-D-aspartic acid 1-tert.-butyl-2,2-dimethyl ester in 10 mL of trifluoroacetic acid was stirred overnight and then concentrated in vacuo. The residue was dried under high vacuum and dissolved in 3.0 mL of 0.5N sodium hydroxide and this mixture was stirred for four hours and then acidified to pH 3 with 1.0N hydrochloric acid to yield 0.070 g (69%) of N-(N-{4- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3 -d!pyrimidin-6-yl)ethyl!benzoyl} -L-γ-glutamyl)-D-aspartic acid as a white solid. m.p. 229°-242° C. (dec); Mass Spectrum (FAB+): M+=559; IR (KBr, cm -1 ) =545, 644, 753, 845, 1018, 1203, 1349, 1397, 1503, 1540, 1651, 1711, 2930, 3336; UV (C 2 H 5 OH) λ max =203, 224, 279 (ε=34992, 27290, 12284); 1 H NMR (300 MHz, DMSO d6 ) δ1.52-1.60 (m, 3H), 1.81-1.93 (m, 2H), 2.01-2.05 (m, 1H), 2.21-2.31 (m,'-2H), 2.51-2.79 (m, 6H), 2.94-3.05 (m, 1H), 4.27-4.34 (m, 1H), 4.45-4.52 (m, 1H), 6.00 (s, 2H), 6.29 (s, 1H), 7.29 (d, J=7.9 Hz, 2H), 7.78 (d, J=7.8 Hz, 2H), 8.22 (d, J=7.8 Hz, 1H), 8.56 (d, J=7.2 Hz, 1H). EXAMPLE 2 N-(N-{5- 2-(2-Amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!primidin-6-yl)ethyl!thien-2-ylcarbony}-L-γ-glutamyl-D-aspartic Acid A. To a solution of 0.25 g (0.79 mmol) of 5- 2-(amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!thien-2-ylcarboxylic acid in 4.0 mL of anhydrous dimethylformamide was added 0.20 mL (1.80 mmol) of 4-methylmorpholine and 0.14 g (0.80 mmol) of 2-chloro-4,6-dimethoxy-1,3,5-triazine. The reaction mixture was stirred at room temperature for 70 minutes, and 0.28 g (0.81 mmol) of dimethyl N-(4-amino-4-tert.-butoxycarbonylbutanoyl)-D-aspartate in 1.0 mL of anhydrous dimethylformamide was added. The reaction mixture was stirred for another 3 hours and then concentrated in vacuo. The crude material was then chromatographed on silica gel using a gradient of 4-10% CH 3 OH/CHCl 3 to give 0.19 g (37%) of N-(N-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!thien-2-ylcarbonyl}-L-γ-glutamyl)-D-aspartic acid 1-tert.-butyl-2,2-dimethyl ester as an off-white solid.; Rf=0.39 (20% CH 3 OH/CHCl 3 ); Mass Spectrum (FAB+): M+=649; IR (KBr, cm -1 )=640, 737, 772, 1153, 1220, 1368, 1461, 1545, 1635, 1740, 2929, 3383; UV (ETOH) λ max =222, 279 (ε=25233, 24541); 1 H NMR (300 MHz, DMSO d6 ) δ1.38 (s, 9H), 1.48-1.60 (m, 3H), 1.77-2.02 (m, 3H), 2.18-2.23 (m, 2H), 2.62-2.86 (m, 6H), 3.14-3.17 (M, 1H), 3.58 (s, 6H), 4.19-4.21 (m, 1H), 4.8-4.60 (m, 1H), 5.72 (s, 2H), 6.26 (s, 1H), 6.89 (s, 1H), 8.40 (d, J=6.2 Hz, 1H), 8.51 (d, J=6.0 Hz), 9.69 (s, 1H). B. A sample of 0.098 g (0.15 mmol) of N-(N-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!thien-2-ylcarbonyl }-L-γ-glutamyl)-D-aspartic acid 1-tert.-butyl-2,2-dimethyl ester was dissolved in 10 mL of trifluoroacetic acid and stirred overnight. This solution was then concentrated in vacuo and pumped to dryness under high vacuum. This solid material was then dissolved in 3.0 mL of 0.5N sodium hydroxide and stirred for four hours. The reaction mixture was then acidified to pH 3 with 1.0N hydrochioric acid to yield 0.055 g (65%) of N-(N-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)-ethyl!thien-2-ylcarbonyl}-L-γ-glutamyl)-D-aspartic acid as a white solid. m.p. 246°-262° C. (dec.); Mass Spectrum (FAB+): M+=565.2; IR (KBr, cm -1 ) =545, 643, 724, 754, 801, 1140, 1205, 1266, 1400, 1461, 1548, 1654, 2930, 3356; UV (C 2 H 5 OH) λ max =222, 279 (ε=17930, 17930); 1 H NMR (300 MHz, DMSO d6 ) δ1.55-1.68 (m, 3H), 1.81-2.19 (m, 3H), 2.20-2.25 (m, 2H), 2.60-2.89 (m, 6H), 3.07-3.10 (m, 1H), 4.25-4.27 (m, 1H), 4.46-4.90 (m, 1H), 5.88-5.90 (m, 2H), 6.23-6.25 (m, 1H), 6.87 (d, J=3.3 Hz, 1H), 7.65 (d, J=3.5 Hz, 1H), 8.20 (d, J=8.3 Hz, 1H), 8.52 (d, J=8.0 Hz, 1H), 9.82 (br s, 1H). EXAMPLE 3 N-(N-{4- 2-(2-Amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3 -d!pyrimidin-6-yl)ethyl!benzoyl}-L-γ-glutamyl)-D-glutamic Acid A. A mixture of 1.12 g (3.31 mmnol) of N-carbobenzyloxy-L-glutamic acid α-tert.-butyl ester in 20 mL of methylene chloride was cooled to 0° C. in an ice bath, and 0.50 mL (3.58 mmol) of triethylamine was added. The reaction mixture was stirred for 15 minutes and 0.49 mL (3.77 mmol) of isobutyl chloroformate was added. The reaction mixture was stirred for 35 minutes at 0° C. and 1.25 g (3.33 mmol) of D-glutamate diethyl ester tosylate and 1.05 mL (7.52 mmol) of triethylamine was added. The reaction mixture was then stirred at 0° C. for 1.5 hours and allowed to warm slowly over 72 hours to room temperature. The reaction mixture was then diluted with 50 mL methylene chloride and was washed sequentially with 5% sodium bicarbonate, 0.5N hydrochloric acid and brine. The organic layer was dried over sodium sulfate, filtered and concentrated in vacuo. The residue was then chromatographed on silica gel eluting with 70% hexanes/EtOAc to give 1.14 g (75%) of diethyl N- 4-(benzyloxycarbonylamino)-4-tert.-butoxycarbonylbutanoyl!-D-glutamate as a thick clear oil. Rf=0.64 (10%CH 3 OH/CHCl 3 ); Mass Spectrum (FD+): M+1=523; IR (CHCl 3 , cm -1 l) =843, 1029, 1053, 1156, 1303, 1348, 1371, 1395, 1455, 1478, 1510, 1675, 1729, 2939, 2984, 3011, 3028, 3425; UW (C 2 H 5 OH): λmax=203 (ε=10960); Anal. Calcd. for C 26 H 38 N 2 O 9 : C, 59.76; H, 7.33; N, 5.36; Found: C, 59.99; H, 7.15; N, 5.51. 1 H NMR (300 MHz,CDCl 3 ) δ1.13-1.23 (m, 6H), 1.40 (s, 9H), 1.85-1.95 (m, 2H), 2.06-2.17 (m, 2H), 2.23-2.36 (m, 4H), 4.03-4.23 (m, 5H), 4.45-4.5 (m, 1H), 5.04 (s, 2H), 5.91 (d, J=8.0 Hz, 1H), 7.12 (d, J=7.6 Hz, 1H), 7.24-7.29 (m, 5H). B. To a solution of 3.12 g (5.9 mmol) of diethyl N- 4-(benzyloxycarbonylamino)-4-tert.-butoxycarbonylbutanoyl!-D-glutamate in 27 mL of anhydrous ethanol was added 0.66 g of 10% Pd/C. The reaction mixture was then stirred under an atmosphere of hydrogen overnight. The catalyst was removed by filtration through Celite® and the filtrate was concentrated in vacuo to give 1.83 g (81%) of diethyl N-(4-amino-4-tert.-butoxycarbonylbutanoyl)-D-glutamate as a white gum. Mass Spectrum (FD+): M+1=389; IR (CHCl 3 , cm -1 )=845, 1023, 1156, 1370, 1394, 1448, 1477, 1507, 1602, 1673, 1729, 2983, 3024, 3426, 3690; Anal. Calcd. for C 18 H 32 N 2 O 7 : C, 55.66; H, 8.30; N, 7.21.; Found: C, 55.93; H, 8.01; N, 7.26; 1 H NMR (300 MHz, CDCl 3 ) δ1.22-1.30 (m, 6H), 1.45 (s, 9H), 1.75-1.84 (m, 2H), 1.96-2.02 (m, 2H), 2.14-2.22 (m, 2H), 2.32-2.43 (m, 4H), 4.09-4.22 (m, 5H), 4.58-4.60 (m, 1H), 6.96 (d, J=7.4 Hz, 1H). C. To 0.21 g (0.60 mmol) of 4- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!benzoic acid in a three-necked round bottomed flask under an atmosphere of nitrogen were added 3.5 mL of anhydrous dimethylformamide and 0.14 mL (1.3 mmol) of 4-methylmorpholine. To this reaction mixture was then added 0.11 g (0.61 mmol) of 2-chloro-4,6-dimethoxy-1,3,5-triazine. The reaction was stirred at room temperature for 80 minutes and then 0.40 g (1.03 mmol) of diethyl N-(4-amino-4-tert.-butoxycarbonylbutanoyl)-D-glutamate was added in 1.0 mL of anhydrous dimethylformamide. After 3 hours, the reaction was concentrated in vacuo and the crude product was chromatographed on silica gel eluting with a gradient of 5-7 % CH 3 OH/CHCl 3 to yield 0.22 g (52%) of N-(N-{4- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!benzoyl}-L-γ-glutamyl)-D-glutamic acid 1 -tert.-butyl-2,2-diethyl ester as a white solid. Rf=0.15 (10% CH 3 OH/CHCl 3 ); m.p. 143°-146° C. (foam, dec.); Mass Spectrum (FAB+): M+1=685; IR (KBr, cm -1 l)=574, 773, 847, 1020, 1154, 1304, 1368, 1465, 1480, 1502, 1540, 1645, 1737, 2932, 2980, 3381; UV (C 2 H 5 OH) λ max =224, 280 (ε=27153, 12096); 1 H NMR (300 MHz, DMSO d6 ) δ1.14 (t, J=7.0 Hz, 6H), 1.38 (s, 9H), 1.49-1.55 (m, 3H), 1.75-1.84 (m, 2H), 1.87-1.93 (m, 2H), 1.94-1.98 (m, 1H), 2.21-2.34 (m, 4H), 2.68-2.75 (m, 3H), 3.15 (d, J=10.3 Hz, 1H), 3.97-4-07 (m, 4H), 5.89 (s, 2H), 6.23 (d, J=1.2 Hz, 1H), 7.29 (d, J=7.9 Hz), 7.77 (d, J=7.8 Hz, 2H), 8.25 (d, J=7.5 Hz, 1H), 8.52 (d, J=7.3 Hz, 1H), 9.65 (S, 1H). D. A solution of 0.12 g (0.18 mmol) of N-(N-{4- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!benzoyl}-L-γ-glutamyl)-D-glutamic acid 1-tert.-butyl-2,2-diethyl ester in 10 mL trifluoroacetic acid was stirred at room temperature overnight. The solution was concentrated in vacuo and the solid residue was then dissolved in 3.0 mL of 0.N NAOH and stirred at room temperature for 72 hours. The solution was acidified with 1.0N hydrochloric acid to pH=2-3, and the precipitate was filtered and dried in a vacuum oven at 60° C. to give 0.092 g (71%) of N-(N-{4- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!benzoyl}-L-γ-glutamyl)-D-glutamic acid as a tan solid; Mass Spectrum (FAB+): M+=573; IR (KBr, cm -1 )=550.75, 651, 749, 840, 1189, 1349, 1539, 1635, 1717, 2926, 3381; UV (C 2 H 5 OH) λ max =224 (ε=28760); 1 H NMR (300 MHz, DMSO d6 ) δ1.49-1.63 (m, 3H), 1.68-1.95 (m, 4H), 2.00-2.17 (m, 1H), 2.21-2.31 (m, 4H), 2.64-2.81 (m, 3H), 3.17-3.28 (m, 1H), 4.13-4.20 (m, 1H), 4.30-4.33 (m, 1H), 6.20-6.26 (m, 2H), 6.43 (d, J=1.6 Hz, 1H), 7.29 (d, J=7.9 Hz, 2H), 7.79 (d, J=7.9 Hz, 2H), 8.13 (d, J=7.5 Hz, 1H), 8.50 (d, J=7.1 Hz, 1H). EXAMPLE 4 N-(N-{5- 2-(2-Amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!thien-2-ylcarbonyl}-L-γ-glutamyl)-D-glutamic Acid A. To 0.15 g (0.43 mmol) of 5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!thien-2-ylcarboxylic acid in a three-necked round bottomed flask under an atmosphere of nitrogen were added 3.0 mL of anhydrous dimethylformamide and 0.12 mL (1.08 mmol) of 4-methylmorpholine followed by 0.085 g (0.48 mmol) of 2-chloro-4,6-dimethoxy-1,3,5-triazine. The reaction mixture was stirred at room temperature for 2.5 hours and 0.20 g (0.51 mmol) of diethyl N-(4-amino-4-tert.-butoxycarbonylbutanoyl)-D-glutamate was then added in 2.0 mL anhydrous dimethylformamide. The reaction mixture was stirred at room temperature for an 4 hours and concentrated in vacuo. The residue was chromatographed on silica gel eluting with 10% CH 3 OH/CHCl 3 to yield 0.050 g (15%) of N-(N-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!thien-2-ylcarbonyl) -L-γ-glutamyl}-D-glutamic acid 1-tert.-butyl-2,2-diethyl ester as a white solid. Rf=0.14 (10% CH 3 OH/CHCl 3 ) m.p.=160°-166° C. (foam, dec.); Mass Spectrum (FAB+): M+=691; IR (KBr, cm -1 )=641, 773, 810, 1024, 1153, 1219, 1304, 1369, 1462, 1545, 1632, 1737, 2932, 2980, 3371; UV (C 2 H 5 OH) λ max =222, 279 (ε=25604, 24847); Anal. Calcd. for C 32 H 46 N 6 O 9 S: C, 55.64; H, 6.71; N, 12.17; Found: C, 55.41; H, 6.69; N, 11.98; 1 H NMR (300 MHz, CDCl 3 ) δ 1.22-1.31 (m, 6H), 1.48 (s, 9H), 1.99-2.45 (m, 12H), 2.64-2.68 (m, 1H), 2.90-2.98 (m, 3H), 3.30-3.34 (m, 1H), 4.08-4.23 (m, 4H), 4.54-4.57 (m, 1H), 4.65-4.66 (m, 1H), 5.10-5.11 (m, 1H), 5.40-5.43 (m, 2H), 6.77 (d, J=3.0 Hz, 1H), 7.17-7.23 (m, 2H), 7.42 (s, 1H). B. A solution of 0.036 g (0.052 mmol) of N-(N-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3 -d!pyrimidin-6-yl)ethyl!thien-2-ylcarbonyl}-L-γ-glutamyl)-D-glutamic acid 1-tert.-butyl-2,2-diethyl ester in 1.5 mL of trifluoroacetic acid was stirred at room temperature overnight. The solution was concentrated in vacuo and the solid redissolved in 2.0 mL of 0.5N sodium hydroxide and this solution was stirred overnight and then acidified with 1.0N hydrochloric acid to pH 2-3. The precipitate was filtered, washed with water, and dried in vacuo to give 0.019 g (62%) of N-(N-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!thien-2-ylcarbonyl}-L-γ-glutamyl)-D-glutamic acid as an off-white solid. Exact Mass: Calcd. for 579.1873; Found 579.1829; IR (KBr, cm -1 ) 1250, 1351, 1459, 1546, 1646, 1710, 2927, 3347; UV (C 2 H 5 OH) λ max =222 (ε=18588); 1 HNMR (300 MHz, DMSO d6 ) δ1.54-2.17 (m, 8H), 2.18-2.29 (m, 4H), 2.73-2.86 (m, 3H), 3.14-3.22 (M,--1H), 4.15-4.19 (m, 1H), 4.25-4.30 (m, 1H), 5.95 (s, 2H), 6.27 (S, 1H), 6.88 (d, J=3.3 Hz, 1H), 7.67 (d, J=3.4 Hz, 1H), 8.15 (d, J=7.5 Hz, 1H), 8.54 (d, J=7.6 Hz, 1H). EXAMPLE 5 N-{5- 2-(2-Amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!thien-2-ylcarbonyl}glycine Ethyl Ester To 0.15 g (0.47 mmol) of 5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!-pyrimidin-6-yl)ethyl!thien-2-ylcarboxylic acid in a three-necked round bottomed flask under an atmosphere of nitrogen were added 3.0 mL of anhydrous dimethylformamide and 0.11 mL (0.99 mmol) of 4-methylmorpholine. To this was then added 0.84 g (0.48 mmol) of 2-chloro-4,6-dimethoxy-1,3,5-triazine. The reaction mixture was stirred at room temperature for 35 minutes and a solution of 0.072 g (0.51 mmol) of glycine ethyl ester hydrochloride in 1.0 mL of anhydrous dimethylformamide was added together with 0.65 mL (5.85 mmol) of 4-methylmorpholine. After 35 minutes, an additional 0.015 g (0.11 mmol) of glycine ethyl ester hydrochloride and 0.2 mL (1.80 mmol) of 4-methylmorpholine was added. The reaction was stirred for 3 hours and concentrated in vacua. The crude mixture then was chromatographed on silica gel eluting with a gradient of 2-12% CH 3 OH/CHCl 3 to give 0.072 g (38%) of N-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!thien-2-ylcarbonyl}glycine ethyl ester as a white solid. Rf=0.34 (20% CH 3 OH/CHCl 3 ) m.p.=152°-160° C. (foam, dec.) Mass Spectrum (FD+): M+=405; IR (CHCl 3 , cm -1 )=1046, 1196, 1304, 1464, 1602, 1745, 2363, 2977, 3025, 3619; UV (C 2 H 5 OH) λ max =222, 279 (ε=24333, 23816); 1 H NMR (300 MHz, DMSO d6 ) δ1.17 (t, J=6.5 Hz, 3H), 1.52-1.60 (m, 3H), 1.77-1.84 (m, 1H), 2.40-2.44 (m, 1H), 2.72-2.8(m, 3H), 3.14-3-24 (m, 1H), 3.91 (d, J=4.7 Hz, 2H), 4.05-4.12 (m, 2H), 6.24 (s, 2H), 6.89 (s, 1H, 7.57 (s, 1H), 8.80 (s, 1H), 9.66 (s, 1H). EXAMPLE 6 N-{5- 2-(2-Amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!thien-2-ylcarbonyl}glycine A solution of 0.052 g (0.13 mmol) of N-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethylthien-2-ylcarbonyl}glycine ethyl ester in 2.5 mL of 0.5N sodium hydroxide was stirred overnight at room temperature. The solution was acidified to pH 2-3 with 1.0N hydrochloric acid and the solid collected, washed with water, and dried in a vacuum oven to give 0.037 g of N-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)-ethyl!thien-2-ylcarbonyl}glycine as a white solid. Rf=0.12 (1:1 CH 3 OH/CHCl 3 ); Mass Spectrum (FAB+): M+=378; IR (KBr, cm -1 )=504, 549, 580, 657, 748, 815, 1019, 1215, 1238, 1354, 1399, 1489, 1542, 1638, 1719, 2928, 3243, 3378, 1 H NMR (300 MHz, DMSO d6 /TFA d4 ) δ1.54-1.69 (m, 3H), 1.84 1.92 (m, 1H), 2.42-2.51 (m, 1H), 2.78-2.89 (m, 3H), 3.31 (d, J=12.1 Hz, 1H), 3.84 (s, 2H), 6.87 (d, J=3.6 Hz, 1H), 7.57 (d, J=3.6 Hz, 1H). EXAMPLE 7 N-(N-{5- 2-(2-Amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!thien-2-ylcarbonyl}-γ-L-glutamyl)-D-glutamate tris-(tert.-Butyl) Ester To a reaction mixture of 0.16 g (0.46 mmol) of 5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!thien-2-ylcarboxylic acid in 4.0 mL of anhydrous dimethylformamide and 0.06 mL (0.55 mmol) of 4-methylmorpholine was added under a nitrogen atmosphere 0.091 g (0.52 mmol) 2-chloro-4,6-dimethoxyl,3,5-triazine. The reaction was stirred at room temperature for 40 minutes and 0.24 g (0.54 mmol) of N-(γ-L-glutamyl)-D-glutamate-tris-(tert.-butyl) ester in 2.0 mL of anhydrous dimethylformamide was added. The reaction mixture was stirred at room temperature overnight and then concentrated in vacuo. The crude residue was then chromatographed on silica gel eluting with a gradient of 2-10% CH 3 OH/CHCl 3 to give 0.088 g (23%) of N-(N-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3 -d!pyrimidin-6-yl)ethyl!thien-2-ylcarbonyl}-γ-L-glutamyl)-D-glutamate tris-(tert.-butyl) ester as a white solid; Rf=0.13 (10% CH 3 OH/CHCl 3 ); m.p. 151°-160° C. (foam, dec.); Mass Spectrum (FD+): M+1=748; IR (KBr, cm -1 )=843, 1047, 1154, 1305, 1369, 1394, 1463, 1482, 1509, 1544, 1602, 1642, 1726, 2933, 2982, 3007, 3332, 3414; UV (C 2 H 5 OH) λ max =222, 279 (ε=26778, 25396); 1 HNMR (300 MHz, CDCl 3 ) δ1.43 (s, 9H), 1.44 (s, 9H), 1.47 (s, 9H), 1.60-1.74 (m, 2H), 1.89-2.19 (m, 7H), 2.20-2.44; (m, 5H), 2.64-2.68 (m, 1H), 2.89-2.97 (m, 3H), 3.28-3.33 (m, 1H), 4.43-4.50 (m, 1H), 4.53-4.58 (m, 1H), 5.34-5.35 (m, 2H), 5.65-5.67 (m, 2H), 6.74 (d, j=2.3 Hz, 1H), 6.93 (q, J=7.8 Hz, 1H), 7.39-7.42 (m, 2H). EXAMPLE 8 N-{5- 2-(2-Amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)-ethyl!thien-2-ylcarbonyl!}-L-homocysteic Acid α-Methyl Ester A. To a solution of 0.99 g (5.4 mmol) of L-homocysteic acid in 45 mL of anhydrous methanol at 0° C. were added 9.0 mL of thionyl chloride. The mixture was stirred overnight J. Med. Chem., 27, 603 (1984)!. The resulting clear solution was then concentrated in vacuo to give 1 g (93%) of L-homocysteic acid α-methyl ester hydrochloride as a fine white solid. Mass Spectrum (FAB+): M+=233; IR (KBr, cm -1 ) =538, 608, 751, 780, 984, 1031, 1045, 1083, 1213, 1243, 1335, 1441, 1454, 1522, 1632, 1743, 2958, 3430; 1 H NMR (300 MHz, D20) δ2.28-2.41 (m, 2H), 3.02-3.09 (m, 2H), 3.82 (s, 3H), 4.30 (t, J=6.5 Hz, 1H). B. To a solution of 0.106 g (0.33 mmol) of 5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!thien-2-ylcarboxylic acid in 2.0 mL anhydrous dimethylformamide and 0.045 mL (0.41 mmol) of 4-methylmorpholine was added 0.058 g (0.33 mmol) of 2-chloro-4,6-dimethoxy-1,3,5-triazine. The reaction mixture was stirred for 30 minutes at room temperature and 0.084 g (0.36 mmol) of α-methyl ester L-homocysteic acid hydrochloride was added in 1.0 mL anhydrous dimethylformamide and 0.08 mL (0.72 mmol) of 4-methylmorpholine. The reaction mixture was stirred at room temperature for an additional 3 hours and then concentrated in vacuo. The residue was then purified on a Chromatotron® silica gel plate, eluting with a gradient of 100% EtOAc to 10% CH 3 OH/CHCl 3 to 75/25/1 (CHCl 3 /CH 3 OH/NH 4 OH) to give 0.044 g (27%) of N-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)-ethyl!thien-2-ylcarbonyl}-L-homocysteic acid α-methyl ester as an off-white solid. Rf=0.68 (50/50/2:CHCl 3 /CH 3 OH/NH 4 OH); m.p. 221°-226° C. (foam, dec.); Mass Spectrum (FD+): M+1=501; IR (CHCl 3 , cm -1 )=500, 528, 656, 748, 800, 1017, 1038, 1134, 1207, 1279, 1353, 1405, 1457, 1545, 1642, 1696, 3129; UV ((C 2 H 5 OH) λ max =222, 279 (ε=21585, 21991); 1 H NMR (300 MHz, DMSO d6 ) δ1.58-1.69 (m, 3H), 1.89-1.95 (m, 2H), 2.04-2.12 (m, 3H), 2.87-2.90 (m, 3H), 3.14 (s, 1H), 3.23-3.34 (m, 1H), 3.61 (s, 3H), 4.36-4.38 (m, 1H), 6.89 (d, J=1.7 Hz, 1H), 6.97 (s, 1H), 7.14 (s, 1H), 7.31 (s, 1H), 7.65 (d, J=2.7 Hz, 2H), 9.09 (d, J=6.2 Hz, 1H). EXAMPLE 9 N-{5- 2-(2-Amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2.3-d!pyrimidin-6-yl)-ethyl!thien-2-ylcarbonyl}-L-homocysteic Acid A solution of 0.022 g (0.066 mmol) of N-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)-ethyl!thien-2-ylcarbonyl}-L-homocysteic acid α-methyl ester in 0.6 mL of 0.5N sodium hydroxide was stirred at room temperature overnight. The solution was then acidified with 1.0N hydrochloric acid to pH 2-3, and the precipitate was filtered, washed with water, and dried in vacuo to give 0.018 g (84%) of N-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)-ethyl!thien-2-ylcarbonyl}-L-homocysteic acid as a tan solid; Exact Mass=Calcd. for 486.1117; Found 486.1103; IR (KBr, cm -1 )=544, 751, 1038, 1206, 1351, 1460, 1547, 1653, 1700, 2926, 3363; UV (0.1N NaOH) λ max =218 (ε=18619); 1 H NMR (300 MHz, DMSO d6 /TA d4 ) δ1.57-1.70 (m, 3H), 1.842.17 (m, 4H), 2.63-2.68 (m, 2H), 2.82-2.89 (m, 3H), 3.30 (d, J=13.3 Hz, 1H), 4.35 (dd, 1H, J=7.4, 4.84 Hz), 6.86 (d, J=3.3 Hz, 1H), 7.66 (d, J=3.5 Hz, 1H). EXAMPLE 10 N-{5- 2-(2-Amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)-ethyl!thien-2-ylcarbonyl}hydroxylamine To 10 mL of anhydrous methanol was added 0.33 g (14.4 mmol) of sodium metal and a solution of 0.050 g (0.72 mmol) of hydroxylamine hydrochloride in 7 mL of methanol was then added. The resulting reaction mixture was stirred for 15 minutes and 0.23 g (0.5 mmol) of methyl 5- 2-(2-pivaloylamino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!thien-2-ylcarboxylate was added under nitrogen. The reaction mixture was stirred for 30 minutes, 0.011 g (0.16 mmol) of hydroxylamine hydrochloride was added, and the reaction was stirred a total of 4.5 hours, and then filtered. The filtrate was then treated with diethyl ether and the solid collected and dried in vacuo to give 0.13 g (71%) of N-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!thien-2-ylcarbonyl}hydroxylamine as a tan colored solid. Rf=0.09 (10% CH 3 OH/CHCl 3 ); 1 H NMR (300 MHz, DMSO d6 /TFA d4 ) δ1.55-1.70 (m, 4H), 1.83; 1.91 (m, 1H), 2.82-2.87 (m, 4H), 3.29-3.33 (m, 1H), 6.82 (d, J=3.6 Hz, 1H), 7.43 (d, J=1.4 Hz, 1H); EXAMPLE 11 1,3-bis-(Tetrazol-5-yl)-1-{4- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3d!pyrimidin-6-yl)ethyl!benzoylamino}propane Diammonium Salt After flame drying a 15 mL two-neck round bottom flask under argon, 0.15 g (0.43 mmol) of 4- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!benzoic acid hydrochloride was suspended in 2 mL of anhydrous N,N-dimethylformamide, followed by the addition of 0.14 mL (1.28 mmol) of 4-methylmorpholine. After stirring the reaction mixture at room temperature for 15 minutes, 0.111 g (0.64 mmol) of 2-chloro-4,6-dimethoxy-1,3,5-triazine was added. The reaction was stirred at room temperature for 30 minutes, 0.125 g (0.624 mmol) of 1-amino-1,3-bis-(tetrazol-5-yl)propane was added, and the reaction mixture was stirred at room temperature for an additional 3 hours. The volatiles were removed in vacuo, and the residue was treated with 10 mL of water and the white solid collected by filtration, and dried in a vacuum oven at 60° C. The solid was loaded onto a 4 mm Chromatotron® silica gel plate and eluted with a gradient of 10% CH 3 OH/CHCl 3 to 70:25:5 CHCl 3 /CH 3 OH/NH 4 OH. The correct fractions were combined and concentrated in vacuo to give 0.090 g (40%) of 1,3-bis-(tetrazol-5-yl)-1-{4- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3d!pyrimidin-6-yl)ethyl!benzoylamino}propane diammonium salt as a white solid. Rf=0.11 (6:3.2:0.8) (CHCl 3 /CH 3 OHNH 4 OH); m.p. 226°-229° C. (foam); IR (KBr, cm -1 )=512, 774, 1109, 1345, 1459, 1538, 1634, 3401; UV (C 2 H 5 OH) λ max =279, 224, 204 (ε=12391, 28588, 35911) Exact Mass: Calcd=492.2332; Found=492.2306; 1 H NMR (300 MHz, DMSO d6 ) δ1.50-1.60 (m, 4H), 1.77-1.85 (m, 1H), 2.14-2.28 (m, 2H), 2.47-2.70 (m, 6H), 5.29-5.39 (m, 1H), 5.97 (s, 2H), 6.25 (S, 1H), 7.26 (d, J=8.1 Hz, 211), 7.81 (d, J=7.7 Hz, 2H), 8.66 (q, J=3.5 Hz, 1H). EXAMPLE 12 2-{4- 2-(2-Amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2.3-d!pyrimidin-6-yl)ethyl!benzoylamino}-3-(2H-tetrazol-5-yl)propanoic Acid Diammonium Salt After flame drying a 15 mL two-neck round bottom flask under argon, 0.20 g (0.57 mmol) of 4- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!benzoic acid hydrochloride was suspended in 2 mL of anhydrous N,N-dimethylformamide, followed by the addition of 0.19 mL (1.7 mmol) of 4-methylmorpholine. The reaction mixture was stirred at room temperature for 15 minutes, and 0.15 g (0.86 mmol) of 2-chloro-4,6-dimethoxy-1,3,5-triazine was added. The reaction mixture was stirred at room temperature for an additional 30 minutes and 0.135 g (0.86 mmol) of L-2-amino-3-(2H-tetrazol-5-yl)propanoic acid then was added. The reaction mixture was stirred at room temperature for 3 hours, the volatiles removed in vacuo, and the residue treated with 50 mL of water. The white solid was filtered and dried in a vacuum oven at 60° C. The crude solid was purified by rotary chromatography on a 2 mm Chromatotron® silica gel plate, and eluted with a gradient of 20% CH 3 OH/CHCl 3 to 60:30:10 CHCl 3 /CH 3 OH/NH 4 OH. The correct fractions were combined and concentrated in vacuo to give 0.12 g (43%) of 2-{4- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!benzoylamino}-3-3-(2H-tetrazol-5-yl)propanoic acid diammonium salt. Rf 0.21 (5:3.5:1.5) (CHCl 3 /CH 3 OH/NH 4 OH); m.p. 221°-222° C. (foam); IR (KBr, cm -1 )=817, 857, 951, 1106, 1159, 1308, 1402, 1463, 1548, 1615, 3162; UV (0.1N NaOH) λ max =273, 242, 216 (ε=8931, 13640, 22182); Exact Mass: Calcd=454.1951; Found=454.1950; 1 H NMR (300 MHz, DMSO d6 ) δ1.48-1.59 (m, 4H), 1.75-1.83 (m, 1H), 2.62-2.76 (m, 4H), 3.73 (quintet, J=6.1 Hz, 2H), 4.55-4-61 (m, 1H), 5.91 (s, 2H), 6.22 (s, 1H), 7.29 (d, J=8.0 Hz, 2H), 7.71 (d, J=7.9 Hz, 2H), 8.72 (d, J=7.3 Hz, 1H), 9.70 (br s, 1H). EXAMPLE 13 2-{5- 2-(2-Amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl ethyl!thien-2-ylcarbonylamino}-3-(2H-tetrazol-5-yl)propanoic Acid Diammonium Salt After flame drying a 15 mL two-neck round bottom flask under argon, 0.18 g (0.57 mmol) of 5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!-thien-2-ylcarboxylic acid was suspended in 2 mL of anhydrous N,N-dimethylformamide, followed by the addition of 0.19 mL (1.7 mmol) of 4-methylmorpholine. After allowing the reaction mixture to stir at room temperature for 15 minutes, 0.15 g (0.86 mmol) of 2-chloro-4,6-dimethoxyl,3,5-triazine was added. The reaction was stirred at room temperature for 30 minutes, 0.135 g (0.86 mmol) of amino-3-(2H-tetrazol-5-yl)propanoic acid was added, and the reaction mixture was stirred at room temperature for an additional 3 hours. The volatiles were removed in vacuo, and the residue was treated with 50 mL of water and the solid was filtered and dried in a vacuum oven at 60° C. The crude solid was purified using rotary chromatography on a 2 mm Chromatotron® silica gel plate, and eluted with a gradient of 20% CH 3 OH/CHCl 3 to 60:30:10 CHCl 3 /CH 3 OH/NH 4 OH. The correct fractions were combined and concentrated in vacuo to give 0.050 g (18%) of 2-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!-pyrimidin-6-yl)ethyl!thien-2-ylcarbonylamino}-3-(2H-tetrazol-5-yl)propanoic acid diammonium salt as a white solid. Rf 0.22 (5:3.5:1.5) (CHCl 3 /CH 3 OH/NH 4 OH); m.p. 228° C. (foam); IR (KBr, cm -1 )=553, 616, 746, 814, 1098, 1307, 1396, 1460, 1546, 1617, 3216; UV (0.1N NaOH) λ max =277, 217 (ε=19367, 19896); Exact Mass: Calcd=460.1515; Found=460.1508; 1 H NM (300 MHz, DMSO d6 ) δ1.52-1.64 (m, 3H), 1.76-1.84 (m, 1H), 2.51-2.88 (m, 3H), 3.07-3.23 (m, 4H), 4.45-4.51 (m, 1H), 5.92 (s, 2H), 6.23 (s, 1H), 6.86 (d, J=3.1 Hz, 1H), 7.50 (d, J=3.4 Hz, 1H), 8.56 (d, J=7.3 Hz, 1H); EXAMPLE 14 2-{4- 2-(2-Amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!benzoylamino}bicyclo 2.2.1!heptane-2-carboxylic Acid Ammonium Salt After flame drying a 15-mL two-neck round bottom flask under argon, 0.20 g (0.57 mmol) of 4- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!-benzoic acid hydrochloride was suspended in 2 mL of anhydrous N,N-dimethylformamide, followed by the addition of 0.19 mL (1.7 mmol) of 4-methylmorpholine. After stirring the reaction at room temperature for 15 minutes, 0.15 g (0.86 mmol) of 2-chloro-4,6-dimethoxy-1,3,5-triazine was added. The reaction was stirred at room temperature for 30 minutes and 0.134 g (0.86 mmol) of 2-aminonorbornane-2-carboxylic acid was added. The reaction mixture was stirred at room temperature for 3 hours. The volatiles were concentrated in vacuo, and the residue was treated with 50 mL of H20, and the white solid was filtered and dried in a vacuum oven at 60° C. The crude solid was purified using rotor chromatography on a 2 mm Chromatotron® silica gel plate, and eluted with a gradient of 20% CH 3 OH/CHCl 3 to 75:25:1 CHCl 3 /CH 3 OH/NH 4 OH. The correct fractions were combined and removed in vacuo to give 0.025 g (9%) of 2-{4- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!benzoylamino}bicyclo 2.2.!heptane-2-carboxylic acid ammonium salt as a white solid. Rf=0.30 (6/3.2/0.8) (CHCl 3 /CH 3 OH/NH 4 OH); m.p. 241° C. (foam); IR (KBr, cm -1 )=615, 647, 772, 1019, 1121, 1218, 1307, 1370, 1477, 1538, 1641, 2952, 3344; UV (0.1N NaOH) λ max =273, 241, 218 (ε=9839, 14408, 21458); Exact mass: Calcd=452.2298; Found=452.2338 5; 1 H NMR (300 MHz, DMSO d6 ) δ1.26-1.37 (m, 2H), 1.48-1.81 (m, 7H), 1.84-1.88 (m, 4H), 2.63-2.83 (m, 4H), 3.19-3.27 (m, 2H), 5.97 (s, 2H), 6.27 (S, 1H), 7.31 (d, J=8.1 Hz, 2H), 7.78 (d, J=7.9 Hz, 2H), 8.53 (s, 1H). EXAMPLE 15 Ammonium 1-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!thien-2-ylcarbonylamino}cyclohexane-1-carboxylate To a flame-dried three-neck 25 mL round bottom flask under nitrogen was added 0.2 g (0.62 mmol) of 5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethylthien-2-yl!carboxylic acid in 6 mL of anhydrous N-methylpyrrolidinone, followed by 0.20 mL (1.86 mmol) of 4-methylmorpholine and 0.25 g (0.93 mmol) of 25 phenyl N-phenylphosphoramidochloridate. The mixture was heated at 75° C. for 45 minutes, 0.133 g (0.93 mmol) of 1-amino-1-cyclohexanecarboxylic acid was added, and the reaction mixture was heated at 95° C. for 22 hours. The solvent was concentrated under vacuum (0.5 mm Hg at 70° C.) and the residue was triturated in 100 mL of water, filtered, washed with water, and dried in a vacuum oven at 60° C. The crude solid was loaded onto a 2 mm Chromatotron® silica gel plate, and eluted with a gradient of 20% CH 3 OH/CHCl 3 to 70/25/5 CHCl 3 /meOH/NH 4 OH. The correct fractions were combined and removed in vacuo to give 0.047 g (16%) of ammonium 1-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!thien-2-ylcarbonylamino}cyclohexane-1-carboxylate as a white solid. Rf 0.25 (6/3.2/0.8) (CHCl 3 /CH 3 OHONH 4 OH), m.p. 211° C. (foam); IR (KBr, cm -1 )=515, 545, 612, 747, 772, 1117, 1164, 1220, 1305, 1346, 1388, 1457, 1543, 1653, 1700, 2854, 2925, 3386; UV (0.1N NaOH) λ max =277, 216 (ε=20571, 22222); Exact Mass: Calcd=446.1862; Found=446.1881; 1 H NMR (300 MHz, DMSO d6 ) δ1.42-1.72 (m, 11H), 1.73-1.86 (m, 1H), 2.10-2.14 (m, 2H), 2.77-2.88 (m, 3H), 3.18-3.22 (m, 2H), 6.00 (s, 2H), 6.90 (d, j=3.4 Hz, 1H), 7.71 (d, 30 J=3.5 Hz, 1H), 8.04 (s, 1H). EXAMPLE 16 Ammonium 1-{5- 2-(2-Amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!thien-2-ylcarbonylamino }cyclopropane-1-carboxylate To a flame-dried three-neck 25 mL round bottom flask under nitrogen was added 0.2 g (0.62 mmol) of 5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethylthien-2-yl!carboxylic acid in 6 mL of anhydrous N-methylpyrrolidinone, followed by 0.20 mL (1.86 mmol) of 4-methylmorpholine and 0.25 g (0.93 mmol) of phenyl N-phenylphosphoramidochloridate. The mixture was heated at 75° C. for 45 minutes, 0.094 g (0.93 mmol) of 1-amino-1-cyclopropanecarboxylic acid was added, and the reaction mixture then heated to 95° C. for 22 hours. The solvent was removed under vacuum (0.5 mmHg at 70° C.), and the residue triturated in 100 mL of water, filtered, washed with water, and dried in a vacuum oven at 60° C. The solid was loaded onto a 2 mm Chromatotrong silica gel plate, and eluted with a gradient of 20% CH 3 OH/CHCl 3 to 70/25/5 CHCl 3 /CH 3 OH/NH 4 OH. The correct fractions were combined and concentrated in vacuo to give 0.047 g (16%) of ammonium 1-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!thien-2-ylcarbonylamino}cyclopropane-1-carboxylate as a white solid. Rf 0.18 (6/3.2/0.8) (CHCl 3 /CH 3 OH/NH 4 OH); m.p. 231° C. (foam); IR (KBr, cm -1 )=593, 747, 772, 812, 938, 1033, 1233, 1306, 1346, 1399, 1460, 1544, 1621, 2923, 3332; UV (0.1N NaOH) ) λ max =277, 216 (ε=2103 6, 23197); Exact Mass: Calcd=404.1393; Found=404.1429 1 H NMR (300 MHz, DMSO d6 ) δ1.00 (s, 2H), 1.31 (s, 2H), 1.56-1.68 (m, 3H), 1.80-1.88 (m, 1H), 2.76-2.93 (m, 4H), 6.06 (br s, 2H), 6.27 (s, 1H), 6.88 (d, j=3.4 Hz, 1H), 7.58 (d, J=3.4 Hz, 1H), 8.79 (s, 1H). EXAMPLE 17 1-{5- 2-2-Amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pymidin-6-yl)ethyl!thien-2-ylcarbonylamino}cyclopentane-1-carboxylic Acid To a flame-dried three-neck 50 mL round bottom flask under nitrogen was added 0.2 g (0.62 mnmol) of 5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethylthien-2-yl!carboxylic acid in 6 mL of anhydrous N-methylpyrrolidinone, 0.20 mL (1.86 mmol) of 4-methylmorpholine and 0.25 g (0.93 mmol) of phenyl N-phenylphosphoramidochloridate. The mixture was heated at 75° C. for 45 minutes, 0.12 g (0.93 mmol) of 1-amino-1-cyclopentanecarboxylic acid, was added, and the reaction mixture heated at 95° C. for 22 hours. The mixture was concentrated under vacuum (0.5 mm Hg at 70° C.), and this residue was triturated in 100 mL of water, filtered, washed with water, and dried in a vacuum oven at 60° C. The solid was loaded onto a 2 mm Chromatotron® silica gel plate, and eluted with a gradient of 20% CH 3 OH/CHCl 3 to 70/25/5 CHCl 3 /CH 3 OH/ H 4 OH. The correct fractions were combined and concentrated in vacuo to give a white solid which was further purified by loading the sample onto an anion exchange column and eluted with 3N acetic acid to give 0.015 g (6%) of 1-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!thien-2-ylcarbonylamino}cyclopentane-1-carboxylic acid as a white solid. Rf=0.29 (6/3.2/0-8) (CHCl 3 /CH 3 OH/NH 4 OH) m.p. 229° C. (foam); IR (KBr, cm -1 )=545, 613, 759, 1121, 1220, 1264, 1309, 1346, 1392, 1457, 1522, 1544, 1637, 1696, 2930, 3379; UV (0.1N NaOH) λ max =277, 216 (ε=17094, 19845); Exact Mass: Calcd=432.1706; Found=432.1726; 1 H NMR (300 MHz, DMSO d6 ) δ1.42-1.60 (m, 6H), 1.63-2-00 (m, 7H), 2.33-2.46 (m, 1H), 2.68-2.88 (m, 3H), 5.89 (s, 2H), 6.23 (S, 1H), 6.84 (d, J=3.0 Hz, 1H), 7,58 (d, J=3.2 Hz, 1H), 8.35 (s, 1H), 9.87 (br s, 1H). EXAMPLE 18 Methyl 1-{5- 2-(2-Amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!thien-2-ylcarbonyl}pyrrolidine-3-carboxylate A. A solution of 4.29 g (48.9 mmol) of 3-hydroxypyrrolidine in 30 mL of 2N potassium hydroxide was cooled to 0° C. and 10.2 mL of benzyl chloroformate were added with stirring. The reaction was stirred for four hours at 0° C. and then extracted with ethyl acetate (3×100 mL). The extracts were combined, washed with brine, dried over sodium sulfate, filtered, and concentrated in vacua. The residue was chromatographed on silica gel with 70/30 hexanes/ethyl acetate. The correct fractions were combined and concentrated in vacuo to give 8.87 g (81%) of benzyl 3-hydroxypyrrolidine-1-carboxylate as a viscous clear oil. Rf=0.11 in 50/50 hexanes/ethyl acetate Mass Spectrum (FD+): M+221; IR (CHCl 3 , cm -1 ): 913, 977, 993, 1100, 1117, 1175, 1236, 1360, 1427, 1454, 1498, 1694, 2884, 2954, 3013, 3020, 3436 (broad), 3610; UV (C 2 H 5 OH) λ max =205 (ε=9112), 264 (ε=142); 1 H NMR (300 MHz, CDC 13 ) δ: 1.91-2.05 (m-, 2H); 3.00 (broad s, 1H); 3.39-3.61 (m, 4H); 4.41 (s, 1H); 5.12 (s, 2H); 7.30-7.43 (m, 5H). B. Twelve grams (54.2 mmol) of benzyl 3-hydroxypyrrolidine-1-carboxylate were dissolved in 150 mL of pyridine. This solution was cooled to 0° C. in an ice/water bath and 23.66 g (124.5 mmol) of p-toluenesulfonyl acid chloride were added at once. The reaction was allowed to stand at refrigerator temperatures for 18 hours and then acidified with 5N hydrochloric acid to pH<2. This residue was extracted with ethyl acetate (4×200 mL). The extracts were combined, washed with brine, dried over sodium sulfate, filtered, and concentrated in vacua. The residue was chromatographed on silica gel with 50% ethyl acetate/hexane and the product eluted to give 13.4 g (66%) of benzyl 3-p-methylbenzene-sulfonyloxy)pyrrolidine-1-carboxylate as an orange oil. Rf=0.49 (1/1 hexanes/ethyl acetate); Mass Spectrum (FD+): M+=375; IR (CHCl 3 , cm -1 ): 815, 837, 899, 953, 1020, 1050, 1086, 1115, 1175, 1307, 1359, 1425, 1452, 1497, 1600, 1699, 2897, 3692; UV (C 2 H 5 OH) λ max =226 (ε=11821), 263 (ε=725), 274 (ε=439); Anal. Calcd. for C 19 H 21 N 1 O 5 S: C,60.78; H,5.64; N,3.73; S, 8.54. Found: C, 60.57; H, 5.69; N, 3.52; S, 8.56; 1 H NMR (300 MHz,CDCl 3 ) δ1.96-2.13 (m, 2H); 2.42 (s, 3H); 3.43-3.62 (m, 4H); 5.05 (s, 1H); 5.10 (s, 2H); 7.33 (s, 7H); 7.77 (d, j=7.9 Hz, 2H). C. To a solution of 13.4 g (35.7 mmol) of benzyl 3-(p-methylbenzenesulfonyloxy)pyrrolidine-1-carboxylate in 49 mL of DMSO were added 2.58 g (50.6 mmol) of finely powdered sodium cyanide. The reaction mixture was heated at 80° C. for 3.5 hours and then cooled to room temperature. The crude was diluted with 100 mL of brine and extracted with diethyl ether (5×250 mL). The extracts were combined, washed with brine, dried over sodium sulfate, filtered and concentrated in vacuo. The residue was chromatographed on silica gel with 60% ethyl acetate/hexanes to give 6.8 g (83%) of benzyl 3-cyanopyrrolidine-1-carboxylate as a clear oil. Rf=0.46 in 100% ethyl acetate; Mass Spectrum (FD+): M+=230; IR (CHCl 3 , cm -1 ): 882, 912, 986, 1030, 1119, 1169, 1292, 1347, 1362, 1424, 1451, 1468, 1486, 1498, 1702, 2891, 2962, 3021; UV (C 2 H 5 OH) λ max =206 (ε=9299), 258 (ε=214); Anal. Calcd. for C 13 H 14 N 2 O 2 : C,67.81; H,6.13; N,12.17; Found: C, 67.58; H. 6.26; N, 12.43; 1 H NMR (300 MHz, CDC 13 ) δ2.25-2.31 (m, 2H); 3.11 (t, J=6.5 Hz, 1H); 3.48-3.75 (m, 3H); 5.15 (s, 2H); 7.37 (s, 5H). D. A solution of 5.3 g of benzyl 3-cyanopyrrolidine-1-carboxylate in 53 mL of anhydrous CH 3 OH saturated with HCl was stirred at room temperature for 36 hours and then quenched with the addition of 14.85 g of sodium bicarbonate. The reaction mixture was allowed to stand at refrigerator temperatures overnight and then concentrated in vacuo. The residue was triturated with THF and the salts removed by filtration. The solution was again concentrated in vacuo and chromatographed on silica gel (9/1 hexanes/ethyl acetate) to yield 4.36 g (72%) of benzyl 3-carbomethoxypyrrolidine-1-carboxylate as a clear oil. Rf=0.54 in 100% ethyl acetate; Mass Spectrum (FD+): M+1=263; IR (CHCl 3 , cm -1 ): 880, 1029, 1091, 1122, 1175, 1275, 1343, 1361, 1426, 1452, 1498, 1696, 1735, 2890, 2956, 3013, 3019, 3025; UV (C 2 H 5 OH): λ max =205 (ε=9796), 259 (ε=191); 1 H NMR (300 MHz,CDCl 3 ) δ2.04-2.10 (m, 2H); 2.99-3.02 (m, 1H); 3.36-3.47 (m, 1H); 3.51-3.67 (m, 6H); 5.08 (s, 2H); 7.22-7.31 (m, 5H). E. To a solution of 4.6 g of benzyl 3-carbomethoxypyrrolidine-1-carboxylate in 150 mL of anhydrous methanol was added 0.92 g of 10% Pd/C. The reaction mixture was placed under an atmosphere of hydrogen and stirred overnight at room temperature. The reaction mixture was then filtered through a Celite® pad, and the filtrate concentrated in vacuo. The residue was chromatographed on silica gel with 2-16% CH 3 OH/CHCl 3 to give 1.40 g (62% yield) of 3-carbomethoxypyrrolidine as a clear oil, 1 H NMR (300 MHz, CDCl 3 ) δ1.90-2.10 (m, 2 H); 2.97-3.11 (m, 4H); 3.18-3.29 (m, 2H); 3.44 (s, 3H). F. To a sample of 150 mg (0.47 mmol) of 5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!thien-2-ylcarboxylic acid in a three-necked round bottomed flask under an atmosphere of nitrogen were added 3.6 mL anhydrous dimethylformamide and 0.11 mL (0.99 mmol) of N-methylmorpholine. The reaction mixture was stirred and 90 mg (0.51 mmol) of 2-chloro-4,6-dimethoxy-1,3,5-triazine were added at once. The reaction mixture was stirred at room temperature for 0.5 hours and 162 mg (1.25 mmol) of 3-carbomethoxypyrrolidine were added in 1.0 mL of dimethylformamide. After stirring at room temperature for another 3.5 hours, the reaction was concentrated in vacuo and the residue was chromatographed on silica gel with 2-8% CH 3 OH/CHCl 3 to give 78 mg (40%) of methyl 1-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!thien-2-ylcarbonyl}pyrrolidine-3-carboxylate as a white solid. Mass Spectrum (FAB+): M+1=432; IR (KBr, cm -1 ): 643, 734, 768, 809, 1219, 1336, 1417, 1464, 1601, 1684, 1736, 2854, 2924, 3390; UV (C 2 H 5 OH): λ max =222 (ε=21034), 279 (ε=19777). EXAMPLE 19 trans-Dimethyl 1-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!-pyrimidin-6-yl)-ethyl!thien-2-ylcarbonyl}pyrrolidine-2,4-dicarboxylate To a sample of 225 mg (0.70 mmol) of 5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!thien-2-ylcarboxylic acid in a three-necked round bottomed flask under an atmosphere of nitrogen were added 3.5 mL anhydrous dimethylformamide and 0.08 mL (0.72 mmol) of N-methylmorpholine. The reaction mixture was stirred at room temperature and 135 mg (0.77 mmol) 2-chloro-4,6-dimethoxy-1,3,5-triazine were added at once. The reaction was stirred for 0.5 hours at room temperature, and 213 mg (1.14 mmol) of trans-dimethyl pyrrolidine-2,4-dicarboxylate were added in 1.0 mL of dimethylformamide. After stirring at room temperature for another 3.5 hours, the reaction was concentrated in vacuo and chromatographed on silica gel with 2-8% CH 3 OH/CHCl 3 to give 185 mg (54%) of trans-dimethyl 1-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)-ethyl!thien-2-ylcarbonyl}pyrrolidine-2,4-dicarboxylate as a tan solid. Mass Spectrum (FAB+): M+1=490; 1 H NMR (300 MHz, DMSO) δ: 1.54-1.64 (m, 3H); 1.76-1.84 (m, 1H); 2.11-2.29 (m, 3H); 2.36-2.43 (m,--1H); 2.72-2.79 (m, 1H); 2.86-2.88 (m, 2H); 3.07-3.23 (m, 2H); 3.61 (s, 6H); 3.95-4.08 (m, 2H); 4.49-4.54 (M, 1H); 5.92 (s, 2H); 6.24 (d, J=1.6 Hz, 1H); 6.91-6.92 (m, 1H); 7.48 (d, J=2.4 Hz, 1H). EXAMPLE 20 N-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)-ethyl!thien-2-ylsulfonyl}glycine To 1.065 g (4.1 mmol) of 2-bromothiophene-5-sulfonyl chloride, 1.1 mL of triethylamine, and a catalytic amount of dimethylaminopyridine in 10 mL of methylene chloride at room temperature was added 0.57 g (4.1 mmol) of ethyl glycinate hydrochloride. The resulting reaction mixture was then stirred at room temperature for 6 hours, diluted with water, and extracted with methylene chloride. The extracts were washed with brine, dried over sodium sulfate and concentrated in vacuo to 1.19 g of N-(5-bromothien-2-ylsulfonyl)glycine ethyl ester as a tan solid. 1 H NMR (300 MHz, DMSO d6 ) δ: 1.13 (t, 3H), 3.75 (d, J=5 Hz, 2H), 4.01 (q, 2H), 7.31 (d, J=4 Hz, 1H), 7.42 (d, J=4 Hz, 1H), 8.58 (t, J=5 Hz, IH). A mixture of 436 mg (1.27 mmol) of 2-pivaloylamino-4-hydroxy-6-ethynylpyrido 2,3-d!pyrimidine, 415 mg of N-(5-bromothien-2-ylsulfonyl)glycine ethyl ester, 20 mg of palladium chloride, 54 mg of triphenylphosphine, 10 mg of cuprous iodide, and 0.4 mL of triethylamine in 7 mL of acetonitrile was heated to reflux under nitrogen for 1 hour. The resulting reaction mixture was then concentrated in vacuo and the residue flash chromatographed with 4% CH 3 OH/chloroform to give 610 mg of N- 5-(2-pivaloylamino-4-hydroxypyrido 2,3-d!pyrimidin-6-ylethynyl)thien-2-ylsulfonyl!glycine ethyl ester as a tan solid. 1 H NMR (300 MHz, DMSO- d6 ) δ1.13 (t, J=7 Hz, 3H), 1.25, (s, 9H), 3.79 (d, J=5.8 Hz, 2H), 3.99 (q, J=7 Hz, 2H), 7.48 (d, J=3.6 Hz, 1H), 7.56 (d, J=3.6 Hz, 1H), 8.51 (s, 1H), 8.65 (t, J=5.8 Hz, 1H), 8.99 (s, 1H). To a mixture of 150 mg of N- 5-(2-pivaloylamino-4-hydroxypyrido 2,3-d!pyrimidin-6-ylethynyl)thien-2-ylsulfonyl!glycine ethyl ester in 25 mL of glacial acetic acid was added 100 mg of platinum oxide. This mixture was stirred under hydrogen for 24 hours and an additional 100 mg of platinum oxide was added. The hydrogenation was resumed for another 24 hours and the reaction mixture was then filtered through Celite® and the filtrate concentrated in vacuo. The residue was flash chromatographed on silica gel using 3.5% CH 3 OH and chloroform to give 48 mg of N-{5- 2-(2-pivaloylamino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)-ethyl!thien-2-ylsulfonyl}glycine ethyl ester as a white solid. 1 H NMR (300 MHz, DMSO- d6 , δ1.10 (t, J=7 Hz, 3H), 1.17 (s, 9H), 1.62 (m, 3H), 1.90 (m, 1H), 2.52 (m, 1H), 2.91 (m, 3H), 3.25 (m, 1H), 3.68 (d, J=4.9 Hz, 2H), 3.97 (q, J=7 Hz, 2H), 6.45 (s, 1H), 6.92 (d, J=3.5 Hz, 1H, 7.38 (d, J=3.5 Hz, 1H), 8.31 (t, J=4.9 Hz, 1H). A solution of 33 mg (0.062 mmol) of N-{5- 2-(2-pivaloylamino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)-ethyl!thien-2-ylsulfonyl}glycine ethyl ester in 3.0 mL of 1.0N sodium hydroxide was stirred at room temperature for 24 hours. The reaction mixture was then acidified with 1.0N hydrochloric acid and the white precipitate was collected by filtration to give 28 mg of N-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)-ethyl!thien-2-ylsulfonyl}glycine. EXAMPLE 21 Hard gelatin capsules containing a compound of Formula I ("active ingredient") are prepared using the following ingredients: ______________________________________Quantity (mg/capsule)______________________________________Starch, dried 200Magnesium stearate 10Active ingredient 250Total 460______________________________________ EXAMPLE 22 A tablet containing a compound of Formula I is prepared using the ingredients below: ______________________________________Quantity (mg/capsule)______________________________________Active ingredient 250Cellulose, microcrystalline 400Silicon dioxide, fumed 10Stearic acid 5Total 665______________________________________ The components are blended and compressed to form tablets each weighing 665 mg. EXAMPLE 23 An aerosol solution containing a compound of Formula I is prepared containing the following components: ______________________________________ Percent______________________________________Active ingredient 0.25Ethanol 25.75Propellant (Chlorodifluoromethane) 74.00Total 100.00______________________________________ The active compound is mixed with ethanol and the mixture added to a portion of the propellant 22, cooled to -30° C. and transferred to a filling device. The required amount is then fed to a stainless steel container and diluted with the remainder of the propellant. The valve units are then fitted to the container. EXAMPLE 24 Tablets, each containing 60 mg of a compound of Formula I, are prepared as follows: ______________________________________ Quantity (mg/tablet)______________________________________Active ingredient 60Starch 45microcrystalline cellulose 35Polyvinylpyrrolidone 4(as 10% solution in water)Sodium carboxymethyl starch 4.5Magnesium stearate 0.5Talc 1Total 150______________________________________ The active ingredient, starch and cellulose are passed through a No. 45 mesh U.S. sieve and mixed thoroughly. The aqueous solution containing polyvinylpyrrolidone is mixed with the resultant powder, and the mixture then is passed through a No. 14 mesh U.S. sieve. The granules so produced are dried at 50° C. and passed through a No. 18 mesh U.S. sieve. The sodium carboxymethyl starch, magnesium stearate and talc, previously passed through a No. 60 mesh U.S. sieve, then are added to the granules which, after mixing, are compressed on a tablet machine to yield tablets each weighing 150 mg. EXAMPLE 25 Capsules, each containing 80 mg of a compound of Formula I, are made as follows: ______________________________________ Quantity (mg/capsule)______________________________________Active ingredient 80Starch 59microcrystalline celluose 59Magnesium stearate 2Total 200______________________________________ The active ingredient, cellulose, starch, and magnesium stearate are blended, passed through a No. 45 mesh U.S. sieve, and filled into hard gelatin capsules in 200 mg quantities. EXAMPLE 26 Suppositories, each containing 225 mg of a compound of Formula I, are made as follows: ______________________________________ Quantity (mg/unit)______________________________________Active ingredient 225Saturated fatty acid glycerides 2,000Total 2,225______________________________________ The active ingredient is passed through a No. 60 mesh U.S. sieve and suspended in the saturated fatty acid glycerides previously melted using the minimum heat necessary. The mixture is then poured into a suppository mold of nominal 2 g capacity and allowed to cool. EXAMPLE 27 Suspensions, each containing 50 mg of a compound of Formula I per 5 mL dose, are made as follows: ______________________________________ Quantity______________________________________Active ingredient 50 mgSodium carboxymethyl cellulose 50 mgSyrup 1.25 mLBenzoic acid solution 0.10 mLFlavor q.v.Color q.v.Purified water to total 5 mL______________________________________ The active ingredient is passed through a No. 45 mesh U.S. sieve and mixed with the sodium carboxymethyl cellulose and syrup to form a smooth paste. The benzoic acid solution, flavor and color are diluted with a portion of the water and added, with stirring. Sufficient water is then added to produce the required volume. EXAMPLE 28 An intravenous formulation containing a compound of Formula I can be prepared as follows: ______________________________________ Quantity______________________________________Active ingredient 100 mgIsotonic saline 1000 mL______________________________________ EXAMPLE 29 N-(N-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3 -d!pyrimidin-6-yl)ethyl!thien-2-ylcarbonyl}-L-γ-glutamyl)-D-aspartic acid was evaluated against 6C3HED lymphosarcoma tumor in C3H female mice with the compound given daily, IV bolus injection, for 8 days. Compounds were administered in units of mg/kg of body weight. At the end of treatment, tumor weight was estimated using an electronic caliper interfaced to a microcomputer, and average tumor weight was calculated for each dosing level and a control group. Percentage inhibition of tumor growth was calculated as % inhibition of tumor growth according to the expression: 1-(average tumor weight experimental group/average tumor weight control group)!×100. Percentage inhibition was not calculated at a particular dosing level if mortality exceeded 20%. Cumulative dose was calculated by multiplying the daily dose by the number of days doses were administered. N-(N-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!thien-2-ylcarbonyl}-L-γ-glutamyl)-D-aspartic acid showed 100% inhibition at both 200 and 100 mg/kg. EXAMPLE 30 The Ki inhibition constant (nanomoles) against human monofunctional GARFT for N-(N-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)-ethyl!thien-2-ylcarbonyl}-L-γ-glutamyl)-D-aspartic acid is 0.244 nM; for N-(N-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!thien-2-ylcarbonyl}-L-γ-glutamyl)-D-glutamic acid 1-tert.-butyl-2,2-diethyl ester the Ki is 7.7 nM; for N-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)-ethyl!thien-2-ylcarbonyl}-L-homocysteic acid α-methyl ester, the Ki is 3.5 nM; and for 2-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!thien-2-ylcarbonylamino}-3-(2H-tetrazol-5-yl)propanoic acid diammonium salt the Ki is 155.8 nM See: Henderson, Biochem, J., 127: 321-333, (1972) for linear equation of steady-state kinetics of enzymes and subcellular particles interacting with tightly bound inhibitors!. EXAMPLE 31 Folate binding protein derived from human KB cells See Habeck, Cancer Research, 54: 1021-1026, (1994)! for N-(N-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido- 2,3-d!pyrimidin-6-yl)-ethyl!thien-2-ylcarbonyl}-L-γ-glutamyl)-D-aspartic acid is 0.387 and for N-(N-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!thien-2-ylcarbonyl}-L-γ-glutamyl)-D-glutamic acid 1-tert.-butyl-2,2-diethyl ester it is 2.238. EXAMPLE 32 The IC 50 , that is the concentration inhibiting cell growth of a CCRF-CEM cell line by 50% as compared to control measured in micrograms, for N-(N-{4- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!benzoyl}-L-γ-glutamyl)-D-aspartic acid is 1.6 μg/mL. For N-(N-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)-ethyl!thien-2-ylcarbonyl}-L-γ-glutamyl)-D-aspartic acid, the IC 50 is 0.100 μg/mL. For N-(N-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!thien-2-ylcarbonyl}-L-γ-glutamyl)-D-glutamic acid 1-tert.-butyl-2,2-diethyl ester, the IC 50 is 1.0 μg/mL. For N-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)-ethyl!thien-2-ylcarbonyl}-L-homocysteic acid α-methyl ester, the IC 50 is 0.200 μg/mL. For N-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)-ethyl!thien-2-ylcarbonyl}-L-homocysteic acid, the IC 50 is 0.82 μg/mL. For 2-{4- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!benzoylamino}-3-(2H-tetrazol-5-yl)propanoic acid diammonium salt, the IC 50 is 28.6 μg/mL. For 2-{5- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!thien-2-ylcarbonylamino}-3-(2H-tetrazol-5-yl)propanoic acid diammonium salt the IC 50 is >100 μg/mL.

2-Amino-4-hydroxy-4,5,6,7-tetrahydropyrido 2,3-d!pyrimidine derivatives of aromatic amides, such as a benzamide or thienylcarboxamide in which the amino portion of the amide is other than L-glutamic acid are inhibitors of enzymes which utilize folic acid, in particular glycinamide ribonucleotide formyl transferase. A typical embodiment is N-(N-{4- 2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d!pyrimidin-6-yl)ethyl!benzoyl}-L-γ-glutamyl)-D-aspartic acid.

TECHNICAL FIELD [0001] The present application relates to intake systems including a vacuum aspirator, for generating vacuum for use in a brake booster, for example. BACKGROUND AND SUMMARY [0002] Spark-ignited vehicles may use intake manifold vacuum to provide brake boost or power assist. Engine downsizing reduces the ability of these engines to provide brake booster vacuum. One existing solution is to add a vacuum pump, however the vacuum pump leads to parasitic fuel economy losses and increases overall vehicle cost. [0003] In one approach described in U.S. Pat. No. 7,610,140, a vehicle ejector system has an ejector, a state change device that causes the ejector to function or stop functioning, and a control device that controls the state change device (Summary). “Furthermore . . . the control device may include a control prohibition portion that prohibits the control device from controlling the state change device so as to cause the ejector to function if water temperature of a cooling water of the internal combustion engine is less than or equal to a predetermined temperature” (col. 4 ll. 8-13). [0004] The inventors herein recognize various issues with the above described approaches. During cold start, engine conditions (such as high manifold air pressure and low barometric pressure due to low temperature and/or high altitude) may limit the available vacuum for various engine systems, such as the brake booster. In downsized engines including a supercharger and/or turbocharger, boosting may further reduce the conditions under which brake vacuum is available. Further, as a range of cylinder pressures increase, so does a range of intake passage pressures increase. Intake systems including a single fixed geometry aspirator may function inefficiently or not at all at some pressures of the increased pressure range. [0005] Consequently, methods, systems and devices for a vacuum aspirator included in an intake system are described. In a first example, an intake system includes an intake passage including a compressor, a throttle and an intake manifold, and an aspirator having a motive inlet communicating with the intake passage intermediate to the compressor and the throttle and the aspirator having an entraining inlet communicating with a vacuum reservoir via a first check valve, the reservoir different from the intake manifold, and the first check valve limiting flow from the intake passage to the vacuum reservoir. [0006] In a second example, an intake system includes, a throttle, the throttle including a first inlet, a second inlet, and a plate, the plate located intermediate the first inlet and the outlet, the second inlet located intermediate to the throttle plate and the first inlet, the throttle positioned in an intake passage, and an aspirator having a motive inlet in communication with the intake passage, the aspirator having an outlet in communication with the second inlet of the throttle, the aspirator having an entraining inlet in communication with a vacuum reservoir via a first check valve, the first check valve limiting flow from the second inlet to the vacuum reservoir. [0007] In a third example, an intake system having a plurality of vacuum boosters for a vacuum reservoir, includes a first aspirator having a first motive inlet, first entraining inlet, and first outlet, the first motive inlet in communication with an intake passage adjacent a high pressure outlet of a compressor, and a second aspirator having a second motive inlet, second entraining inlet, second outlet, and second check valve, where either the second outlet is in communication with the first entraining inlet or the second motive inlet is in communication with the first outlet, and the second entraining inlet in communication with a vacuum reservoir via the second check valve, the second check valve limiting from the second entraining inlet to the vacuum reservoir. [0008] One advantage of the above examples is that excess compressor pressure and flow is used to generate vacuum. In this way, downsized engines including a turbocharger or supercharger may generate vacuum, even during cold start. Further, an example throttle including a first inlet and a second inlet may control flow through an example aspirator, as well as flow to an example manifold not from the aspirator, simplifying an intake system configuration. In examples including a plurality of aspirators one of the plurality may be configured for high flow and another may be configured for low flow, increasing an intake system's efficiency at generating vacuum over a wide pressure range. [0009] It will be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description, which follows. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined by the claims that follow the detailed description. Further, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure. BRIEF DESCRIPTION OF THE DRAWINGS [0010] FIG. 1 shows a first example intake system for an engine. [0011] FIG. 2 shows a first example aspirator. [0012] FIG. 3 shows a second example aspirator. [0013] FIGS. 4-7 show further example intake systems for an engine. [0014] FIGS. 8 and 9 show a first example passive control valve. [0015] FIG. 10 shows a sixth example intake system for an engine. [0016] FIGS. 11 and 12 show a first example throttle included in an intake system, and in communication with an aspirator. [0017] FIGS. 13-18 show example multi-aspirator intake systems. [0018] FIG. 19 shows a first example of an intake system including an aspirator integrated with additional engine systems. [0019] FIG. 20 shows a second example of an intake system including an aspirator integrated with additional engine systems. DETAILED DESCRIPTION [0020] A first example intake system for an engine is described, with respect to FIG. 1 , to introduce possible devices, arrangements and configurations of an intake system including an aspirator. Example aspirators are discussed in more detail with respect to FIGS. 2 and 3 . Additional example intake systems are described with respect to FIGS. 4-7 and 10 . FIGS. 8 and 9 show an example passive control valve included in some example intake systems. An example throttle included in example intake systems is discussed with respect to FIG. 10-12 . Finally, multi-aspirator intake systems are described with respect to FIGS. 13-18 . Integration of example intake systems with additional engine systems, such as fuel vapor purge and positive crankcase ventilation systems, is discussed with respect to FIGS. 19 and 20 . [0021] FIG. 1 shows a first example intake system 10 for an engine 12 . In the present example, engine 12 is a spark-ignition engine of a vehicle, the engine including a plurality of cylinders 14 , each cylinder including a piston. Combustion events in each cylinder 14 drive the pistons which in turn rotate crankshaft 16 , as is well known to those of skill in the art. Further, engine 12 may include a plurality of engine valves, the valves coupled to the cylinders 14 and controlling the intake and exhaust of gases in the plurality of cylinders 14 . [0022] In the present example, intake system 10 includes an intake passage 18 and an aspirator 20 . The intake passage 18 includes throttle 22 and an intake manifold 24 . Manifold 24 provides air to engine 12 . Air may enter intake passage 18 from an air intake system (AIS) including an air filter in communication with the vehicle's environment, for example. Further, throttle 22 is located intermediate to the intake manifold 24 and a compressor 25 , the throttle 22 limiting the air entering intake manifold 24 . [0023] In the present example, intake passage 18 also includes compressor 25 and intercooler 26 . Compressor 25 may be coupled to a turbine in an exhaust of engine 12 . Further compressor 25 may be, at least in part, driven by an electric motor or crankshaft 16 . Compressor 25 further includes a bypass passage 28 and compressor bypass valve (CBV) 30 . CBV 30 may be used to control a level of air pressure in a portion of intake passage 18 between compressor 25 and engine 12 , and in this way regulate a boost level, control for surge, etc. [0024] As briefly described above, intake system 10 includes aspirator 20 . Aspirator 20 may be an ejector, injector, eductor, venturi, jet pump, or similar passive device. Aspirator 20 has a motive flow entering inlet 32 . Motive inlet 32 communicates with the intake passage 18 intermediate the compressor 25 and the throttle 22 at a high pressure outlet 34 of the compressor 25 . In further examples, motive inlet 32 may communicate with additional high air pressure inputs. In the present example, and the aspirator having an entraining inlet 36 communicating with a vacuum reservoir 38 via a first check valve 40 . High pressure air at the motive inlet 32 may be converted to flow energy in the aspirator 20 , thereby creating a low pressure communicated to entraining inlet 36 and drawing air through entraining inlet 36 . The first check valve 40 allows vacuum reservoir 38 to retain any of its vacuum should the pressures in 36 and 38 equalize. Further, aspirator 20 includes an outlet 44 , in communication with the intake manifold. In the present example, the aspirator is the three port device including 32 , 44 , and 36 . However, in further examples, check valves 40 and 42 are integrated into the device, and it will be appreciated that the device at 20 retains its name, “aspirator.” [0025] Further still, it should be appreciated that a flow path from 38 through 42 and continuing to 24 is designed carefully to not be flow restrictive. In this way vacuum may be recovered, should vacuum reservoir 38 ever be depleted. [0026] Additionally, vacuum reservoir 38 is always different from the intake manifold 24 . Vacuum reservoir 38 is a portion of, or device in, an engine system that utilizes vacuum. For example, vacuum reservoir 38 may be a vacuum cavity behind a diaphragm in a brake booster or a low pressure storage tank included in a fuel vapor purge system. [0027] In the present example, intake system 10 further includes an optional auxiliary check valve 42 . Auxiliary check valve 42 is in communication with the vacuum reservoir 38 and in communication with an outlet 44 of the aspirator. Further, the auxiliary check valve 42 limits flow from the outlet 11 , to the vacuum reservoir 38 . In this way, the auxiliary check valve 42 allows the vacuum reservoir 38 to retain its vacuum in the case where intake manifold 24 pressure rises above vacuum reservoir 38 pressure. Auxiliary check valve 42 limits communication from intake manifold 24 to vacuum reservoir 38 , as well. Auxiliary check valve 42 is shown integrated into the aspirator 20 , however in additional examples, auxiliary check valve 42 is separate from the aspirator 20 . [0028] Additionally, intake system 10 may include a control system 46 including a controller 48 , sensors 50 and actuators 52 . Example sensors include engine speed sensor 54 , engine coolant temperature sensor 56 , a mass air flow sensor 58 , and manifold air pressure sensor 60 . Example actuators include engine valves, CBV 30 , and throttle 22 . Controller 48 may further include a physical memory with instructions, programs and/or code for operating the engine. [0029] A plurality of arrows 62 illustrate example flowpaths by which intake air may pass through the intake system 10 . Air flows into intake passage 18 and reaches a low pressure compressor inlet 33 . Aspirator 20 communicates with intake passage 18 at 34 , and a passage at 34 may include profile or diameter which determines a rate at which air flows into the motive inlet 32 . In this way, a pressure difference between the compressor outlet 34 and the intake manifold 24 may be used to generate vacuum in the vacuum reservoir. Consequently, in downsized engines including a turbocharger or supercharger even during cold start, vacuum may be generated, regardless of an intake manifold pressure and without inclusion of a vacuum pump. For example, even when little manifold vacuum is present, sufficient vacuum may still be generated by harvesting the pressure difference compressor pressure and intake manifold pressure. [0030] Turning now to FIG. 2 , a first example aspirator 200 is shown. Aspirator 200 is a venturi-type in the present example. In the present example, motive air is received at inlet 202 . Motive inlet 202 receives high pressure air, for example from a compressor outlet. Gas flowing out of aspirator 200 leaves via outlet 204 at a lower pressure, and continues, for example, to an intake manifold and/or a low pressure compressor inlet. A profile (e.g., a cross-sectional area) of the aspirator 200 tapers from the motive inlet 202 to an entraining inlet 206 , and then expands from the entraining inlet 206 to the outlet 204 . As a result, a high velocity, and a low pressure may be induced at the entraining inlet 206 , thus drawing air through the entraining inlet 206 from an example vacuum reservoir in communication with the aspirator, (e.g., via passage 208 ). A first check valve 210 limits reverse flow from the entraining opening to the vacuum reservoir. In this way, gases are removed from the vacuum reservoir but may be prevented from entering via the entraining inlet 206 . [0031] Further, aspirator 200 may include an auxiliary check valve 212 (shown in dashed lines to indicate its optional inclusion). In the present example, auxiliary check valve 212 limits flow from the outlet 204 to the example vacuum reservoir, the reservoir in communication with check valve 212 via passage 208 . In this way, when the outlet 204 has a low pressure, for example when it's in communication with an example intake manifold, auxiliary check valve 212 acts to increase vacuum in the example vacuum reservoir by facilitating the flow of gas to the outlet 204 . [0032] Further, the venturi-type aspirator 200 , may produce vacuum at 206 from flow going from 202 to 204 and from flow going from 204 to 206 . In some examples, aspirator symmetry allows for vacuum production in either flow direction. One advantage is that when the venturi is connected between an example intake manifold and an example intake passage a pressure difference between the intake manifold and intake passage pulls in air or vents air out, regardless of direction and produces vacuum in an example vacuum reservoir. [0033] Turning now to FIG. 3 , a second example aspirator 300 is shown. Aspirator 300 is an ejector-type passive valve in the present example. In the present example, motive air flow is received at an inlet 302 . Motive inlet 302 receives high pressure air from, for example, a compressor outlet. Gas flowing out of aspirator 300 leaves via outlet 304 at a low pressure, and continues, for example, to an intake manifold and/or a low pressure compressor inlet. [0034] Aspirator 300 includes a motive nozzle, 312 . A profile (e.g., a cross-sectional area) of the motive inlet narrows along the length of the nozzle 312 , to a tip 314 of motive nozzle. As a result, a high velocity, and a low pressure may be induced at the nozzle tip 314 , thus drawing air through an entraining inlet 306 from an example vacuum reservoir in communication with the aspirator, (e.g., via passage 308 ). Further, the aspirator may include a profile that converges from the nozzle tip 314 and entraining inlet 306 to a throat 316 and then diverges from throat 316 to the outlet 304 . In one example, the throat 316 has a low pressure, and high velocity gas, further drawing air through the entraining inlet 306 . [0035] In the present example, aspirator 300 includes a first check valve 310 and auxiliary check valve 318 . However, both first check valve 310 and auxiliary check valve 318 are shown in dashed lines in FIG. 3 to indicate their optional nature. In further examples of aspirator 300 , motive flow may come in through the inlet at 306 and entrained flow may come in passage 302 . Thus in the present example, the motive flow can either be on the inner core flow as shown explained above, or the motive flow can on the outer annular flow as is known to those of skill in the art. [0036] Turning now to FIG. 4 , a second example intake system 410 for an example engine 412 is shown. Intake system 410 , includes example intake passage 418 , further including example compressor 425 , intercooler 426 , throttle 422 , and intake manifold 424 . Compressor 425 includes a high pressure outlet 434 , a bypass 428 and CBV 430 , and a low pressure inlet 433 , as described above with reference to FIG. 1 . Additionally intake system 410 includes example control system 446 . [0037] Further, intake system 410 includes aspirator 420 , which itself includes example motive inlet 432 , entraining inlet 436 , outlet 444 , first check valve 440 and auxiliary check valve 442 . As described above, aspirator motive inlet 432 is in communication with intake passage 418 at compressor outlet 434 . Entraining inlet 436 is coupled to an example vacuum reservoir 438 . Further, outlet 444 is in communication with manifold 424 , as well as auxiliary check valve 442 . [0038] In the present example a solenoid valve 450 is included in intake system 410 . Solenoid valve may be a continuously variable valve, such as a butterfly valve. Solenoid valve 450 is coupled intermediate to the intake passage 418 and the motive inlet 432 of the aspirator 420 . Solenoid valve 450 may open and close in response to signals from controller 448 included in control system 446 . In a first mode, solenoid valve 450 may allow communication between intake passage 418 and aspirator 420 and in a second mode, solenoid valve may close and limit communication between intake passage 418 and aspirator 420 . In this way, solenoid valve 450 may ensure that a minimum vacuum threshold is maintained in manifold 424 . Further, the solenoid valve can be closed (partially or wholly) when the airflow is higher than desired and the intake manifold is already producing target vacuum levels. Solenoid valve 450 is one example of a valve that can control flow through aspirator 420 and also ensure that a minimum vacuum threshold is maintained in manifold 424 (further examples are discussed below). [0039] Turning now to FIG. 5 , a third example intake system 510 for an example engine 512 is shown. Intake system 510 includes example intake passage 518 , further including example compressor 525 , intercooler 526 , throttle 522 , and intake manifold 524 . Compressor 525 includes a high pressure outlet 534 , a bypass 528 and CBV 530 , and a low pressure inlet 533 , as described above with reference to FIG. 1 . Additionally intake system 510 includes example control system 546 . [0040] Further, intake system 510 includes aspirator 520 , which itself includes example motive inlet 532 , entraining inlet 536 , outlet 544 , first check valve 540 and auxiliary check valve 542 . As described above, aspirator motive inlet 532 is in communication with intake passage 518 adjacent compressor outlet 534 . Entraining inlet 536 is coupled to an example vacuum reservoir 538 . Further, outlet 544 is in communication with auxiliary check valve 542 . [0041] Additionally, in the present example, intake system 510 further includes a manifold check valve 550 intermediate the outlet 544 of the aspirator 520 and the manifold 524 . The manifold check valve 550 limits flow from the intake manifold 524 to the outlet 544 . Further, outlet 544 of the aspirator 520 is in communication with the intake passage of the compressor, adjacent low pressure compressor inlet 533 . Because low pressure compressor inlet 533 is the point at which compressor 525 receives air before that air travels further on in intake system 510 , inlet 533 is said to be upstream of compressor 525 . Intake system 510 further includes an intake check valve 552 intermediate to the outlet 544 of the aspirator 520 and the intake passage 518 . The intake check valve 552 limits flow from the intake passage to the outlet. In additional examples, intake system 510 may include only one of the manifold check valve 550 and intake check valve 552 . [0042] In the present example, the resistance of the check valves 550 and 552 may maintain a minimum vacuum threshold in manifold 524 . Further, the check valves may ensure that the outlet 544 is in communication with one of the intake passage 518 upstream of the compressor 525 or the manifold 524 , depending on which of these two locations has a lower pressure. The aspirator inlet 532 may be the highest pressure point in the system. In further examples, the placement of check valves 552 and 550 passively control pressure so that the aspirator outlet is the lowest pressure point in intake system 510 . Thus the aspirator may enjoy the benefit of using the greatest available air pressure difference to produce vacuum. [0043] Turning now to FIG. 6 , a fourth example intake system 610 for an example engine 612 is shown. Intake system 610 , includes example intake passage 618 , further including example compressor 625 , intercooler 626 , throttle 622 , and intake manifold 624 . Compressor 625 includes a high pressure outlet 634 , a bypass 628 and CBV 630 , and a low pressure inlet 633 , as described above with reference to FIG. 1 . Additionally intake system 610 includes example control system 646 . [0044] Further, intake system 610 includes aspirator 620 , which itself includes example motive inlet 632 , entraining inlet 636 , outlet 644 , and first check valve 640 . Entraining inlet 636 is coupled to an example vacuum reservoir 638 . As described above, aspirator motive inlet 632 is in communication with intake passage 618 at compressor outlet 634 . Further, outlet 644 is in communication with a low pressure compressor inlet 633 , upstream of compressor 625 in intake passage 618 . An auxiliary check valve limiting communication between outlet 644 and vacuum reservoir 638 is not shown included in intake system 610 . However, it will be understood that intake system 610 may further include such an example auxiliary check valve. [0045] Additionally, intake system 610 includes example manifold check valve 650 intermediate vacuum reservoir 638 and the manifold 624 . Manifold check valve 650 limits flow from the intake manifold 624 to the vacuum reservoir 638 in the present example. The resistance of manifold check valve 650 may maintain a minimum vacuum threshold in manifold 624 and/or in vacuum reservoir 638 . Further, by including manifold check valve 650 independent of aspirator 620 vacuum in vacuum reservoir 638 is maintained regardless of a pressure at either the compressor inlet 633 or outlet 634 . [0046] Turning now to FIG. 7 , a fifth example intake system 710 for an example engine 712 is shown. Intake system 710 , includes example intake passage 718 , further including example compressor 725 , intercooler 726 , throttle 722 , and intake manifold 724 . Compressor 725 includes a high pressure outlet 734 , a bypass 728 and CBV 730 , and a low pressure inlet 733 , as described above with reference to FIG. 1 . Additionally intake system 710 includes example control system 746 . [0047] Further, intake system 710 includes aspirator 720 , which itself includes example motive inlet 732 , entraining inlet 736 , outlet 744 , first check valve 740 and auxiliary check valve 742 . As described above, aspirator motive inlet 732 is in communication with intake passage 718 at compressor outlet 734 . Entraining inlet 736 is in communication with an example vacuum reservoir 738 . Further, outlet 744 is in communication with manifold 724 , as well as auxiliary check valve 742 . [0048] In the present example a passive control valve 750 is included in intake system 710 . Passive control valve 750 is intermediate the intake passage 718 and the motive inlet 732 of the aspirator 720 . Passive control 750 may be located anywhere along a flow conduit 721 between 734 and 724 . At high levels of intake manifold 724 vacuum, passive valve 750 can restrict or shut. In this case, the vacuum needed for vacuum reservoir 738 is provided mainly from intake manifold 724 . At low levels of intake manifold 724 vacuum, passive valve 750 can open resulting in copious flow through the ejector thus providing the vacuum required at vacuum reservoir 738 . [0049] Also, passive control valve 750 may increase or limit communication between intake passage 718 and aspirator 720 in response to a pressure difference between the intake passage 718 and aspirator 720 . Further, one example of passive control valve 750 (discussed below with respect to FIGS. 8 and 9 ) may include a first operating mode having a first flow rate, and a second operating mode having a second flow rate, the first flow rate greater than the second. [0050] An example device having a similar flow characteristic to 750 is a Positive Crankcase Ventilation valve (PCV valve). When vacuum is high, valve 750 restricts flow. When vacuum is low, valve 750 un-restricts flow. Further, valve 750 has a third mode; when a threshold pressure is present at valve 750 , it may shut. In this way valve 750 may vary flow restriction based on pressure differential. In a PCV valve, this is called the backfire mode. In additional configurations where valve 750 lies between 724 and 744 , valve 750 may take on the function of valve 742 , making valve 742 optional. [0051] In additional examples, passive control valve 750 is positioned intermediate to the aspirator 720 and at least one of intake manifold 724 or low pressure compressor input 733 . Further, passive control valve 750 may ensure that a minimum vacuum threshold is maintained in manifold 724 , and may have analogous to a two port pressure regulator. Passive control valve 750 is one example of a valve that can control flow through aspirator 720 and also ensure that a minimum vacuum threshold is maintained in manifold 724 . [0052] FIG. 8 shows an example passive control valve 800 in a first position, the first position being a closed position. The closed position shown in FIG. 8 is one example of a rest position. The rest position is one example of a backfire position where intake manifold pressure exceeds crankcase pressure and is the maximally flow restrictive position. Valve 800 includes a valve body 802 having a stem 804 . Stem 804 has a first profile 806 and a second profile 808 . Further, valve 800 includes a valve housing 810 that defines both a main opening 812 , a stem opening 814 , a first chamber 816 , and a second chamber 818 , the housing 810 sustainably containing valve body 802 . Valve housing further defines a second chamber 818 ; valve stem 804 penetrates through stem opening 814 into the second chamber 818 . Further, a valve head 822 included in valve body 802 is coupled to a spring 824 . [0053] In the present closed position a valve head 822 (included in valve body 802 and coupled to the stem 804 ) seals main opening 812 from first chamber 816 . Further, pressure in first chamber 816 may be greater than at opening 812 . In additional examples, spring 824 extends from valve head 816 to valve housing 810 adjacent stem opening 814 , and increases the force on valve head 822 against housing 810 . [0054] FIG. 9 shows the example passive control valve 800 in a second, open position. Spring 824 is during a compressed spring mode. FIG. 9 is illustrative and a spacing between coils of spring 824 may be less than a spacing shown in FIG. 8 . A force on valve head 822 from the pressure communicated via main opening 812 overcomes a force exerted on valve body 802 from spring 824 and second chamber 818 . An annular passage 820 between first chamber 816 and second chamber 818 is defined by one of the first profile 806 or the second profile 808 and stem opening 812 . Annular passage 820 includes a cross-sectional area that partially determines a rate of flow through the stem opening 812 and thus through valve 800 . [0055] The profile of the stem 804 defining annular passage 820 may change in response to the displacement of the valve body. In the present example, second profile 808 and stem opening 812 collectively define the annular passage 820 (e.g., the valve 800 controls for a second flow rate in a second operating mode). In the additional examples, first profile 806 and stem opening 812 collectively define the annular passage 820 (e.g., the valve 800 controls for a first flow rate in a first operating mode). As a pressure on valve head 814 increases, the force on spring 824 increases, changing the displacement of the valve body 802 . In this way a pressure difference between a second chamber and the first chamber may control flow through the valve 800 . Additional examples of valve 800 include additional profiles (e.g., a cone profile, or profile including a parabolic-shaped edge), to further control an example annular passage cross-sectional area in response to displacement of the valve body 802 . As illustrated, valve 800 depends on a gravitational orientation. Further examples do not have this orientation dependence. [0056] Turning now to FIG. 10 , a sixth example intake system 1010 for an example engine 1012 is shown. Intake system 1010 includes example intake passage 1018 , further including example compressor 1025 , intercooler 1026 , and intake manifold 1024 . Optional compressor 1025 includes a high pressure outlet 1034 , a bypass 1028 and CBV 1030 , and a low pressure inlet 1033 , as described above with reference to FIG. 1 . Additionally intake system 1010 includes example control system 1046 . [0057] Further, intake system 1010 includes aspirator 1020 , which itself includes example motive inlet 1032 , entraining inlet 1036 , outlet 1044 , and first check valve 1040 . As described above, aspirator motive inlet 1032 is in communication with intake passage 1018 at compressor outlet 1034 . However, in further examples of intake system 1010 , motive inlet 1032 may be in communication with intake passage 1018 at additional locations, such as at compressor inlet 1033 (as indicated by dashed line 1050 ). Entraining inlet 1036 is coupled to an example vacuum reservoir 1038 . Further, outlet 1044 is in communication with manifold 1024 . [0058] Further, intake system 1010 includes a throttle 1052 positioned in intake passage 1018 , the throttle 1052 including a first inlet 1054 , a second inlet 1056 , and a plate 1058 . Throttle 1052 is one example of a ported throttle. The plate 1058 is located intermediate the first inlet 1054 and an outlet 1060 , the second inlet 1056 located intermediate the throttle plate 1058 and the first inlet 1054 . The outlet 1044 of the aspirator 1020 is in communication with the second inlet 1056 of the throttle 1052 . When a throttle plate 1058 is rotated to a first angle, second inlet 1056 may be in fluid communication with outlet 1060 , while the throttle plate 1058 limits communication between the first inlet 1054 and the outlet 1060 . In this way, throttle 1052 may control flow through aspirator 1020 . Intake system 1010 includes example ported throttle 1052 so that flow through an example aspirator as well as flow to an example manifold not from the aspirator may be controlled by a single valve. In this way intake system 1010 has a simplifying configuration. Further, throttle 1052 is discussed in more detail below with respect to FIGS. 10 and 11 [0059] Further, intake system 1010 includes a second check valve 1042 (an example manifold check valve) coupled intermediate the vacuum reservoir 1038 and the manifold 1024 . The second check valve 1042 limits flow from the intake manifold 1024 to the vacuum reservoir 1038 . [0060] Turing now to FIGS. 11 and 12 , an example ported throttle 1110 positioned in an example intake passage 1100 , the throttle 1110 including a first inlet 1112 , a second inlet 1114 , an outlet 1116 , and a plate 1118 . As described above with respect to FIG. 10 , the plate 1118 is located intermediate the first inlet 1112 and outlet 1116 , the second inlet 1114 located intermediate the throttle plate 1118 and the first inlet 1112 . An example aspirator outlet is in communication with the second inlet 1114 . [0061] FIG. 11 shows throttle plate 1118 in a first, closed position. In the present example, throttle 1110 is a butterfly-type valve that may be rotated to control fluid communication of at least one of the first inlet 1112 and the second inlet 1114 with the outlet 1116 . During a warm idle air flow rate, the throttle is closed, as illustrated. In further examples the throttle plate 1118 may be near closed. In a closed or near closed position, the throttle plate 1118 limits communication between the second inlet 1114 and the outlet 1116 . In this way, throttle 1110 may reduce air flow through an example aspirator. Further, in the present example an example intake manifold may supply vacuum. [0062] FIG. 12 shows throttle plate 1118 in a second, substantially open position. When the throttle is substantially open (for example, during a cold start emission reduction (CSER) event) the throttle enables fluid communication between the second inlet 1114 and the outlet 1116 . In this way the throttle opens enough to expose second inlet 1114 to an example intake manifold vacuum, thus causing air flow through an example aspirator coupled to second inlet 1114 . [0063] Turning now to FIG. 13 , shows a first example of an intake system 1310 having a plurality of aspirators. Multi-aspirator intake system 1310 includes at least first example aspirator 1314 and second example aspirator 1316 and may be included as part of an intake in an example vehicle to provide air for an example engine. First and second aspirators ( 1312 and 1314 respectively) may be example ejectors, injectors, eductors, venturi valves, jet pumps, or similar passive valve to generate vacuum (as discussed above, for example with respect to FIGS. 2 and 3 . Further, first aspirator 1314 may be a different type of aspirator than second aspirator 1316 , and may have smaller or larger physical dimensions than second aspirator 1316 . In some examples, one of the first or second aspirator may be configured for high flow and the other of the two may be configured for low flow, thereby increasing an intake system's efficiency at generating vacuum over a wide pressure range. In this way, the aspirators 1314 and 1316 may be staged so that low pressure produced by one aspirator used by the other aspirator. By staging the aspirators in this way a deeper vacuum may be created than would otherwise be created with a single aspirator. [0064] First aspirator 1314 has a first motive inlet 1318 , first entraining inlet 1320 , and first outlet 1322 . The first motive inlet 1318 is in communication with an air pressure input 1334 . One example of air pressure input 1334 is a high pressure outlet of a compressor (as described above, with respect to FIGS. 1 , 4 - 7 , and 10 ). Additional examples of air pressure input 1334 include an intake passage, for example adjacent a low pressure compressor inlet. First aspirator may include first check valve 1324 and is shown in dashed lines to indicate its optional nature. First check valve 1324 is positioned intermediate first entraining inlet 1320 and an example vacuum reservoir 1342 . Furthermore, first check valve 1324 may limit communication from the first entraining inlet 1320 to vacuum reservoir 1342 . Additionally, first outlet 1322 is in communication with a low pressure output 1338 , examples of which include an intake manifold, and an intake passage (e.g., at a low pressure compressor input). [0065] Second aspirator 1314 has a second motive inlet 1326 , second entraining inlet 1328 , second outlet 1330 , and second check valve 1332 . In some examples, second motive inlet 1326 is in communication with input 1334 . In the present example, the second outlet 1330 is in communication with the first entraining inlet 1320 . In the present example entraining passage 1350 couples the second outlet 1330 and the first entraining inlet 1320 , and first check valve 1324 is coupled to the entraining passage 1350 . In further examples, the second motive inlet 1326 is in communication with the first outlet 1320 and the second outlet 1330 may be in communication with low pressure output 1338 (e.g., as described below with respect to FIG. 18 ). Further, the second entraining inlet 1328 is in communication with vacuum reservoir 1342 via second check valve 1332 . The second check valve 1332 limits communication from the second entraining inlet 1328 to the vacuum reservoir 1342 . [0066] Additionally, a third check valve 1344 is positioned intermediate the first outlet 1322 and the vacuum reservoir 1342 . The third check valve 1344 limits flow from the vacuum reservoir 1342 to the first outlet 1322 . In further examples of intake system 1310 include additional examples a solenoid valve is positioned intermediate the input 1334 and at least one of the first motive inlet 1318 and the second motive inlet 1326 . [0067] Turning now to FIG. 14 , a second example of an intake system 1410 having a plurality of aspirators is shown. Multi-aspirator intake system 1410 includes at least first aspirator 1414 and second aspirator 1416 . First aspirator 1414 may be a different type of aspirator than second aspirator 1416 , and may have smaller or larger physical dimensions than second aspirator 1416 . Further, first aspirator 1414 has a first motive inlet 1418 , first entraining inlet 1420 , and first outlet 1422 . The first motive inlet 1418 is in communication with an example air pressure input 1434 . Also, first aspirator may optionally include first check valve 1424 limiting communication from the first entraining inlet 1420 to vacuum reservoir 1442 . [0068] Additionally, first outlet 1422 is in communication with example intake manifold 1438 and intake passage 1440 (e.g., adjacent a low pressure compressor inlet). An outlet passage 1452 couples the first outlet 1422 to the intake manifold 1438 , the outlet passage 1452 coupling the first outlet 1422 to the intake passage 1440 as well. A manifold check valve 1446 is positioned in the outlet passage 1452 intermediate the first outlet 1422 and the intake manifold 1438 . The manifold check valve 1446 limits flow from the intake manifold 1438 to the first outlet 1422 . An intake check valve 1448 is positioned in the outlet passage intermediate the first outlet 1422 and the intake passage 1440 , the intake check valve limiting flow from the intake passage to the first outlet. [0069] Second aspirator 1416 has a second motive inlet 1426 , second entraining inlet 1428 , second outlet 1430 , and second check valve 1432 . In some examples, second motive inlet 1426 is in communication with input 1434 . In the present example, the second outlet 1430 is in communication with the first entraining inlet 1420 via an entraining passage 1450 . First check valve 1424 is coupled to the entraining passage 1450 . The second entraining inlet 1428 is in communication with vacuum reservoir 1442 via second check valve 1432 which limits communication from the second entraining inlet 1428 to the vacuum reservoir 1442 . Additionally, a third check valve 1444 is optionally positioned intermediate the first outlet 1422 and the vacuum reservoir 1442 . The third check valve 1444 limits flow from the vacuum reservoir 1442 to the first outlet 1422 . [0070] FIG. 15 shows a third example of an intake system 1510 having a plurality of aspirators. Multi-aspirator intake system 1510 includes at least first aspirator 1514 and second aspirator 1516 . Furthermore, intake system 1510 includes intake passage 1540 , which itself includes an example compressor 1560 , intercooler 1562 and throttle 1564 . [0071] First aspirator 1514 may be a different type of aspirator than second aspirator 1516 , and may have smaller or larger physical dimensions than second aspirator 1516 . Further, first aspirator 1514 has a first motive inlet 1518 , first entraining inlet 1520 , first outlet 1522 , and first check valve 1524 . The first motive inlet 1518 is in communication with a high pressure compressor outlet 1534 , which is a first air pressure input. First check valve 1524 limits communication from the first entraining inlet 1520 to vacuum reservoir 1542 . Additionally, first outlet 1522 is in communication with example intake manifold 1538 . Further examples of intake system 1510 include the first outlet 1522 in communication with intake passage 1540 , e.g., adjacent a low pressure compressor inlet. [0072] Second aspirator 1516 has a second motive inlet 1526 , second entraining inlet 1528 , second outlet 1530 , and second check valve 1532 . In the present example, motive inlet 1526 is in communication with intake passage 1548 adjacent low pressure compressor inlet 1536 . Further, an entraining passage 1550 couples the second outlet 1530 and the first entraining inlet 1520 , thereby placing them in fluid communication. First check valve 1524 is coupled to the entraining passage 1550 . Further, the second entraining inlet 1528 is in communication with vacuum reservoir 1542 via second check valve 1532 which limits communication from the second entraining inlet 1528 to the vacuum reservoir 1542 . Additionally, third check valve 1544 is positioned intermediate the first outlet 1522 and the vacuum reservoir 1542 . The third check valve 1544 limits flow from the vacuum reservoir 1542 to the first outlet 1522 . [0073] FIG. 16 shows a fourth example of an intake system 1610 having a plurality of aspirators. Multi-aspirator intake system 1610 includes at least first aspirator 1614 and second aspirator 1616 . First aspirator 1614 may be a different type of aspirator than second aspirator 1616 , and may have smaller or larger physical dimensions than second aspirator 1616 . Further, first aspirator 1614 has a first motive inlet 1618 , first entraining inlet 1620 , and first outlet 1622 . The first motive inlet 1618 is in communication with an example air pressure input 1634 , which includes a compressor outlet pressure (COP) and/or a throttle inlet pressure (TIP). Also, first aspirator may optionally include first check valve 1624 limiting communication from the first entraining inlet 1620 to vacuum reservoir 1642 . [0074] Additionally, first outlet 1622 is in communication with example intake passage 1640 (e.g., adjacent a low pressure compressor inlet). Intake passage 1640 includes a barometric pressure (BP). In additional examples an intake check valve 1648 is positioned intermediate the first outlet 1622 and the intake passage 1640 (for example adjacent a low pressure inlet) the intake check valve limiting flow from the intake passage to the first outlet. [0075] Second aspirator 1616 has a second motive inlet 1626 , second entraining inlet 1628 , second outlet 1630 , and second check valve 1632 . In some examples, second motive inlet 1626 is in communication with input 1634 . In the present example, the second outlet 1630 is in communication with the first entraining inlet 1620 via an entraining passage 1650 . The second entraining inlet 1628 is in communication with vacuum reservoir 1642 via second check valve 1632 . The second check valve 1632 limits communication from the second entraining inlet 1628 to the vacuum reservoir 1642 . [0076] In the present example a first check valve 1624 is positioned in the entraining passage 1650 intermediate the second outlet 1630 and the first entraining inlet 1620 . The first check valve 1624 limits flow from the first entraining inlet 1620 to the second outlet 1630 . Further, an outlet passage 1652 is coupled the entraining passage 1650 intermediate the second outlet 1630 and the first check valve 1624 . The outlet passage 1652 is also coupled to intake manifold 1638 , the manifold 1638 including an intake manifold pressure (MAP) and a manifold check valve 1648 limits flow from the intake manifold 1638 to the entraining passage 1650 . [0077] In the present example, a fuel vapor purge system 1660 is coupled to the entraining passage 1650 intermediate the second outlet 1630 and the outlet passage 1652 . Air passing through aspirator 1614 may draw air through entraining inlet 1620 . In this way, aspirator 1614 is may be used to assist in fuel vapor purge. In further examples of intake system 1610 , a PCV system is coupled to the entraining passage 1650 intermediate the second outlet 1630 and the outlet passage 1652 . [0078] FIG. 17 shows a fifth example intake system 1710 having a plurality of aspirators. Multi-aspirator intake system 1710 includes at least first aspirator 1714 and second aspirator 1716 . First aspirator 1714 may be a different type of aspirator than second aspirator 1716 , and may have smaller or larger physical dimensions than second aspirator 1716 . Further, first aspirator 1714 has a first motive inlet 1718 , first entraining inlet 1720 , and first outlet 1722 . The first motive inlet 1718 is in communication with an example air pressure input 1734 . Also, first aspirator may optionally include first check valve 1724 limiting communication from the first entraining inlet 1720 to vacuum reservoir 1742 . [0079] Additionally, first outlet 1722 is in communication with intake manifold 1738 . Throttle 1760 is one example of a ported throttle, discussed above (with respect to FIG. 10 ). Throttle 1760 is positioned in intake passage 1740 and includes a first inlet 1762 , a second inlet 1764 , outlet 1766 and a plate 1768 . The outlet 1722 of the aspirator 1714 is in communication with the second inlet 1764 of the throttle 1760 . Throttle 1760 controls the pressure communicated to first outlet 1722 . In one example, when throttle plate 1768 is rotated to a first angle, second inlet 1764 may be in communication with outlet 1766 , while the throttle plate 1768 limits communication between the first inlet 1762 and the outlet 1766 . [0080] Second aspirator 1716 has a second motive inlet 1726 , second entraining inlet 1728 , second outlet 1730 , and second check valve 1732 . In the present example, the second outlet 1730 is in communication with the first entraining inlet 1720 . In the present example entraining passage 1750 couples the second outlet 1730 and the first entraining inlet 1720 , and first check valve 1724 is coupled to the entraining passage 1750 . In further examples, the second motive inlet 1726 is in communication with the first outlet and the second outlet 1730 may be in communication with intake passage 1740 , e.g., adjacent an example low pressure output. Further, the second entraining inlet 1728 is in communication with vacuum reservoir 1742 via second check valve 1732 . The second check valve 1732 limits communication from the second entraining inlet 1728 to the vacuum reservoir 1742 . [0081] Additionally, a third check valve 1744 is positioned intermediate the first outlet 1722 and the vacuum reservoir 1742 . The third check valve 1744 limits flow from the vacuum reservoir 1742 to the first outlet 1722 . [0082] FIG. 18 shows a sixth example intake system 1810 having a plurality of aspirators. Multi-aspirator intake system 1810 includes at least first aspirator 1814 and second aspirator 1816 . First aspirator 1814 may be a different type of aspirator than second aspirator 1816 , and may have smaller or larger physical dimensions than second aspirator 1816 . Further, first aspirator 1814 has a first motive inlet 1818 , first entraining inlet 1820 , and first outlet 1822 . The first motive inlet 1818 is in communication with a high pressure compressor outlet 1834 , which includes a COP and/or a TIP. Also, first aspirator includes first check valve 1824 limiting communication from the first entraining inlet 1820 to vacuum reservoir 1842 . [0083] Second aspirator 1816 has a second motive inlet 1826 , second entraining inlet 1828 , second outlet 1830 , and second check valve 1832 . In the present example, the first outlet 1822 is in communication with second motive inlet 1826 . First outlet 1822 and second motive inlet 1826 are in communication with intake passage 1840 adjacent an example low pressure inlet of a compressor and includes a BP. Further, the second entraining inlet 1828 is in communication with vacuum reservoir 1842 via second check valve 1832 . The second check valve 1832 limits communication from the second entraining inlet 1828 to the vacuum reservoir 1842 . Second outlet 1830 is in communication with an intake manifold 1838 which includes a MAP. A manifold check valve 1846 is positioned intermediate the second outlet 1830 and intake manifold 1838 to limit flow from the intake manifold 1838 to the second outlet 1830 . Additionally, a third check valve 1844 is intermediate the second outlet 1830 and vacuum reservoir 1842 , the third check valve 1844 limiting flow from the second outlet 1830 to the vacuum reservoir 1842 . [0084] In this configuration, any flow between BP to MAP through an aspirator contributes to actuator vacuum. Any flow from COP or TIP to BP contributes to actuator vacuum. Either of these flow paths may be controlled by solenoid valves, passive valves, or ported throttles. [0085] Turning now to FIG. 19 a first example of an intake system 1910 , including an aspirator 1920 integrated with additional engine systems is shown. Intake system 1910 includes an example manifold 1924 in communication with an example engine 1912 . Intake system 1910 further includes example intake passage 1918 including throttle 1922 . Intake air, such as from an example AIS or intercooler comes from input 1926 . As discussed above, throttle 1922 may limit the air entering intake manifold 1924 . [0086] In the present example, fuel vapor purge system 1950 is in communication with manifold 1924 via fuel vapor purge valve 1952 . Further, PCV system 1954 is in communication with manifold 1924 . Intermediate PCV system 1954 and manifold 1924 is an example passive control valve 1956 , valve 1956 limiting communication from manifold 1924 to PCV system 1954 . [0087] PCV system 1954 is also in communication with aspirator 1920 . Aspirator 1920 includes example motive inlet 1932 , entraining inlet 1936 , outlet 1944 , first check valve 1940 and auxiliary check valve 1942 . Entraining inlet 1936 is in communication with an example vacuum reservoir 1938 . Further, outlet 1944 is in communication with manifold 1924 , as well as auxiliary check valve 1942 . [0088] In the present example, aspirator 1920 is positioned intermediate passive control valve 1956 and manifold 1924 . Crankcase gases vented to manifold 1924 pass through aspirator motive inlet 1932 , drawing air from entraining inlet 1936 , and leaving via outlet 1944 . In this way, air and crankcase gases may be used to generate vacuum during crankcase ventilation. [0089] FIG. 20 shows a second example intake system 2010 including an aspirator 2020 integrated with additional engine systems. Intake system 2010 includes an example manifold 2024 in communication with an example engine 2012 . Intake system 2010 further includes example intake passage 2018 including throttle 2022 . Intake air, such as from an example AIS or an example compressor and example intercooler comes from input 2026 . As discussed above, throttle 2022 may limit the air entering intake manifold 2024 . [0090] In the present example, fuel vapor purge system 2050 is in communication with manifold 2024 via fuel vapor purge valve 2052 . Further, PCV system 2054 is in communication with manifold 2024 . Intermediate PCV system 2054 and manifold 2024 is an example passive control valve 2056 , valve 2056 limiting communication from manifold 2024 to PCV system 2054 . [0091] Further, fuel vapor purge system 2050 is in communication with aspirator 2020 . Aspirator 2020 includes example motive inlet 2032 , entraining inlet 2036 , outlet 2044 , first check valve 2040 and auxiliary check valve 2042 . Entraining inlet 2036 is in communication with an example vacuum reservoir 2038 . Additionally, outlet 2044 is in communication with manifold 2024 , as well as auxiliary check valve 2042 . [0092] In the present example, aspirator 2020 is positioned intermediate fuel vapor purge valve 2052 and manifold 2024 . Purged fuel vapor, hydrocarbons and air vented to manifold 2024 pass through aspirator motive inlet 2032 , drawing air from entraining inlet 2036 , and leaving via outlet 2044 . In this way, fuel vapor and hydrocarbon gases may be used to generate vacuum during fuel vapor purge. In further examples, including additional flowpaths, passageways and/or check valves, vacuum can be generated from both PCV flow and purge flow. [0093] Finally, it will be understood that the articles, systems and methods described herein are exemplary in nature, and that these specific embodiments or examples are not to be considered in a limiting sense, because numerous variations are contemplated. Accordingly, the present disclosure includes all novel and non-obvious combinations and sub-combinations of the various systems and methods disclosed herein, as well as any and all equivalents thereof.

In some examples, reduced engine displacement reduces an engine's ability to provide brake booster vacuum. The present application relates to intake systems including a vacuum aspirator to generate vacuum.

FIELD OF THE INVENTION [0001] The invention relates generally to improved semiconductor imaging devices and in particular to an imaging device which can be fabricated using a standard CMOS process. Particularly, the invention relates to a CMOS imager having a storage capacitor formed in parallel with a light sensitive node of the CMOS imager. BACKGROUND OF THE INVENTION [0002] There are a number of different types of semiconductor-based imagers, including charge coupled devices (CCDs), photodiode arrays, charge injection devices and hybrid focal plane arrays. CCDs are often employed for image acquisition and enjoy a number of advantages which makes it the incumbent technology, particularly for small size imaging applications. CCDs are also capable of large formats with small pixel size and they employ low noise charge domain processing techniques. However, CCD imagers also suffer from a number of disadvantages. For example, they are susceptible to radiation damage, they exhibit destructive read out over time, they require good light shielding to avoid image smear and they have a high power dissipation for large arrays. Additionally, while offering high performance, CCD arrays are difficult to integrate with CMOS processing in part due to a different processing technology and to their high capacitances, complicating the integration of on-chip drive and signal processing electronics with the CCD array. While there has been some attempts to integrate on-chip signal processing with the CCD array, these attempts have not been entirely successful. CCDs also must transfer an image by line charge transfers from pixel to pixel, requiring that the entire array be read out into a memory before individual pixels or groups of pixels can be accessed and processed. This takes time. CCDs may also suffer from incomplete charge transfer from pixel to pixel during charge transfer which also results in image smear. [0003] Because of the inherent limitations in CCD technology, there is an interest in CMOS imagers for possible use as low cost imaging devices. A fully compatible CMOS sensor technology enabling a higher level of integration of an image array with associated processing circuits would be beneficial to many digital applications such as, for example, in cameras, scanners, machine vision systems, vehicle navigation systems, video telephones, computer input devices, surveillance systems, auto focus systems, star trackers, motion detection systems, image stabilization systems and data compression systems for high-definition television. [0004] The advantages of CMOS imagers over CCD imagers are that CMOS imagers have a low voltage operation and low power consumption; CMOS imagers are compatible with integrated on-chip electronics (control logic and timing, image processing, and signal conditioning such as A/D conversion); CMOS imagers allow random access to the image data; and CMOS imagers have lower fabrication costs as compared with the conventional CCD since standard CMOS processing techniques can be used. Additionally, low power consumption is achieved for CMOS imagers because only one row of pixels at a time needs to be active during the readout and there is no charge transfer (and associated switching) from pixel to pixel during image acquisition. On-chip integration of electronics is particularly advantageous because of the potential to perform many signal conditioning functions in the digital domain (versus analog signal processing) as well as to achieve a reduction in system size and cost. [0005] A CMOS imager circuit includes a focal plane array of pixel cells, each one of the cells including either a photogate, photoconductor or a photodiode overlying a substrate for accumulating photo-generated charge in the underlying portion of the substrate. A readout circuit is connected to each pixel cell and includes at least an output field effect transistor formed in the substrate and a charge transfer section formed on the substrate adjacent the photogate, photoconductor or photodiode having a sensing node, typically a floating diffusion node, connected to the gate of an output transistor. The imager may include at least one electronic device such as a transistor for transferring charge from the underlying portion of the substrate to the floating diffusion node and one device, also typically a transistor, for resetting the node to a predetermined charge level prior to charge transference. [0006] In a CMOS imager, the active elements of a pixel cell perform the necessary functions of: (1) photon to charge conversion; (2) accumulation of image charge; (3) transfer of charge to the floating diffusion node accompanied by charge amplification; (4) resetting the floating diffusion node to a known state before the transfer of charge to it; (5) selection of a pixel for readout; and (6) output and amplification of a signal representing pixel charge. Photo charge may be amplified when it moves from the initial charge accumulation region to the floating diffusion node. The charge at the floating diffusion node is typically converted to a pixel output voltage by a source follower output transistor. The photosensitive element of a CMOS imager pixel is typically either a depleted p-n junction photodiode or a field induced depletion region beneath a photogate. For photodiodes, image tag can be eliminated by completely depleting the photodiode upon readout. [0007] CMOS imagers of the type discussed above are generally known as discussed, for example, in Nixon et al., “256×256 CMOS Active Pixel Sensor Camera-on-a-Chip,” IEEE Journal of Solid-State Circuits, Vol. 31(12) pp. 2046-2050, 1996; Mendis et al, “CMOS Active Pixel Image Sensors,” IEEE Transactions on Electron Devices, Vol. 41(3) pp. 452-453, 1994 as well as U.S. Pat. No. 5,708,263 and U.S. Pat. No. 5,471,515, which are herein incorporated by reference. [0008] To provide context for the invention, an exemplary CMOS imaging circuit is described below with reference to FIG. 1. The circuit described below, for example, includes a pliotogate for accumulating photo-generated charge in an underlying portion of the substrate. It should be understood that the CMOS imager may include a photodiode or other image to charge converting device, in lieu of a photogate, as the initial accumulator for photo-generated charge. [0009] Reference is now made to FIG. 1 which shows a simplified circuit for a pixel of an exemplary CMOS imager using a photogate and having a pixel photodetector circuit 14 and a readout circuit 60 . It should be understood that while FIG. 1 shows the circuitry for operation of a single pixel, that in practical use there will be an MxN array of pixels arranged in rows and columns with the pixels of the array accessed using row and column select circuitry, as described in more detail below. [0010] The photodetector circuit 14 is shown in part as a cross-sectional view of a semiconductor substrate 16 typically a p-type silicon, having a surface well of p-type material 20 . An optional layer 18 of p-type material may be used if desired, but is not required. Substrate 16 may be formed of, for example, Si, SiGe, Ge, and GaAs. Typically the entire substrate 16 is p-type doped silicon substrate and may contain a surface p-well 20 (with layer 18 omitted), but many other options are possible, such as, for example p on p− substrates, p on p+ substrates, p-wells in n-type substrates or the like. The terms wafer or substrate used in the description includes any semiconductor-based structure having an exposed surface in which to form the circuit structure used in the invention. Wafer and substrate are to be understood as including , silicon-on-insulator (SOI) technology, silicon-on-sapphire (SOS) technology, doped and undoped semiconductors, epitaxial layers of silicon supported by a base semiconductor foundation, and other semiconductor structures. Furthermore, when reference is made to a wafer or substrate in the following description, previous process steps may have been utilized to form regions/junctions in the base semiconductor structure or foundation. [0011] An insulating layer 22 such as, for example, silicon dioxide is formed on the upper surface of p-well 20 . The p-type layer may be a p-well formed in substrate 16 . A photogate 24 thin enough to pass radiant energy or of a material which passes radiant energy is formed on the insulating layer 22 . The photogate 24 receives an applied control signal PG which causes the initial accumulation of pixel charges in n+ region 26 . The n+ type region 26 , adjacent one side of photogate 24 , is formed in the upper surface of p-well 20 . A transfer gate 28 is formed on insulating layer 22 between n+ type region 26 and a second n+ type region 30 formed in p-well 20 . The n+ regions 26 and 30 and transfer gate 28 form a charge transfer transistor 29 which is controlled by a transfer signal TX. The n+ region 30 is typically called a floating diffusion region. It is also a node for passing charge accumulated thereat to the gate of a source follower transistor 36 described below. A reset gate 32 is also formed on insulating layer 22 adjacent and between n+ type region 30 and another n+ region 34 which is also formed in p-well 20 . The reset gate 32 and n+ regions 30 and 34 form a reset transistor 31 which is controlled by a reset signal RST. The n+ type region 34 is coupled to voltage source VDD, e.g., 5 volts. The transfer and reset transistors 29 , 31 are n-channel transistors as described in this implementation of a CMOS imager circuit in a p-well. It should be understood that it is possible to implement a CMOS imager in an n-well in which case each of the transistors would be p-channel transistors. It should also be noted that while FIG. 1 shows the use of a transfer gate 28 and associated transistor 29 , this structure provides advantages, but is not required. [0012] Photodetector circuit 14 also includes two additional n-channel transistors, source follower transistor 36 and row select transistor 38 . Transistors 36 , 38 are coupled in series, source to drain, with the source of transistor 36 also coupled over lead 40 to voltage source VDD and the drain of transistor 38 coupled to a lead 42 . The drain of row select transistor 38 is connected via conductor 42 to the drains of similar row select transistors for other pixels in a given pixel row. A load transistor 39 is also coupled between the drain of transistor 38 and a voltage source VSS, e.g. 0 volts. Transistor 39 is kept on by a signal VLN applied to its gate. [0013] The imager includes a readout circuit 60 which includes a signal sample and hold (S/H) circuit including a S/H n-channel field effect transistor 62 and a signal storage capacitor 64 connected to the source follower transistor 36 through row transistor 38 . The other side of the capacitor 64 is connected to a source voltage VSS. The upper side of the capacitor 64 is also connected to the gate of a p-channel output transistor 66 . The drain of the output transistor 66 is connected through a column select transistor 68 to a signal sample output node VOUTS and through a load transistor 70 to the voltage supply VDD. A signal called “signal sample and hold” (SHS) briefly turns on the S/H transistor 62 after the charge accumulated beneath the photogate electrode 24 has been transferred to the floating diffusion node 30 and from there to the source follower transistor 36 and through row select transistor 38 to line 42 , so that the capacitor 64 stores a voltage representing the amount of charge previously accumulated beneath the photogate electrode 24 . [0014] The readout circuit 60 also includes a reset sample and hold (S/H) circuit including a S/H transistor 72 and a signal storage capacitor 74 connected through the S/H transistor 72 and through the row select transistor 38 to the source of the source follower transistor 36 . The other side of the capacitor 74 is connected to the source voltage VSS. The upper side of the capacitor 74 is also connected to the gate of a p-channel output transistor 76 . The drain of the output transistor 76 is connected through a p-channel column select transistor 78 to a reset sample output node VOUTR and through a load transistor 80 to the supply voltage VDD. A signal called “reset sample and hold” (SHR) briefly turns on the S/H transistor 72 immediately after the reset signal RST has caused reset transistor 31 to turn on and reset the potential of the floating diffusion node 30 , so that the capacitor 74 stores the voltage to which the floating diffusion node 30 has been reset. [0015] The readout circuit 60 provides correlated sampling of the potential of the floating diffusion node 30 , first of the reset charge applied to node 30 by reset transistor 31 and then of the stored charge from the photogate 24 . The two samplings of the diffusion node 30 charges produce respective output voltages VOUTR and VOUTS of the readout circuit 60 . These voltages are then subtracted (VOUTS-VOUTR) by subtractor 82 to provide an output signal terminal 81 which is an image signal independent of pixel to pixel variations caused by fabrication variations in the reset voltage transistor 31 which might cause pixel to pixel variations in the output signal. [0016] [0016]FIG. 2 illustrates a block diagram for a CMOS imager having a pixel array 200 with each pixel cell being constructed in the manner shown by element 14 of FIG. 1. Pixel array 200 comprises a plurality of pixels arranged in a predetermined number of columns and rows. The pixels of each row in array 200 are all turned on at the same time by a row select line, e.g., line 86 , and the pixels of each column are selectively output by a column select line, e.g., line 42 . A plurality of rows and column lines are provided for the entire array 200 . The row lines are selectively activated by the row driver 210 in response to row address decoder 220 and the column select lines are selectively activated by the column driver 260 in response to column address decoder 270 . Thus, a row and column address is provided for each pixel. The CMOS imager is operated by the control circuit 250 which controls address decoders 220 , 270 for selecting the appropriate row and column lines for pixel readout, and row and column driver circuitry 210 , 260 which apply driving voltage to the drive transistors of the selected row and column lines. [0017] [0017]FIG. 3 shows a simplified timing diagram for the signals used to transfer charge out of photodetector circuit 14 of the FIG. 1 CMOS imager. The photogate signal PG is nominally set to 5V and pulsed from 5V to 0V during integration. The reset signal RST is nominally set at 2.5V. As can be seen from the figure, the process is begun at time to by briefly pulsing reset voltage RST to 5V. The RST voltage, which is applied to the gate 32 of reset transistor 31 , causes transistor 31 to turn on and the floating diffusion node 30 to charge to the VDD voltage present at n+ region 34 (less the voltage drop Vth of transistor 31 ). This resets the floating diffusion node 30 to a predetermined voltage (VDD-Vth). The charge on floating diffusion node 30 is applied to the gate of the source follower transistor 36 to control the current passing through transistor 38 , which has been turned on by a row select (ROW) signal, and load transistor 39 . This current is translated into a voltage on line 42 which is next sampled by providing a SHR signal to the S/H transistor 72 which charges capacitor 74 with the source follower transistor output voltage on line 42 representing the reset charge present at floating diffusion node 30 . The PG signal is next pulsed to 0 volts, causing charge to be collected in n+ region 26 . A transfer gate voltage TX, similar to the reset pulse RST, is then applied to transfer gate 28 of transistor 29 to cause the charge in n+region 26 to transfer to floating diffusion node 30 . It should be understood that for the case of a photogate, the transfer gate voltage TX may be pulsed or held to a fixed DC potential. For the implementation of a photodiode with a transfer gate, the transfer gate voltage TX must be pulsed. The new output voltage on line 42 generated by source follower transistor 36 current is then sampled onto capacitor 64 by enabling the sample and hold switch 62 by signal SHS. The column select signal is next applied to transistors 68 and 70 and the respective charges stored in capacitors 64 and 74 are subtracted in subtractor 82 to provide a pixel output signal at terminal 81 . It should also be noted that CMOS imagers may dispense with the transfer gate 28 and associated transistor 29 , or retain these structures while biasing the transfer transistor 29 to an always “on” state. [0018] The operation of the charge collection of the CMOS imager is known in the art and is described in several publications such as Mendis et al., “Progress in CMOS Active Pixel Image Sensors,” SPIE Vol. 2172, pp. 19-29 1994; Mendis et al., “CMOS Active Pixel Image Sensors for Highly Integrated Imaging Systems,” IEEE Journal of Solid State Circuits, Vol. 32(2), 1997; and Eric R, Fossum, “CMOS Image Sensors: Electronic Camera on a Chip,” IEDM Vol.95 pages 17-25 (1995) as well as other publications. These references are incorporated herein by reference. [0019] Prior CMOS imagers suffer from poor signal to noise ratios and poor dynamic range as a result of the inability to fully collect and store the electric charge collected by the photosensitive area. Since the size of the pixel electrical signal is very small due to the collection of photons in the photo array, the signal to noise ratio and dynamic range of the pixel should be as high as possible. There is needed, therefore, an improved active pixel photosensor for use in an APS imager that exhibits improved dynamic range, a better signal-to-noise ratio, and improved charge capacity for longer integration times. A method of fabricating an active pixel photosensor exhibiting these improvements is also needed. SUMMARY OF THE INVENTION [0020] The present invention provides a CMOS imager having a storage capacitor connected to the light sensitive node to improve collected charge storage. The storage capacitor is formed in parallel with the light sensitive node of the imager and may be any type of capacitor formed on the pixel cell over a non-light sensitive area. Also provided are methods for forming the CMOS imager of the present invention. [0021] Additional advantages and features of the present invention will be apparent from the following detailed description and drawings which illustrate preferred embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS [0022] [0022]FIG. 1 is a representative circuit of a CMOS imager. [0023] [0023]FIG. 2 is a block diagram of a CMOS pixel sensor chip. [0024] [0024]FIG. 3 is a representative timing diagram for the CMOS imager. [0025] [0025]FIG. 4 is a representative pixel layout showing a 2×2 pixel layout. [0026] [0026]FIG. 5 is a cross-sectional view of a pixel sensor according to one embodiment of the present invention. [0027] [0027]FIG. 6 is a cross-sectional view of a semiconductor wafer according to FIG. 5 undergoing the process of an embodiment of the invention. [0028] [0028]FIG. 7 shows the wafer of FIG. 6 at a processing step subsequent to that shown in FIG. 6. [0029] [0029]FIG. 8 shows the wafer of FIG. 6 at a processing step subsequent to that shown in FIG. 7. [0030] [0030]FIG. 9 shows the wafer of FIG. 6 at a processing step subsequent to that shown in FIG. 8. [0031] [0031]FIG. 10 shows the wafer of FIG. 6 at a processing step subsequent to that shown in FIG. 9. [0032] [0032]FIG. 11 shows the wafer of FIG. 6 at a processing step subsequent to that shown in FIG. 10. [0033] [0033]FIG. 12 shows the wafer of FIG. 6 at a processing step subsequent to that shown in FIG. 11. [0034] [0034]FIG. 13 shows the wafer of FIG. 6 at a processing step subsequent to that shown in FIG. 12. [0035] [0035]FIG. 14 shows the wafer of FIG. 6 at a processing step subsequent to that shown in FIG. 13. [0036] [0036]FIG. 15 is a cross-sectional view of a pixel sensor according to another embodiment of the present invention. [0037] [0037]FIG. 16 is a cross-sectional view of a semiconductor wafer according to FIG. 15 undergoing the process of an embodiment of the invention. [0038] [0038]FIG. 17 shows the wafer of FIG. 16 at a processing step subsequent to that shown in FIG. 16. [0039] [0039]FIG. 18 shows the wafer of FIG. 16 at a processing step subsequent to that shown in FIG. 17. [0040] [0040]FIG. 19 shows the wafer of FIG. 16 at a processing step subsequent to that shown in FIG. 18. [0041] [0041]FIG. 20 shows the wafer of FIG. 16 at a processing step subsequent to that shown in FIG. 19. [0042] [0042]FIG. 21 shows the wafer of FIG. 16 at a processing step subsequent to that shown in FIG. 20. [0043] [0043]FIG. 22 shows the wafer of FIG. 16 at a processing step subsequent to that shown in FIG. 21. [0044] [0044]FIG. 23 is a cross-sectional view of a pixel sensor according to another embodiment of the present invention. [0045] [0045]FIG. 24 is an illustration of a computer system having a CMOS imager according to the present invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS [0046] In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized, and that structural, logical and electrical changes may be made without departing from the spirit and scope of the present invention. [0047] The terms “wafer” and “substrate” are to be understood as including silicon-on-insulator (SOI) or silicon-on-sapphire (SOS) technology, doped and undoped semiconductors, epitaxial layers of silicon supported by a base semiconductor foundation, and other semiconductor structures. Furthermore, when reference is made to a “wafer” or “substrate” in the following description, previous process steps may have been utilized to form regions or junctions in the base semiconductor structure or foundation. In addition, the semiconductor need not be silicon-based, but could be based on silicon-germanium, germanium, or gallium arsenide. [0048] The term “pixel” refers to a picture element unit cell containing a photosensor and transistors for converting electromagnetic radiation to an electrical signal. For purposes of illustration, a representative pixel is illustrated in the figures and description herein, and typically fabrication of all pixels in an imager will proceed simultaneously in a similar fashion. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims. [0049] The structure of the pixel cell 114 of a first embodiment is shown in more detail in FIG. 5. The pixel cell 114 may be formed in a substrate 116 having a doped layer 120 of a first conductivity type, which for exemplary purposes is treated as a p-type substrate. A field oxide layer 115 , which serves to surround and isolate the cells may be formed by thermal oxidation of the doped layer 120 , or by chemical vapor deposition of an oxide material. This field oxide layer 115 may be formed before or after the gate stacks (described below) are formed. The doped layer 120 is provided with five doped regions 110 , 126 , 130 , 134 and 155 , which are doped to a second conductivity type, which for exemplary purposes is treated as n type. The first doped region 110 underlies photogate 102 , which is a thin layer of material transparent to radiant energy, such as polysilicon. The second doped region 126 electrically connects photogate transistor 125 to the transfer transistor gate 128 . An insulating layer 100 of silicon dioxide, silicon nitride, or other suitable material is formed over a surface of the doped layer 120 of the substrate 116 . [0050] The third doped region 130 is the floating diffusion region, sometimes also referred to as a floating diffusion node. The floating diffusion region 130 is connected to the source follower transistor 136 by a contact line 144 which is typically a metal contact line. The source follower transistor 136 outputs a signal proportional to the charge accumulated in the floating diffusion region 130 to a readout circuit 60 when the row select transistor 138 is turned on as shown above in FIG. 1. While the source follower transistor 136 and transistor 138 are illustrated in FIG. 5 in circuit form above substrate 120 , it should be understood that these transistors are typically formed in substrate 120 in a similar fashion to transistors 128 and 132 . [0051] The fourth doped region 134 is the drain of the reset transistor 131 , and is also connected to voltage source VDD. The pixel cell thus far described with reference with FIG. 5 operates in a manner similar to the pixel cell described above with reference to FIGS. 1 - 4 in terms of collecting and reading out charges to the readout circuit 60 . In addition, FIG. 5 also shows a fifth doped region 155 which is formed adjacent to the photogate 102 and serves to transfer charge to a storage capacitor 162 from the photosensitive area under the photogate by contact 150 . [0052] One means of forming the storage capacitor 162 is shown in FIG. 5. The storage capacitor 162 is formed over the substrate 116 as described below. An insulating layer 106 is formed over the substrate containing the pixel cell active area, including the photogate and the pixel transistors. The insulating layer 106 may be formed of BPSG (borophosphorosilicate glass), BSG (borosilicate glass), PSG (phosphorosilicate glass), USG (undoped silicate glassy or the like as described further below provided that the material does not block light to the photosensor (in the illustrated embodiment, this is a photogate). A portion of the insulating layer 106 is etched away to form a conduit which is filled with conductive material forming a contact 150 . Contact 150 connects the region 155 which is coupled to the charge accumulation area under the photogate 102 to a first electrode 156 of storage capacitor 162 . The storage capacitor 162 is illustrated in FIG. 5 as a planar plate capacitor. The storage capacitor 162 has first electrode 156 , a second electrode 160 , and a dielectric layer 158 formed therebetween. Second electrode 160 is preferably connected to a ground potential source. The storage capacitor 162 is formed such that it does not block the photosensitive area of the imager. As shown in FIG. 5, the storage capacitor 162 overlies at least a portion of the field oxide 115 ; however, it should be understood that the storage capacitor 162 may be formed over any non-photosensitive area, such as, for example, over the transfer gate 128 , the reset gate 132 , the source follower transistor 136 , or the row select transistor 138 where the capacitor would additionally and advantageously also function as a light shield. [0053] The CMOS imager illustrated in FIG. 5 is fabricated by a process described as follows, and illustrated by FIGS. 6 through 14. Referring now to FIG. 6, a substrate 116 , which may be any of the types of substrates described above, is doped to form a doped substrate layer 120 of a first conductivity type, which for exemplary purposes will be described as p-type. The substrate layer 120 is masked and doped region 110 is formed in the substrate 120 . Any suitable doping process may be used, such as ion implantation. [0054] Referring now to FIG. 7, an insulating layer 100 is now formed over the substrate 116 by thermal growth or chemical vapor deposition, or other suitable means. The insulating layer 100 may be of silicon dioxide, silicon nitride, or other suitable insulating material, and has a thickness of approximately 2 to 100 nm. It is formed to completely cover the substrate 116 , and to extend to the field oxide layer 115 . [0055] Referring now to FIG. 8, the transfer gate stack 128 , reset transistor gate stack 132 , and photogate 102 are now formed. The photogate 102 includes silicon dioxide or silicon nitride insulator 100 on the doped layer 120 and a conductive layer 108 over the insulating layer. Conductive layer 108 is formed of a doped polysilicon or other transparent conductors. The thickness of the conductive layer 108 in photogate 102 may be any suitable thickness, e.g., approximately 200 to 5000 Angstroms. [0056] Conductive layers 108 in gates 128 and 132 may be formed of doped polysilicon, a refractory metal silicide such as tungsten, tantalum, or titanium silicides or other suitable materials such as a barrier/metal. The conductive material is formed by CVD or other suitable means. A silicide or barrier/metal layer (not shown) may be used as part of the polysilicon layer, if desired. The gate stacks may be formed by applying layers 108 (and a silicide layer, if used) over the substrate and then etching them to form gate stacks 102 , 128 and 132 . Insulating sidewalls 112 are also formed on the sides of the gate stacks 102 , 128 , 132 . These sidewalls may be formed of, for example, silicon dioxide, silicon nitride, or ONO: While these gate stacks may be formed before or after the process of the photogate 102 described below, for exemplary purposes and for convenience the photogate formation has been described as occurring during transistor gate stack formation. [0057] After spacer formation 112 , doped regions 126 , 130 , 134 and 155 are then formed in the doped layer 120 . Any suitable doping process may be used, such as ion implantation. A resist and mask (not shown) are used to shield areas of the layer 120 that are not to be doped. Four doped regions are formed in this step: doped region 126 , which forms a transfer region; doped region which is floating diffusion region 130 (which connects to the source follower transistor 136 by contact 144 as shown in FIG. 5); doped region which is a drain region 134 ; and doped region 155 which serves to connect the photocollection area with the storage capacitor 162 . The doped regions 126 , 130 , 134 and 155 are doped to a second conductivity type, which for exemplary purposes will be considered to be n-type. Several masks may be used to implant the regions 126 , 130 , 134 and 155 to the same or different doping concentrations. Preferably, the doped regions 126 , 130 , 134 and 155 are heavily n-doped with arsenic, antimony or phosphorous at a dopant concentration level of from about 1×10 15 ions/cm 2 to about 1×10 16 ions/cm 2 . [0058] Reference is now made to FIG. 9. The photosensor cell is essentially complete at this stage, and conventional processing methods may now be used to form contacts and wiring to connect gate lines and other connections in the pixel cell. The entire surface of the substrate 116 is covered with an insulating layer 106 of, e.g., silicon dioxide, USG, BPSG, PSG, BSG or the like which is CMP planarized and etched to provide contact holes, which are then metallized to provide contacts to the photogate, reset gate, and transfer gate. Conventional multiple layers of conductors and insulators may also be used to interconnect the structures in the manner shown in FIG. 1. [0059] Reference is now made to FIG. 10 to show how contact 150 and capacitor 162 are formed. A resist and mask (not shown) are applied to the insulating layer 106 and photolithographic techniques are used to define the area to be etched out to form holes for contact 150 to the fourth doped layer 155 . This etching may be done at the same time as the etching for the contact holes for the photogate, reset gate and transfer gate contacts as described above The contact 150 may be formed in the etched hole by depositing therein a conductive material, such as doped polysilicon, or a metal such as titanium/titanium nitride/tungsten. [0060] Reference is now made to FIG. 11. After the etched hole has conductor 150 formed therein a first conductive layer 156 , which forms a first electrode of the capacitor 162 , is deposited over the insulating layer 106 after application of a resist and mask (not shown). The term electrode, as used herein, shall be understood to mean any material that is electrically conducting. The conductive layer 156 may be formed of any conductive material. Non-limiting examples of materials that may be used to form the conductive layer 156 are doped polycrystalline silicon (referred to herein as polysilicon or poly), platinum, tungsten, TiN, refractory metals, RuO 2 , Ir, IrO 2 , Rh, RhO X , and alloys, such as Pt—Ru or Pt—Rh. The conductive layer 156 may be formed on the insulating layer 106 by CVD, LPCVD, PECVD, MOCVD, sputtering or other suitable deposition techniques. The conductive layer 156 formed during deposition which overlies the photogate is next removed from the insulating layer 106 by known techniques, such as wet or dry etching. [0061] Reference is now made to FIG. 12. A dielectric layer 158 is formed over conductive layer 156 . The term dielectric or insulator as used herein shall be understood to mean any solid, liquid or gaseous material that can sustain an electrical field for use in the capacitor of an integrated circuit device containing a capacitor. The dielectric layer 158 may be formed of any insulating material such as oxides, such as silicon oxide, nitrides, such as silicon nitride, ONO, NO (nitride oxide), ON (oxide nitride), high-k dielectrics such as Ta 2 O 5 or BST, ferroelectrics or the like. The preferred dielectric layer is a nitride layer which can be formed using various known methods such as CVD deposition, rapid thermal nitridation (RTN) processing or the like. [0062] Reference is now made to FIG. 13. A second conductive layer 160 , which forms the second electrode of the capacitor 162 , is patterned and formed over the dielectric layer 158 in a method similar to that of the first conductive layer 156 . The second conductive layer 160 may be formed of the same or difference conductive materials from those used for the first conductive layer 156 . Preferably, both the first and second conductive layers are formed of doped polysilicon with a nitride dielectric layer 158 formed between the two conductive layers 156 , 160 . A passivation layer 164 is then deposited over the capacitor 162 as shown in FIG. 14. The passivation layer 164 may be any material, such as USG, BPSG, PSG, BSG, provided that the material does not interfere with the collection of light in the photoarea. A hole is etched and a metal contact 166 is formed therein in the passivation layer 164 to connect the second electrode 160 of the capacitor 162 to an electrical circuit, e.g., a ground source potential. As set forth above, the storage capacitor 162 may be formed over any non-photosensitive area of the pixel cell 114 . For example, the storage capacitor 162 may be formed over the transfer transistor 128 , the reset transistor 132 , the source follower transistor 136 or the row select transistor 138 . [0063] It should be understood that fabrication of the FIG. 5 structure is not limited to the methods described with reference to the attached figures. For example, the doped regions 110 , 126 , 130 , 134 and 155 may be formed in the doped layer 120 after the transistor gates 102 , 128 , 132 are formed over the substrate, as discussed below, by masking the transistor gates 102 , 128 and 132 and forming the doped regions 110 , 126 , 130 , 134 and 155 in the doped layer 120 so as to form self-aligned gates. Additionally, the first conductive layer 156 , the dielectric layer 158 and the second conductive layer 160 may be deposited together and over the entire substrate and then etched away to form capacitor 162 . [0064] The structure of a pixel cell of a second embodiment of the present invention is shown in FIG. 15. The pixel cell 314 may be formed in a substrate 316 having a doped layer 320 of a first conductivity type, which for exemplary purposes is treated as a p-type substrate. A field oxide layer 315 , which serves to surround and isolate the cells may be formed by thermal oxidation of the doped layer 320 , or by chemical vapor deposition of an oxide material. The doped layer 320 is provided with five doped regions 310 , 326 , 330 , 334 and 355 , which are doped to a second conductivity type. For exemplary purposes regions 326 , 330 , 334 , and 355 are treated as n+type. The first doped region 310 is formed under photogate 302 to collect charge and may also be doped n+. Second doped region 326 serves to electrically connect the photosite diffusion 310 to the transfer gate transistor 322 . An insulating layer 300 of silicon dioxide, silicon nitride, or other suitable material is formed between the photogate 302 and the photosensitive diffusion 310 , and extends to the pixel-isolating field oxide region 315 and over a surface of the doped layer 320 of the substrate 316 . [0065] The third doped region 330 is the floating diffusion region, sometimes also referred to as a floating diffusion node. The floating diffusion region 330 is connected to source follower transistor 336 by a diffusion contact line 344 which is typically a metal contact line. The source follower transistor 336 outputs the charge accumulated in region 326 via the floating diffusion region 330 and diffusion contact line 344 via transistor 338 to a readout circuit as discussed above. [0066] The fourth doped region 334 is the drain of the reset transistor 332 , and is also connected to voltage source VDD. The pixel cell thus far described with reference with FIG. 15 operates in a manner similar to the pixel cell described above with reference to FIGS. 1 - 4 in terms of collecting and reading out charges to the readout circuit 60 . In addition, FIG. 15 shows a fifth doped region 355 which is formed adjacent to the photogate 302 and serves to transport charge to a trench storage capacitor 362 from the photosensitive area under the photogate. [0067] The trench storage capacitor 362 is formed in the substrate 316 . The trench storage capacitor 362 is formed of a first electrode 356 and a second electrode 360 with a dielectric layer 358 therebetween. The second electrode 360 is preferably connected to a ground source. The trench storage capacitor 362 is formed in the pixel cell 314 such that it takes up as little area of the photocollection area as possible. The CMOS imager of the invention is manufactured by a process described as follows, and illustrated by FIGS. 16 through 22. Referring now to FIG. 16, substrate 316 , which may be any of the types of substrates described above, is doped to form a doped substrate layer 320 of a first conductivity type, which for exemplary purposes will be described as p-type. The substrate layer 320 is masked and doped region 310 is formed in the substrate 320 . Any suitable doping process may be used, such as ion implantation. [0068] Referring now to FIG. 17, an insulating layer 300 is now formed over the substrate 316 by thermal growth or chemical vapor deposition, or other suitable means. The insulating layer 300 may be of silicon dioxide, silicon nitride, or other suitable insulating material, and has a thickness of approximately 2 to 100 nm. It is formed to completely cover the substrate 316 , and to extend to the field oxide layer 315 . [0069] Referring now to FIG. 18, the transfer gate stack 328 , reset transistor gate stack 332 , and photogate 302 are now formed. The photogate 302 includes silicon dioxide or silicon nitride insulator 300 on the doped layer 320 and a conductive layer 308 over the insulating layer. Conductive layer 308 is formed of a doped polysilicon or other transparent conductors. The thickness of the conductive layer 308 in photogate 302 may be any suitable thickness, e.g., approximately 200 to 5000 Angstroms. [0070] Conductive layers 308 in gates 328 and 332 may be formed of doped polysilicon, a refractory metal silicide such as tungsten, tantalum, or titanium silicides or other suitable materials such as a barrier/metal. The conductive material is formed by CVD or other suitable means. A silicide or barrier/metal layer (not shown) may be used as part of the polysilicon layer, if desired. The gate stacks may be formed by applying layers 308 (and a silicide layer, if used) over the substrate and then etching them to form gate stacks 302 , 328 and 332 . Insulating sidewalls 312 are also formed on the sides of the gate stacks 302 , 328 , 332 . These sidewalls may be formed of, for example, silicon dioxide, silicon nitride, or ONO. While these gate stacks may be formed before or after the process of the photogate 302 described below, for exemplary purposes and for convenience the photogate formation has been described as occurring during transistor gate stack formation. [0071] The doped regions 326 , 330 , 334 and 355 are then formed in the doped layer 320 . Any suitable doping process may be used, such as ion implantation. A resist and mask (not shown) are used to shield areas of the layer 320 that are not to be doped. Four doped regions are formed in this step: doped region 326 , which forms a transfer region; doped region which is floating diffusion region 330 (which connects to the source follower transistor 336 by contact 344 as shown in FIG. 15); doped region which is a drain region 334 ; and doped region 355 which connects the photocollection area with the trench storage capacitor 362 . The doped regions 326 , 330 , 334 and 355 are doped to a second conductivity type, which again for exemplary purposes will be considered to be n-type. Preferably, the doped regions 326 , 330 , 334 and 355 are heavily n-doped with arsenic, antimony or phosphorous at a dopant concentration level of from about 1×10 15 ions/cm 2 to about 1×10 16 ions/cm 2 . [0072] Reference is now made to FIG. 19. An insulating layer 367 e.g., silicon dioxide or BPSG, which is CMP planarized, is formed over the device. A trench 366 is next formed in the insulating layer 367 and doped layer 320 . A resist and mask (not shown) are applied, and photolithographic techniques are used to define the area to be etched-out. A directional etching process such as Reactive Ion Etching (RIE), or etching with a preferential anisotropic etchant is used to etch into the doped layer 320 to a sufficient depth, e.g., about 200 to 2000 nm, to form a trench 366 . The depth of the trench 366 should be sufficient to form the trench capacitor 362 of the present invention therein. The resist and mask are removed, leaving a structure that appears as shown in FIG. 19. [0073] Reference is now made to FIG. 20. A first conductive layer 356 , which forms a first electrode of the capacitor 362 , is deposited in the trench 366 . The conductive layer 356 may be formed of any conductive material. The conductive layer 356 is coupled to the charge accumulation area under the photogate 302 by fourth doped region 355 by the conductive layer 356 being formed adjacent and in contact with fourth doped region 355 . Non-limiting examples of materials that may be used to form the conductive layer 356 are doped polysilicon, platinum, tungsten, TiN, refractory metals, RuO 2 , Ir, IrO 2 , Rh, RhO X , and alloys, such as Pt—Ru or Pt—Rh. The conductive layer 356 may be formed in the trench 366 by CVD, LPCVD, PECVD, MOCVD, sputtering or other suitable deposition techniques. [0074] Reference is now made to FIG. 21. A dielectric layer 358 is formed over conductive layer 356 . The dielectric layer 358 may be formed of any insulating material such as oxides, including silicon oxide, nitrides, such as silicon nitride, ONO, NO, ON, high-k dielectrics, such as Ta 2 O 5 , BST and ferroelectrics or the like as described above. A second conductive layer 360 , which forms the second electrode of the capacitor 362 , is formed over the dielectric layer 358 in a method similar to that of the first conductive layer 356 , as shown in FIG. 22. The first and second conductive layers 356 , 366 may be formed of the same or different materials. [0075] The pixel cell 314 of the second embodiment is essentially complete at this stage, and conventional processing methods may then be used to form contacts and wiring to connect gate lines and other connections in the pixel cell 314 . For example, the entire surface may then be covered with an insulating layer of, e.g., silicon dioxide or BPSG, which is CMP planarized and etched to provide contact holes, which are then metallized to provide contacts to the photogate, reset gate, and transfer gate. Conventional multiple layers of conductors and insulators may also be used to interconnect the structures in the manner shown in FIG. 1. [0076] It should be understood that fabrication of the FIG. 15 structure is not limited to the methods described with reference to the attached figures. For example, the doped regions 310 , 326 , 330 , 334 and 355 may be formed in the doped layer 320 after the transistor gates 302 , 328 , 332 are formed over the substrate, as discussed below, by masking the transistor gates 302 , 328 and 332 and forming the doped regions 310 , 326 , 330 , 334 and 355 in the doped layer 320 so as to form self-aligned gates. [0077] A third embodiment of the present invention is described with reference to FIG. 23. It should be understood that similar reference numbers correspond to similar elements as previously described with reference to FIGS. 614 and 16- 22 . The structure set forth in FIG. 23 differs from the above described embodiments in that a stacked storage capacitor 373 is formed in the insulating layer 106 to store charge collected under photogate 102 . The processing of the third embodiment is similar to the processing described above with reference to FIGS. 6 - 9 . A hole is etched in the insulating layer 106 down to the fourth doped region 155 and a conductor is formed therein as shown in FIG. 10 to create contact 375 ; however the etched hole is not filly filled with the conductive material which forms contact 375 . The conductor may be formed as a doped polysilicon plug, or as a metallized conductor. A trench 378 is then formed, for example, by etching, in the insulating layer 106 similar to that formed in the substrate as shown in FIG. 19 and a storage capacitor 373 is then formed as described above with reference to FIGS. 19 - 22 . A first conductive layer 376 is formed in the trench 378 which contacts with the fourth doped region 155 through contact 375 . A dielectric layer 379 is formed over the first conductive layer 376 . A second conductive layer 380 is then formed over the dielectric layer 379 to form the storage capacitor 373 . Non-limiting examples of materials that may be used to form the conductive layers 376 and 380 are doped polysilicon, platinum, tungsten, TiN, refractory metals, RuO 2 , Ir, IrO 2 , Rh, RhO X , and alloys, such as Pt—Ru or Pt—Rh. The conductive layers 376 and 380 may be formed in the trench 366 by CVD, LPCVD, PECVD, MOCVD, sputtering or other suitable deposition techniques. The storage capacitor 373 formed in the insulating layer 106 has the advantages that the storage capacitor 373 is formed in the insulating layer 106 and not in the substrate thereby improving the charge storage capacity of the imager without reducing the size of the photosensitive area. [0078] It should be understood that while the illustrated embodiments show the storage capacitors 162 , 362 , 373 connected to the substrate through doped region 155 , 355 , it is also possible to dispense with region 155 , 355 and have the storage capacitors 162 , 362 , 373 connect directly with region 126 using the same basic structure illustrated in FIGS. 5, 15 and 23 . [0079] A typical processor based system which includes a CMOS imager device according to the present invention is illustrated generally at 400 in FIG. 24. A processor based system is exemplary of a system having digital circuits which could include CMOS imager devices. Without being limiting, such a system could include a computer system, camera system, scanner, machine vision system, vehicle navigation system, video telephone, surveillance system, auto focus system, star tracker system, motion detection system, image stabilization system and data compression system for high-definition television, all of which can utilize the present invention. [0080] A processor system, such as a computer system, for example generally comprises a central processing unit (CPU) 444 that communicates with an input/output (I/O) device 446 over a bus 452 . The CMOS imager 442 also communicates with the system over bus 452 . The computer system 400 also includes random access memory (RAM) 448 , and, in the case of a computer system may include peripheral devices such as a floppy disk drive 454 and a compact disk (CD) ROM drive 456 which also communicate with CPU 444 over the bus 452 . CMOS imager 442 is preferably constructed as an integrated circuit which includes pixels containing a photosensor such as a photogate or photodiode formed in a trench, as previously described with respect to FIGS. 5 through 12 . The CMOS imager 442 may be combined with a processor, such as a CPU, digital signal processor or microprocessor, in a single integrated circuit. [0081] As can be seen by the embodiments described herein, the present invention encompasses a photosensor including a storage capacitor connected in parallel to the charge collection area of the imager. The imager has an improved charge capacity due to the increase in the charge storage by the capacitor. [0082] It should again be noted that although the invention has been described with specific reference to CMOS imaging circuits having a photogate and a floating diffusion region, the invention has broader applicability and may be used in any CMOS imaging apparatus. Also, although exemplary capacitor structures have been described and illustrated many variations in capacitor structure could be made. Similarly, the processes described above are merely exemplary of many that could be used to produce the invention. The above description and drawings illustrate preferred embodiments which achieve the objects, features and advantages of the present invention. It is not intended that the present invention be limited to the illustrated embodiments. Any modification of the present invention which comes within the spirit and scope of the following claims should be considered part of the present invention.

A CMOS imager having an improved signal to noise ratio and improved dynamic range is disclosed. The CMOS imager provides improved charge storage by fabricating a storage capacitor in parallel with the photocollection area of the imager. The storage capacitor may be a flat plate capacitor formed over the pixel, a stacked capacitor or a trench imager formed in the photosensor. The CMOS imager thus exhibits a better signal-to-noise ratio and improved dynamic range. Also disclosed are processes for forming the CMOS imager.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation-in-part of U.S. patent application Ser. No. 11/820,211 filed Jun. 18, 2007 which is a continuation-in-part of U.S. patent application Ser. No. 11/136,871, filed May. 25, 2005, issued as U.S. Pat. No. 7,244,508 on Jul. 17, 2007, said applications and patent co-owned with the present invention and incorporated fully herein for all purposes and from which applications and patent the present invention and application claim priority under the Patent Laws. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention is directed to frosting coating materials, coated articles, coating methods, and, in certain particular aspects, to coating methods and materials useful in producing a frosted plastic or glass article. [0004] 2. Description of Related Art [0005] A substrate of glass or plastic may become frosted when a surface temperature thereof is heated, e.g. to 355-365 degrees F. and then cooled to room temperature. In certain prior art methods, a frosting coating is provided with, e.g. thermosetting polymers and other chemicals which produce a frosting effect due to moisture adjustment (expulsion) by heating. The prior art discloses a wide variety of systems and methods for coating articles to produce a frosted article. U.S. Pat. Nos. 6,476,093; 6,777,092; 6,641,755; 6,193,831; 5,916,938; 4,892,906; 4,842,613; 4,139,514; 3,983,307; U.S. Applications published with numbers 20040049052, 20040058078, 20040067311, 20030150729, 20060047051; and the references listed in these patents and applications provide a sampling of prior references and of frosted articles (e.g. lenses, U.S. Pat. Nos. 5,015,523 and 5,458,820; mirrors and prisms, U.S. Pat. Nos. 4,898,435 and 5,513,039; and optical elements, U.S. Pat. Nos. 6,582,884, 5,933,273, and 5,621,838). [0006] Frosted articles and frosted glass plastic containers are well known and are used for foods, beverages, alcoholic liquors, cosmetics and other materials because they prevent UV transmission and/or improve a design with decoration and an impression of quality or artistry. In many prior art methods, to finish a surface of a glass container so it is frosted, a method is used in which the surface is etched with a hydrofluoric acid solution with added salts such as ammonium fluoride, or a mixed solution of hydrofluoric acid and sulfuric acid with added salts such as ammonium fluoride. Such a method can provide a frosted surface, but the use of a strong acid, such as hydrofluoric acid as an etching agent, can make the handling of agents difficult and can require washing with an acid and water. The treatment of resulting acidic waste water can present problems regarding safety, environment, productivity, and cost. A method for finishing a surface of a glass container without using such harmful agents includes mixing a fine silica particle as a matting agent into a thermosetting resin or a photocurable resin to form a frosted coating on the surface of the glass container (see, e.g. JP-A 2518/1978 and JP-B 68418/1993); but when such a frosted glass container is immersed into a washing solution such as an aqueous sodium hydroxide solution in a step of alkali washing, the coating can turn white and can peel from the container and, when such a glass container passes through an alkali washing line or a bottling line, cracking and peeling of the coating can occur by collision between bottles due to insufficient impact resistance of the coating. One attempted solution to these problems disclosed in U.S. Pat. No. 6,476,093 is a frost-coating composition, which includes a hydrophobic silica particle or a polymer particle, in addition to a photocurable compound; and a frosted glass container coated with such a composition. One such frost-coating composition includes 5-50 parts by weight of a hydrophobic fine silica particle based on 100 parts by weight of a photocurable compound, such that said frost-coating composition forms a frosted coating having alkaline resistance. Certain coatings of U.S. Pat. No. 6,476,093 include a solvent-based solution with a relatively high VOC content and, in certain manufacturing processes an epoxy polymer solution is heated for a minimum of two hours at one hundred fifty degrees centigrade. [0007] There is a need, recognized by the present inventor, for efficient and effective materials and methods for frosting coatings. [0008] There is a need, recognized by the present inventor, for such frosting coating materials and methods useful for producing a coating with high surface hardness to combat undesirable etching, e.g. acid etching, of an article. BRIEF SUMMARY OF THE INVENTION [0009] The present invention discloses, in certain aspects, frosting coatings, methods for producing them, and articles with such coatings. In certain aspects, a frosting coating material according to the present invention forms an insoluble coating film that is hydrophobic; permanent; resistant to mild acids, alkalis, alcohols, abrasion, and scratching; excellent in surface hardness; and, optionally, UV absorbent and/or light stabilized. Any coating according to the present invention may be used on plastic or glass substrates, such as glasses, wine bottles, pieces of glass, panes of glass, jars, containers, laminated glass or plastic (e.g., in the architectural, cosmetic, pharmaceutical and food industries) lenses, optical parallel plates, optical mirrors, elements, prisms, glass articles, and/or plastic articles; and/or for decoration on such items; and/or on articles to produce frosted articles as disclosed in the patents and patent application references previously incorporated herein by reference. [0010] In certain aspects, the present invention provides a coating material for a frosting coating film that is hydrophobic; permanent; resistant to mild acids, alkalis, alcohols, abrasion, and scratching; UV light absorbent; and excellent in surface hardness. [0011] In certain aspects, the present invention provides frosted articles with a coating film according to the present invention. [0012] Accordingly, the present invention includes features and advantages which are believed to enable it to advance frosted coating technology. Characteristics and advantages of the present invention described above and additional features and benefits will be readily apparent to those skilled in the art upon consideration of the following detailed description of preferred embodiments and referring to the accompanying drawings. [0013] Certain embodiments of this invention are not limited to any particular individual feature disclosed here, but include combinations of them distinguished from the prior art in their structures, functions, and/or results achieved. Features of the invention have been broadly described so that the detailed descriptions that follow may be better understood, and in order that the contributions of this invention to the arts may be better appreciated. There are, of course, additional aspects of the invention described below and which may be included in the subject matter of the claims to this invention. Those skilled in the art who have the benefit of this invention, its teachings, and suggestions will appreciate that the conceptions of this disclosure may be used as a creative basis for designing other structures, methods and systems for carrying out and practicing the present invention. The claims of this invention are to be read to include any legally equivalent devices or methods which do not depart from the spirit and scope of the present invention. [0014] What follows are some of, but not all, the objects of this invention. In addition to the specific objects stated below for at least certain preferred embodiments of the invention, there are other objects and purposes which will be readily apparent to one of skill in this art who has the benefit of this invention's teachings and disclosures. It is, therefore, an object of at least certain preferred embodiments of the present invention to provide the embodiments and aspects listed above and: [0015] New, useful, unique, efficient, non-obvious frosted articles, frosting liquids and frosting methods. [0016] The present invention recognizes and addresses the problems and needs in this area and provides a solution to those problems and a satisfactory meeting of those needs in its various possible embodiments and equivalents thereof. To one of skill in this art who has the benefits of this invention's realizations, teachings, disclosures, and suggestions, various purposes and advantages will be appreciated from the following description of preferred embodiments, given for the purpose of disclosure, when taken in conjunction with the accompanying drawings. The detail in these descriptions is not intended to thwart this patent's object to claim this invention no matter how others may later attempt to disguise it by variations in form or additions of further improvements. [0017] The Abstract that is part hereof is to enable the U.S. Patent and Trademark Office and the public generally, and scientists, engineers, researchers, and practitioners in the art who are not familiar with patent terms or legal terms of phraseology to determine quickly from a cursory inspection or review the nature and general area of the disclosure of this invention. The Abstract is neither intended to define the invention, which is done by the claims, nor is it intended to be limiting of the scope of the invention or of the claims in any way. [0018] It will be understood that the various embodiments of the present invention may include one, some, or all of the disclosed, described, and/or enumerated improvements and/or technical advantages and/or elements in claims to this invention. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS [0019] A more particular description of embodiments of the invention briefly summarized above may be had by references to the embodiments which are shown in the drawings which form a part of this specification. These drawings illustrate certain preferred embodiments and are not to be used to improperly limit the scope of the invention which may have other equally effective or legally equivalent embodiments. [0020] FIG. 1A is a cross-section view of a prior art bottle. [0021] FIG. 1B is a cross-section view of a bottle with frosting according to the present invention. [0022] FIG. 1C is an enlarged view of part of the bottle of FIG. 1B . [0023] FIG. 2A is a perspective view of a prior art artwork. [0024] FIG. 2B is a front view of the artwork of FIG. 2A framed according to the present invention. [0025] FIG. 2C is an exploded view of the framed artwork of FIG. 2B . [0026] FIG. 3A is a perspective view of a prior art glass block. [0027] FIG. 3B is a perspective view showing the glass block of FIG. 3A frosted according to the present invention. [0028] FIG. 4A is a perspective view of a piece of glass frosted according to the present invention. [0029] FIG. 4B is a perspective view of the glass of FIG. 4 A with additional frosting. [0030] Presently preferred embodiments of the invention are shown in the above-identified figures and described in detail below. Various aspects and features of embodiments of the invention are described below and some are set out in the dependent claims. Any combination of aspects and/or features described below or shown in the dependent claims can be used except where such aspects and/or features are mutually exclusive. It should be understood that the appended drawings and description herein are of preferred embodiments and are not intended to limit the invention or the appended claims. On the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the invention as defined by the appended claims. In showing and describing the preferred embodiments, like or identical reference numerals are used to identify common or similar elements. The figures are not necessarily to scale and certain features and certain views of the figures may be shown exaggerated in scale or in schematic in the interest of clarity and conciseness. [0031] As used herein and throughout all the various portions (and headings) of this patent, the terms “invention”, “present invention” and variations thereof mean one or more embodiment, and are not intended to mean the claimed invention of any particular appended claim(s) or all of the appended claims. Accordingly, the subject or topic of each such reference is not automatically or necessarily part of, or required by, any particular claim(s) merely because of such reference. So long as they are not mutually exclusive or contradictory any aspect or feature or combination of aspects or features of any embodiment disclosed herein may be used in any other embodiment disclosed herein. DETAILED DESCRIPTION OF THE INVENTION [0032] In one particular embodiment of a system and method according to the present invention, there is provided a frosting coating material or composition with: thermoset acrylic resin; polymethyl methacrylate, N,N-dimethylethanolamine (DMEA); polysiloxanes; 2-methoxymethylthoxypropanol (DPM); emulsion of wax; water based polyamide solution; methylated melamine-formaldehyde resins; and alkoxylated alcohol. The coating material may further contain hydroxyphenyl benzotriazol, bis(1,2,2,6,6-pentamethyl-4-piperidnyl)sebacate and methyl(1,2,2,6,6-pentamethyl-4-piperidnyl)sebacate. Such a frosting coating material according to the present invention may further contain hydroxyphenyl benzotriazol, bis(1,2,2,6,6-pentamethyl-4-piperidnyl)sebacate and methyl(1,2,2,6,6-pentamethyl-4-piperidnyl)sebacate. The hydroxyphenyl benzotriazol, bis(1,2,2,6,6-pentamethyl-4-piperidnyl)sebacate and methyl(1,2,2,6,6-pentamethyl-4-piperidnyl)sebacate may preferably be used in 2-3 wt. parts (as solid) per 100 wt. parts (as solid) of the total of the thermoset acrylic resin material. [0033] In one aspect a frosted article according to the present invention is prepared by blending components of the frosting coating material to form a cloudy coating liquid. Then, the coating liquid is applied onto at least one surface of a substrate (e.g. of a glass or plastic item) and dried to a cured coating solution under heating in an oven, e.g. for at least ten minutes at a temperature of at least 350° F., or in a temperature range between 350-375° F. to provide a frosted article according to the present invention. Such a coating may be 0.002 inches thick. Such coating may be repeated several times, as desired, to provide an increased thickness of the coating film, with or without heating after each application. The heating may also be performed after several coating applications. [0034] Coating films according to the present invention may have a thickness of between 0.001-0.020 inches, e.g., for a cosmetic bottle between 0.001-0.010 inches and e.g. for window panels between 0.010-0.020 inches. The coating film thickness may be adjusted appropriately by applying a thinner or thicker layer of the coating liquid or by repeatedly applying the coating liquid in superposed applications. [0035] In one preferred embodiment of the frosting coating material according to the present invention, N,N-dimethylethanolamine (DMEA), methylated melamine-formaldehyde resin is mixed with water to form (e.g. agitated for 5 minutes) a uniform coating mixture liquid. Then polysiloxanes, emulsion of wax, water based polyamide solution, alkoxylated alcohol and polymethyl methacrylate are added, preferably with continuous high speed mixing, e.g. using a five horsepower floor-mounted electric-powered high speed dispenser running at a speed of 2500 rpm. The mixing speed is reduced (e.g. to 1200 rpm) and thermoset acrylic resin is added. For UV light absorbance properties hydroxyphenyl benzotriazol, bis(1,2,2,6,6-pentamethyl-4-piperidnyl)sebacate and methyl (1,2,2,6,6-pentamethyl-4-piperidnyl) sebacate are added to the uniform coating mixture liquid, which may be dried to provide a uniform film layer through uniform drying. [0036] In another embodiment of the frosting coating material according to the present invention, N,N-dimethylethanolamine (DMEA), methylated melamine-formaldehyde resin, water, polysiloxanes, emulsion of wax, water based polyamide solution, alkoxylated alcohol and polymethyl methacrylate are added (to water) with, optionally, continuous high speed mixing. The mixing speed is reduced to low, followed by the addition of the thermoset acrylic resin. For UV light absorbance properties hydroxyphenyl benzotriazol, bis(1,2,2,6,6-pentamethyl-4-piperidnyl)sebacate and methyl (1,2,2,6,6-pentamethyl-4-piperidnyl) sebacate are added to the uniform coating mixture liquid, which may be dried to provide a uniform film layer through uniform drying. [0037] In one particular embodiment—Embodiment A—according to the present invention, a coating liquid has, by weight: N,N-dimethylethanolamine (DMEA) 3.57 wt. parts, methylated melamine-formaldehyde resin 2.77 wt. parts, water 60.93 wt. parts, silicone solution 0.51 wt. parts {18.5 wt. % solution of polysiloxane in 81.5 wt. % of 2-methoxy methyl ethoxy propanol (DPM)}, polyacrylate copolymer solution 0.51 wt. parts {52.0 wt % solution of polyacrylate copolymer in 48.0 wt. % of 2-methoxy methyl ethoxy propanol (DPM)}, alkoxylated alcohol 0.51 wt. parts, polymethyl methacrylate 4.81 wt. parts, emulsion of wax 2.70 wt. parts (95.0 wt. % solution of non-ionic carnauba wax in 5.0 wt. % of butyl cellosolve) polyamide aqueous solution 1.82 wt. % (20.0 wt. % solution of polyamide-based thixotrope in 7.0 wt. % propylene glycol mono methyl ether and 73.0 wt. % water), clear water reducible thermosetting acrylic emulsion 21.86 wt. parts {75.0 wt. % in solvent (butoxyethanol/n-butanol 83/17, acid value on solid=56%, hydroxyl number on solids=54)}. [0047] A coating liquid was prepared with the components as in Embodiment A. N,N-dimethylethanolamine (DMEA) 3.57 wt. parts, methylated melamine-formaldehyde resin 2.77 wt. parts, water 60.93 wt. parts, polysiloxane solution 0.51 wt. parts, polyacrylate copolymer solution 0.51 wt. parts, alkoxylated alcohol 0.51 wt. parts, polymethyl methacrylate 4.81 wt. parts, emulsion of carnauba wax 2.70 wt. parts, polyamide aqueous solution 1.82 wt. parts were mixed together for 30 minutes at room temperature (about 25° C.) and the resultant mixture was further stirred for 10 min. at room temperature (25° C.), followed by the addition of clear water reducible thermosetting acrylic emulsion 21.86 wt. parts, stirred for 15 minutes at ambient temperature, to produce a coating liquid (coating liquid A). This coating liquid was clear and was applied onto a glass panel by spraying, followed by 10 min. of drying in a conventional oven at 350° F. (177° C.) providing a uniform, colorless and clear coating film with a thickness of several thicknesses (from 0.005-0.010 inches). In another aspect, the thus-prepared coating liquid A was clear and applied onto a glass panel by brushing, followed by 10 minutes of drying in a conventional oven at 350° F. (177° C.), providing a uniform, colorless and clear coating film having a thickness of several thicknesses (from 0.005-0.010 inches). [0048] In another aspect this thus-prepared coating liquid A was clear and was applied onto a glass panel by spraying, followed by 3.0 minutes of drying in a conventional infrared oven at 350° F. (177° C.), providing a uniform, colorless and clear coating film having a thickness of several thicknesses (from 0.005-0.010 inches). [0049] In another aspect the thus-prepared coating liquid A was clear and applied onto a glass panel by brushing, followed by 3.0 minutes of drying in a conventional infrared oven at 350° F. (177° C.), providing a uniform, colorless and clear coating film having a thickness of several thicknesses (from 0.005-0.010 inches). [0050] Such coated glass panels were then left standing in an environment of ambient temperature for 5.0 minutes for cooling. [0051] The following tests were performed for these coated panels: Tape adhesion as per ASTM D3359, Method A (X-cut tape test); Pencil hardness as per ASTM D3363: Abrasion resistance as per ASTM D4060; Accelerated weathering as per ASTM G23, ASTM G26 and ASTM G53; Corrosion resistance by Salt fog method as per ASTM B117; Humidity as per ASTM D2247 and D4585; and Chemical resistance using different chemicals. Test results were: Adhesion Test According to ASTM D-3359, apply approximately 25×12 nm of an adhesive tape was applied to the coated Aqua-222, Aqua-333UV and Aqua-444UV surface. After the snap removal (normal to surface) of the tape, no deterioration of the coating was visible with unaided eye under normal illumination. Abrasion Test According to ASTM D-4060 by using the equipment manufactured by Taber Instrument (Model 5130), the coated surface which can be turned on a vertical axis is contacted by two abrading wheels (Hardness: CS-10) under the load of 500 g, the coated sample is then driven to turn. After 20 circles, the coated surface does not show any evidence of damage or coating removal with unaided eye under normal illumination. Solubility Test The coated glass was immersed to salt water (concentration: 45 g/l) for 24 hours at room temperature. After being washed with DI water and dried up with soft cloth, the coating showed no evidence of flaking, peeling, cracking or blistering with unaided eye under normal illumination. Humidity Test The coated glass was exposed to an atmosphere of 90-95% relative humidity and 55° C. for 16 hours. No deterioration of the coating was visible with unaided eye under normal illumination. Chemical Durability Test (ASTM D-1308) With unaided eye under normal illumination, the coating showed no evidence of deterioration after one of the following agents remained on the coated surface for more than 24 hours. Agents: Acetone; Methanol alcohol; Isopropanol alcohol; Glass polishing agent (A1302) Stamping ink; Permanent marker; Tea; Coffee; Chocolate; Glass cleaning detergents (Ajax). Salt Spray (fog) Resistance [0064] Also known as salt fog testing is generally conducted according to ASTM B-117. The aqua coated glass samples were prepared and suspended in a sealed chamber where they were subjected to a spray or fog of a neutral 5% salt solution atomized at a temperature of 95° F. No deterioration of the coating was visible with unaided eye under normal illumination. QUV Accelerated Weathering (ASTM F-883) This test reproduces the damage caused by sunlight, rain and dew. The aqua coated glass samples were prepared and placed in a chamber where they were exposed to alternating cycles of light and moisture at controlled, elevated temperatures. The QUV simulates the effect of sunlight with fluorescent ultraviolet lamps. The test simulates dew and rain with condensing humidity and water sprays. No deterioration of the coating was visible with unaided eye under normal illumination. [0067] One particular embodiment of a coating liquid according to the present invention—Embodiment B—has, by weight: N,N-dimethylethanolamine (DMEA) 3.54 wt. parts, methylated melamine-formaldehyde resin 2.75 wt. parts, water 60.45 wt. parts, silicone solution 0.50 wt. parts {18.5 wt. % solution of polysiloxane in 81.5 wt. % of 2-methoxy methyl ethoxy propanol (DPM)}, polyacrylate copolymer solution 0.50 wt. parts {52.0 wt.% solution of polyacrylate copolymer in 48.0 wt. % of 2-methoxy methyl ethoxy propanol (DPM)}, alkoxylated alcohol 0.50 wt. parts, polymethyl methacrylate 4.78 wt. parts, emulsion of wax 2.68 wt. parts (95.0 wt. % solution of non-ionic carnauba wax in 5.0 wt. % of butyl cellosolve) polyamide aqueous solution 1.81 wt. % (20.0 wt. % solution of polyamide-based thixotrope in 7.0 wt. % propylene glycol mono methyl ether and 73.0 wt. % water), UV absorber 0.47 wt. parts (50.0 wt. % ?-[3-[3-(2H-Benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydro xyphenyl)-1-oxopropyl]-hydroxypoly(oxo-1,2-ethanediyl), 38.0 wt. % -[3-[3-(2H-Benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydrox yphenyl]-1-oxopropyl]-?-[3-[3-(2H-benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropoxy]poly(oxy-1,2-et hanediyl); 12.0 wt. % polyethyleneglycol 300, light stabilizer 0.33 wt. parts (50.0 wt. % bis(1,2,2,6,6-pentamethyl-4-piperidinyl)sebacate Molecular weight, 50.0 wt. % Methyl(1,2,2,6,6-pentamethyl-4-piperidinyl)sebacateMolecular weight: 370), clear water reducible thermosetting acrylic emulsion 21.69 wt. parts {75.0 wt. % in solvent (butoxyethanol/n-butanol 83/17, acid value on solid =56%, hydroxyl number on solids=54)}. [0078] A coating liquid was prepared with these components as in Embodiment B. N,N-dimethylethanolamine (DMEA) 3.54 wt. parts, methylated melamine-formaldehyde resin 2.75 wt. parts, water 60.45 wt. parts, polysiloxane solution 0.50 wt. parts, polyacrylate copolymer solution 0.50 wt. parts, alkoxylated alcohol 0.50 wt. parts, polymethyl methacrylate 4.78 wt. parts, emulsion of carnauba wax 2.68 wt. parts, polyamide aqueous solution 1.81 wt. parts, UV absorber 0.47 wt. parts, light stabilizer 0.33 wt. parts were mixed together, and the resultant mixture was further stirred for 10 min. at room temperature (25° C.), followed by the addition of clear water reducible thermosetting acrylic emulsion 21.69 wt. parts and 15 minutes of stirring at ambient temperature, producing a coating liquid (coating liquid B). [0079] Such a coating liquid B was clear and was applied onto a glass panel by spraying, followed by 10 minutes of drying in a conventional oven at 350° F. (177° C.), providing a uniform, colorless and clear coating film having a thickness of several thicknesses (from 0.005-0.010 inches). [0080] Such a coating liquid B was clear and was applied onto a glass panel by brushing, followed by 10 minutes of drying in a conventional oven at 350° F. (177° C.), providing a uniform, colorless and clear coating film having a thickness of several thicknesses (from 0.005-0.010 inches). [0081] Such a coating liquid B was clear and was applied onto a glass panel by spraying, followed by 3.0 minutes of drying in a conventional infrared oven at 350° F. (177° C.), providing a uniform, colorless and clear coating film having a thickness of several thicknesses (from 0.005-0.010 inches). [0082] Such a coating liquid B was clear and applied onto a glass panel by brushing, followed by 3.0 minutes of drying in a conventional infrared oven at 350° F. (177° C.), providing a uniform, colorless and clear coating film having a thickness of several thicknesses (from 0.005-0.010 inches). [0083] Such coated glass panels were then left standing in an environment of ambient temperature for 5.0 minutes for cooling. [0084] The following tests were performed for these coated panels: Tape adhesion as per ASTM D3359, Method A (X-cut tape test); Pencil hardness as per ASTM D3363: Abrasion resistance as per ASTM D4060; Accelerated weathering as per ASTM G23, ASTM G26 and ASTM G53; Corrosion resistance by Salt fog method as per ASTM B117; Humidity as per ASTM D2247 and D4585; and Chemical resistance using different chemicals. Test results were: Adhesion Test According to ASTM D-3359, approximately 25×12 nm of an adhesive tape was applied to the coated Aqua-222, Aqua-333UV and Aqua-444UV surface, after the snap removal (normal to surface) of the tape, no deterioration of the coating was visible with unaided eye under normal illumination. Abrasion Test According to ASTM D-4060 by using the equipment manufactured by Taber Instrument (Model 5130), the coated surface which can be turned on a vertical axis was contacted by two abrading wheels (Hardness: CS-10) under the load of 500 g, the coated sample was then driven to turn. After 20 circles, the coated surface did not show any evidence of damage or coating removal with unaided eye under normal illumination. Solubility Test The coated glass was immersed to salt water (concentration: 45 g/l) for 24 hours at room temperature. After being washed with DI water and dried up with soft cloth, the coating showed no evidence of flaking, peeling, cracking or blistering with unaided eye under normal illumination. Humidity Test The coated glass is exposed to an atmosphere of 90-95% relative humidity and 55° C. for 16 hours. No deterioration of the coating was visible with unaided eye under normal illumination. Chemical Durability Test (ASTM D-1308) With unaided eye under normal illumination, the coating showed no evidence of deterioration after one of the following agents remained on the coated surface for more than 24 hours. Agents: Acetone; Methanol alcohol; Isopropanol alcohol; Glass polishing agent (A1302) Stamping ink; Permanent marker; Tea; Coffee; Chocolate; Glass cleaning detergents (Ajax). Salt Spray (fog) Resistance Also known as salt fog testing is generally conducted according to ASTM B-117. The aqua coated glass samples were prepared and suspended in a sealed chamber where they were subjected to a spray or fog of a neutral 5% salt solution atomized at a temperature of 95° F. No deterioration of the coating was visible with unaided eye under normal illumination. QUV Accelerated Weathering (ASTM F-883) This test reproduces the damage caused by sunlight, rain and dew. The aqua coated glass samples were prepared and placed in a chamber where they were exposed to alternating cycles of light and moisture at controlled, elevated temperatures. The QUV simulates the effect of sunlight with fluorescent ultraviolet lamps. The test simulates dew and rain with condensing humidity and water sprays. No deterioration of the coating was visible with unaided eye under normal illumination. [0100] The present invention provides a frosted article with: a substrate and a coating film formed on the substrate (any coating disclosed herein), e.g., but not limited to, a coating formed by application of a solution containing a thermoset acrylic resin, polymethyl methacrylate, N,N-dimethylethanolamine (DMEA), polysiloxanes, 2-methoxymethylthoxypropanol (DPM), emulsion of wax, water based polyamide solution, methylated melamine-formaldehyde resins and alkoxylated alcohol and hydroxyphenyl benzotriazol, bis(1,2,2,6,6-pentamethyl-4-piperidnyl)sebacate and methyl(1,2,2,6,6-pentamethyl-4-piperidnyl)sebacate. These coatings can be applied by spraying, e.g. with a High Volume Low Pressure (HVLP) unit, e.g. a Campbell Hausfeld HVLP Spray gun; and/or they can be brushed on with a typical paint brush or paint roller. [0101] In certain aspects a frosting coating film formed of the frosting coating material according to the present invention is water-insoluble, and has a high surface hardness and excellent durability. Without being tied to any specific theory, process or mechanism, it is noted that such properties in certain aspects according to the present invention may be attributable to an improved-mutual solubility between the thermoset acrylic resin, polymethyl methacrylate, N,N-dimethylethanolamine (DMEA), and methylated melamine-formaldehyde resin. More specifically, a thermoset acrylic resin compound and methylated melamine-formaldehyde resin form a uniform coating film. The coating film is hard, excellent in durability and water-insoluble. This is presumably because the improved mutual solubility between the polyacrylic resin compound and methylated melamine-formaldehyde resin promotes mutual interaction of polymer chains of these compounds to provide an insoluble coating film. [0102] In certain particular embodiments a coating liquid for Embodiment A or Embodiment B contains the following ingredients (and the liquid is mixed and prepared in any method as described above for these embodiments): 1. An hydroxyl functional thermosetting water reducible acrylic resin which is reduced to about 30% solids by weight in water at a pH between 8.0 to 8.5 assisted by DMEA to become completely soluble in water. 2. Particulate material for a frosting appearance; e.g. fine particle silica and/or polymethyl methacrylate polymer. 3. A tertiary amine (e.g. DMEA) which combines characteristics of amines and alcohols, increases resin solubility, and improves solution stability by reducing pH drift (a natural phenomenon in which pH changes). This ingredient improves adhesion to glass and improves scratch and rub resistance properties. 4. A silicone defoamer for aqueous systems which inhibits or destroys foam created in the coating manufacturing process, combined with a solvent used in the formulation (e.g. 2-methoxy methyl ethoxy propanol solvent). 5. An additive to improve leveling (achieving a desired degree of flatness of a film surface) without adversely affecting surface tension, e.g. a solution of polyacrylate copolymers. 6. A polyamide thixotrope which becomes active when heated, e.g. a water-based polyamide solution which has good stability upon aging, good shear thinning (the ability to become sufficiently, even highly, fluid during application), non-seeding (prevention of undesirable particle aggregation and/or of coating defects due to material insolubility) and optimum anti-sagging/anti-settling properties. 7. A cross linking agent, e.g. a commercial grade hexamethoxy methyl melamine in liquid form (preferably a greater-than 98% non-volatile form) used as a cross linking agent with the thermoset acrylic resin (to become soluble in water) to produce good hardness in coating film flexibility 8. A foam-inhibiting and substrate wetting agent, e.g. a silicone-free additive for aqueous systems (e.g. alkoxylated alcohol). According to the present invention, in a coating liquid according to the present invention, of the eight ingredients listed above, ingredients 3, 4, 5, 6, and 8 are optional. [0111] Regarding the embodiments described above, a coating liquid prepared according to any of them can be manually applied, sprayed on, or roller coated (onto glass). [0112] By changing the concentration of ingredients 1-8 listed above different properties and different levels of properties can be achieved in a final coating. [0113] In other embodiments of the present invention, one, some, or all of the following ingredients are used: 9. A UV-filtering additive (e.g. certain hindered amine UV light stabilizers) which converts ultraviolet light waves into energy emitted in the infrared portion of the electromagnetic spectrum and does not produce infrared energy at levels which can damage certain items (e.g. artworks on canvas, parchment, cloth, paper, or the like); in one aspect an additive which blocks harmful UV from 70% to 99.9%, and, in one particular aspect, which blocks 99% or more (e.g. 99.9%) of UV at wavelengths of 300-380 nm) in very thin films, e.g. about 1 mil thick or less. 10. A slow evaporating ether-ester solvent with good film formation properties due to enhanced flow and leveling characteristics, low surface tension with ether-ester functionality (e.g. UCAR Ester EEP or ethyl 3-ethoxy propionate) 11. A synthetic paraffin used to provide a smooth feel, lubricity, and gloss control (e.g. a modified amide wax) 12. An additive used to form a thin layer (e.g. less than one micron) on a coating's surface improving slip (level of frictional resistance) blocking (high volatility materials which improve escape from drying films) mar resistance and scratch resistance (e.g. a polyether-modified methyl polysiloxane additive with, as an active ingredient, 75% by weight Dowanol DPnB (dipropylene glycol n-butyl ether). 13. A toughening additive to toughen a coating and improve chemical resistance and cure at reduced temperatures, (e.g. an amine blocked sulfonic acid catalyst). 14. A dye to reduce yellowness in a coating surface, e.g. anthraquinine dye C.I. (e.g. Acid Violet 43). 15. An additive with a high degree of toughness and lubricity to increase rub resistance, abrasion resistance and slip properties, e.g. a combination of polyethylene waxes and polytetrafluoroethylene (PTFE) (in one aspect, added in powder form). [0121] According to the present invention, each ingredient 9-15 listed above is optional for a coating liquid according to the present invention. [0122] In one particular embodiment, to produce a coating liquid according to the present invention, the following ingredients are mixed together in a blending apparatus with water at a slow speed and, optionally the resulting liquid is filtered e.g. using a 50 micron mesh filtration bag: [0123] 1. Water [0124] 2. Thermoset acrylic resin (water reducible acrylic [0125] 3. N,N-dimethylethanolamine (DMEA) [0126] 4. Polysiloxanes [0127] 5. Polyacrylate copolymer [0128] 6. Water based polyamide solution [0129] 7. Methylated melamine-formaldehyde resin [0130] 8. Alkoxylated alcohol [0131] 9. Polymethyl methacrylate [0132] 10. SCAR Ester EEP [0133] 11. Modified amide wax [0134] 12. Polyether-modified methyl polysiloxane [0135] 13. Amine blocked sulfonic acid catalyst [0136] 14. Polyethylene waxes and polytetrafluorethylene [0137] 15. Hindered amine UV light stabilizer [0138] 16. Anthraquinone Dye, C.I. [0139] In certain specific preferred embodiments of coating liquids according to the present invention, the ingredients listed above are used and adjusted for coating, preferably, specific items. Some of these are described below. [0140] Coating Liquid I can be used to coat, e.g. wine bottles, glassware, dishes and vases. [0141] Coating Liquid II, a UV blocking waterborne glass coating which filters ultraviolet (UV) damaging rays, can be used to coat wine bottles, glassware, dishes and vases. [0142] Coating Liquid III can be used for decoration of automotive windshields, glass-topped stoves and oven doors, shower doors and frosted or decorated glass panels. Coating Liquid III filters about 70% of ultraviolet light in the 300-380 nm wavelength range. [0143] Coating Liquid IV can be used for decoration of automotive windshields, glass-topped stoves and oven doors, shower doors and frosted or decorated glass panels. Coating Liquid IV filters 98% of ultraviolet light in the 300-380 nm wavelength range. [0144] Coating Liquid V can be used for glass for framing artworks and glass for “high-end framing.” This is known (e.g. in USA) as “non-glare” and (incorrectly) as non-reflecting glass with one or both surfaces altered to scatter or diffuse the reflected portion of visible light. Coating Liquid filters 70% of ultraviolet light in the 300-380 nm wavelength range. [0145] Coating Liquid VI can be used for glass for framing art works and for glass for “high-end framing.” Coating Liquid VI filters 98% of ultraviolet light in the 300-380 nm wavelength range. [0146] Coating Liquid VII can be used to produce a very thin coating. [0000] Coating Liquid I By Weight % 1. Water 60.81 2. Thermoset acrylic resin (water reducible acrylic) 18.97 3. N,N-dimethylethanolamine (DMEA) 1.57 4. Polysiloxanes 0.20 5. Polyacrylate copolymer 0.20 6. Water based polyamide solution 0.78 7. Methylated melamine-formaldehyde resin 7.44 8. Alkoxylated alcohol 0.20 9. Polymethyl methacrylate 0.60 10. SCAR Ester EEP 5.74 11. Modified amide wax 0.20 12. Polyether-modified methyl polysiloxane 0.35 13. Amine blocked sulfonic acid catalyst 0.47 14. Polyethylene waxes and polytetrafluorethylene 0.47 [0000] Coating Liquid II By Weight % 1. Water 50.0-65.0 2. Thermoset acrylic resin (water reducible acrylic) 15.0-20.0 3. N,N-dimethylethanolamine (DMEA) 1.0-3.0 4. Polysiloxanes 0.1-0.4 5. Polyacrylate copolymer 0.1-0.4 6. Water based polyamide solution 1.0-2.0 7. Methylated melamine-formaldehyde resin 5.0-9.0 8. Alkoxylated alcohol 0.1-0.4 9. Polymethyl methacrylate 2.0-4.0 10. SCAR Ester EEP 4.0-7.0 11. Modified amide wax 0.1-0.4 12. Polyether-modified methyl polysiloxane 0.2-0.5 13. Amine blocked sulfonic acid catalyst 0.3-0.7 14. Polyethylene waxes and polytetrafluorethylene 0.4-0.7 16. UV absorbency hydroxyphenyl benzotriazol 0.2-0.4 17. Hindered amine light stabilizer 0.1-0.3 bis(1,2,2,6,6-pentamethyl-4-piperidnyl)sebacate & methyl(1,2,2,6,6-pentamethyl-r-piperidnyl)sebacate [0000] Coating Liquid III By Weight % 1. Water 50.0-70.0 2. Thermoset acrylic resin (water reducible acrylic) 17.0-25.0 3. N,N-dimethylethanolamine (DMEA) 0.5-1.5 4. Polysiloxanes 0.1-0.3 5. Polyacrylate copolymer 0.1-0.3 6. Water based polyamide solution 0.1-0.3 7. Methylated melamine-formaldehyde resin 6.0-9.5 8. Alkoxylated alcohol 0.1-0.3 9. Polymethyl methacrylate 1.5-3.0 10. SCAR Ester EEP 3.0-5.0 11. Modified amide wax 0.1-0.3 12. Polyether-modified methyl polysiloxane 0.1-0.3 13. Amine blocked sulfonic acid catalyst 0.3-0.6 14. Polyethylene waxes and polytetrafluorethylene 0.3-0.5 15. Hindered amine UV light stabilizer 2.0-4.0 [0000] Coating Liquid IV By Weight % 1. Water 55.0-65.0 2. Thermoset acrylic resin (water reducible acrylic) 15.0-20.0 3. N,N-dimethylethanolamine (DMEA) 0.5-1.5 4. Polysiloxanes 0.1-0.3 5. Polyacrylate copolymer 0.1-0.3 6. Water based polyamide solution 0.3-0.7 7. Methylated melamine-formaldehyde resin 6.0-9.0 8. Alkoxylated alcohol 0.1-0.3 9. Polymethyl methacrylate 2.0-4.0 10. SCAR Ester EEP 2.5-4.5 11. Modified amide wax 0.1-0.2 12. Polyether-modified methyl polysiloxane 0.1-0.3 13. Amine blocked sulfonic acid catalyst 0.3-0.6 14. Polyethylene waxes and polytetrafluorethylene 0.7-1.0 15. Hindered amine UV light stabilizer 5.0-8.0 [0000] Coating Liquid V By Weight % 1. Water 55.0-70.0 2. Thermoset acrylic resin (water reducible acrylic) 18.0-25.0 3. N,N-dimethylethanolamine (DMEA) 0.7-1.5 4. Polysiloxanes 0.1-0.3 5. Polyacrylate copolymer 0.1-0.3 6. Water based polyamide solution 0.2-0.3 7. Methylated melamine-formaldehyde resin 7.0-9.0 8. Alkoxylated alcohol 0.1-0.3 9. Polymethyl methacrylate 0.3-0.5 10. SCAR Ester EEP 3.0-5.0 11. Modified amide wax 0.1-0.3 12. Polyether-modified methyl polysiloxane 0.2-0.3 13. Amine blocked sulfonic acid catalyst 0.4-0.7 14. Polyethylene waxes and polytetrafluorethylene 0.3-0.5 15. Hindered amine UV light stabilizer 2.0-2.5 [0000] Coating Liquid VI By Weight % 1. Water 50.0-62.0 2. Thermoset acrylic resin (water reducible acrylic) 17.0-22.0 3. N,N-dimethylethanolamine (DMEA) 0.7-1.2 4. Polysiloxanes 0.1-0.3 5. Polyacrylate copolymer 0.1-0.3 6. Water based polyamide solution 0.3-0.6 7. Methylated melamine-formaldehyde resin 6.5-8.5 8. Alkoxylated alcohol 0.1-0.3 9. Polymethyl methacrylate 0.4-0.6 10. SCAR Ester EEP 2.7-5.0 11. Modified amide wax 0.1-0.3 12. Polyether-modified methyl polysiloxane 0.2-0.3 13. Amine blocked sulfonic acid catalyst 0.3-0.6 14. Polyethylene waxes and polytetrafluorethylene 0.8-1.2 15. Hindered amine UV light stabilizer 5.5-8.0 [0147] In one aspect, Coating Liquid VII is prepared by mixing the following ingredients: [0000] By Coating Liquid VII Weight % 1. Water 0. 2. Thermoset acrylic resin (water reducible acrylic) — 3. N,N-dimethylethanolamine (DMEA) — 4. Polysiloxanes — 5. Polyacrylate copolymer 0. 6. Water based polyamide solution 0. 7. Methylated melamine-formaldehyde resin 7.44 8. Alkoxylated alcohol 0.20 9. Polymethyl methacrylate 0.60 10. SCAR Ester EEP 5.74 11. Modified amide wax 0.20 12. Polyether-modified methyl polysiloxane 0.35 13. Amine blocked sulfonic acid catalyst 0.47 14. Polyethylene waxes and polytetrafluorethylene 0.47 15. Hindered amine UV light stabilizer 16. UV absorbency hydroxyphenyl benzotriazol 17. Hindered amine light stabilizer bis (1,2,2,6,6-pentamethyl-4-piperidnyl) sebacate & methyl) (1,2,2,6,6-pentamethyl-4-piperidnyl sebacat [0148] In certain embodiments, a coating (e.g. any coating according to the present invention e.g., but not limited to, Coating Liquid I or II) is applied to a clean glass item, e.g. a bottle or block, by spraying and the coating is then baked and cooled. For example, a clean bottle 10 , FIG. 1A , is sprayed with the selected coating, producing a coating 12 (not to scale, sized exaggerated as shown). The bottle 10 a is then baked, e.g. in a convection oven at 350° F. (177° C.) for 10 minutes or in an infrared oven at 350° F. (177° C.) for 2 minutes. Alternatively, any coating according to the present invention (e.g., but not limited to Coating Liquids III and VI) is applied to an item, e.g. a bottle, or a glass panel with a roller or sprayed with a spray gun and baked as described above in a convection oven, an infrared oven, or both. [0149] The methods described above according to the present invention can be used to coat and frost a pane of glass to be used to protect an artwork, e.g. a painting, print, etching, drawing, tapestry, document, photograph, or lithograph, e.g. in a frame system with a frame and/or with a backing layer, plate, or piece. For example, a piece of transparent glass 20 , FIG. 2A , is coated with a coating according to the present invention, using any method or coating described above and baked according to any method according to the present invention. The coated, baked piece of glass 20 is then placed over an artwork, e.g. artwork 22 and framed with a frame 24 , with a backing element 26 . Optionally the backing element, frame, or both are deleted. [0150] FIG. 3A shows a prior art glass block GB. FIG. 3B shows a glass block 30 according to the present invention which is a block like the block GB, but with a surface 32 coated with a coating 34 according to the present invention (any coating disclosed herein). The coating liquids described above are well-suited for coating glass blocks. Any and all surfaces of a glass block may be coated according to the present invention. [0151] In one particular embodiment C-1 of a system and method according to the present invention, there is provided a frosting coating material or composition with: thermoset acrylic resin; polymethyl methacrylate, N,N-dimethylethanolamine (DMEA); polysiloxanes; 2-methoxymethylthoxypropanol (DPM); emulsion of wax; water based polyamide solution; methylated melamine-formaldehyde resins; alkoxylated alcohol, and any two of the following or all three of the following are added: (a.) an adhesion promoter which may also be a cross linking agent and surface modifier, e.g. ((3-(2,3, epoxypropoxy) propyl) trimethoxysilane)), 3-glycidyloxypropyl-trimethoxysilane, e.g. commercially available Dynasylan (registered trademark) GLYMO material from Evonik Industries; (b.) an ultraviolet light disperser e.g. which scatters and/or reflects ultraviolet light, e.g. an aqueous ultrafine titanium dioxide dispersion for waterborne coatings, e.g. ultraviolet disperser DAPRO (registered trademark) UV CW 30 material from Elementis Specialties, Inc.; and (c.) a material freeze-thaw protector which, in certain aspects, levels a coating's surface film, e.g. propylene glycol. The coating material may further contain hydroxyphenyl benzotriazol, bis(1,2,2,6,6-pentamethyl-4-piperidnyl)sebacate and methyl(1,2,2,6,6-pentamethyl-4-piperidnyl)sebacate. Such a frosting coating material according to the present invention may further contain hydroxyphenyl benzotriazol, bis(1,2,2,6,6-pentamethyl-4-piperidnyl)sebacate and methyl(1,2,2,6,6-pentamethyl-4-piperidnyl)sebacate. The hydroxyphenyl benzotriazol, bis(1,2,2,6,6-pentamethyl-4-piperidnyl)sebacate and methyl(1,2,2,6,6-pentamethyl-4-piperidnyl)sebacate may preferably be used in 2-3 wt. parts (as solid) per 100 wt. parts (as solid) of the total of the thermoset acrylic resin material. [0152] In one particular embodiment—Embodiment C-1—according to the present invention, a coating liquid has, by weight: N,N-dimethylethanolamine (DMEA) 3.57 wt. parts, methylated melamine-formaldehyde resin 2.77 wt. parts, water 60.93 wt. parts, silicone solution 0.51 wt. parts {18.5 wt. % solution of polysiloxane in 81.5 wt. % of 2-methoxy methyl ethoxy propanol (DPM)}, polyacrylate copolymer solution 0.51 wt. parts {52.0 wt % solution of polyacrylate copolymer in 48.0 wt. % of 2-methoxy methyl ethoxy propanol (DPM)}, alkoxylated alcohol 0.51 wt. parts, polymethyl methacrylate 4.81 wt. parts, optionally, emulsion of wax 2.70 wt. parts (95.0 wt. % solution of non-ionic carnauba wax in 5.0 wt. % of butyl cellosolve) polyamide aqueous solution 1.82 wt. % (20.0 wt. % solution of polyamide-based thixotrope in 7.0 wt. % propylene glycol mono methyl ether and 73.0 wt. % water), clear water reducible thermosetting acrylic emulsion 21.86 wt. parts {75.0 wt. % in solvent (butoxyethanol/n-butanol 83/17, acid value on solid=56%, hydroxyl number on solids=54)}. [0162] In an Embodiment C-2 (like C-1), the emulsion of wax is deleted and any two of the following or all three of the following are added: (a.) an adhesion promoter which may also be a cross linking agent and surface modifier, e.g. ((3-(2,3, epoxypropoxy) propyl) trimethoxysilane)), 3-glycidyloxypropyl-trimethoxysilane, e.g. commercially available Dynasylan (registered trademark) GLYMO material from Evonik Industries; (b.) an ultraviolet light disperser e.g. which scatters and/or reflects ultraviolet light, e.g. an aqueous ultrafine titanium dioxide dispersion for waterborne coatings, e.g. ultraviolet disperser DAPRO (registered trademark) UV CW 30 material from Elementis Specialties, Inc.; and (c.) a material freeze-thaw protector which, in certain aspects, levels a coating's surface film, e.g. propylene glycol. In certain aspects, in the total volume of the coating liquid, the two or three added ingredients are present by volume as follows: [0000] Range Preferred Adhesion Promoter 2% to 5% 3% UV Disperser  .50% to 2.00% .68% or .98% Freeze-Thaw Protector 3% to 7% 4.61% or 5.19% [0163] Coating liquids C-1 and C-2 are prepared with the components as in Embodiment A. The ingredients (a.), (b.), and/or (c.) are stirred into the mixture. [0164] One particular embodiment of a coating liquid according to the present invention—Embodiment D-1—has, by weight: N,N-dimethylethanolamine (DMEA) 3.54 wt. parts, methylated melamine-formaldehyde resin 2.75 wt. parts, water 60.45 wt. parts, silicone solution 0.50 wt. parts {18.5 wt. % solution of polysiloxane in 81.5 wt. % of 2-methoxy methyl ethoxy propanol (DPM)}, polyacrylate copolymer solution 0.50 wt. parts {52.0 wt. % solution of polyacrylate copolymer in 48.0 wt. % of 2-methoxy methyl ethoxy propanol (DPM)}, alkoxylated alcohol 0.50 wt. parts, polymethyl methacrylate 4.78 wt. parts, optionally, emulsion of wax 2.68 wt. parts (95.0 wt. % solution of non-ionic carnauba wax in 5.0 wt. % of butyl cellosolve) polyamide aqueous solution 1.81 wt. % (20.0 wt. % solution of polyamide-based thixotrope in 7.0 wt. % propylene glycol mono methyl ether and 73.0 wt. % water), UV absorber 0.47 wt. parts (50.0 wt. % ?-[3-[3-(2H-Benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydro xyphenyl]-1-oxopropyl]-hydroxypoly(oxo-1,2-ethanediyl), 38.0 wt. % -[3-[3-(2H-Benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydrox yphenyl]-1-oxopropyl]-?-[3-[3-(2H-benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropoxy)poly(oxy-1,2-et hanediyl); 12.0 wt. % polyethyleneglycol 300, light stabilizer 0.33 wt. parts (50.0 wt. % bis(1,2,2,6,6-pentamethyl-4-piperidinyl)sebacate Molecular weight, 50.0 wt. % Methyl(1,2,2,6,6-pentamethyl-4-piperidinyl)sebacateMolecular weight: 370), clear water reducible thermosetting acrylic emulsion 21.69 wt. parts {75.0 wt. % in solvent (butoxyethanol/n-butanol 83/17, acid value on solid=56%, hydroxyl number on solids=54)}. [0175] In one Embodiment D-2 (like D-1), the emulsion of wax is deleted and any two of the following or all three of the following are added: (a.) an adhesion promoter which may also be a cross linking agent and surface modifier, e.g. ((3-(2,3, epoxypropoxy) propyl) trimethoxysilane)), 3-glycidyloxypropyl-trimethoxysilane, e.g. commercially available Dynasylan (registered trademark) GLYMO material from Evonik Industries; (b.) an ultraviolet light disperser e.g. which scatters and/or reflects ultraviolet light, e.g. an aqueous ultrafine titanium dioxide dispersion for waterborne coatings, e.g. ultraviolet disperser DAPRO (registered trademark) UV CW 30 material from Elementis Specialties, Inc.; and (c.) a material freeze-thaw protector which, in certain aspects, levels a coating's surface film, e.g. propylene glycol. In certain aspects, in the total volume of the coating liquid, the two or three added ingredients are present by volume as follows: [0000] Range Preferred Adhesion Promoter 2% to 5% 3% UV Disperser  .50% to 2.00% .68% or .98% Freeze-Thaw Protector 3% to 7% 4.61% or 5.19% [0176] Coating liquids D-1 and D-2 are prepared with their components as in Embodiment B. The ingredients (a.), (b.), and/or (c.) are stirred into the mixture. [0177] In certain particular embodiments a coating liquid according to the present invention contains the following ingredients (and the liquid is mixed and prepared in any method as described herein): 1. An hydroxyl functional thermosetting water reducible acrylic resin which is reduced to about 30% solids by weight in water at a pH between 8.0 to 8.5 assisted by DMEA to become completely soluble in water. 2. Particulate material for a frosting appearance; e.g. fine particle silica and/or polymethyl methacrylate polymer. 3. A tertiary amine (e.g. DMEA) which combines characteristics of amines and alcohols, increases resin solubility, and improves solution stability by reducing pH drift (a natural phenomenon in which pH changes). This ingredient improves adhesion to glass and improves scratch and rub resistance properties. 4. A silicone defoamer for aqueous systems which inhibits or destroys foam created in the coating manufacturing process, combined with a solvent used in the formulation (e.g. 2-methoxy methyl ethoxy propanol solvent). 5. An additive to improve leveling (achieving a desired degree of flatness of a film surface) without adversely affecting surface tension, e.g. a solution of polyacrylate copolymers. 6. A polyamide thixotrope which becomes active when heated, e.g. a water-based polyamide solution which has good stability upon aging, good shear thinning (the ability to become sufficiently, even highly, fluid during application), non-seeding (prevention of undesirable particle aggregation and/or of coating defects due to material insolubility) and optimum anti-sagging/anti-settling properties. 7. A cross linking agent, e.g. a commercial grade hexamethoxy methyl melamine in liquid form (preferably a greater-than 98% non-volatile form) used as a cross linking agent with the thermoset acrylic resin (to become soluble in water) to produce good hardness in coating film flexibility 8. A foam-inhibiting and substrate wetting agent, e.g. a silicone-free additive for aqueous systems (e.g. alkoxylated alcohol); and Any two of the following or all three of the following: (a.) an adhesion promoter which may also be a cross linking agent and surface modifier, e.g. ((3-(2,3, epoxypropoxy) propyl) trimethoxysilane)), 3-glycidyloxypropyl-trimethoxysilane, e.g. commercially available Dynasylan (registered trademark) GLYMO material from Evonik Industries; (b.) an ultraviolet light disperser e.g. which scatters and/or reflects ultraviolet light, e.g. an aqueous ultrafine titanium dioxide dispersion for waterborne coatings, e.g. ultraviolet disperser DAPRO (registered trademark) UV CW 30 material from Elementis Specialties, Inc.; and (c.) a material freeze-thaw protector which, in certain aspects, levels a coating's surface film, e.g. propylene glycol. According to the present invention, in a coating liquid according to the present invention, of the eight ingredients listed above, ingredients 3, 4, 5, 6, and 8 are optional. [0187] Regarding the embodiments described above, a coating liquid prepared according to any of them can be manually applied, sprayed on, or roller coated (onto glass). [0188] By changing the concentration of ingredients 1-8 listed above different properties and different levels of properties can be achieved in a final coating. [0189] In other embodiments of the present invention, one, some, or all of the following ingredients are used: 9. A UV-filtering additive (e.g. certain hindered amine UV light stabilizers) which converts ultraviolet light waves into energy emitted in the infrared portion of the electromagnetic spectrum and does not produce infrared energy at levels which can damage certain items (e.g. artworks on canvas, parchment, cloth, paper, or the like); in one aspect an additive which blocks harmful UV from 70% to 99.9%, and, in one particular aspect, which blocks 99% or more (e.g. 99.9%) of UV at wavelengths of 300-380 nm) in very thin films, e.g. about 1 mil thick or less. 10. A slow evaporating ether-ester solvent with good film formation properties due to enhanced flow and leveling characteristics, low surface tension with ether-ester functionality (e.g. UCAR Ester EEP or ethyl 3-ethoxy propionate) 11. A synthetic paraffin used to provide a smooth feel, lubricity, and gloss control (e.g. a modified amide wax) 12. An additive used to form a thin layer (e.g. less than one micron) on a coating's surface improving slip (level of frictional resistance) blocking (high volatility materials which improve escape from drying films) mar resistance and scratch resistance (e.g. a polyether-modified methyl polysiloxane additive with, as an active ingredient, 75% by weight Dowanol DPnB (dipropylene glycol n-butyl ether). 13. A toughening additive to toughen a coating and improve chemical resistance and cure at reduced temperatures, (e.g. an amine blocked sulfonic acid catalyst). 14. A dye to reduce yellowness in a coating surface, e.g. anthraquinine dye C.I. (e.g. Acid Violet 43). 15. An additive with a high degree of toughness and lubricity to increase rub resistance, abrasion resistance and slip properties, e.g. a combination of polyethylene waxes and polytetrafluoroethylene (PTFE) (in one aspect, added in powder form). [0197] According to the present invention, each ingredient 9-15 listed above is optional for a coating liquid according to the present invention. [0198] In one particular embodiment, to produce a coating liquid according to the present invention, the following ingredients are mixed together in a blending apparatus with water at a slow speed and, optionally the resulting liquid is filtered e.g. using a 50 micron mesh filtration bag: 1. Water 2. Thermoset acrylic resin (water reducible acrylic 3. N,N-dimethylethanolamine (DMEA) 4. Polysiloxanes 5. Polyacrylate copolymer 6. Water based polyamide solution 7. Methylated melamine-formaldehyde resin 8. Alkoxylated alcohol 9. Polymethyl methacrylate 10. SCAR Ester EEP 11. Modified amide wax 12. Polyether-modified methyl polysiloxane 13. Amine blocked sulfonic acid catalyst 14. Hindered amine UV light stabilizer 15. Anthraquinone Dye, C.I.; and Any two of the following or all three of the following: (a.) an adhesion promoter which may also be a cross linking agent and surface modifier, e.g. ((3-(2,3, epoxypropoxy) propyl) trimethoxysilane)), 3-glycidyloxypropyl-trimethoxysilane, e.g. commercially available Dynasylan (registered trademark) GLYMO material from Evonik Industries; (b.) an ultraviolet light disperser e.g. which scatters and/or reflects ultraviolet light, e.g. an aqueous ultrafine titanium dioxide dispersion for waterborne coatings, e.g. ultraviolet disperser DAPRO (registered trademark) UV CW 30 material from Elementis Specialties, Inc.; and (c.) a freeze-thaw protector, e.g. propylene glycol. In certain aspects, in the total volume of the coating liquid, the two or three added ingredients (a.), (b.), and/or (c.) are present by volume as follows: [0000] Range Preferred Adhesion Promoter 2% to 5% 3% UV Disperser  .50% to 2.00% .68% or .98% Freeze-thaw Protector 3% to 7% 4.61% or 5.19% [0214] In any of the Coating Liquid I-Coating Liquid VII listed above, ingredient No. 14 may be deleted and the Coating Liquid may include any two of the following or all three of the following: (a.) an adhesion promoter which may also be a cross linking agent and surface modifier, e.g. ((3-(2,3, epoxypropoxy) propyl) trimethoxysilane)), 3-glycidyloxypropyl-trimethoxysilane, e.g. commercially available Dynasylan (registered trademark) GLYMO material from Evonik Industries; (b.) an ultraviolet light disperser e.g. which scatters and/or reflects ultraviolet light, e.g. an aqueous ultrafine titanium dioxide dispersion for waterborne coatings, e.g. ultraviolet disperser DAPRO (registered trademark) UV CW 30 material from Elementis Specialties, Inc.; and (c.) a material freeze-thaw protector which, in certain aspects, levels a coating's surface film, e.g. propylene glycol. In certain aspects, in the total volume of the coating liquid, the two or three added ingredients are present by volume as follows: [0000] Range Adhesion Promoter 2% to 5% UV Disperser  .50% to 2.00% Freeze-Thaw Protector 3% to 7% [0215] In certain particular aspects, the two or three added ingredients for the Coating I are present by volume as follows: [0000] Adhesion Promoter   3% UV Disperser 0.68% Freeze-Thaw Protector 4.61% [0216] In certain particular aspects, the two or three added ingredients are present by volume in the Coating Liquids II-VII as follows: [0000] Adhesion Promoter   3% UV Disperser 0.98% Freeze-Thaw Protector 5.19% [0217] FIG. 4A shows a pane of glass 40 according to the present invention with a coating 42 (any coating according to the present invention). The specks indicating the coating 42 are shown as exaggerated for purposes of illustration only. The coating 42 may be as thick as any coating according to the present invention described above. [0218] The pane of glass 40 as shown in FIG. 4B has the coating 42 and, additionally or alternatively, has a peripheral border 44 which is made by applying any coating according to the present invention in a much thicker amount than the thickness of the coating 42 . In certain aspects, the material to form the border 44 is applied at a thickness of a mil or several mils, e.g. between 1 and 7 mils thick. In certain aspects the border 44 is applied to a thickness at which it appears solids (and opaque). In other aspects, as shown, the border 44 is applied at a thickness (e.g. in one aspect 4 mils) so that air bubbles 46 are formed and permanently entrapped in the border. Optionally, instead of a border, the coating material is applied at a thickness as for the border, but to form a design (e.g. a figure, logo, wording, or symbol) on an item, e.g. the design 48 shown in dash-dot lines. [0219] The present invention, therefore, in at least some, but not necessarily all embodiments, provides a solid frosted article with a substrate, a film formed on the substrate, the film comprising a frosting coating, the frosting coating comprising thermoset acrylic resin, polymethyl methacrylate, polyacrylate copolymer, and methylated melamine-formaldehyde resin, and wherein the solid frosted article is one of a glass block, glass panel and glass bottle. Such an article may have one or some (in any possible combination) of the following: the thermoset acrylic resin includes an hydroxyl functional thermosetting water reducible acrylic resin which is reduced to about 30% solids by weight in water at a pH between 8.0 to 8.5 assisted by DMEA to become completely soluble in water; the frosting coating further including particulate material for enhancing frosting appearance; wherein the particulate material is fine particle silica; the frosting coating further including a cross linking agent for enhancing hardness and flexibility; the frosting coating further including an hydroxyl functional thermosetting water reducible acrylic resin which is reduced to about 30% solids by weight in water at a pH between 8.0 to 8.5 assisted by DMEA to become completely soluble in water, particulate material comprising fine particle silica, a tertiary amine for improving adhesion to glass and improving scratch and rub resistance, a silicone defoamer, a polyamide thixotrope activated when heated, a cross linking agent, and a foam-inhibiting and substrate wetting agent; and/or wherein the frosting coating includes UV absorber, and light stabilizer. [0220] The present invention, therefore, in at least some, but not necessarily all embodiments, provides a solid frosted article having a substrate, a film formed on the substrate, the film comprising a frosting coating, the frosting coating comprising thermoset acrylic resin, polymethyl methacrylate, polyacrylate copolymer, and methylated melamine-formaldehyde resin, and wherein the substrate is glass panel. Such an article may have one or some (in any possible combination) of the following: an artwork adjacent the glass panel; a backing member, the artwork between the backing member and the glass panel; and/or a frame holding the glass panel. [0221] The present invention, therefore, in at least some, but not necessarily all embodiments, provides a solid frosted article including a substrate, a film formed on the substrate, the film comprising a frosting coating, the frosting coating comprising thermoset acrylic resin, polymethyl methacrylate, polyacrylate copolymer, and methylated melamine-formaldehyde resin, and wherein the substrate is part of a glass block. [0222] The present invention, therefore, in at least some, but not necessarily all embodiments, provides a solid frosted article including a substrate, a film formed on the substrate, the film comprising a frosting coating, the frosting coating comprising thermoset acrylic resin, polymethyl methacrylate, polyacrylate copolymer, and methylated melamine-formaldehyde resin, and wherein the substrate is part of a glass bottle. [0223] The present invention, therefore, in at least some, but not necessarily all embodiments, provides a method for frosting a solid object; the solid object being one of a glass panel, a glass bottle, and a glass block; the method including applying a frosting coating composition to an object, the frosting coating composition comprising thermoset acrylic resin, polymethyl methacrylate, polyacrylate copolymer, and methylated melamine-formaldehyde resin. Such a method may have one or some (in any possible combination) of the following: wherein the frosting coating further comprises N,N-dimethylethanolamine (DMEA); wherein components of the frosting coating are present by weight parts as polymethyl methacrylate—4.81, polyacrylate copolymer—0.48, methylated melamine-formaldehyde resin—2.77, N,N-dimethylethanolamine—3.61; wherein said thermoset acrylic resin comprises at least one member selected from the group consisting of polyacrylic resin and polymethacrylic resin; wherein the frosting coating includes alkoxylated alcohol, and emulsion of wax; wherein the frosting coating has polyamide aqueous solution and components of the frosting coating are present by weight parts of each 100 parts as alkoxylated alcohol—0.48, polyamide aqueous solution—1.81, emulsion of wax—2.72; and/or wherein the frosting coating has UV absorbent material, and wherein the UV absorbent material is hydroxyphenyl benzotriazol and hindered amine light stabilizer bis(1,2,2,6,6-pentamethyl-4-piperidnyl)sebacate and methyl(1,2,2,6,6-pentamethyl-4-piperidnyl)sebacate. [0224] The present invention, therefore, in at least some, but not necessarily all embodiments, provides a solid frosted article including a substrate; a film formed on the substrate, the film being a frosting coating; the frosting coating including thermoset acrylic resin, polymethyl methacrylate, polyacrylate copolymer, and methylated melamine-formaldehyde resin; and any two or all three of an adhesion promoter, an ultraviolet light disperser, and a freeze-thaw protector. Such a frosted article may have one or some (in any possible combination) of the following: wherein the frosting coating includes all three of the adhesion promoter, ultraviolet light disperser, and freeze-thaw protector; wherein the solid frosted article is one of a glass block, glass panel, and glass bottle; wherein the adhesion promoter comprises 3-glycidyloxypropyl-trimethoxysilane; wherein the adhesion promoter is present by volume in the frosting coating between 2% to 5%; wherein the ultraviolet light disperser is an aqueous ultrafine titanium dioxide dispersion; wherein the ultraviolet light disperser is present by volume in the frosting coating between 0.50% to 2.00%; wherein the freeze-thaw protector is propylene glycol; wherein the freeze-thaw protector is present by volume in the frosting coating between 3% to 7%; wherein an amount of the frosting coating is at least one mil thick; wherein the solid frosted article is a pane of glass, and wherein the amount of frosting coating at least one mil thick forms a border around a periphery of the pane of glass; and/or wherein the amount of frosting coating at least one mil thick forms a design on the solid frosted article. [0225] The present invention, therefore, in at least some, but not necessarily all embodiments, provides a solid frosted article including: a substrate; a film formed on the substrate, the film comprising a frosting coating; the frosting being comprising thermoset acrylic resin, polymethyl methacrylate, polyacrylate copolymer, and methylated melamine-formaldehyde resin; any two or all three of adhesion promoter, ultraviolet light disperser, and freeze-thaw protector, and wherein the substrate comprises a glass pane. Such a frosted article may have one or some (in any possible combination) of the following: an artwork adjacent the glass pane; wherein an amount of the frosting coating is at least one mil thick, wherein the solid frosted article is a pane of glass, and wherein the amount of frosting coating at least one mil thick forms a border around a periphery of the pane of glass; and/or wherein the amount of frosting coating at least one mil thick forms a design on the solid frosted article. [0226] The present invention, therefore, in at least some, but not necessarily all embodiments, provides a method for frosting a solid object, the method including applying a frosting coating composition to an object, the frosting coating composition being thermoset acrylic resin, polymethyl methacrylate, polyacrylate copolymer, and methylated melamine-formaldehyde resin, and any two or all three of adhesion promoter, ultraviolet light disperser, and freeze-thaw protector. Such a method may have one or some (in any possible combination) of the following: wherein the frosting coating further includes N,N-dimethylethanolamine (DMEA); wherein the adhesion promoter comprises 3-glycidyloxypropyl-trimethoxysilane; wherein the ultraviolet light disperser is an aqueous ultrafine titanium dioxide dispersion; and wherein the freeze-thaw protector is propylene glycol; and/or wherein the adhesion promoter is present by volume in the frosting coating between 2% to 5%, wherein the ultraviolet light disperser is present by volume in the frosting coating between 0.50% to 2.00%, and wherein the freeze-thaw protector is present by volume in the frosting coating between 3% to 7%. [0227] In conclusion, therefore, it is seen that the present invention and the embodiments disclosed herein and those covered by the appended claims are well adapted to carry out the objectives and obtain the ends set forth. Certain changes can be made in the subject matter without departing from the spirit and the scope of this invention. It is realized that changes are possible within the scope of this invention and it is further intended that each element or step recited in any of the following claims is to be understood as referring to the step literally and/or to all equivalent elements or steps. The following claims are intended to cover the invention as broadly as legally possible in whatever form it may be utilized. The invention claimed herein is new and novel in accordance with 35 U.S.C. §102 and satisfies the conditions for patentability in §102. The invention claimed herein is not obvious in accordance with 35 U.S.C. §103 and satisfies the conditions for patentability in §103. This specification and the claims that follow are in accordance with all of the requirements of 35 U.S.C. §112. The inventors may rely on the Doctrine of Equivalents to determine and assess the scope of their invention and of the claims that follow as they may pertain to apparatus not materially departing from, but outside of, the literal scope of the invention as set forth in the following claims. All patents and applications identified herein are incorporated fully herein for all purposes. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures. Thus, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment of fastening wooden parts, a nail and a screw may be equivalent structures. It is the express intention of the applicant not to invoke 35 U.S.C. §112, paragraph 6 for any limitations of any of the claims herein, except for those in which the claim expressly uses the words ‘means for’ together with an associated function.

A solid frosted article including, in certain aspects, a substrate, a film formed on the substrate, the film made with a frosting coating, the frosting coating including thermoset acrylic resin, polymethyl methacrylate, polyacrylate copolymer, methylated melamine-formaldehyde resin, and any two or all three of an adhesion promoter, an ultraviolet light disperser, and a freeze-thaw protector, e.g. propylene glycol; and wherein the solid frosted article is glass block, glass panel and glass bottle. This abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure and is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims, 37 C.F.R. 1.72(b).

This application is a continuation in part of application Ser. No. 823,759 filed Jan. 29, 1986 now abandoned. BACKGROUND OF THE INVENTION This invention relates to apparatus for use in control and metering of Pay-television signals over a cable network. Most Pay TV systems employed to date require that the Premium signals be scrambled to prevent reception by unauthorized cable TV subscribers. Authorized subscribers pay for the premium programming on a flat fee basis. Such systems have had a difficult time in the marketplace because of the high cost for the sophisticated descrambling equipment, or the unauthorized use of descrambling equipment where inexpensive scrambling systems are employed by the cable TV operator, and/or, the uncertainty of the value of the premium services to non-pay TV subscribers in view of the required flat rate payment commitment. Other Pay-for-Use proposals such a Spencer (U.S. Pat. No. 3,504,109), Eisele (U.S. Pat. No. 3,368,031), Sargent (U.S. Pat. No. 3,335,421) and Murphy (U.S. Pat. No. 3,989,887) have failed to make an impact because of the high cost of their implementation. Spencer requires additional wiring be installed in each subscriber's residence; and Sargent proposes the D.C. power for system control be provided from the cable operators studio, most existing cable systems do not allow D.C. (or utility frequency A.C.) power to pass unhindered from the operator's studio into the subscriber's home. In addition both Sargent and Eisele do not allow for both premium pay services and normal cable TV services being distributed on the same coaxial distribution system. Murphy does allow for such an arrangement but specifies the use of JAMMING circuitry that generates undesirable radio frequency energy. Also because of the jamming method employed Murphy's system is cumbersome to implement as it requires the use of one filter for each channel to be jammed. The use of low-cost commonly available broadband multichannel band blocking filters is precluded. Murphy had not foreseen the need to custom tailor each subscribers filtering arrangement, or the need to switch 6 to 15 channels simultaneously. Why Murphy chose to employ jamming circuitry is uncertain, but from the circuitry shown in his patent it appears that he could not obtain adequate filtered channel insertion loss and thus was forced to jam the channel as well as filter it. His patent fails to instruct any method of keeping the level of a filtered channel 50 dB below that of the unfiltered channel as his system does not require such. In addition to extensive trap filter circuitry and jamming circuits, Murphy also requires simultaneously positive and negative power to operate his apparatus making it expensive for a one unit per home installation. None of these systems make allowance for parental control requirements, simultaneous viewing of 2 or more premium services, multiple-point operation, and control by external apparatus such as video recorders and simple timers. Murphy and the others have also not foreseen the need to employ sampling or preview circuitry to stimulate impulse buying. DiLorenzo (U.S. Pat. No. 4,317,213) teaches how Parental Lockout may be accomplished through the generation and transmission of interfering radio frequencies, he does not instruct how it could be accomplished to the satisfaction of radio spectrum regulatory agency requirements. Rifken (U.S. Pat. No. 4,272,791) illustrates a scheme to permit the simultaneous recording of a Premium TV channel and viewing of a non-scrambled channel, or vice-versa. Rifken's solution solves a problem that subscribers with VCRs have if their premium programming is scrambled but is not applicable to the apparatus embodied in this invention as no scrambling is required. Rifken foresees no requirement for the VCR to control any switching apparatus. SUMMARY OF THE INVENTION It is one object of the invention there to provide an improved cable transmission system. According to a first aspect of the invention there is provided a secure pay-for-use television distribution system comprising a cable distribution network arranged to distribute Subscription television and PFU television signals from a central cable station to a plurality of subscriber premises, a plurality of filter units each mounted between the cable network and a subscriber premises to control the transmission of said television signals to the subscriber premises, a plurality of subscriber actuable control units each for mounting in a respective subscriber premises and connectable to the respective filter unit by a line for supplying control signals to the unit and for receiving therefrom said television signals, said filter unit comprising inlet terminal means for connection to the cable network, outlet terminal means for connection to said line, means defining a first and a second circuit path between said inlet terminal means and said outlet terminal means, filter means in at least said first circuit path arranged to provide sufficient rejection loss to said PFU television signals so that the PFU signals emitted from the first circuit path cannot generate a TV picture and arrange to provide a sufficiently low insertion loss to the Subscription television signals so as not to interfere with the generation of a TV picture therefrom, said second circuit path being arranged to transmit at least said PFU television signals, and switching circuit means in said first and second circuit paths responsive to said control signals from said control unit to open and close alternate ones of said first and second circuit paths, said switching circuit means being arranged to open and close said first circuit path upstream and downstream of said filter means. According to a second aspect of the invention there is provided a secure pay-for-use television distribution system comprising of cable, distribution network, distribution of signals from a central cable station to a plurality of subscriber premises, a plurality of filter units each mounted between the cable network and a subscriber premises to control the transmission of signals to the subscriber premises, a plurality of subscriber actuable control units each for mounting in a respective subscriber premises and connectable to the respective filter unit by a line for supplying control signals to the unit and for receiving therefrom the transmitted signals, said filter unit comprising inlet terminal means for connection to the cable network, outlet terminal means for connection to said line, means defining a first and a second circuit path between said inlet terminal means and said outlet terminal means, filter means in at least said first circuit path arrange to provide sufficient rejection loss to a TV channel signal so that the TV channel signal emitted from the first circuit path cannot generate a TV picture and arrange to provide a sufficiently low insertion loss to the TV channel signals so as not to interfere with the generation of a TV picture therefrom, and switching circuit means in said first and second circuit paths responsive to said control signals from said control unit to open and close alternate ones of said first and second circuit paths, said switching circuit means being arranged to open and close said first circuit path upstream and downstream of said filter means including metering means for providing a record of time of use of at least one of said first and second circuit paths, microprocessor means responsive to said control signals for actuating said switching means and said metering means and a single telephone pair connected to a plurality of said filter units and to a central telephone station, said microprocessor of each of said plurality of filter units being arranged to directly modulate on said telephone pair information from said metering means. According to a third aspect of the invention there is provided a secure pay-for-use television distribution system comprising of cable, distribution network, distribution of signals from a central cable station to a plurality of subscriber premises, a plurality of filter units each mounted between the cable network and a subscriber premises to control the transmission of signals to the subscriber premises, a plurality of subscriber actuable control units each for mounting in a respective subscriber premises and connectable to the respective filter unit by a line for supplying control signals to the unit and for receiving therefrom the transmitted signals, said filter unit comprising inlet terminal means for connection to the cable network, outlet terminal means for connection to said line, means defining a first and a second circuit path between said inlet terminal means and said outlet terminal means, filter means in at least said first circuit path arrange to provide sufficient rejection loss to a TV channel signal so that the TV channel signal emitted from the first circuit path cannot generate a TV picture and arrange to provide a sufficiently low insertion loss to the TV channel signal so as not to interfere with the generation of a TV picture therefrom, and switching circuit means in said first and second circuit paths responsive to said control signals from said control unit to open and close alternate ones of said first and second circuit paths, said switching circuit means being arranged to open and close said first circuit path upstream and downstream of said filter means including a plurality of separate fibre-optic transmission systems each communicating from a central fibre-optic station to a respective one of a plurality of separate groups of said plurality of subscriber premises, means for transmitting to each of said groups a control channel providing a schedule of programs to be transmitted on the respective one of said fibre-optic transmission systems to the respective group, each of said filter units including means for decoding and transmitting to the subscriber premises signals on said fibre-optic transmission system and means for metering a time of use of said decoding means. According to a fourth aspect of the invention there is provided a secure pay-for-use television distribution system comprising a cable distribution network arranged to distribute Subscription television and PFU television signals from a central cable station to a plurality of subscriber premises, a plurality of filter units each mounted between the cable network and a plurality of subscriber premises to control the transmission of said television signals to the subscriber premises, a plurality of subscriber actuable control units each for mounting in a respective subscriber premises and connectable to the respective filter unit by a line for supplying control signals to the unit and for receiving therefrom said television signals, said filter unit comprising inlet terminal means for connection to the cable network, means defining a first and a second circuit path from said inlet terminal means, filter means in at least said first circuit path arrange to provide sufficient rejection loss to said PFU television signals so that the PFU signals emitted from the first circuit path cannot generate a TV picture and arrange to provide a sufficiently low insertion loss to the Subscription television signals so as not to interfere with the generation of a TV picture therefrom, said second circuit path being arranged to transmit at least said PFU television signals, and said filter unit including for each subscriber line a first and a second amplifier each connected to a respective one of said first and second circuit paths and switching circuit means associated with said first and second circuit amplifiers responsive to said control signals from said control unit to open and close alternate ones of said first and second circuit paths. This apparatus can permit programming to be sold to the subscriber by the month, by the program, and by the hour of any portion thereof Payment by the month is known as Subscription Television. Payment by the program is known as Pay-per-View. Payment by viewing time is known as Pay-for-Use (PFU) television. It also permits the Cable Operator to share revenues with independent programming suppliers sharing some portion of the cable TV distribution system. This apparatus also can allow subscribers to sample premium programming being delivered prior to engagement of the metering process in order to encourage viewing of premium services. Unlike preview systems employed in many hotel Pay-per-View apparatus this preview feature is cheat-proof as it uses a capacitive charge memory to foil attempts to reset the timer that limits the duration of the preview sample permitted. It also incorporates fault detection circuitry to simplify troubleshooting and protect the power supply from over-load. The specific apparatus described hereinafter was designed according to the following design objectives: 1. Maximize pay TV revenues maximize penetration little or no payment of non use -incorporate cheat-proof preview capabilities 2. Minimum cost for equipment, simplest installation. reuse existing subscriber's coaxial cable for signalling, power, and control purposes. minimum amount of circuitry for the basic configuration. simple installations should be able to be completed in 10 minutes. compatible with existing cable TV distribution facilities (minimum insertion loss, minimum generation of RFI and intermodulation distortion products). capacity to carry both the Premium TV Pay Services and the normal Cable TV Subscription Services on the existing cable distribution system be reliable and capable of withstanding short circuits on the interconnecting coaxial cable for long periods of time. detect and signal an indication of a fault to the subscriber or installer. exterior equipment capable of surviving severe environmental conditions. basic apparatus must not require expensive pole installation. 3. Multiple Location Control to allow subscribers to access and monitor the system for any room in their home where there is a TV set using existing cabling. 4. Incorporation of a lockout control feature to prevent access to Premium Pay Programming by unauthorized individuals, such as children. 5. Permit tiering of different levels of Premium TV services at varying rates of cost. 6. Use field changeable filters to permit individual custom tiering of each subscribers Subscription and PFU channels. 7. Ability to allow Premium Programming to be turned ON and OFF by external apparatus such as timers and video recorders. 8. Integrate a Cable television broadcast system with a non-broadcast or limited broadcast, view on demand television delivery system. Provide apparatus that will allow the view on demand system to be constructed at the minimum per subscriber cost and permit sharing of revenues. 9. Provide the Cable Operator with the option of reading the meters remotely from a central location using as much existing facilities and equipment as possible in order to keep the cost at a minimum. 10. Provide Pay-per-View capabilities as an option. The apparatus according to another specific embodiment can provide for the simultaneous multiple random access of any programming stored in a library of video programs. Such an invention together with development of extremely high capacity fibre optic transmission facilities allows for the development of video distribution libraries which can be accessed privately, or semi privately, by a subscriber whose residence is connected to the system. Subscribers will request a library program using the telephone system, the library operator will directly invoice the subscriber accordingly. The subscriber could have access to one or more such libraries. The apparatus for the reception of the signals at the subscribers premises is required to integrate with the existing cable television broadcast distribution facility. The apparatus embodied here is designed to meet the expected requirements. As the licensed cable operator may not have any interest in the demand programming library or the fibre-optic distribution system, yet be directly involved where the two systems interface, a need for revenue sharing is anticipated. An apparatus for the metering of the use of the video library system is provided for that purpose. The embodied apparatus is designed to economically meet these requirements. With the foregoing in view, and other advantages as will become apparent to those skilled in the art to which this invention relates as this specification proceeds, the invention is herein described by reference to the accompanying drawings forming a part hereof, which includes a description of the best mode known to the applicant and of the preferred typical embodiment of the principle of the present invention, in which: DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall illustration of the implementation of the pay-for-use broadcast television aspects of this invention. FIG. 2 shows the simplest configuration for the set-top control unit. FIG. 3 is similar to FIG. 2 but utilizes both positive and negative D.C. signals. This unit is ideal for control of the semiconductor switching system. FIG. 4 is a semiconductor switching system set-top control unit that is ideal for multi-point control. This unit allows for complete ON/OFF control from any location. With this unit a subscriber can turn the premium programming off from any location regardless of where the programming was previously turned on from. FIG. 5 shows the simplest implementation of the external unit using electro-mechanical switching. FIG. 6 shows the simplest implementation of the external unit using semiconductor switching. FIG. 6A is similar to FIG. 6 but illustrates how flatrate Subscription Services can be tiered, how PFU services can be tiered and incorporation of optional remote meter reading capabilities. FIG. 7 shows a fault detection circuitry for use in the device of FIG. 6. FIG. 8 shows a low cost cheat-proof preview circuit for use in the device of FIG. 6. FIG. 9 shows a multi-tier apartment block system, complete with optional paired-cable interface for remote meter reading. FIGS. 10 and 11 illustrate the implementation of a multitier premium TV pay-for-use system with FIG. 10a showing a set-top internal control unit and FIG. 11 one method of configuring a multi-tier switching network. FIG. 12 illustrates a central metering system. FIG. 13 illustrates the interfacing of the broadcast cable TV system in accordance with the principles of this invention and a demand programming fibreoptic distribution system. FIG. 14 illustrates apparatus for economically integrating demand programming technology with existing coaxial cable television distribution apparatus. The system is very economical as it utilizes a kind of Video Party-Line. In the drawings like characters of reference indicate corresponding parts in the different figures. DESCRIPTION OF PREFERRED EMBODIMENTS With reference to FIG. 1, there is shown an overview of the general principles of this invention. The cable company broadcasts in unscrambled form television signals via a coaxial cable distribution system 10. These signals enter a secure external switching and control unit 11 where the Pay-per-Use signals are blocked when all set top units 12, 13 are switched off. Should that be the case only the Subscription Services are passed on to the subscriber's television receivers for viewing. Unit 12 cooperates with a TV 14 and unit 13 with a TV 15. A third TV is indicated at 16. Should a subscriber using one of the Set-top Control Units 12, 13, which may include an associated timing apparatus 17 such as a video recorder shown connected to Television Receiver set 15, turn ON a D.C. current which flows to the external switching apparatus via the same coaxial cable that carries the television signals into the residence, that current will activate both the switching apparatus and the metering unit within the control unit 11. When activated the switching apparatus routes the Pay-for-Use programming signals around a filter that previously blocked the Pay-for-Use programming and thus such signals are passed on for viewing via the same coaxial cable that is carrying the low voltage D.C. power to the external unit. If the external Switching/Metering Unit 11 does not incorporate a preview feature described in detail hereinafter the D.C. power will simultaneously turn on the metering system. The metering system being calibrated to record either the time that the PFU signals are accessed or the charges to be billed for the time that the PFU programming is accessed. The metering system, which does not require D.C. power for meter reading, is a digital system using temperature stabilized circuitry. The metering system can be calibrated to register hours, fractions of hours, or minutes of useage. When the set-up control unit is turned on, status display lights on all set-top units light to indicate that the pay-for-use premium television system is active. Should the subscriber not wish to have a set top control unit installed near each television receiver a D.C. blocking device 19, which are commercially available, may be installed to protect sensitive equipment. TV Receiver 16 is so connected Such a receiver is still capable of receiving the PFU programming, however, the PFU programming must be turned on at a location where there is a set-top control unit. A fibre optic line for supplying demand-TV system is indicated at 20 and a tap boxes on the line 22. With reference now to FIG. 2, there is illustrated a television set-top control unit 12, 13 in accordance with the basic principles of this invention. D.C. power is supplied from a source separate from the unit and connected at jack 26. Should an ON Switch 24 be activated and a Parental Lock Switch 25 also be ON, D.C. current will flow through a normally closed Jack 27, and through the Radio Frequency Blocking circuit 28 to the External Switching and Control Unit 11 via the shown coaxial cable 18. This same D.C. source will also light an Activity Monitor 29 on the Set-Top Control Unit via a diode 30. Note that should the auxiliary timing contacts 31 on the Video Cassette Recorder 17 be utilized, ON timing can be automatically controlled. So far no VCR manufacturer has forseen a need for timing contacts to control external apparatus. FIG. 3 shows a very similar circuit for a Set-Top Control Unit 13. However, this Unit employs a modified ON switch 24A which is arranged as shown to supply a negative voltage to the coaxial cable when the Unit is turned OFF. This negative voltage can be used to improve the transmission performance of semiconductor switching circuits used in the External Switching and Metering Unit 11, or as a method of requesting a higher tier level of PFU programming. One example of a unit 11 is shown in FIG. 6 and uses the negative polarity to forward bias diodes 32 and 33 which switches in a Band Reject Filter 34 and to reverse bias diodes 35 and 36 to switch out a filter bypass circuit 37. In FIG. 13 the negative polarity is used to switch in a second level of Pay-for-Use tier of premium programming, while switching off the first tier of premium Pay-for-Use Programming. FIG. 4 illustrates an alternative arrangement of set-top unit 13B incorporating a unique combination of a bridge circuit and a bistable multivibrator circuit This circuit allows the subscriber to use any Set-top Unit to turn off the premium tier of programming regardless of which control unit was used to turn on the programming. This circuit is a condition following, reversing power supply circuit. For example, should a subscriber have two television receivers and one of these Set-top Units with each and should both be in the OFF condition, that is each is supplying a negative D.C. voltage to the centre conductor of the coaxial cable 18 (which is connected to the External Switching and Control Unit via a D.C. passing splitter), then in both units transistors 38 and 39 will be switched on and 40 and 41 will be switched off. Thus the negative side of the power supply will be connected to the centre conductor of the coax via transistor 39 and the positive side of the power supply to the outer conductor of the coax, or ground, via transistor 38. Should the subscriber have the keyed switch 25 of one unit closed, and momentarily close the switch 24 of the same set-top unit then the steering circuit will enable the closing of ON Momentary Contacts 42 which in turn will pull the collector of transistor 41 to the negative side of the Power Supply. The voltage across transistor 41 drop, and the base current to transistor 39 is reduced, the voltage across transistor 39 will rise as it begins to shut off, and the base current to transistor 41 will rise thus reinforcing the drop in the collector voltage of transistor 41. The circuit goes regenerative. Similarly the base current to transistor 40 will increase and the base current to transistor 38 will decrease. Transistors 40 and 41 switch ON, transistors 38 and 39 switch OFF. The centre conductor of this Unit is now connected to the positive side of the power supply and the outer conductor is now connected to the negative side. This switching of polarity will simultaneously influence any other Set-top Control Units connected in the subscribers home. The more positive voltage on transistor 39 will tend to turn ON transistor 41 and turn OFF transistor 38 as transistor 4; turns ON its collector voltage drops thus reducing the base current to transistor 39 which begins to turn OFF, similarly the base current to transistor 40 increases thus turning it on. To turn OFF the system switch 24 need only be momentarily closed, the steering circuit now enables the closing of the OFF contacts 43 and a similar pull down/push up action will occur forcing all units connected OFF. The On and Off Momentary contacts can be electronic or electro-mechanical. The Light Emitting Diode 29 connected to the centre conductor of the coax on all units will light whenever a positive D.C. polarity is passed out to the External Switching and Control Unit. Thus the ON/OFF status of the system can be monitored from any room where a Set-top Control Unit resides. A positive voltage on the centre conductor of the coax that carries the TV signals into the home turns on the PFU Premium TV bypass path around the Premium TV Filter and all TV receivers connected to the system in the home are then capable of viewing the Premium programming. The positive polarity signal will also energize the metering circuitry. Should all keyed lock off switches be turned off, then momentarily closing switch 24 on any unit will have no effect. Resistance values in the circuit are chosen such that upon initial power up the circuit will regenerate into the OFF state. The RF Block 28 prevents the radio frequencies that carry the TV signals from entering the Power Supply system and the DC Block 44 prevents D.C. power being passed to the TV Receivers or other related reception equipment. Jacks are provided for connection to external timing control equipment such as Video Recorders, etc. The Auxiliary Contacts 45 and 46 located on such equipment, not provided in the unit, can be used to switch the premium programming ON and Off automatically at the desired time of day. The jacks used to access these external auxiliary contacts have normally OPEN contacts. FIG. 5 shows one embodiment of a simple electro-mechanically switched Exterior Switching and Metering Unit 11 connected on one side to the cable 47 to the tap box 21 and on the other side to the cable 18 to the set top unit. With no D.C. power on the coax 18 from the subscribers home an R.F. shielded relay 55 has contacts 48 and 49 in their normally closed state, and contacts 50 and 51 in their normally open state. Thus the band reject filter 52 which rejects the various channels of premium programming is switched IN with the filter bypass path 53 switched OUT. Also no power is available to run the metering circuit. A threshold detection circuit 54 is used to foil tampering. A D.C. block 59 is positioned between the cable 18 and the filter circuit. A DPDT relay is used for two reasons. First it increases the isolation between the Filtered Path and the Unfiltered Path. Second it eliminates the need for a splitter at the point where the incoming signal divides. It should be pointed out that Murphy (U.S. Pat. No. 3,989,877) uses a SPDT switch at the output end and a Splitter at the input end. As Murphy's apparatus requires the use of the splitter and SPDT switch the isolation is less (necessitating tee need for jamming) and the insertion loss will be 3.5 dB greater. When the internal Set-to Control Unit is switched ON the D.C. signal from unit B is passed on to the relay 55 via an RF Blocking circuit 56 if the voltage level is sufficient to activate the threshold detector 54. The relay 55 is energized and the filter 52 now becomes switched OUT and the bypass path 53 switched IN. All programming including the Premium channels are now passed to the residence for viewing. D.C. power is now supplied to a temperature compensating clock generating circuit 56. Via a voltage regulator 58, the time that the unit is active counts up and the accumulated total is displayed on a read-out unit 57 for viewing by both the subscriber and meter-reading personnel. Both electronic and electro-mechanical displays can be used. The advantage of the electro-mechanical readout is that it requires no power for meter-reading purposes. FIG. 6 shows an External Switching and Metering Unit that utilizes semi-conductor switching. Should no D.C. power be supplied from the subscribers residence no programming, neither regular subscription Cable TV programming or the PFU Premium Programming, will be passed on to the subscribers home. The unique diode switching circuitry insert up to 60 dB of insertion loss in both the Premium TV Reject Path and the Premium TV Bypass path. However when D.C. power of a negative polarity is supplied from the home, diode switching circuits 32 and 33 switch closed as they are now forward biased by the D.C. current. The very low forward A.C. resistance of the diodes allows the R.F. signals carrying the TV programming to now be switched through the Band Reject Filter 34. The Subscription Cable TV Programming is passed on for viewing but the PFU Premium Programming is blocked by the filter. When the subscriber switches the polarity of the D.C. power, diode switching circuits 32 and 33 are now switched OPEN as they are reversed biased, and switching circuits 35 and 36 become forward biased and switch CLOSED. All programming is now passed on for viewing as the Filter 34 has been bypassed. Also the metering system, consisting of a temperature compensated clock generator 56, a digital accumulator and display circuit 57, is activated. The metering circuit shown here is identical to that shown in FIG. 5. In order for the diode switching apparatus to work, that is to maintain maximum isolation between the Filtered and Unfiltered paths a diode with minimum forward A.C. resistance and minimum unbiased capacitance must be employed. Several diodes can be connected in series to reduce the unbiased capacitance, however, the total forward resistance and Insertion Loss will increase. More than 4 diodes in series usually adds too much loss. In FIG. 6 diodes 35 and 36 would each be comprised of 2 diodes in series. The reason for diodes 35 and 36 being shown with opposing polarities is to maximize high signal level isolation when neither positive nor negative power is supplied from the subscriber's home. One diode product that is suitable for this application is Motorola's MBD101, this diode is a silicon hot-carrier diode (Schottky Barrier Diode) commonly used in UHF Mixer applications. Most engineers would attempt to use PIN diodes for this application. They will NOT work as they have excessive unbiased capacitance. Should the subscriber disconnect the Power Supply on his Set-Top Unit he will receive no intelligent receive signal when the MBD101s are employed. When PIN diodes are employed a degraded but watchable picture will result without the metering system recording the useage. The security of the system would be compromised. It should be noted that Murphy in his reference to PIN diodes resolves the security problem by resorting to RF Jamming, an unsatisfactory solution. The danger of course being leakage back into the cable plant and interference with aeronautical and land mobile communications. When an RF amplifier is added to the external Switching and Metering Unit, the addition of a bridge rectifier will enable the amplifier to operate using the D.C. power from the coaxial cable regardless of the polarity of the centre conductor being positive or negative. The incorporation of a simple low-cost single transistor common-emitter amplifier in the external unit, not shown, to provide slope adjustment and to offset cabling losses in the home will save the installer installation time and problems associated with having to bypass the D.C. around an amplifier installed in the home in the usual manner. When the amplifier is added D.C. power is required at the external unit at all times in order to ensure that both Subscription Services and the PFU Premium Services are amplified. A zener diode 60 prohibits the Bypass Circuit from being turned on if the D.C. voltage is too low. The purpose is to prevent the PFU programming from being transmitted to the home without the meter running correctly. It is important to use threshold detection circuitry of this type to foil subscriber tampering. Similar threshold detection is indicated at 54 in FIG. 5. FIG. 6A shows a yet further embodiment of exterior metering and switching unit. This embodiment is similar to that of FIG. 6. It is however modified firstly in that it includes a logic circuit 61 which receives control and power signals through the RF Block 56 from the set-top unit. The logic circuit is arranged to control a first RF switch 62, a second RF switch 63 and a third RF switch 64. The first two switches are positioned in the circuit containing the band reject filters of which there are two in this embodiment indicated at 65 and 66 respectively. The logic circuit is connected to a memory 67 and to a digital display 57 of the type shown in FIG. 6. A tamper detector 68 is also provided and connected to the logic circuit. An additional filter or filters is provided at 69 and is connected upstream of the filters 65 and 66. The filter 69 is inserted to notch out non-switched Subscription Services in order to tier flat rate services or to eliminate PFU services that the subscriber does not wish to receive. The use of two separate filters at 65 and 66 allows non-adjacent bands of channels to be useage switched. The logic circuit acts to carry out the following functions. (a) It decodes the control signals transmitted from the set-top unit and operates the RF switches 62, 63 and 64 accordingly. (b) It generates the clock signals for transmission to the accumulator/display unit 57. (c) It operates a preview feature as explained hereinafter. (d) It operates a remote meter reading information system through an interface 70 as will be explained hereinafter. FIG. 7 illustrates a low-cost resetable electronic over-current circuit interrupter for use in the set-top unit of FIG. 2. This apparatus will reduce the current fed to the coaxial cable drastically if it detects an overload condition. If the coaxial cable load is a very low resistance (such as a short circuit) due to a cable fault when the plug-in power supply is connected to the power utility supply, 7R3 will be shorted out and sufficient voltage will be supplied via 7R4 that the zener diode 7Z1 will be turned on and 7Q2 subsequently driven into saturation: the collector-emitter voltage across 7Q2 will be low and 7Q1 will be held in the OFF state. If the short-circuit is cleared 7Q1 will remain OFF and 7Q2 ON. If the fault has been cleared the circuit breaker can be reset by disconnecting the power supply and reconnecting it. When the power supply is disconnected 7C1 will discharge through 7R5. When the power supply is reconnected the base current through 7Q1 will rise more rapidly than that through 702, as it takes time for 7C1 to charge. The circuit will regenerate to the state of 7QI ON and 7Q2 OFF. The circuit will remain in this state unless the output coaxial cable 18 is shorted. Should a momentary overload occur, other than a complete short circuit, 7C1 will begin to charge up through the load. As it ,takes time for the voltage across 7C1 to increase, 7Z1 will not immediately trip on. The duration of the delay can be varied by changing the value of 7C1, and/or the Zener voltage of 7Z1. An overload of sufficient duration and low resistance will turn OFF 7Q1, and light the fault light LED 7D1, thus alerting the installer to check the cable connections, or the subscriber to phone the cable company and report the fault. This is a stable state and the circuit will remain i- this state until the fault is cleared and the circuit reset. In most cases it is expected that the fault will have occurred because the subscriber was rearranging the cable connections, perhaps connecting a TV unauthorized by the cable company. Verbal instructions will probably be adequate to correct most such occurrences. FIG. 8 shows a cheat-proof preview timer forming part of the logic circuit 61 of FIG. 6A. This circuit would typically be designed to allow the subscriber to view two minutes of PFU programming free of charge once every ten minutes. The free viewing duration and the repeatability duration can both be programmed by changing the values of 8R1 and 8R2 respectively. The circuit delays the application of power to the metering circuit. If the circuit has been OFF for a sufficient duration to completely discharge the capacitor 8C, then upon application of the supply power indicated on 8V, 8C will charge through 8D1 and 8R1. When 8C reaches a sufficient threshold voltage the current flowing through 8R3, 8Z1 and 8Q1 base-emitter circuit will be adequate to drive 8Q1 to saturation thus energizing the metering circuit. From the time that the supply voltage 8V is first applied to the time that the zener circuit turns ON the subscriber will be able to view the PFU programming without the useage being recorded. If the subscriber turns OFF his Set-Top Control Unit the supply voltage 8V is removed and 8C will discharge. If the switch is OFF for a sufficiently long period of time, in this example ten minutes, 8C will have had time to discharge through 8D2 and 8R2. The circuit will then have been reset and again the free viewing time will be available. If the subscriber turns OFF the PFU programming using the switch on the Set-Top Control Unit for only one minute, and then turns it back ON, he will recover only a few seconds of free viewing time. If the subscriber turns OFF the PFU for five minutes he may recover one full minute of free programming. Few subscribers would want to miss five minutes of programming in order to watch one minute for free. The advantage of this apparatus is that it requires no power during the period that it is timing out. Unlike many previewing timers in use this circuit cannot be circumvented without the subscriber physically breaking into the secure enclosure containing the preview capacitor. A diode 8D3 in series with the supply voltage V prevents the subscriber from using a negative voltage to significantly speed up the discharge rate. FIG. 9 shows a further embodiment of a Switching/Metering Unit for use with Multiple Family Dwelling Buildings (Apartment Complexes), or High Density Housing Districts. The Unit differs from the single residence unit of FIG. 6A in the following ways. (a) Only one set of filters is required for all N subscriber residences. Thus a first filter 71, provides a signal free from a first tier of programming, a second filter 72 provides a signal free from a second tier at programming and a third circuit 73 provides all programming. A splitter is indicated at 74. From each of the filters 71, 72, 73, the signal is communicated to a respective pair of resistors 71A, 71B and is tapped between the resistors to feed to amplifier circuits 81. This technique provides the necessary impedance at the output from the filters while attenuating the signals by a factor of 10. The attenuation can be accepted by the presence of the amplifiers 81. (b) Only one Power Supply 75 is required for all N subscribers. The Low Voltage/Current Power is delivered from the central Power Supply out over the N individual coaxial drop cables, one of which is indicated at 76, to each apartment or home. The current required to be fed to each home is considerably reduced, as its only job is to light an ON/OFF light and to generate an ON/OFF or Tier Level signal to the control logic circuit 61A. The current fed to the coaxial cable 76 can therefore be limited by the series resistor 77, no overcurrent protection is required. (c) The Set-Top Control Units are considerably simpler. The DC/RF filter 78 rejects the low frequency or D.C. control signal and passes the radio frequency signal on to the TV receiver. It also rejects the R.F. signal and passes the control signal on to a control switch 79. In the example shown the OFF of Tier I condition may be a voltage of say 8 volts, PFU Tier II 6 volts and Tier III 4 volts. If the power supply puts out 12 volts, then in the example when the control switch is in position 80 the Zener Diode will pull down the voltage being applied to the Control Logic circuit 61A to 8 volts from 12. (d) The Logic control circuit controls one of a plurality of switched amplifier circuits 81A, 81B, 81C, each associated with a respective signal from the circuits 71, 72, 73. Each circuit includes an amplifier 81D, 81E, 81F and a diode switch device of the type described herein and indicated at 81G, 81H, 81J. The logic control circuit switches on the respective amplifier by controlling the power supply thereto as schematically indicated. Each home or drop is associated with a separate set of such circuits indicated at 81K. The Logic Circuit therefore decodes the above signal as a request for subscription programming only. The Control Circuit turns on the Switched Amplifier Circuit 81A and the signals with the premium PFU signals filtered out would be amplified and passed on to the subscribers residence via a D.C. Block 82. If a subscriber is unwilling to purchase: all of the flat-rated subscription services, then an additional filter(s) may be inserted at the output from Block 12, but not shown on the diagram, inside the secure enclosure. The subscribers monthly flat-rate payment would correspondingly be reduced. Should the subscriber repositions the switch to position 83 the control voltage would pull-down to 4 volts, and the control circuit would turn-on switched amplifier circuit 81B. All subscription services and a tier of premium PFU channels would then be passed on to all TV receivers in the subscribers residence for viewing. The control unit 61A would also turn on the appropriate meter in the meter bank 84. Should the subscriber wish to access additional PFU premium channels, a higher tier of offerings, there are a number of different configurations which can be used. In FIG. 9 with each subscribers control logic circuit 61A would be a switch 61B to be set by the installer, if set in one position only the less expensive first tier of PFU premium services (Tier 11) would be accessed by the subscriber, if set in the alternate position only the second tier of premium PFU service would be accessed (Tier 111) when the subscriber sets his control switch in position 88. For this configuration the meters would accumulate time and at the end of each month the cable operators billing computer would correctly translate time into money according to which tier of PFU service the subscriber is accessing. A lower cost alternative would be to include only 2 switched amplifier circuits for each subscriber but use one switching circuit board 85 for those that want only the first tier (Tier II) of PFU services and a second switching circuit board for those that want the second tier of PFU services (Tier III). Other alternatives would be to use two sets of meters, one for each PFU tier, or a single set of meters and 2 clock generators running at different rates, or where a microprocessor is used to run the control logic record the PFU tier useage in a set of non-volatile memories. The requested Tier could be encoded in any electrical form, voltage (as described), current, capacitance, resistance, pulse width, frequency, etc. The switched amplifier circuit 81A, 81B, 81C consists of a common emitter RF amplifier as well as the RF Diode Switching circuit referred to in FIG. 6. Both are simultaneously switched ON and OFF. This is necessary to further increase the Isolation between the signal paths, to overcome Tap Loss and to Slope Adjust the channels. It should be noted that in Murphy (U.S. Pat. No. 3,989,887) it would be very difficult to make work in such an apartment block application as it is important to stop the RF jamming interference frequencies from leaking into the unfiltered signal path. Should a building have 100 apartments there would be 100 signal paths radiating interference. At least 45 dB of isolation between the jamming signals and the desired signals is required. Similarly the apparatus described herein requires that the 100 Unfiltered Paths not radiate into the 100 Filtered Paths, again 45 dB of isolation is the minimum requirement. The present Apparatus has an advantage over Murphy due to the superior Isolation of the switching system. This centralized switch point apparatus is referred to as a PFU Switched-Star configuration as the Cable TV signals are transmitted to one central point and switched out over individual cables to a group of subscribers. Metering and control being centralized at the star point. When the microprocessor is used meter reading can be simplified to simply dumping the useage data through a connector to a portable data acquisition memory. Alternatively the microprocessor can be programmed to transmit and receive FSK data by directly modulating and demodulating a Voice Frequency signal through an interface Circuit 86 on a paired cable 87. To keep the cost down the paired cable can be a spare telephone pair. Several hundred units are paralleled onto the spare pair, each has its own address and the microprocessor spills the useage data to a billing computer when polled. The protocol and frequencies utilized are non-standard to resist tampering. Logic 0 is in the 400-1000 Hz range and be 2 cycles in duration, Logic 1 is in the 1000-1500 Hz range and 3 cycles in duration. The paired cable interface includes a filter to roll off the high frequencies inherent in the square wave signal generated by the microprocessor modem. The Timer in pin on the microprocessor is used for the demodulation process. The microprocessor based version shown in FIG. 9 can also incorporate Pay-per-View capabilities. Whenever the cost of a program changes the cost of the new PPV program is broadcast to all Switching/Metering Units, all individual residence units and all apartment block and high density housing units. The current cost of a specific PPV program being broadcast is stored in a non volatile memory and should the subscriber request that program the appropriate switched amplifier is activated and the program along with the subscription services is passed to the home. At the end of the month the PFU usage is read in hours and the PPV useage is also read in monetary value. Alternatively the PPV useage can be recorded and stored in the non-volatile memory by program rather than monetary value. After transferring the useage to the central billing computer the computer would translate the useage into monetary value. It is important for PPV sporting events that the subscriber audience size is known. The PPV useage can then be transmitted to the central computer monthly or daily as required. The subscriber need not request the Pay-per-View program using the telephone or any communication facility other than the coaxial cable linking the Set-Top Control Unit to the external Switching/Metering Unit. Costly two-way trunking amplifiers on the Cable TV distribution network are not required. Telephone trunking and switching circuit overloads due to massive simultaneous impulse purchasing will not occur. An embodiment of the external switching and control unit suitable for a plurality of single family dwellings of the type shown in FIG. 9 is not illustrated. This apparatus differs from the apparatus shown in FIG. 1 in the following ways. (a) The Switching/Metering Unit is located at the subscribers drop tap location and serves 4 or 8 single family dwelling homes. (b) It is connected to the same spare telephone pair as 256 other similar units. (c) It incorporates remote meter reading of both PFU and PPV useage. (d) Turning on and off both the active tap amplifier and the switching network improves switching isolation. (e) Centralized Power Supply using A.C. power transmitted on the CATV distribution cable. (f) A microprocessor controls the switching, metering and communications functions: the microprocessor directly modulates and demodulates the remote meter reading data signals. (g) Incorporates a tamper detection circuit to signal the central billing computer that unauthorized access to the circuitry has occurred. (h) The unit does not reside on the exterior of the dwelling but either in the pedestal where the subscriber drop tap resides for buried distribution, or up on the strand which supports the aerial distribution cable. The embodiment of the Switched-Star Tap Unit is very similar in function to the Switched-Star Multi-Family Dwelling Unit shown in FIG. 9, the fundamental difference is that the unit provides solely the use of remote meter reading, the Multi-Family has also a directly readable meter bank. In a hotel environment, the apparatus can use either the splitter/drop tap arrangement or the star configuration described above. The system may or may not use meters. The registration clerk may sell the guests the Premium Television Programming by the night by adding a surcharge to the room rate. Should the guest request the additional programming the guest is given a key to the Set-Top Control Unit. The key then allows the premium programming to be accessed. Alternatively the premium programming can be switched by a Switching and Control Unit located behind the TV receiver that records and transmits useage data on a daily basis to a central billing computer. The data bypasses the tap using a low-pass filter. This apparatus is very similar to the remote meter reading apparatus previously described. This apparatus allows the programming to be sold by the hour. Using the star arrangement, the premium programming can be sold on a flat rate per night basis or on a metered basis. If sold on a flat rate basis the programming is switched ON or OFF by the registration clerk using a nearby switch bank. If sold on a metered basis the useage registers on a bank of meters or a central billing computer. In both cases the Switching Unit is similar to the Switched Star Unit shown FIG. 9. FIG. 10 shows a Master Set-Top Control Unit for a Multi-Tier System which is very similar to the device shown in FIG. 4. Only one of these units is provided in a subscribers residence: this unit allows the subscriber to access any or all of the PFU Premium Programming Services, additional Set-Top Control Units allow the user to access only the Tier I Premium Services. A Polarity Switching and Synchronizer circuit provided at 88 is similar to the Condition Follower circuit shown in FIG. 4. A subscriber Tier Level Selection switch 89 allows the user to select the Premium Programming Tier(s) that are desired and a Selection Monitor 90 displays the selection status. A Modulator 91 impresses the selection onto the D.C. carrier provided by the Power Supply 23. This can be accomplished by adding a frequency (or amplitude or pulse width) modulated A.C. signal, or amplitude modulating the D.C. voltage or current, or by pulling the D.C. level low (or reversing its polarity) for a short duration, where the duration of the low level D.C. communicates the tier level selection. FIG. 11 shows a corresponding External Switching and Metering Unit for the Multi-Tier System of FIG. 10. The unit is very similar in construction to the unit shown in FIG. 6. Thus when the polarity of the D.C. power is negative only the Premium TV Reject Filter path 65 is switched IN all other filter paths 66, 92, 93 are switched OUT, when a positive D.C. power is detected by the Demodulator and Control Unit 61 the Tier I path 66 is also switched IN. When the Demodulator and Control Unit detects modulation on the D.C. carrier it decodes the modulation and switches in the appropriate filter paths 92, 93. It also controls the operation of the billing meters 52. The billing meters are capable of being programmed to reflect different costs for the various tiers of Premium Programming Services. A separate meter for each tier may be employed or only two meters one for the Tier I services and a second for the higher tier services may be used. Where only two meters are used the Control Unit is programmed to regulate the billing meter for the Tier II and higher programming services such that the separate rate for each Tier is appropriately accounted for. FIG. 12 provides a general overview of a cable network including a central metering system. The total system comprises a central cable TV office 141 which supplies cable TV signals along a cable TV trunk 142 including trunk-bridger amplifiers 143 of a conventional construction. One line of the trunk is indicated at 144 and includes a plurality of the switched star External ControlUnits indicated at 145 and generally of the type illustrated in FIG. 9. Each Control Unit 145 provides a plurality of drops one of which is indicated to a single family dwelling unit at 146. An extender amplifier is indicated at 147. A tap for feeding an apartment block is indicated at 148 with the apartment blocks schematically indicated at 149. A Unit of the type illustrated in FIG. 6 is indicated at 150. The cable TV office 141 also communicates with a telephone company office indicated at 151 via a plurality of telephone pairs indicated at 152. A patch pair in the telephone office is indicated at 153 which communicates with a spare telephone pair indicated at 154 which is connected to a plurality of the external units including the unit 150 and a plurality of the units 144. The system thus uses a spare telephone paired cable as a common bus to connect up to 256 subscribers per pair to the cable TV office 141. FIG. 13 shows an exterior Control Unit similar to that of FIG. 6 but with two Tiers of Premium Pay-for-Use Television integrated with a fibre-optic Programming-On-Demand random access library system. When a positive D.C. polarity is delivered from the Set-Top Control Unit, power is supplied to a Time Clock Power Supply indicated at 94, a Tier I Accumulator/ Display Power Supply 95 and the Fibre Optic Receiver 95, an Audio/Video Demultiplexor and Demodulator Subunit 97 and a UHF Modulator Subunit 98. The video and audio signals which are either frequency division multiplexed or time division multiplexed over a channel unique to the subscribers address via the fibre optic distribution system are converted from a light signal to electrical signals and demultiplexed and demodulated into separate audio and video signals, they are subsequently modulated onto an unused television channel for subsequent transmission into the subscribers home. The subscriber must pay the video library operator directly for the programming accessed, the utility that owns the fibre-optic distribution system (which may or may not be the cable TV operator) for the utilization of the fibre channel, and for the use of the Exterior Interfacing Unit and the Interior Control Unit. The embodiment of FIG. 13 further includes the filtering and switching network of the type generally shown previously in FIG. 6. Specifically a first circuit path 99 includes a band reject filter 100 which is arranged to filter out the premium TV channels leaving the basic cable channel on the line 99. A second line 101 includes a notch filter 102 which filters out a specific premium channel to provide a PFU series of channels of a Tier II Level. A third line 103 is arranged to allow all Tv channels to pass through so that a premium generally higher priced channel is also available in addition to the Tier II Level. The filter 104 may allow through all channels or may be arranged to allow through only the premium high cost channel. The lines 101 and 103 are switched as previously described by the provision on the line of a positive biasing voltage for a plurality of diodes which is 105, 106, 107, 108 generally of the same type as previously described. A specific diode switch is shown in more detail at 105 and comprises a pair of diodes 109, 110 which can be biased by a direct voltage applied on a line 111 which passes through resistors 112 and 113 to ground at 114 through the diodes and through an inductance 115. Capacitors 116 and 117 block the passage of the D.C. current from the line 111 to the cable system. Thus the biasing of the diodes 109 and 110 allow the diode switch 105 to pass the signal along the line 103 through the filter 104 and through the switch 106 to the cable 18 connected to the control unit. The switches 107 and 108 operate in similar manner by a positive voltage generated on a line 118. Control of the switching of the diode switches 105, 106, 107, 108 is provided by the supply of either positive or negative voltage on the cable 18. On supply of a positive voltage at the cable 18 from the Control Unit, this positive voltage is transmitted along a line 119 through the RF Block 56 to the poles of a relay 120. The relay is actuated by a relay switch 121 downstream of a reverse bias diode 122 so it is only actuated on provision of a negative voltage on the line 119. Thus when a positive voltage is on the line 119, the relay takes up the position shown in FIG. 13 so that positive voltage is transmitted to a point 123 which is used to power the accumulator/display unit 95. In addition the positive voltage is transmitted through a line 124 to the line 118 and to the fibre-optic cable programming system and in particular the modulator 98. Thus the provision of the positive voltage from the Control Unit allows signals to pass along the line 101 and from the fibre-optic system as can be selected by the user at his TV set. The Tier I accumulated display unit 95 thus can be set to a lower value per unit time so that the cable operator can collect a payment for use of the basic system in which the demand programming on the fibre-optic cable is paid for separately as explained hereinafter or wherein the cheaper Tier I programs are used. When a negative voltage is supplied on the cable 18 from the Control Unit, the relay switch 121 actuates the contacts 120 to switch to the opposite position from that shown in FIG. 13. The D.C. Block 59 is arranged to replace the actual ground of the cable 18 with an effective ground of the unit so that the effective ground becomes an apparent positive voltage supply applied at the contact 125 of the contacts 120. This positive voltage passes along a line 126 to be applied to the line 111 of the diode switches 105 and 106 thus actuating those diode switches and allowing programming to pass through the filter 104 which is/or includes the high cost premium channel The positive voltage at terminal 125 is also transmitted to point 127 which acts to power the premium Tier II accumulator/display unit indicated at 128. The diodes 109, 110 provide a very low forward A.C. resistance (approx. 1 ohm) and very low unbiased capacitance (approx. 1 pF). The connection of two diodes in series further reduces the capacitance. The diode switches 105 and 106 are provided on the upstream and downstream side of the filter so as to isolate the downstream side of the three lines 99, 101, 103. Thus there is no possibility of even deteriorated signals leaking from one line to another thus providing an unmetered albeit degrading signal which can be watched by the subscriber. The filters and switching circuitry are arranged so that they have a high rejection loss (50 +dB), low insertion lost to out of band channels (0.3 dB) and are temperature stable. Thus the circuitry has sufficient insertion lost to a filtered channel so as to render a filter channel unuseable should the signal level deliver to the subscriber's home be typical for cable TV system (less than 6,000 uV). The filtered programming remains unuseable even when the subscriber disconnects the power supply to the apparatus. The circuit does not require the use of a splitter in order to separate the filtered path from the unfiltered path and has an insertion loss of less than 3 dB. Where an amplifier is used it again cancels all system losses and compensates for any slope on the received channels. While the device as shown provides the filters only on the switched parallel paths, it is possible to install filters on the unswitched path upstream of the switched paths so that a subscriber can tailor the system to any required useage pattern, for example totally eliminating an unrequired channel. FIG. 14 shows a configuration of the apparatus that permits demand programming to be integrated with an existing coaxial cable distribution system economically. As it is costly to provide a unique private television channel to each home a cost effective alternative that permits the delivery of programming upon the request of the subscriber is required. Subscribers wishing to use the system tune in a continuously available Activity Schedule provided on one of the transmitted channels. They then make a decision as to whether they wish to view one of the scheduled programs shown or order their own program. When the Activity Schedule includes an empty channel, if the user wishes to order a program it could be scheduled for that time and channel. Programs that are shown have been requested by other subscribers living in the same neighborhood. If one of these programs is accessed only a system useage charge will be billed to the subscriber, if the user orders a program, through the placing of a telephone call, the operator of the programming library charges the user an additional charge. Programs are transmitted along a fibre-optic cable from a programming library 130. One fibre feeds each neighborhood. The programs are modulated onto a band of channels acceptable to TV sets using commonly available modulators 131 The broadband signal is directly modulated onto the fibre-optic cable 133. The fibre cable is overbuilt along the existing cable TV trunking route 135. At the point where a bridger amplifier taps off the cable TV to feed a neiqhbourhood, the fibre feeding that neighborhood is terminated at a demodulator 134 and the programming library signals are demodulated, amplified and combined with the cable TV signals distributed to the neighborhood from the cable TV trunking. The demand programming channels do not interfere with the Cable TV channels on cable 135 as they are separated by frequency. The exterior Switching and Metering Unit records the useage of both the PFU premium TV signals and the programming library service, the same meter or separate meters could be used. Since various modifications can be made in my invention as hereinabove described, and many apparently widely different embodiments of same made within the spirit and scope of the claims without departing from such spirit and scope, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense.

An improved control and metering system for pay television distribution over a cable network. A control unit is located near each receiver on a subscribers premises and a secure filter, switching and metering unit is located external to the subscribers home. For the basic apparatus power and control signals needed to operate the external unit require no separate wiring as these signals are multiplexed over the coaxial cable that carries the TV signal into the home. An improved switch in the external unit activates a temperature compensated digital metering unit that displays either (or both) the time that the premium programming has been accessed or the totalized cost of the pay programming accessed. When implemented in high density housing districts common equipment is centralized and the apparatus is known as a switched star configuration. Also included is apparatus that permits metering to be accomplished at a central location for a community. The apparatus allows for tiering of pay programming utilizing different rates. The system is secure without scrambling or jamming. Another version of the apparatus permits Cable TV Operators to sell common carrier services to independent programmers according to utilization. The apparatus also allows for interfacing the cable TV network with a fibre optic television distribution network, for subscribed switching between the two systems and the metering of the utilization of such an apparatus. The system introduces the idea of a fibre optic video party-line to reduce implementation costs.

This is a continuation of application Ser. No. 08/389,853, filed Feb. 17, 1995, now abandoned. BACKGROUND OF THE INVENTION The invention relates to a method of locally controllably altering the magnetization direction in a body of magnetic material. The invention also relates to a device making use of such a method, in particular a magnetic head. The invention further relates to a method of controllably representing binary information in such a device. A method as elucidated in the opening paragraph is well known from common elementary teachings, and involves the subjection of the magnetic body to an external magnetic field whose magnitude exceeds the body's coercive field H c , thereby forcing the magnetization in the magnetic body to align itself parallel to the external field. An equally well-known variant of this method involves heating the body in the presence of an external magnetic field of magnitude less than H c (at ambient temperature), by virtue of which heating the coercivity of the material decreases, so that the magnetization direction in the body can nevertheless be forced into parallelism with the external field. Such external magnetic fields may be derived from a permanently magnetized material or from an electromagnet. The principles hereabove elucidated are fundamental to many known methods of magnetically recording information. For example, the magnetic head in a common tape recorder is used to transform a varying electrical signal into a fluctuating magnetic field, which in turn alters the magnetization direction in small magnetic domains within the tape, thereby endowing it with magnetically patterned information. See, for example, "The complete handbook of magnetic recording", F. Jorgensen, TAB BOOKS Inc., Pennsylvania (1980), in particular Chapter 3. Alternatively, so-called magnetic-field-modulated magneto-optical recording methods employ a laser beam to locally heat a confined region of a magnetic disc, in which region the local magnetization direction is concurrently manipulated into one of two directions using a fluctuating external magnetic field generated by a coil, thereby achieving the storage of binary information. See, for example, U.S. Pat. No. 4,466,004. A disadvantage of such known methods is that they require the application of a fluctuating external magnetic field. Magnetic fields are generally very difficult to localize, i.e. to confine in a well-defined manner to a limited region of specified spatial extent. As a result, highly localized manipulation of the magnetization in a magnetic body is difficult to achieve with external magnetic fields alone. For such a purpose, therefore, reliance must generally be made upon the assistant heating effect of a sharply focused laser beam, whereby, regardless of the spatial extent of the applied external magnetic field, only the magnetization in that region heated by the laser beam will allow itself to be directionally altered. However, satisfactory enaction of such a laser-assisted method is practically limited to magnetic materials having a relatively low Curie temperature, since the laser power otherwise required becomes incompatible with the electrical power provisions of many battery-operated devices. Furthermore, the effect of laser-assisted methods is practically limited to the surfaces of the laser-irradiated body. A further drawback of the use of a fluctuating external magnetic field is that the means by which it is generated are intrinsically "macroscopic", which conflicts with continuing modern trends towards device miniaturization. In the case of non-superconducting coils, the magnitude of the required magnetic field dictates the minimum cross-sectional area and multiplicity of the coil windings, thereby placing a lower limit on the coil dimensions corresponding to a given field strength. For the fluctuating magnetic fields conventionally employed in modern recording apparatus, this limitation results in typical coil dimensions of the order of a millimeter. Reduction of coils to microscopic dimensions is possible, at considerable expense, but such mini-coils generate magnetic fields which are insufficiently strong for many intended practical applications. To somewhat enhance the magnetic field strength delivered by such mini-coils, a magnetic yoke may be incorporated as a core. Such a measure, however, involves considerable additional fabrication processing, and places additional demands on available space, contrary to miniaturisation demands. The resulting magnetic field remains insufficient for many practical applications. SUMMARY OF THE INVENTION It is an object of the invention to provide a method as stated in the opening paragraph, without reliance on an external fluctuating magnetic field. It is a further object of the invention that such a method should be easily compatible with modern trends towards miniaturization, portability and low power consumption. It is yet another object of the invention that such a method should achieve relatively rapid alteration of the magnetization direction in the magnetic body concerned. Still another object of the invention is that such alteration should be, if so desired, highly localizable. These and other objects are achieved in a method of locally controllably altering the magnetization direction in a body of magnetic material, characterized in that a layer of non-metallic material is disposed on a surface of the body, on which layer is provided a body of magnetic material having a fixed magnetization direction, whereby both bodies of magnetic material may be magnetically coupled across the interposed non-metallic layer, the nature of this magnetic coupling being locally alterable by means of locally subjecting the layer of non-metallic material to a controllable electric field. The terminology introduced hereabove is intended to have the following scope: The term "magnetic body" should be widely interpreted as referring to such objects as, for example, individual thin films and layers, multilayer structures, thick films and layers, bulk plates or blocks of material, magnetic yokes, magnetic heads, etc., all of which at least partially comprise magnetic material, and all of which can demonstrate a non-zero net local magnetization direction. Such bodies may, where appropriate, be hollow or solid, flat or contoured, plain or structured, singular or composite, etc. The magnetic material itself may, for example, be ferromagnetic or ferrimagnetic, pure or alloyed, crystalline or amorphous. The magnetic bodies involved in the inventive method may, of course, be of mutually different composition; The term "non-metallic" should not be interpreted as referring to exterior physical appearance, but applies instead to a particular class of electronic band structures, which will be elucidated in more detail herebelow. Non-metallic substances falling within the scope of the term as here employed include semiconductor materials, so-called semi-metallic materials and insulator materials; The term "fixed" as hereabove employed is intended to have a relative meaning: the magnetization M 1 in a first magnetic body is "fixed" with respect to the magnetization M 2 in a second magnetic body if, under the sole influence of a variable external magnetic field of strength H, the value of H required to achieve the directional reversal of M 1 is higher than that required to achieve the directional reversal of M 2 . An exemplary method of fixing the magnetization direction in a magnetic body is to exchange-bias it to another magnetic material (the general principles of exchange-biasing are discussed in articles by W. H. Meiklejohn and C. P. Bean in Phys. Rev. 102 (1956), pp 1413-1414 and Phys. Rev. 105 (1957), pp 904-913; a particular example of an exchange-biased system is NiFe/FeMn). Alternatively, if the coercive field of a first magnetic body exceeds that of a second magnetic body, then the magnetization of the first magnetic body may be regarded as being "fixed"; The "nature" of the magnetic coupling J refers essentially, though not exclusively, to its sign and/or strength. In the context of this definition, the following coupling examples may be considered as being of mutually different "nature": Ferromagnetic coupling and anti-ferromagnetic coupling; Weak coupling and strong coupling, regardless of sign; Bilinear coupling (ferromagnetic or anti-ferromagnetic) and biquadratic coupling (90-degree coupling); Absence and presence of coupling, irrespective of further classification of nature. This list is given for purposes of clarification only, and is by no means exhaustive. The insights on which the inventive method are based will now be elucidated. It has been known for a number of years that two layers of ferromagnetic material can be magnetically coupled across an interposed layer of metallic material. See, for example, the article by P. Grunberg et al. in Phys. Rev. Lett. 57 (1986), pp 2442-2445. Depending on the thickness of the interposed layer, such coupling may demonstrate a ferromagnetic (F) or antiferromagnetic (AF) nature, as discussed by S. S. P. Parkin et al. in Phys. Rev. Lett. 64 (1990), pp 2304-2307. With this background knowledge, the inventors have noted an important distinction between the electronic band structure of metals and non-metals. In metals, there is no energy gap between the valence band and the conduction band, and the Fermi level is populated by electrons which are capable of partaking in conduction and inducing magnetic coupling. In non-metals (such as semiconductors, semi-metals and insulators) however, the valence band is separated from the conduction band by an energy gap which straddles the Fermi level; as a result, there are essentially no conduction electron states at the Fermi level. Further information with regard to electronic band structure is given in the following publications: A. J. Dekker, "Solid State Physics", Macmillan and Co. Ltd., London (1960), in particular Chapter 14. S. M. Sze, "Physics of semiconductor devices", second edition, John Wiley and Sons, New York (1981), in particular Chapter 8. On the basis of this insight, the inventors have realized that, if electrons having an energy approximately equal to the Fermi energy could be injected into a non-metal, then such a non-metal could be endowed with a certain degree of metallic character. Such an electronically modified non-metal could then be expected to demonstrate a degree of magnetic coupling, just as in the case of conventional metals. The present invention achieves the above-described electronic injection by subjecting a non-metallic material to a controllable electric field, in particular by applying a controllable DC electrical voltage difference across it. If the size of the energy gap in the employed non-metal is relatively small, then satisfactory electronic injection can occur for a correspondingly small electrical voltage difference (e.g. in the range 0-6 V). This basic concept lies at the heart of the inventive method. For example: Consider two ferromagnetic bodies which are sandwiched about an interposed layer of non-metallic material, but are not magnetically coupled across it. The net magnetizations in these two bodies will be essentially independent of one another; If, however, the non-metallic material is given a partially metallic character, thereby invoking magnetic coupling across it, then the net magnetizations in the two bodies will adopt a well-defined mutual configuration (e.g. anti-parallel in the case of AF coupling). Since the magnetization direction in one of the ferromagnetic bodies is fixed, the adoption of such a definite configuration will, in general, require the magnetization direction in the other ferromagnetic body to alter its direction; In an alternative scenario, the initial coupling across the non-metallic interlayer is weakly ferromagnetic, as a result of so-called "pinhole formation" between the ferromagnetic bodies. The inventive method may then be employed, for example, either to strengthen this existing coupling, or to otherwise change its nature. The inventors have successfully achieved strong anti-ferromagnetic coupling across both semiconductors and semi-metals. For example: A multilayer sample comprising 20×(3 nm Fe+1.4 nm Si) demonstrated a room-temperature saturation field of approximately 700 kA/m; A multilayer sample comprising 20×(3 nm Fe+2 nm FeSi) demonstrated a room-temperature saturation field of approximately 600 kA/m. In principle, insulator materials (such as Si oxides) can also be employed as non-metallic interlayers in the inventive method. In general, it is desirable to ensure that the magnitude of the magnetic coupling across the non-metallic material is as large as possible. As evident from the above-cited article by Parkin et al., the magnitude of the magnetic coupling across a metallic interlayer is a function of the thickness of that interlayer, and generally increases as that thickness is decreased. Assuming that a similar dependence applies to a non-metallic interlayer as used in the inventive method, an optimum magnitude of the interlayer coupling will be obtained when the thickness of the non-metallic interlayer does not exceed 10 nm. Although not fundamentally required according to the invention, the inventive method may also be enacted with the assistance of a static external magnetic field. Such a field may, for example, be employed to more efficiently manipulate the magnetization in one of the magnetic bodies after or during alteration of the coupling across the non-metallic interlayer. The invention also relates to a device suitable for use in the inventive method. According to the invention, such a device is characterized in that it comprises at least two bodies of magnetic material which are magnetically coupled across an interposed layer of non-metallic material, one of the magnetic bodies having a fixed magnetization direction, the device further comprising means for at least locally subjecting the non-metallic material to a controllable electric field so as to controllably locally alter the nature of the said magnetic coupling. In such a device, the required electric field may be provided by, for example, connecting the magnetic bodies to opposite poles of a controllable DC voltage source. If both magnetic bodies have a continuous interface with the non-metallic interlayer, then connection of the bodies across such a voltage source will cause an electric field to be applied across the entire extent of the intervening non-metallic material. If, however, at least one of the magnetic bodies is suitably structured into a multiplicity of electrically isolated potions (e.g. with the aid of a selective etching process), each of which portions has an interface with the non-metallic interlayer and each of which can separately be electrified, then a controllable electric field can be applied across the interlayer on a selective localized basis. If the bodies of magnetic material in the inventive device are to demonstrate optimal electrical conductivity, so as to facilitate the efficient generation of an electrical field between them, then they should preferably comprise a non-oxidic metallic material, such as non-oxidic Fe. Another suitable material in this category is, for example, Co. It is of course possible to embody at least one of the magnetic bodies in the inventive device as a magnetic multilayer structure. The term "magnetic multilayer" as here employed is intended to refer to any plurality of layers, at least one of which is magnetic. Well-known examples of magnetic multilayer systems are Co/Pt, Co/Pd, Co/Ni, Co/Cu and Fe/Cr, among many others. A preferential embodiment of a device according to the preceding paragraph is characterized in that the multilayer structure demonstrates a spin-valve magneto-resistance effect. The electrical resistance of such a magneto-resistive multilayer is dependent on the relative orientation of the magnetizations in its constituent magnetic layers. If the magnetization direction in at least one such layer is altered using the inventive method, then the electrical resistance of the multilayer structure will change accordingly. In this way, resistance measurements in the multilayer can be used to deduce the nature of the magnetic coupling across the non-metallic interlayer, since it is the coupling which dictates the mutual magnetization configuration in the magnetic bodies at any given time. The various materials in the inventive device, and in particular the non-metallic interlayer, can be provided by a variety of suitable techniques. These include, for example, sputter deposition, laser ablation deposition, physical and chemical vapor deposition and molecular beam epitaxy (MBE). The chosen deposition method can influence, for example, the strength of the coupling across the non-metallic interlayer. Particularly large coupling strengths are obtainable with MBE and sputter deposition. In addition to the layer of non-metallic material, the inventive device may, of course, comprise additional (multi)layers of material. Such additional layers may, for example, be necessary to enact exchange biasing of (at least) one of the magnetic bodies to another magnetic material. Alternatively, such layers may fulfil specific device functions, and may include insulating layers, anti-corrosion layers, adhesion layers, patterned layers of electrically conducting tracts, etc. It should be noted that the magnetic anisotropy of the magnetic bodies in the inventive method and device as hereabove described may display various directions with respect to the plane of the non-metallic interlayer. For example, the magnetization of at least one of the magnetic bodies may be substantially parallel or perpendicular to the interlayer. The device according to the invention has many important applications. A particularly striking example is its employment as an ultrathin magnetic head for recording purposes. For example, such an embodiment can be envisaged as follows: A conventional magnetic head essentially comprises an electrical coil which is wound around part of a split magnetic yoke. Electrical current fluctuations in the coil are translated into magnetic flux fluctuations in the yoke, particularly in the region of the split. A magnetic medium in proximity to this split can thus be subjected to a localized fluctuating magnetic field, which can locally alter the magnetization direction in the medium, thereby endowing it with magnetically patterned information; In the inventive device, the magnetization direction in one of the magnetic bodies can be controllably altered by employing an electrical field to predictably change the nature of the magnetic coupling across the non-metallic interlayer. For example, if this coupling is altered between a ferromagnetic and anti-ferromagnetic nature, then, since the magnetization direction in one of the magnetic bodies is fixed, the magnetization direction in the other magnetic body can be controllably flipped back and forth. If the electrical field across the interlayer is modulated in accordance with certain binary data to be recorded, then a magnetic medium in proximity to this flipping magnetization can be endowed with that binary data. If the magnetic bodies are embodied as thin films, then the inventive magnetic head can be very thin indeed, and certainly much smaller than a conventional magnetic head. Furthermore, such an inventive head is much easier to fabricate, since it does not involve a coil-winding procedure. An important potential application of the device and method according to the present invention is in the "trimming" of a magnetic circuit. During operation, an undesirable magnetic domain structure can develop in magnetic circuits such as, for example, recording heads, magneto-resistive sensors and transformer yokes. Using the inventive method, however, the circuit's original magnetic domain structure may be at least locally restored. This may be achieved by interposing a non-metallic layer between (part of) the magnetic circuit and a reference magnetic body with a "fixed" magnetic domain pattern. If there is intrinsically little or no magnetic coupling across the non-metallic interlayer, then the magnetic circuit will not be influenced by the reference magnetic body. However, if stronger magnetic coupling is temporarily invoked across the interlayer (by subjecting it to an electric field, in accordance with the invention), then the domain pattern in the magnetic circuit can temporarily be "exposed" to, and reconfigured by, the fixed domain pattern in the magnetic reference body. The invention further relates to an exemplary method of controllably representing binary information in the inventive device. In accordance with the invention, such a method is characterized in that a first binary symbol is represented by locally invoking ferromagnetic coupling across the non-metallic interlayer so as to locally induce substantially mutually parallel alignment of the magnetizations in the two magnetic bodies, whereas a second binary symbol is represented by locally invoking antiferromagnetic coupling across the non-metallic interlayer so as to locally induce substantially mutually anti-parallel alignment of the magnetizations in the two magnetic bodies. In such a method, a spin-valve magneto-resistive multilayer structure (for example) may be employed as hereabove elucidated to monitor the mutual orientation of the magnetizations in the two magnetic bodies at any given time i.e. to determine which binary symbol "1" or "0") is therein represented. This same monitoring can also be achieved via, for example, magnetometry or magneto-optical Kerr measurements. Using such a method in conjunction with a device according to the invention, it is possible to make magnetic memory devices with very short access times and high storage densities. In a particular embodiment of the inventive device lending itself to this application, two layers of magnetic material are ferromagnetically coupled across an interposed non-metallic layer (as a result of pinhole formation, for example). One of the magnetic layers is continuous and has a fixed magnetization direction, whereas the other is divided into a number of isolated electrode segments (using, for example, a selective etching technique). These isolated electrode segments are individually connected to controllable DC voltage sources, so that they can be individually electrified. The continuous magnetic layer, on the other hand, is kept at a fixed electrical potential. By suitably electrifying a given electrode segment, an electric field will be locally applied across the piece of intervening non-metallic material between that particular electrode segment and a directly opposed portion of the continuous magnetic layer, thereby inducing AF coupling across that piece of intervening material. As a result, the magnetization direction in the said electrode segment will reverse its direction, and this can be verified using spin-valve magneto-resistance measurements. A device of this type can be used to make a magnetic random-access memory (MRAM). BRIEF DESCRIPTION OF THE DRAWING The invention and its attendant advantages will be further elucidated with the aid of exemplary embodiments and the accompanying schematic drawing, not of uniform scale, wherein: FIG. 1 renders a cross-sectional view of part of a device according to the invention; FIG. 2 shows the subject of FIG. 1 after enaction of the inventive method for controllably altering a magnetization direction; FIG. 3 is a schematic electronic band structure diagram pertaining to the situation in FIG. 1; FIG. 4 is a schematic electronic band structure diagram pertaining to the situation in FIG. 2; FIG. 5 gives a cross-sectional depiction of part of a device according to the invention, which device includes a spin-valve magneto-resistive multilayer structure; FIG. 6 shows the subject of FIG. 5 after enaction of the inventive method for controllably altering a magnetization direction; and FIG. 7 cross-sectionally depicts part of a device according to the invention, in which device both magnetic bodies are embodied as an array of electrically isolated electrode segments. DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 and 2 cross-sectionally depict part of a device according to the present invention, which can be employed, for example, as a magnetic recording head. Corresponding parts of both figures are labelled using the same reference numerals. In FIG. 1, a body 1 of magnetic material is magnetically coupled across a layer 3 of non-metallic material to a layer 5 of magnetic material. Bodies 1 and 5 comprise, for example, Fe; layer 3 comprises, for example, Si. The magnetization direction in layer 5 is fixed. The bodies 1 and 5 are connected across controllable voltage supply means 7, which are here not yet invoked. The nature of the magnetic coupling across the interlayer 3 is, in this case, intrinsically ferromagnetic (as a result of pinhole formation, for example). As a result, the net magnetization vector 11 in body 1 is substantially parallel to the net magnetization vector 9 in layer 5. In FIG. 2, the controllable voltage supply means 7 have been invoked to apply an electrical field across the layer 3. According to the invention, the presence of this electric field induces a certain degree of metallic character in the non-metallic material of layer 3. As a result, the magnetic coupling across the layer 3 becomes temporarily anti-ferromagnetic. Consequently, the magnetization vectors 9 and 11 adopt a substantially anti-parallel configuration. Since vector 9 is fixed, this entails the reversal of vector 11 with respect to its orientation in FIG. 1. The inventive method has therefore achieved controllable alteration of the magnetization direction in the body 1. In the absence of strong coercivity, removal of the applied electrical field across the layer 3 will cause the magnetization vectors 9 and 11 to revert to the essentially parallel configuration depicted in FIG. 1. As explained hereabove, a device such as this can be employed as a magnetic recording head. FIGS. 3 and 4 are highly simplified schematic electronic band structure diagrams pertaining, respectively, to the depicted scenarios in FIGS. 1 and 2. Both figures essentially render a graph of electronic potential energy E as a function of position x perpendicular to the plane of layer 3, in the vicinity of the interfaces between layer 3 and the bodies 1 and 5. Corresponding parts of both figures are labelled using the same reference symbols. In FIG. 3, labels 21f and 25f respectively denote the Fermi levels of the metallic bodies 1 and 5 depicted in FIG. 1; by definition, all electronic states below these levels are filled. Labels 23v and 23e respectively denote the extremities of the valence band and the conduction band of non-metallic layer 3 in FIG. 1; by definition, all electronic states below level 23v (i.e. in the valence band) are filled, whereas essentially all those above level 23c (i.e. in the conduction band) are empty. Between levels 23v and 23c there is an energy gap (forbidden zone), which straddles the Fermi level. Since the conduction band is essentially empty, layer 3 does not conduct electrically of its own accord. Electrons from levels 21f and 25f in the neighboring metals also cannot tunnel into the conduction band of layer 3, since level 23e is located above levels 21f and 25f. FIG. 4 shows the effect of applying an electric field across layer 3, as depicted in FIG. 2. Fermi level 25f is now raised with respect to Fermi level 21f by an amount E 7 (corresponding to the electrical potential delivered by the means 7). Consequently, the edges 23v and 23e in the non-metallic interlayer become canted (see, for example, the above-cited book by Sze, page 491). As a result of this canting, part of the conduction band in layer 3 falls below the new Fermi level 25f, so that electrons can now successfully runnel from layer 5 into the conduction band of layer 3. Such tunnelled electrons impart limited metallic character to the material of layer 3. FIGS. 5 and 6 cross-sectionally depict part of a device according to the present invention, which can be employed, for example, as a magnetic memory device. Corresponding parts of both figures are labelled using the same reference numerals. In FIG. 5, a layer 31 of magnetic material is magnetically coupled across a layer 33 of non-metallic material to a layer 35 of magnetic material. The layer 35 is further magnetically coupled across a metallic layer 37 to a magnetic layer 39. The layers 35, 37 and 39 respectively comprise a Fe/Cr/Fe trilayer, which demonstrates a spin-valve magneto-resistance effect. The layer 31 comprises, for example, Fe; the layer 33 comprises, for example, Si. The magnetization direction in layer 31 is fixed. The magnetization direction in layer 39 is also fixed. The layers 31 and 35 are connected across controllable voltage supply means 311, which are here not yet invoked. The nature of the magnetic coupling across the interlayer 33 is intrinsically ferromagnetic (for example, due to pinhole formation). As a result, the net magnetization vector 315 in layer 31 is substantially parallel to the net magnetization vector 317 in layer 35. The layers 35 and 39 are connected across electrical resistance measuring means 313. The nature of the magneto-resistive effect in the trilayer 35/37/39 is such that the measured electrical resistance corresponding to a parallel configuration of the magnetization vectors 317 and 319 is lower than that corresponding to an anti-parallel configuration of magnetization vectors 317 and 319. As here symbolically depicted, the means 313 are embodied to measure the resistance perpendicular to the layers 35, 39 (so-called CPP geometry); it is, of course, also possible to measure the lateral electrical resistance across the trilayer structure, using the so-called CIP geometry. In FIG. 6, the controllable voltage supply means 311 have been invoked to apply an electrical field across the layer 33. According to the invention, the presence of this electric field induces a certain degree of metallic character in the non-metallic material of layer 33. As a result, the magnetic coupling across the layer 33 becomes temporarily anti-ferromagnetic. Consequently, the magnetization vectors 315 and 317 adopt a substantially anti-parallel configuration. Since vector 315 is fixed, this entails the reversal of vector 317 with respect to its orientation in FIG. 5. The inventive method has therefore achieved controllable alteration of the magnetization direction in the layer 35. When the applied electrical field across the layer 33 is removed, the magnetization vectors 315 and 317 revert to the essentially parallel configuration depicted in FIG. 5 (assuming relatively low magnetic coercivity). By employing the means 313 to measure the electrical resistance of the trilayer structure 35/37/39, the magnetization configuration in the layers 31 and 35 can be deduced at any time. As explained hereabove, a device such as this can be employed as a magnetic memory device. FIG. 7 cross-sectionally depicts part of a device according to the invention. A first body 41 of magnetic material is magnetically coupled to a second body 45 of magnetic material across an intervening layer 43 of non-metallic material. Both bodies 41 and 45 comprise a multiplicity of isolated electrode segments, which are arranged in facing pairs (41a, 45a), (41b, 45b), (41c, 45c), (41d, 45d), etc. The various electrode segments can be individually electrified. If, for example, electrode segments 41b and 45b are connected to the poles of a controllable DC voltage source, then the intervening portion of the layer 43 situated immediately between then can be subjected to an electric field. If the magnetization direction in segment 41b is fixed, then such subjection can be used according to the inventive method to alter the magnetization direction in segment 45b. Such a device is suitable for use as a magnetic memory array.

A device and method for controllably locally altering the magnetization direction in a body of magnetic material, whereby a layer of at least one of non-metallic material and a semi-metallic material is disposed on a surface of the body, on which layer is provided a body of magnetic material having a fixed magnetization direction, whereby both bodies of magnetic material are magnetically coupled across the interposed layer, the nature of this magnetic coupling being locally alterable by means of locally subjecting the layer to a controllable electric field.

BACKGROUND OF THE INVENTION 1. Field of The Invention The invention relates to new imidazole derivatives of the formula: ##STR3## wherein R 1 is an (R)- or (S)-1-phenylalkyl group, an (R)- or (S)-1-alkoxycarbonyl-1-phenylmethyl group or an (R)- or (S)-1-aryloxycarbonyl-1-phenylmethyl group, R 2 is hydrogen, a substituted or unsubstituted alkanoyl group, a substituted or an ubsubstituted benzoyl group, a substituted or an unsubstituted benzyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkoxyalkyl group, a pyranyl group, a substituted or an unsubstituted benzenesulfonyl group, an alkylsulfonyl group, a diarylphosphinyl group, a dialkoxyphosphinyl group or a trialkylsilyl group, and A is a sulfur or oxygen atom. These compounds are suitable as intermediate products for the production of (+) biotin. 2. Background Art A process is known from U.S. Pat. No. 2,489,232 according to which racemic biotin is produced. But since, as is known, only the optically active (+) biotin is biologically active; the thus-produced racemic biotin must then still be separated into the optical enantiomers. On the one hand, in such a case all reaction steps are performed with racemic materials, as a result of which the doubled amounts of substance must be processed. On the other hand, resolution of the racemic biotin into the corresponding enantiomers is a very complicated process, which in addition is also unprofitable, since the undesirable enantiomer practically no longer racemizes and can no longer be fed back into the process. An improvement of such process is known from U.S. Pat. No. 2,489,235. In such improvement, the resolution of the racemates is already performed in an earlier step, but still such process has the drawback that most of the reaction steps are performed with racemic material and here too the undesirable enantiomer practically no longer racemizes and can no longer be fed back to the process. M. Murakami et al. developed an improved process for the production of dl-biotin (cf. Japanese Published Patent Document 31669/1970, 37775/1970, 37776/1970 and 3580/1971). The improvement consists in introducing a carboxybutyl group in the 4-position of the dl-1,3-dibenzylhexahydrothioeno-[3,4-d]-imidazole-2,4-dione. Such dione is reacted with a 1,4-dihalomagnesium butane and then carboxylated with carbon dioxide. Gerecke et al., German Published Patent Document No. 2058248, have developed a further improvement, by already producing--in an earlier step by the optical resolution of a triethylamine salt of the following formula, in which R is a cholesteryl radical, or of an ephedrine salt of the following formula, in which R is a cyclohexyl radical: ##STR4## and by the further conversion with alkali metal hydrides--an optically active lactone of the formula: ##STR5## as an optically active intermediate product. A significant drawback for an industrial use of such process consists in the use of the expensive optically active compounds chloresterol and ephedrine as well as expensive alkali metal hydrides. The processes of European Published Patent Applications Nos. 0161580 and 0173185 are tainted with the same drawback, namely the use of expensive optically active compounds. BROAD DESCRIPTION OF THE INVENTION The object of the invention is to provide industrially simply available intermediate products, which, on the one hand, already in an earlier step relative to the total synthesis, can be optically resolved in a simple process step and, on the other hand, already exhibit in the corresponding positions the configuration of the end product. According to the invention the object is achieved with the new imidazole derivatives of formula: ##STR6## wherein R 1 is an (R)- or (S)-1-phenylalkyl group, an (R)- or (S)-1-alkoxycarbonyl-1-phenylmethyl group or an (R)- or (S)-1-aryloxycarbonyl-1-phenylmethyl group, R 2 is hydrogen, a substituted or unsubstituted alkanoyl group, a substituted or an unsubstituted benzoyl group, a substituted or an unsubstituted benzyl group, an alkoxycarbonyl group, and aryloxycarbonyl group, an alkoxyalkyl group, a pyranyl group, a substituted or unsubstituted benzenesulfonyl group, an alkylsulfonyl group, a diarylphosphinyl group, a dialkoxyphosphinyl group or a trialkylsilyl group, and A is a sulfur or oxygen atom. When R 1 is a 1-phenylalkyl, it is preferably 1-phenyl-(C 2 -C 4 )-alkyl and most preferably 1-phenylethyl, is a 1-alkoxycarbonyl-1-phenylmethyl, it is preferably 1-(C 1 -C 4 )-alkoxy-carbonyl-1-phenylmethyl, and is a 1-aryloxycarbonyl-1-phenylmethyl, it is preferably a 1-benzyloxy-carbonyl-1-phenylmethyl- or 1-phenyloxycarbonyl-1-phenylmethyl group. When R 2 is an alkanoyl, it can be (C 1 -C 4 )-alkylcarbonyl, preferably acetyl. The alkanoyl group can be substituted by halogenatoms preferably by chlorine. A preferable representative is the trichloroacetyl group. The benzoyl group and the benzyl group is preferably not substituted but substituents like halogenatoms, lower alkyl groups or lower alkoxy groups are not excluded. For example, a p-methoxybenzyl or a methylbenzyl can be applied as substituted benzyl group. When R 2 is an alkoxycarbonyl, it can be (C 1 -C 4 )-alkoxycarbonyl and aryloxycarbonyl, preferably phenyloxycarbonyl. When R 2 is an alkoxyalkyl, it is preferably (C 1 -C 4 )-alkoxymethyl. The benzolsulfonyl preferably is p-toluolsulfonyl. The alkylsulfonyl preferably is methylsulfonyl. Generally the term alkoxy or alkyl defines an (C 1 -C 4 )-alkyl group and the term aryl defines benzyl or phenyl, preferably unsubstituted. Suitably the compounds, which fall under formula IX are the thienoimidazole derivatives of the formula: ##STR7## wherein R 1 and R 2 have the meaning set out above, and the furoimidazole derivatives of the formula: ##STR8## wherein R 1 and R 2 have the meaning set out above. According to the invention the compounds of formula IX, starting from a tetronic acid of the formula: ##STR9## wherein A has the meaning set out above, are produced by reaction with a diazonium salt. The resultant arylazotetronic acid or the tautomeric arylhydrazone is convered in a further step with a chiral amine into an arylazoamino compound. The process proceeds by reducing the arylazoamino compound, converting the resultant diamine, with phosgene or a phosgene-equivalent reagent, into the corresponding imidazole and optionally introducing a protective group by reaction with a substituted or unsubstituted aliphatic or aromatic acid chloride, an aliphatic or aromatic carboxylic acid anhydride, a haloformic acid alkyl ester, a 1-alkoxyalkyl halide, an enol ether, an aromatic or aliphatic sulfonic acid halide, a diarylphosphinic acid halide, a phosphoric acids dialkyl ester halide, a trialkylsilyl halide or a trialkylsilyl acetamide. This process corresponds to the following Diagram 1: ##STR10## Description of Individual Process Steps: I to II The conversion from compound I to compound II comprises a diazo production known in itself. For A = O, i.e., for tetronic acid, the reaction was described in Tanaka et al., Chem. Pharm. Bull. 32 (1984), pp. 3291 -3298. Usually a diazonium salt of the formula is first produced, wherein R 3 is phenyl, unsubstituted or substituted with alkyl, haloalkyl or nitro groups or halogen atoms, and X is halogen such as chlorine, bromine or iodine, BF 4 or hydrogen sulfate. For this purpose, in a known way, an aniline of the formula: R.sub.3 NH.sub.2 preferably in a diluted aqueous mineral acid such as HCl, H 2 SO 2 or HBF 4 , is reacted with an alkali nitrite at 0° to 10° C. The reaction can also be conducted in the presence of a polar protic solvent, such as lower alcohols or acetic acid, or with a polar aprotic solvent, such as dimethyl sulfoxide, dimethylformamide, dimethylacetamide or dimethoxyethane, or, in the case of where diazonium tetrafluoroborate is used, in acetonitrile or tetrahydrofuran. These solvents as a mixture in different ratios with water can be used. The formed diazonium salt is then reacted to compound II with compound I, which is suitably present dissolved in water or in the above-mentioned solvents, at a temperature suitably from 0° to 40° C., preferably lower than 10° C. It is advantageous to ensure that the pH is in a range of 4 to 7. Optionally, the pH can be adjusted to the desired range with a pH adjusting or correcting agent, such as alkali bicarbonate or a phosphate buffer for aqueous systems, or a tert-amine. Preferably, the conversion from compound I to compound II is performed with benzenediazonium chloride in water. The resultant phenylazotetronic acids can be present [together with their tautomeric phenylhydrazone] in different ratios to one another. Working up can take place in the usual way, preferably by separation of the product from the reaction mixture, and optionally by subsequent recrystallization. II to III A characteristic feature of the conversion from compound II to compound III is the introduction of an amino function in the 4-position of the heterocycle with the help of a chiral amine. As the chiral amine compounds are used of the formula: R.sub.1 NH.sub.2 wherein R 1 represents an (R)- or (S)-1-phenylalkyl group or an (R)- or (S)-1-phenylalkoxycarbonylmethyl group. Preferably (R)- or (S)-1-phenylethylamine is used. The conversion is advantageously performed in the presence of an acid catalyst. As catalysts above all Lewis acids, such as the corresponding aluminum, boron or titanium compounds, and also acids, such as methanesulfonic acid or p-toluenesulfonic acid, are suitable. Suitable Lewis acids are boron trifluoride ethyl etherate, trimethyl borate, triethyl borate, titanium tetrachloride, titanium tetraisopropoxide or aluminum chloride. The catalyst is used suitably in an amount of 1 to 50 mol percent, preferably in an amount of 1 to 20 mol percent. Since a splitting off of water occurs with the reaction, there are suitably used as solvents either water entrainers such as toluene or benzene, or tetrahydrofuran, acetonitrile, dioxane, dimethylformamide, dimethylacetamide, chlorinated hydrocarbons such as chloroform or methylene chloride, also lower alcohols such as methanol, ethanol or propanol, suitably together with the usual drying agents such as molecular sieves, sodium sulfate, calcium sulfate or magnesium sulfate. The work is suitably performed at a temperature between 20° and 120° C. It is also advantageous to perform the reaction in an inert gas atmosphere (e.g., nitrogen or argon). Compound III can then be worked up and isolated according to methods known to one skilled in the art, e.g., by evaporation and subsequent recrystallization. III to IV The reduction of compound III to compound IV can take place either by means of a catalytic hydrogenation with hydrogen or by reaction with zinc in the presence of acetic acid or with hydrochloric acid. Preferably, the reduction is attained by means of a catalytic hydrogenation with hydrogen. Suitably platinum, palladium, rhodium, ruthenium or Raney nickel is used as the hydrogenation catalysts, optionally on a support material such as carbon, clay, pumice, aluminum oxide, aluminum silicate. Preferably platinum is used on carbon as the support material. The catalyst amount is suitably selected between 4 and 20 mol percent. The amount of catalyst on the support material can vary between 1 and 10 percent. It is advantageous to conduct the reaction in the presence of a solvent. Acetic acid alkyl esters such as acetic acid ethyl ester, ethers such as tetrahydrofuran, dioxane or dimethoxyethane, or also dimethylformamide, dimethylacetamide, acetonitrile, acetic acid or lower alcohols are suitable. Acetic acid ethyl ester, tetrahydrofuran or ethanol are especially easy to use. The reaction is suitably conducted at a hydrogen pressure between 1 and 50 bars, preferably between 20 and 40 bars, and at a temperature suitably between 10° and 60° C., preferably between 10° and 30° C. After filtering off the catalyst, the reaction mixture can be worked up in the usual way, e.g., by precipitation of the product in a very nonpolar solvent. IV to V Compound IV is treated with phosgene or a phosgene equivalent for the formation of the imidazole. As a phosgene equivalent, compounds are suitably used of the formula: YCOZ wherein Y and Z are imidazolyl or chlorine, or Y is chlorine and Z is substituted or unsubstituted alkoxy, or substituted or unsubstituted aryloxy. Advantageous phosgene equivalents are the chloroformic acid lower alkyl esters, chloroformic acid phenyl ester, chloroformic acid benzyl ester or carbonyl diimidazolide. The reaction suitably takes place in the presence of a base. Tertiary aliphatic amines, such as triethylamine, aromatic and cyclic tertiary amines, such as pyridine or diazabicylooctane, plus inorganic bases can suitably be used. But preferably tertiary aliphatic amines, such as triethylamine, are used. Use of a base is unnecessary if compound IV is reacted with carbonyl diimidazolide as a phosgene equivalent. It is advantageous to perform the reaction in the presence of ethers such as tetrahydrofuran or dioxane, halogenated hydrocarbons such as chloroform or methylene chloride, aromatic hydrocarbons such as toluene, carboxylic acid amides such as dimethylformamide, acetic acid alkyl esters, or also in acetonitrile as an inert organic solvent. The reaction temperature is suitably selected in a range of 0° to 80° C. Working up takes places in the usual way by separation of the resultant salts, evaporation of the solvent and optionally by purification of the product by, for example, a recrystallization. V To VI Compound V can be used by itself for stereoselective further reaction. But optionally the hydrogen atom in the 3 position of the imidazole ring can be replaced by a protective group R 2 '. The introduction of the protective group R 2 ' can suitably take place by reaction of compound V with substituted or unsubstituted aliphatic or aromatic acid halides, such as, acetyl chloride, propionyl chloride, benzoyl chloride, with benzyl halides, such as benzyl chloride, with chloroformic acid esters, such as chloroformic acid ethyl ester, chloroformic acid tertbutyl ester, chloroformic acid benzyl ester or chloroformic acid phenyl ester, with phosphorus compounds, such as diphenylphosphinic acid chloride or phosphoric acid diethyl ester chloride, with aromatic or aliphatic sulfonic acid halides such as methanesulfonyl chloride, or p-toluenesulfonyl chloride, with silyl compounds, such as bis(trimethylsilyl) acetamide, or tert-butyl dimethyl silyl chloride, with alkoxyalkyl halides such as methoxy methyl chloride, or with enol ethers such as dihydropyran. Just as suitable are substituted or unsubstituted aliphatic or aromatic carboxylic acid anhydrides such as acetic anhydride. The introduction of the protective group can take place according to known methods. Consequently, it is not gone into further. According to this four-step process, or five-step process with the introduction of a protective group, according to the invention it is possible in a simple way and with good yields to reach intermediate product IX (compound VI or IX). This product, on the one hand, already has the skeleton of the end product and allows, in a simple way, the incorporation as the asymmetric center of biotin. The (+) biotin can be prepared by the process wherein a compound of the formula: ##STR11## wherein R 1 is an (R)- or (S)-1-phenylalkyl group, an (R)- or (S)-1-alkoxycarbonyl-1-phenylmethyl group or an (R)- or (S)-1-aryloxcarbonyl-1-phenylmethyl group, and R 2 is hydrogen, a substituted or unsubstituted alkanoyl group, an unsubstituted or a substituted benzoyl group, a substituted or an unsubstituted benzyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an aryloxyalkyl group, an alkoxyalkyl group, a pyranyl group, an unsubstituted or substituted benzenesulfonyl group, an alkysulfonyl group, a diarylphosphinyl group, a dialkoxyphosphinyl group or a trialkylsilyl group, is catalytically hydrogenated with hydrogen, the desired diastereomer of the formula: ##STR12## is separated, if R 2 is H, a protective group is introduced by reaction with substituted or unsubstituted aliphatic or aromatic acid chlorides, aliphatic or aromatic carboxylic acid anhydrides, haloformic acid esters, benzyl halides, 1-alkoxyalkyl halides, aromatic or aliphatic sulfonic acid halides, diarylphosphinic acid halides, phosphoric acid dialkyl ester chlorides, substituted or unsubstituted trialkylsilyl halides or substituted or unsubstituted trialkylsilyl acetamides, the desired diastereomer is converted by a further reaction with a thiocarboxylic acid salt derivative into the corresponding thiolactone, the latter thiolactone is reacted either with a Grignard reagent and subsequent splitting off of water or with a compound of the formula: (C.sub.6 H.sub.5).sub.3 P⊕ (CH.sub.2).sub.4 COOR.sub.3.X⊕XII wherein R 3 is H or alkyl with 1 to 4 C atoms and X represents a halogen atom, in the presence of a base to a compound of the formula: ##STR13## wherein R 3 has the above-mentioned meaning, in a following step this compound is catalytically hydrogenated with hydrogen and then converted into the end product by cleavage of the protective groups. Of crucial importance for the process in this case are the new 1H-furo[3,4-d]imidazol-2,4(3H,3aH)-diones of the formula: ##STR14## wherein R 1 and R 2 have the above-mentioned meanings, but of special importance is the (3aS,6aR)-[(R)-(1-phenylethyl)]-3-benzyldihydro-1H-furo[3,4-d]imidazol-2,4(3H,3aH)-dione of the formula: ##STR15## DETAILED DESCRIPTION OF THE INVENTION Example 1 (a) Production of 3-phenylazontetronic acid [3-phenylazo-4-hydroxyfuran-2(5H)-one] 300 ml of 6N hydrochloric acid solution was placed in a 1.5-liter flask equipped with a 250-ml dropping funnel, a mechanical stirrer and a thermometer. 57.6 g (0.61 mol) of distilled aniline was added with ice cooling. A solution of 43.92 g (0.64 mol) of sodium nitrite in 90 ml of ice water was added dropwise the resulting suspension and stirred for 40 min. The resultant diazonium salt solution was added dropwise to a solution of 60 g (0.6 mol) of tetronic acid and 120 g (0.88 mol) of sodium acetate trihydrate in 900 ml of water for 30 min. After this addition a yellow solid immediately precipitated. The reaction mixture was stirred at 10° C. for 1.5 hours, and filtered off; and the product was washed with 500 ml of cold methanol. It was dried at 35° C. in a vacuum. Concerning the product: Yield: 113.2 g = 92.4 percent. Melting point: 199°-200° C. (decomp.). (b) Production of 3-phenylazo-4-[(S)-(1-phenylethylamino)]-furan-2(5H)-one 20.0 g (98 mmol) of 3-phenylazotetronic acid in 190 ml of toluene was suspended in a 500-ml three-neck flask equipped with a water separator, a thermometer and a magnetic stirrer, and was heated under argon to 80° C. Then 13.1 g (108 mmol) of (S)-phenylethylamine and 2.8 g (19 mmol) of triethyl borate were added. The solvent was refluxed under a vacuum of 300 mbar. After 7 hours, the toluene was evaporated. The black residue was washed with 100 ml of ether until a brown mass precipitated. The mass was triturated in ether and a yellowish product was obtained. The produce, 3-phenylaxo-4[(S)-(1-phenylethylamino)]-furan-2(5H)-one, was filtered off and dried in a vacuum. Concerning the product: Yield: 28.36 g = 94.0 percent. Melting point: 114°-115° C. NMR: (CDCl 3 , 300 MHz) δ in ppm 1.69, d, J = 7 Hz, 3H, 4,42, d, J = 16 Hz, 1H, 4.45, bm, 1H, 4.81, d, J = 16 Hz, 1H, 7.26-7.45m, 8H, 7.78, d, J = 8 Hz, 2H, 10.55, bs, 1H. MS: (E.I. 70 ev) m/e 307 (9%) M + , 195 (25%), 171 (11%), 126 (10%), 105 (100%), 93 (28%). IR: (KBr) cm -1 3064, 3026, 1746 (s), 1621 (s), 1456, 1356, 1288, 1045, 756. UV: (MeOH) λ max: 366 nm (ε = 21.050), 260 nm (ε = 11.540), 235 nm (ε = 12.800). Elementary analysis for C 18 H 17 N 3 O 2 (307.35): calculated: C 70.3%, H 5.6%, N 13.7%, found: C 70.3%, H 5.5%, N 13.4%. [α] D 25 [c=1 CHCl 3 ]+785°. (c) Production of 3-amino-4[(S)-(1-phenylethylamino)]-furan-2(5H)-one 13.50 g (44 mmol) of 3-phenylazo-4-[(S)-(1-phenylethylamino)]-furan-2(5H)-one, 133 ml of acetic acid ethyl ester and 0.77 g of platinum on carbon (5 percent) were put into a 500-ml autoclave. The autoclave was closed and flushed twice with hydrogen while stirring. Then the reaction mixture was hydrogenated with hydrogen under 40 bars of pressure for 30 minutes. The catalyst was filtered off under argon and to the mother liquor was added dropwise with ice cooling, 130 ml of octane. 3-Amino-4-[(S)-(1-phenylethylamino)]-furan-2(5H)-one precipitated in the form of beige crystals. The product was dried under vacuum at room temperature. Concerning the product: Yield: 8.53 g = 89.0 percent. Melting point: 127.5°-128.0° C. NMR: (CDCl 3 , 300 MHz) δ in ppm 1.55, d, J = 7.0 Hz, 3H, 2.35, bs, 2H, 4.21, d, J=15 Hz, 1H, 4.51, d, q, J=7 Hz, 7 Hz, 1H, 4.53, d, J=15 Hz 1H, 4.83, bd, J=7 Hz, 1H, 7.25-7.4, m, 5H. MS: (E.I. 70 ev) m/e 218 (10%) M + , 114 (18%), 105 (100%). IR: (KBr) cm -1 3424, 3341 (s), 1737, 1651, 1584, 1428, 700. UV: (MeOH) λ max 283 nm (ε = 16.610). Elementary analysis for C 12 H 14 N 2 O 2 (218.26): calculated: C 66.0%, H 6.5%, N 12.8%, found: 66.2%, H 6.4%, N 12.8%. [α] d 25 [c=1 CHCl 3 ]+20.5°. (d) Production of 1-[(S)-1-phenylethyl)]-1H-furo-[3,4-d]-imidazol-2,4(3H,6H)-dione 8.06 g (36 mmol) of 3-amino-4-[(S)-(1-phenylethylamino)]-furan-2(5H)-one and 65 ml tetrahydrofuran were placed in a 50-ml three-neck flask, which was equipped with a 50-ml dropping funnel and a magnetic stirrer, and were cooled to 0° C. Then a solution of 5.78 g (36 mmol) of chloroformic acid phenyl ester in 10 ml of tetrahydrofuran and a solution of 3.78 g (36 mmol) of triethylamine in 10 ml of tetrahydrofuran were added at the same time for 40 minutes. The white suspension was filtered and the light brown mother liquor was evaporated. The residue, a brown foam, was dissolved in 60 ml of acetonitrile and this solution was added in 40 minutes to a solution of 3.78 g (36 mmol) of triethylamine in 40 ml of acetonitrile, which was refluxed. The reaction mixture was evaporated and the residue washed with 50 ml of ether. The beige product, [1-(S)-(1-phenylethyl)]-1H-furo[3.4-d]-imidazol-2,4(3H,6H)-dione, was filtered off and dried in a vacuum. After recrystallization in methanol the product yield was 5.75 g=66.0 percent. Concerning the product: Melting point: 159.5 °-160° C. NMR: (CDCl 3 , 300 MHz) in ppm 1.77, d, J = 7 Hz, 3H, 4.07, d, J = 16 Hz, 1H, 4.72, d, J = 16 Hz, 1H, 5.57, q, J = 7 Hz, 1H, 7.35-7.58, m, 5H, 9.75, bs, 1H. MS: (E.I. 70 ev) m/e 244 (16%), 105 (100%), 77 (37%). IR: (KBr) cm -1 3250, 2981, 1761, 1700, 1482, 1450, 1340, 1268, 1000, 739, 705. UV: (MeOH) λ max 266 nm (ε = 12.900). Elementary analysis for C 13 H 12 O 2 N 2 (244.25): calculated: C 63.9%, H 4.9%, N 11.5%, found: C 63.6%, H 4.9%, N 11.3%. [α] D 25 [c=1 CHCl 3 ]-69.5°. EXAMPLE 2 (a) Production of 3-phenylazothiotetronic acid [3-phenylazo-4-hydroxythiophen-2(5H)-one or 2,3,4-trioxotetrahydrothiophene-3-phenylhydrazone] 28 ml of 6N hydrochloric acid solution was placed in a 100-ml beaker, which was equipped with a 100-ml dropping funnel, a thermometer and a mechanical stirrer. 5.02 g (53.9 mmol) of aniline was added with ice cooling. Then a solution of 3.81 g (55.2 mmol) of sodium nitrite in 21 ml of ice water was added dropwise to the resulting suspension in 30 min. with vigorous stirring. The resultant diazonium salt solution was added dropwise to a solution of 5.78 g (50 mmol) of thiotetronic acid in 49 ml of 1N sodium hydroxide solution at 5° C. with vigorous stirring in 30 minutes. At the same time 55 ml of 1N sodium carbonate solution was added to keep the pH of 7.0 constant. The mustard yellow product was filtered off, washed with 30 ml of water and dried in a vacuum. After recrystallization in toluene, the product yield was 10.5 g = 95.0 percent. Concerning the product: Melting point: 195°-196.5° C. NMR: (CDCl 3 , 300 MHz) δ in ppm 3.89, s, 2H, 3.95, s, 1H, 7.32, t, J=7 Hz, 2H, 7.46, t, J=7 Hz, 2H, 7.58, d, J=7 Hz, 2H, 3.89, s, 2H, 6.67, s, 1H, 7.32, t, J=7 Hz, 1H, 7.45, t, J=7 Hz, 2H, 7.57, d, J=7 Hz, 2H. The tautomer ratio of 3-phenylazothiotetronic acid to 2,3,4-trioxotetrahydrothiophene-3-phenylhydrazone is 3 to 1. MS: (E.I. 70 ev) m/e 220 (70%) M + , 143 (13%), 105 (31%) 92 (30%), 77 (100%). IR: (KBr) cm -1 3450, 1688, 1673 s, 1532 s, 1465, 1424, 1397 s, 1129 s, 912 s, 764 s. UV: (MeOH) λ max 408 nm (ε=14.100), 372 (ε=16.700), 235 nm (ε--6.670). Elementary analysis for C 10 H 8 N 2 O 2 S (220.25): calculated: C 54.5%, H 3.7%, N 12.7%, S 14.6%, found: C 54.3%, H 3.5%, N 12.7%, S 14.8%. (b) Production of 3-phenylazo-4-[(S)-(1-phenylethylamino)]-thien-2(5H)-one 6.56 g (29.8 mmol) of 3-phenylazothiotetronic acid was dissolved in 165 ml of toluene with reflux under nitrogen in a 250-ml three-neck flask, which was equipped with a water separator, jacketed coil condensor and magnetic stirrer. Then 14.53 g (119.9 mmol) of (S)-1-phenylethylamine was added and then in 40 minutes a solution of 2.19 g of boron trifluoride ethyl etherate in 5 ml of toluene was added. The reaction mixture was allowed to cool to room temperature. This reaction mixture was extracted with 100 ml of 0.9N hydrochloric acid, then with 50 ml of saturated sodium bicarbonate solution and then with 50 ml of saturated sodium sulfate solution. The dark brown solution was dried over 20 g of magnesium sulfate and evaporated. 50 ml of ether was added to the brown, viscous residue and allowed to rotate under slight vacuum. The resultant solid was dissolved in 6 ml of dichloromethane with reflux and recrystallized after the addition of 14 ml of ether at 0° C. After another recrystallization, the yield of 3-phenylazo-4-[(S)-(1-phenylethylamino)]-thien-2(5H)one was 5.59 g=58 percent. Concerning the product: Melting point 129°-130° C. NMR: (CDCl 3 , 300 MHz) δ in ppm 1.71, d, J = 7 Hz, 3H, 3.64, d, J=17 Hz, 1H, 3.98, d, J=17 Hz, 1H, 4.77, d, q, J=7 Hz, 7 Hz, 1H, 7.25-7.5, m, 8H, 7.76, d, J=8 Hz, 2H, 12.34, bs, 1H. MS: (E.I. 70 ev) m/e 323 (10%) M + , 195 (22%), 105 (100%), 93 (30%), 77 (25%). IR: (KBr) cm -1 3500 b, 1720, 1600 s, 1580 s, 1450, 1280. UV: (MeOH) λ max 410 nm (ε=9.600), 375 nm (ε=21.910), 290 nm (ε=11.880), 231 nm (ε=13.823). Elementary analysis for C 18 H 17 N 3 OS (323.41): calculated: C 66.8%, H 5.3%, N 13.0%, S 9.9%, found: C 66.7%, H 5.2%, N 13.2%, S 9.5%. [α] D 25 [c=1 CHCl 3 ]+889°. (c) Production of 3-amino-4-[(S)-1(1-phenylethylamino)]-thien-2(5H)-one A solution of 5.0 g (15.5 mmol) of 3-phenylazo-4-[(S)-(1-phenylethylamino)]-thien-2(5H)-one in 30 ml of tetrahydrofuran was placed in a 100-ml autoclave. Then 0.49 g of platinum on carbon 5 percent was added. The autoclave was flushed twice and the solution was hydrogenated with a hydrogen pressure of 30 bars for 45 minutes. The catalyst was filtered off under argon and to the mother liquor was added 90 ml of hexane with ice cooling. 3-Amino-4-[(S)-(1-phenylethylamino)]-thien-2(5H)-one precipitated as a beige, viscous oil. Concerning the product: Yield: 2.4 g=65.0 percent. NMR: (CDCl 3 , 300 MHz), δ in ppm 1.54, d, J=7 Hz, 3H, 3.30, bs, 3-4H, 3.37, d, J=16.5 Hz, 1H, 3.72, d, J = 16.5 Hz, 1H, 4.60, q, J=7 Hz, 1H, 7.22-7.37, m, 5H. MS: (E.I. 70 ev) m/e 234 (4%), M + , 130 (18%), 105 (100%). (d) Production of (S)-(1-phenylethyl)-1H-thieno-[3,4-d]-imidazol-2,4(3H,6H)-dione 22 ml of tetrahydrofuran was placed in a 250-ml three-neck flask equipped with two 50-ml dropping funnels, a thermometer and a magnetic stirrer. It was cooled to 0° C. and 11.1 ml of 1.25M phosgene solution in toluene (13.87 mmol) was added under argon. Simultaneously was added a solution of 3.24 g (13.82 mmol) of 3-amino-4-[(S)-(1-phenylethylamino)]-thien-2(5H)-one in 10 ml of tetrahydrofuran and a solution of 2.18 g (27.75 mmol) of triethylamine in 10 ml of tetrahydrofuran was added in 3 hours at 5° C. To it was added 10 ml of 5 percent aqueous ammonia solution. The tetrahydrofuran was evaporated and the aqueous residue was extracted three times with 10 ml of dichloromethane. The solution was evaporated and chromatographed by 100 g of silica gel with 700 ml of ethyl acetate. The yield of (S)-(1-phenylethyl)-thieno[3.4-d]-imidazol-2,4(3H,6H)-dione (beige crystals) was 2.16 g=60 percent. Melting point: 218°-220° C. NMR: (CDCl 3 , 300 MHz) δ in ppm 1.83, d, J=7 Hz, 3H, 3.23, d, J=16.5 Hz, 1H, 3.86, d, J=16.5 Hz, 1H, 5.73, q, J=7 Hz, 1H, 7.40, m, 5H, 8.78, bs, 1H. MS: (E.I. 70 ev) m/e 260 (4%) M + , 156 (4%), 105 (100%), 79 (105), 77 (12%). IR: (KBr) cm -1 3223, 2945, 2918, 1702 s, 1619, 1451, 1351, 1268. UV: (MeOH) λ max 297 nm (ε=9.805), 248 nm (ε --5.960). Elementary analysis for C 13 H 12 N 2 O 2 S (260.31): calculated: C 60.0%, H 4.7%, N 10.7%, S 12.3%, found: C 59.6%, H 4.7%, N 10.8%, S 12.0%. [α] D 25 [c=1 CHCl 3 ]-63.2°. (e) Production of 1-[(S)-(1-phenylethyl)]-3-acetyl-1H-thieno[3,4-d]imidazol-2,4(3H,6H)-dione 0.5 g (1.94 mmol) of 1-[(S)-(1-phenylethyl)]-1H-thieno-3,4-d]-imidazol-2,4(3H,6H)-dione in 20 ml of acetic acid anhydride was heated in a 25-ml flask at 50° C. for 3 hours. Then the solvent was evaporated and the residue washed with 3 ml of ether. The beige product was then dried. The yield of 1-[(S)-(1-phenylethyl)]-3-acetyl-1H-thieno-[3,4-d]imidazol-2,4(3H,6H)-dione was 0.43 g=73.0 percent. Concerning the product: Melting point 187°-189.5° C. NMR: (CDCl 3 , 300 MHz) δ in ppm 1.85, d, J=7 Hz, 3H, 2.71, s, 3H, 3.18, d, J=17.5 Hz, 1H, 3.83, d, J=17.5 Hz, 1H, 5.71, q, J=7 Hz, 1H, 7.35-7.45, m, 5H. MS: (E.I. 70 ev) m/e 302 (1%) M + , 260 (10%), (--CH 2 CO), 165 (5%), 105 (100%), 43 (20%). IR: (KBr) cm -1 2920, 1736 s, 1447, 1376, 1354, 1298. UV: (MeOH) λ max 297 nm (ε=11.480), 248 nm (ε=6.930). Elementary analysis for C 15 H 14 O 3 N 2 S (302.35): calculated: C 59.6%, H 4.7%, N 9.3%, S 10.6%, found: C 58.9%, H 4.7%, N 9.2%, S 10.3%. [α] D 25 [c=1 CHCl 3 ]-63.3°. Example 3 Production of 1-[(S)-(1-phenylethyl)]-3-benzyl-1H-thieno[3,4-d]imidazol-2,4(3H,6H)-dione To a suspension of 75 mg (3.1 mmol) of sodium hydride in 15 ml of tetrahydrofuran were added 0.73 g (2.8 mmol) of 1-[(S)-(1-phenylethyl)]-1H-thieno[3,4-d]imidazol-2,4(3H,6H)-dione, 0.54 g (3.2 mmol) of benzyl bromide and 10 ml of diethylene glycol diethyl ether. The reaction mixture was refluxed for 12 hours. The solvent was evaporated in a vacuum and the residue separated between 10 ml of dichloromethane and 10 ml of water. The aqueous phase was washed twice with 10 ml of dichloromethane. The organic phases were combined, dried with 10 g of magnesium sulfate and evaporated. The solid residue was washed with 5 ml of ether, filtered off and dried. The yield of 1-[(S)-(1-phenylethyl)]-3-benzyl-1H-thieno[3,4-d]imidazol-2,4(3H,6H)-dione was 57.0 mg=60 percent. Concerning the product: Melting point: 143°-145° C. NMR: (CDCl 3 , 300 MHz) δ in ppm 1.79, d, J=7 Hz, 3H, 3.18, d, J=17 Hz, 1H, 3.78, d, J=17 Hz, 1H, 5.03, s, 2H, 5.21, J=7 Hz, 1H, 7.27-7.4, m, 8H, 7.49, d, J=8 Hz, J=1.5 Hz, 2H. MS: (E.I. 70 ev) m/e 350 (4%) M - , 246 (12%), 105 (100%), 91 (40%). IR: (KBr) cm -1 2982, 1707 s, 1672 s, 1456, 1346, 846, 700. UV: (MeOH) λ max 285.8 nm (ε=10.200). Example A (1) Production of (3as,6aR)-1-[(R)-(1-phenylethyl)]-dihydro-1H-furo[3,4-d]imidazol-2,4(3H,3aH)-dione A solution of 8.98 g (36.8 mmol) of 1-[(R)-(1-phenylethyl)]-1H-furo[3,4-d]imidazol-2,4(3H,6H)-dione in 90 ml of dimethylformamide was placed in a 250-ml autoclave and 0.90 g of Rh/Al 2 O 3 (5 percent) is added. Then the autoclave was flushed twice successively with hydrogen, and filled to 40 bars. The mixture was stirred for 10 hours. Then the catalyst was filtered off. The solvent was evaporated at 13.3 mbar and the residue was crystallized with 10 ml of ethyl acetate. (3aS,6aR)-1[(R)-(1-phenylethyl)]-dihydro-1H-furo[3,4-d]imidazol-2,4(3H,3aH)-dione was obtained as a white crystalline product in a yield of 4.89 g=54 percent. Concerning the product: Melting point: 153°-154° C. 1 H-NMR: (CDCl 3 , 300 MHz) δ 1.61, d, J=7Hz, 3H, 3.45, dd, J=10.5 Hz, 1,4 Hz, 1H, 3.95, dd, J=10.5 Hz, 5 Hz, 17H, 4.21, d, J=9.5 Hz, 1H, 4.57, ddd, J=10.5 Hz, 9.5 Hz, 1.4 Hz, 71H, 5.24, bs, 1H, 5.31, q, J=7 Hz, 1H, 7.4, m, 5H. MS: (E.I. 70 ev) m/e 246 (30%) M + , 231 (45%), 161 (28%), 105 (100%). IR: (KBr) cm -1 3388, 1771 (s), 1669 (s), 1422, 1255, 699. UV: (MeOH) λ max 372 nm (ε=119), 256 nm (ε=764). Elementary analysis for C 13 H 14 N 2 O 3 (246.27): calculated: C 63.1%, H 5.7%, N 11.3%, found: C 63.4%, H 5.7%, N 11.4%. [α] D 20 [c=l CHCl 3 ]+211.7°. (2) Production of (3aS,6aR)-1-[(S)-(1-phenylethyl)]-dihydro-1H-furo[3,4-d]imidazol-2,4(3H,3aH)-dione A solution of 3.7 g (15.16 mmol) of 1-[(S)-(1-phenylethyl)]-1H-furo[3,4-d]imidazol-2,4(3H,6H)-dione in 100 ml of acetic acid is placed in a 250-ml autoclave and 0.4 g of palladium on activated carbon (5 percent) was added. Then the autoclave was flushed twice successively with hydrogen and filled to 50 bars. This mixture was stirred for 15 hours at room temperature. The catalyst was then filtered off. The solvent was evaporated at 20 mbars and the residue was chromatographed over silica gel with ethyl acetate. 2.0 g (54 percent yield) of the title product was eluted. Recrystallization in methanol yields white needles. Concerning the product: Melting point: 123°-125° C. 1 H-NMR: (CDCl 3 , 300 MHz) δ 1.65, d, J=7.4 Hz, 3H, 4.08, d, J=8.6 Hz, 1H, 4.12, m, 1H, 4.37, dd, J=10.3 Hz, 4.8 Hz, 1H, 4.48, dd, J =10.2 Hz, 1.3 Hz, 1H, 5.36, q, J=7.3 Hz, 1H, 5.48, s, 1H. MS: (E.I. 70 ev) m/e 246 (30% M + , 231 (45%), 161 (28%), 105 (100%). [α] D 20 [c=0, CHCl 3 ]-6.7%. Subsequently, the [3aR,6aS] isomer was eluted in a yield of 1.05 g (28 percent). Example B (1) Production of (3aS,6aR)-1-[(R)-(1-phenylethyl)]-3-benzyl-dihydro-1H-furo[3,4-d]imidazol-2,4(3H, 3aH)-dione 48 ml of dimethoxyethane and 0.39 g (16.2 mmol) of sodium hydride were placed in a 100-ml three-neck flask equipped with a magnetic stirrer under argon and with complete exclusion of moisture. Then 3.24 g (13.2 mmol) of (3aS,6aR)-1-[(R)-(1-phenylthyl)]-dihydro-1H-furo[3,4-d]imidazol-2,4(3H,3aH)-dione was added. After a stirring time of 10 min., 2.76 g (16.2 mmol) of benzyl bromide was added and the suspension was stirred for 30 min. Then the reaction mixture was evaporated. The residue was dissolved with 25 ml of dichloromethane and 25 ml of water. The phases were separated and the aqueous phase was washed three times, each time with 15 ml of dichloromethane. The organic phases were combined, dried with 5 g of magnesium sulfate and evaporated. (3aS,6aR)-1-[(R)-(1-phenylethyl)]-3-benzyl-dihydro-1H-furo[3,4-d]-imidazol-2,4(3H,3aH)-dione was obtained as a beige product in a yield of 3.56 g (80.5 percent). Concerning the product: Melting point: 163°-164.5° C. 1 H-NMR: (CDCl 3 , 300 MHz) δ 1.58, d, J=7 Hz, 3H, 3.38, dd, J=10 Hz, 3 Hz, 1H, 3.82, dd, J=10 Hz, 5 Hz, 1H, 3.89, d, J=9 Hz, 1H, 4.32, d, J=15 Hz, 1H, 4.44, ddd, J=9 Hz, 5 Hz, 3 Hz, 1H, 5.05, d, J=15 Hz, 1H, 5.36, q, J=7 Hz, 1H, 7.30-7.41, m 10H. MS: (E.I. 70 ev) m/e 336 (26%) M + , 321 (9%), 231 (22%), 187 (16%), 174 (14%), 105 (56%), 91 (100%). Elementary analysis for C 20 H 20 N 2 O 3 (336.39): calculated: C 71.4%, H 6.0%, N 8.3%, found: C 71.3%, H 6.2%, N 8.3%. [α] D 20 [c=0.5 CHCl 3 ]+122.3°. (2) Production of (3aS,6aR)-1-[(R)-(1-phenylethyl)]-3-(4-methoxybenzyl)-dihydro-1H-furo[3,4-d]-imidazol-2,4(3H,3aH)-dione 9.75 g (0.22 mol) of sodium hydride (55 percent in oil) was added in 10 portions in 2 hours at -10° C. under argon to a solution of 50.0 g (0.2 mol) of (3aS,6aR)-1-[(R)-(1-phenylethyl)]-dihydro-1H-furo[3,4-d]imidazol-2,4(3H,3aH)-dione and 39.8 g (0.25 mol) of 4-methoxybenzyl chloride in 500 ml of dried N,N-dimethylformamide. The reaction mixture was stirred at 5° C. for 2 hours and then at room temperature for another 2 hours. Then 8 ml of acetic acid was added. Then the mixture was evaporated to dryness. Then the residue was taken up in 100 ml of water and 200 ml of dichloromethane, the phases were separated and the aqueous phase was extracted twice with 100 ml of dichloromethane. The organic phases were dried over magnesium sulfate and concentrated. After suspension in ethanol with refluxing, cooling and filtering, 53.5 g (72 percent) of the title product was obtained in the form of white needles. Concerning the product: Melting point: 146.1°-146.4° C. 1 H-NMR: (CDCl 3 , 300 Hz) δ 1.58, d, J=7 Hz, 3H, 3.37, dd, J=10 Hz, 3 Hz, 3H, 3.82, s, 3H, 3.82, dd, J=10 Hz, 5.5 Hz, 1H, 3.88, d, J=8.5 Hz, 1H, 4.25, d, J=14.5 Hz, 1H, 4.34, ddd, J=8.5 Hz, 5.5 Hz, 3H, 4.97, d, J=14.5 Hz, 1H, 5.734, q, J=7 Hz, 1H, 6.88, d, J=8.5 Hz, 2H, 7.32-7.38, m, 7H. [α] D 20 [c=1 CHCl 3 ]+104.7°. (3) Production of (3aS,6aR)-1-[(R)-(1-phenylethyl)]-3-tert-butoxycarbonyl-dihydro-1H-furo[3,4-d]-imidazol-2,4(3H,3aH)-dione 3.83 g (88 mmol) of sodium hydride (55 percent in oil) was added in 10 portions in 2 hours at -10° C. under argon to a solution of 20.0 g (81 mmol) of (3aS,6aR)-1-[(R)-(1-phenylethyl)]-dihydro-1H-furo[3,4-d]-imidazol-2,4(3H,3aH)-dione and 21.3 g (97 mmol) of di-tert-butyldicarbonate in 200 ml of dried N,N-dimethylformamide. The reaction mixture was stirred at 5° C. for 2 hours and then at room temperature for another 2 hours. Then 1 ml of acetic acid was added. Then the mixture was evaporated to dryness. The residue was taken up in 50 ml of water and 100 ml of dichloromethane, the phases were separated and the aqueous phase was extracted twice with 100 ml of dichloromethane. The organic phases were dried over magnesium sulfate and concentrated. After suspension in ethanol under fluxing, cooling and filtering, 25.8 g (92 percent) of the title produce was obtained in the form of white needles. Concerning the product: Melting point: 177.4°-178.1° C. 1 H-NMR: (CDCl 3 , 300 MHz) δ 1.59, s, 9H, 1.63, d, J=7.5 Hz, 3H, 3.51, d, J=11 Hz, 1H, 3.97, dd, J=11 Hz, 5 Hz, 1H, 4.50, dd, J=8 Hz, 5 Hz, 1H, 4.90, d, J=8 Hz, 1H, 5.39, q, J=7.5 Hz, 1H, 7.3-7.4, m, 5H. [α] D 20 [c=1 CHCl 3 ]+55.8°. Production of (3aS,6aR-1-[(R)-(1-phenylethyl)]-3-methoxymethyl-dihydro-1H-furo[3,4-d]-imidazol-2,4(3H,3aH)-dione 4.0 g (93 mmol) sodium hydride (55 percent in oil) was added in 10 portions in 2 hours at -10° C. under argon to a solution of 19 g (77 mmol) of (3aS,6aR)-[(R)-(1-phenylethyl)]-dihydro-1H-furo[3,4-d]imidazol-2,4(3H,3aH)-dione and 9.42 g (120 mmol) of chloromethyl methyl ether in 200 ml of dried N,N-dimethylformamide. The reaction mixture was stirred at 5° C. for 2 hours and then at room temperature for another 2 hours. Then 2 ml of acetic acid was added. Then the mixture was evaporated to dryness. Then the residue was taken up in 50 ml of water and 100 ml of dichloromethane, the phases were separated and the aqueous phase was extracted twice with 100 ml of dichloromethane. The organic phases were dried over magnesium sulfate and concentrated. After chromatographing the oily residue over silica gel with 500 ml of dichloromethane ethyl acetate and concentration of the fractions, 4.0 g (18 percent) of the title product was obtained as white powder. Concerning the product: Melting point: 96°-98° C. 1 H-NMR: (CDCl 3 , 300 MHz) δ 1.61, d, J=7.5 Hz, 3H, 3.36, s, 3H, 3.41, dd, J=10 Hz, 3 Hz, 1H, 3.89, dd, J=10 Hz, 6 Hz, 1H, 4.36, d, J=9 Hz, 1H, 4.52, ddd, J=9 Hz, 6 Hz, 3 Hz, 1H, 4.87, d, J=11 Hz, 1H, 4.97, d, J=11 Hz, 1H, 5.34, q, J =7.5 Hz, 1H, 7.35-7.4, m, 5H. Example C Production of (3aS,6aR)-1-[(R)-(1-phenylethyl)]-3-benzyl-dihydro-1H-thieno[3,4-d]-imidazol-2,4(3H,3aH)-dione 2.03 g (6.03 mmol) of (3aS,6aR)-1-[(R)-(1-phenylethyl)]-3-benzyl-dihydro-1H-furo-[3,4-]-imidazol-2,4(3H,3aH)-dione dissolved in 2 ml of dimethylacetamide was placed in a 25-ml flask, equipped with a magnetic stirrer and a ball condenser. The solution was heated in 150° C. and 0.81 g (7.14 mmol) of potassium thioacetate was added. After 45 min. the reaction mixture was allowed to cool and treated with 40 ml of toluene and 40 ml of water. The phases were separated; the toluene phase was washed three times with 20 ml of water and the combined aqueous phases were washed three times, each time with 30 ml of toluene. The toluene phases were combined, dried and evaporated. The resulting brown solid was washed with 5 ml of ether. Then the beige product, (3aS,6aR)-1-[(R)-(1-phenylethyl)]-3-benzyl-dihydro-1H-thieno[3,4-d]-imidazol-2,4(3H,3aH)-dione was filtered off and dried. Concerning the products: Yield: 1.82 g=85 percent. Melting point: 144°-145° C. 1 H-NMR: (CDCl 3 , 300 MHz) δ 1.67, d, J=7 Hz, 3H, 2,71, dd, J=12.5 Hz, 2.5 Hz, 1H, 3.03, dd, J=12.5 Hz, 5 Hz, 1H, 3.81, d, J=8 Hz, 1H, 4.34, d, J=15 Hz, 1H, 4.40, ddd, J=8 Hz, 5 Hz, 2.5 Hz, 1H, 5.04, d, J=15 Hz, 1H, 5.41, q, J =7 Hz, 1H, 7.30-7.50, m, 10H. MS: (E.I. 70 ev) m/e 352 (1%) M + , 324 (30%), 278 (35%), 174 (80%), 146 (30%), 105 (70%), 91 (100%). Elementary analysis for C 20 H 20 N 2 O 2 S (352.46): calculated: C 68.2%, H 5.7%, N 7.9%, S 9.1%, found: C 67.9%, H 5.9%, N 8.0%. [α] D 20 [c=1.5 CHCl 3 ]+128.5°. Example D Production of (3aS,6aR)-hexahydro-1-[(R)-(1-phenylethyl)]-2-oxo-3-benzylthieno[3,4-d]-imidazol-4-ylidene pentanoic acid 159.8 mg (3.66 mmol) of sodium hydride and 1.7 ml of dimethyl sulfoxide were placed in a 25-ml round-bottom flask. The suspension was heated with stirring and under argon to 70° C. It was stirred for 40 minutes more until evolution of hydrogen was complete. The solution was cooled to room temperature and a solution of 801.5 mg (1.8 mmol) of (4-carboxybutyl)-triphenylphosphonium bromide in 1 ml of dimethyl sulfoxide was added. The dark red reaction mixture was stirred for 15 minutes and then added dropwise to a solution of 271 mg (0.77 mmol) of (3as,6aR)-1-[(R)-(1-phenylethyl)]-3-benzyl-dihydro-1H-thieno[3,4-d]-imidazol-2,4(3H,3aH)-dione in 2 ml of dimethyl sulfoxide and 0.2 ml of toluene. The reaction mixture was stirred for 2 hours at room temperature. Then 1 g of ice, 1 ml of conc, HCl and again 9 g of ice were added. After 5 minutes, 5 ml of water, 10 ml of benzene and 5 ml of ethyl acetate were added. Then the mixture was stirred for 1 hour at 60° C. The phases were separated. The brown organic phase was dried with 5 g of magnesium sulfate and separated with 4 preparative silica gel thin-layer plates (1 mm) by means of ethyl acetate. The product, (3aS, 6aR)-hexahydro-1-[(R)-(1-phenylethyl)]-2-oxo-3-benzylthieno[3,4-d]-imidazol-4-ylidene pentanoic acid, a colorless oil, was obtained in a yield of 38.2 mg (12 percent). Concerning the product: 1 H-NMR: (CDCl 3 , 300 MHz) δ 1.58, d, J=7 Hz, 3H, 1,59, q, J=7 Hz, 2H, 1.98, m, 2H, 2.22, t, J=7.5 Hz, 2H, 2.29, dd, J=11.5 Hz, 4 Hz, 1H, 2.41, dd, J=11.5 Hz, 5 Hz, 1H, 3.97, d, J=15 Hz, 1H, 4.18, m, 2H, 4.84, d, J=15 Hz, 1H, 5.30, q, J=7 Hz, 1H, 5.31, t, J=7 Hz, 1H, 7.10-7.40, m, 10H. MS: (E.I. 70 ev) m/e 436 (55%) M + , 331 (55%), 252 (32%), 237 (60%), 120 (40%), 106 (100%). (2) Production of (3aS,6aR)-hexahydro-1-[(R)-(1-phenylethyl)]-2-oxo-3-benzylthieno[3,4-d]imidazol-4-ylidene pentanoic acid 0.802 g (33 mmol) of magnesium chips were put into 5 ml of tetrahydrofuran. Then 2.37 g (11 mmol) of dibromobutane in 30 ml tetrahydrofuran was added in 1 hour. The reaction mixture was refluxed for 2 hours, then 2.55 g (22 mmol) of tetramethylethylenediamine was added and refluxed for another hour. To the suspension, cooled to 0° C., was then added 3.52 g (10 mmol) of (3aS,6aR)-1-[(R)-(1-phenylethyl)]-3-benzyl-dihydro-1H-thieno[3,4-d]imidazol-2,4(3H,3aH)-dione in 50 ml of tetrahydrofuran. Then the reaction mixture was stirred for 2 hours at room temperature and then cooled to °0 C. Carbon dioxide gas was introduced in 1 hour at 0° C. and 1 hour at room temperature. The reaction mixture was poured onto a mixture of 85 g of ice and 11.5 ml of conc. hydrochloric acid and then extracted with ethyl acetate. The combined organic phases were washed with water and saturated sodium chloride solution, dried with magnesium sulfate and finally concentrated. 50 mg of p-toluenesulfonic acid was added to the residue, which was then taken up in 170 ml of toluene. The reaction water was refluxed and distilled off by means of a water separator. The remaining toluene solution was concentrated and the resulting oil was chromotographed over silica gel with acetic acid ethyl ester/toluene. 1.22 g (28 percent) of the title product was obtained as a light yellowish oil. (3) Production of (3aS,6aR)-hexahydro-1-[(R)-(1-phenylethyl)]-2-oxo-3-benzylthieno[3,4-d]imidazol-4-ylidene pentanoic acid 8.6 g of magnesium chips was placed in 75 ml of tetrahydrofuran. Then a mixture of 3.2 g of 1,2-dibromoethane and 2.5 g of 1,4-dichlorobutane in 35 ml of tetrahydrofuran was added within 15 minutes so that the temperature could be kept between 30° and 35° C. Then another b 20.5 g of 1,4-dichlorobutane in 75 ml of tetrahydrofuran was added within 30 minutes. The reaction mixture was stirred for 3 hours at this temperature and then mixed with 9 g of tetramethylethylenediamine and 180 ml of tetrahydrofuran. The reaction solution was cooled to -40° to -45° C. and then mixed with a solution of 30 g of (3aS,6aR)-1-[(R)-(1-phenylethyl)]-3-benzyl-dihydro-1H-thieno[3,4-d]imidazol-2,4(3H,3aH)-dione in 180 ml of tetrahydrofuran within 20 minutes. It was stirred at this temperature for 1 hour and then CO 2 gas was introduced for 30 minutes. The reaction mixture was poured onto 400 ml of 10 percent aqueous sulfuric acid and extracted several times with toluene. The toluene phase was mixed with 0.8 g of conc. sulfuric acid, washed with water and concentrated on a rotary evaporator. The residue was mixed with 400 ml of 10 percent potassium carbonate solution and extracted with ethyl acetate. The organic phase was washed again with 10 percent potassium carbonate solution. The combined aqueous phases were adjusted to pH 7.3 with aqueous sulfuric acid and extracted several times with ethyl acetate. The organic phase was finally dried with magnesium sulfate and concentrated. The product was precipitated by addition of hexane, filtered off and dried. 32.5 g (89.3 percent) of the title product was obtained as snow-white powder with a content (HPLC) of more than 99 percent. Concerning the product: Melting point: 101.0°-102.0° C. [α] D 20 [c=1.0 methanol]+2.53.8°. Example E (e) Production of (3aS,6aR)-hexahydro-1-[(R)-(1-phenylethyl)]-2-oxo-3-benzylthieno[3,4-d]imidazol-4-yl pentanoic acid A solution of 78.6 mg of (3aS,6aR)-hexahydro-1-[(R)-(1-phenylethyl)]-2-oxo-3-benzylthieno[3,4-d]imidazol-4-ylidene pentanoic acid in 5 ml of isopropanol was placed in a 100-ml autoclave and 39 mg of palladium (5 percent) on carbon was added. The autoclave was flushed twice with hydrogen and the mixture was stirred under 50 bars of hydrogen pressure at 50° C. for 24 hours. Then the catalyst was filtered off and the solvent evaporated off. The product, (3aS,6aR)-hexahydro-1-[(R)-(1-phenylethyl)]-2-oxo-3-benzylthieno[3,4-d]imidazol-4-ylidene pentanoic acid, was obtained as a colorless oil in a yield of 56.1 mg (72 percent). Concerning the product: 1 H-NMR: (CDCl 3 , 300 MHz) δ 1.57, m, 6H, 1.61, d, J=7 Hz, 3H, 2.13, m, 1H, 2.33, m, 2H, 3.03, m, 1H, 3.90, dd, J=10 Hz, 5 Hz, 1H, 3.94, d, J=15 Hz, 1H, 4,22, m, 1H, 5.06, d, J=15 Hz, 1H, 5.28, q, J=7 Hz, 1H, 7.20-7.40, m, 10H. MS: (E.I. 70 ev) m/e 438 (13%), 423 (6%), 333 (16%), 187 (30%), 174 (15%), 105 (63%), 91 (100%). Example F Production of d-biotin A solution of 100 mg of (3aS,6aR)-hexahydro-1-[(R)-(1-phenylethyl)]-2-oxo-3-benzylthieno[3,4-d]imidazole-4-ylidene pentanoic acid in 4 ml of hydrobromic acid (48 percent) was heated in a 25-ml round-bottom flask for 3 hours at 120° C. with a vacuum of 400 mbars. After the reaction mixture was cooled, it was extracted with 5 ml of toluene. Then the aqueous phase was distilled off in a vacuum. The residue was dissolved in 10 ml of water and extracted with 10 ml of chloroform at 60° C. The aqueous phase was concentrated to 1 ml and cooled. d-(+) biotin precipitated in 40 mg of beige crystals (72 percent yield). Concerning the product: Melting point: 227°-229° C. [α] D 25 [c=0.1 1N NaOH]+84.5°.

Process for the production of imidazole derivatives of the formula: ##STR1## wherein R 1 is an (R)- or (S)-1-phenylalkyl group, an (R)- or (S)-1-alkoxycarbonyl-1-phenylmethyl group or an (R)- or (S)-1-aryloxycarbonyl-1-phenylmethyl group, R 2 is hydrogen, a substituted or unsubstituted alkanoyl group, an unsubstituted or a substituted benzoyl group, a substituted or an unsubstituted benzyl group, an alkoxycarbonyl group, and aryloxycarbonyl group, an alkoxyalkyl group, a pyranyl group, a substituted or unsubstituted benzenesulfonyl group, an alkylsulfonyl group, a diarylphosphinyl group, a dialkoxyphosphinyl group or a trialkylsilyl group, and A is a sulfur or oxygen atom. A tetronic acid of the formula: ##STR2## wherein A has the above-mentioned meaning, is reacted with a diazonium salt, converting the resultant arylazotetronic acid or the tautomeric arylhydrazone in a further step with a chiral amine into an arylazoamino compound, reducing the arylazoamino compound, converting the resultant diamine, with phosgene or a phosgene-equivalent reagent, into the corresponding imidazole and optionally introducing a protective group by reaction with a substituted or unsubstituted aliphatic or aromatic acid chloride, an aliphatic or aromatic carboxylic acid anhydride, a haloformic acid alkyl ester, a 1-alkoxyalkyl halide, an enol ether, an aromatic or aliphatic sulfonic acid halide, a diarylphosphinic acid halide, a phosphoric acid dialkyl ester halide, a trialkyl silyl halide or a trialkyl silyl acetamide. These imidazole derivatives are suitable as intermediate products for the production of (+) biotin.

CROSS REFERENCES TO RELATED APPLICATIONS This Application is cross-related to U.S. patent application Ser. No. 29/001,773 entitled a "Stacker for Electronic Payment System Key Pad and Printer " by Fred Coblentz and William Watt; U.S. Design Patent Application Ser. No. 29/0-001,771 entitled "Stacker for Electronic Payment System Kdy Pads" by William Watt and Fred Coblentz; and Utility Application Ser. No. 07/981,661 entitled "Stacker for Electronic System Key Pad" by William Watt and Fred Coblentz, all of which are owned by a common assignee." FIELD OF THE INVENTION This application relates to an article of manufacture used to hold and provide access to electronic key pads and printers. BACKGROUND OF THE INVENTION Retail establishments and other commercial outlets usually permit several different options for payments for goods and services. Traditionally, these have included cash, check, and credit card. More recently, certain outlets now permit the use of debit cards which transfer funds from the customer's account to the seller's account electronically through the use of a debit card. Debit cards owe their efficiency to communications systems which link directly various banks and retail establishments. The vehicle by which the customer debits his account is a credit-card-like card, having a magnetic strip and certain information stored on that magnetic strip. Typically, the debit card is slid through a magnetic card reader, either by the customer or by the seller. Customer then enters a secret personal identification number on a keypad which, when verified, will permit the debiting of customer's account and the crediting of seller's account. With the advent of this form of payment, as well as the improved data communication system which currently exists for communication between retail outlet and banks with respect to authorizations for credit card customers and with third party check verifiers there has been an increase in the amount of counter space taken up by these electronic devices. To complicate matters even further, in some outlets sellers desire that their employee slide the credit card through the reader and enter an identification number as well as an amount to obtain credit authorization, at the same time they are checking the signature of the card holder. In addition, with the increased use of debit cards as a replacement for cash, there is a movement to insure that customer does not need to relinquish his debit card to seller or seller's employees. Both employee and customer need access to key pads. Thus, the current situation has increased the numbers of electronic devices needed at the checkout counter. More and more of such systems are being used by retailers for whom counter space is at a premium and resulting in customer spending additional time in checkout lines. These problems are especially acute for small retailers with limited counter space. Thus, there is a need for a compact and inexpensive holder for a number of key pads and printers. SUMMARY OF THE INVENTION Applicants' terminal stacker consists of stacker whose base is comprised of a first holder and a second holder, connected together back to back, where you can put a key pad on each holder a first holder having a first face connected to and forming a first acute angle between the base and the first face and having portions defining both a first recess and a first slot opening into the first recess; a second holder having a second face connected to and forming a second acute angle between the base and second face, connected to the first face and having portions defining a second recess facing in a substantially opposite direction from the first side having portions defining a second slot opening into the second recess; and a third holder having a third face connected to and forming a third acute angle between the base and third face, connected to the first face and having portions defining a third recess facing in a substantially opposite direction from the first side. This invention aids is solving the problems discussed above and has several additional advantages. The terminal stacker provides for an efficient height and angle for easy data entry into both the seller and customer keypad, and easy access to the printer thereby improving efficiency at checkout. FIGURES Applicants' invention can be understood by using the description of the preferred embodiments provided below in conjunction with the attached figures wherein: FIG. 1 is a front perspective view of a holder for an electronic payment system key pad and printer; FIG. 2 is a front elevational view thereof; FIG. 3 is a left side elevational view thereof, the right side elevational view being a mirror image thereof; FIG. 4 is a rear elevational view thereof; FIG. 5 is a top plan view thereof; FIG. 6 is a bottom plan view thereof; and FIG. 7 is a front perspective view of a holder for an electronic payment system key pad and printer with the key pads and printer shown in phantom. DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows a front perspective of a terminal stacker 100 for an electronic payment system key pad 100. For the purposes of this description, terminal stacker 100 will be described in terms of component parts, but applicant's invention may be formed in a single injection or molding process as are well known in the art. Terminal stacker 100 may be constructed of any one of a number of materials, including but not limited to, plastic, plexiglass, or other similar material, and may be either a single piece or a series of components which are attached one to the other by means of either fasteners or glue or some other suitable attaching means which are well known in the art. Terminal stacker 100 has a base 102 shown in both FIG. 1 and FIG. 6. Base 102 has two holes 104, which permit cable access from the bottom of terminal stacker 100 to the various electronic devices in terminal stacker 100. In addition, base 102 has several feet 106 attached to it. These feet can be made several different materials including but not limited to plastic or rubber or other materials as are well known in the art. As can be seen in FIGS. 1, 3, and 6, holes 104 also extend through sidewall 108 to provide not only for bottom but also side access of cables. This affords the user the option and advantage of either concealed cables entering into terminal stacker 100 through the bottom or side entry of cable. Sidewall 108 is attached to base 102 as shown and provides a cable access hole 104 as indicated above. FIG. 3 is a left side elevational view of the holder, the right side elevational view being a mirror image thereof. Sidewall 108 has a first face 110 and a second face 112 as shown in FIGS. 1 and 3. A first recessed area 114, having sidewalls 118 formed using either sidewall 108 or a tray or some other suitable fixture attached to sidewalls 108 is positioned parallel to face 110. Front plate 113 is attached and perpendicular to base 102 and sidewall 108. Front 113 protrudes above the plane at second face 112. In a similar fashion, a second recess 116 is formed on the opposite of terminal stacker 100 having sidewalls 120 which may be formed either by sidewall 108 or by a tray suitably attached to sidewall 108. Each of these recesses is sized for key pads 170 and 172 which are currently available and are well known in the art including but not limited to the Verifone Trans 330 and Verifone 201 key pads as are shown in FIG. 7. Notice that front plate 113 protrudes above the level of plane 112 to cause the top of key pad 170 to engage between top 122. This engagement of key pad provides the advantage of securing the key pad to the holder. As shown in FIGS. 1, 2 and 3 sidewall 108 forms face 130 which is some suitable spacing below and at a suitable angle with the base and with face 110. Recess 132 having sidewall 134 can be either formed the sidewalls 108 or a suitably sized tray attached to sidewalls 108. Recess 132 can be used to hold a printer associated with the key pads and pin pads which are well known in the art including the Verifone 250 roll printer. The exact spacing an angle depend upon such consideration as the type key pads and printer and the height of the counter. Terminal stacker 100 also includes a top member 122 between the two sidewalls 108 and above recesses 114 and 116 as clearly shown on FIGS. 1 and 5. FIG. 5 is a top plan view of the holder. Slots 124 as shown on FIGS. 2 and 4 are positioned in top 122 to easily permit access to the magnetic card reader in the key pads which are in use. In operation, referring to FIG. 7, a debit or credit card would be slipped in through slot 124 to key pad 170. Customer could then enter his personal identification number to complete the transaction. Alternatively, in a credit card transaction, seller's employee could slide the credit card through slot 124 and key pad 172. Seller's employee could then enter the amount and any necessary security or identification codes. When either transaction was complete a receipt or signable document could be provided by the printer 174. In addition, the angle of face 110 and 112 is designed to provide easy access to the entry keys of each of the pin pads. Although several embodiments have been described in detail, it should be understood that various changes, substitutions and alterations can be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

An article of manufacture for providing easy access to electronic key pads and magnetic card readers is provided. The article includes recessed areas for the holding of such key pads and printers at suitable angles to afford easy access and reduces the amount of counter space necessary to utilize such equipment.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] The present application is a continuation of international patent application no. PCT/EP00/13281, filed Dec. 20, 2000, designating the United States of America, the entire disclosure of which is incorporated herein by reference. Priority is claimed based on Federal Republic of Germany patent application no. 100 00 312.5, filed Jan. 5, 2000. BACKGROUND AND SUMMARY OF THE INVENTION [0002] The present invention relates to substituted aminomethyl-phenyl-cyclohexane derivatives and processes for their preparation, their use for the preparation of medicaments and medicaments comprising these compounds. [0003] Treatment of chronic and non-chronic states of pain is of great importance in medicine. There is a worldwide need for pain treatments with a good action for target-orientated treatment of chronic and non-chronic states of pain appropriate for the patient, by which is to be understood successful and satisfactory pain treatment for the patient. This manifests itself in the large number of scientific works which have been published in the field of applied analgesia and basic research in nociception in recent years. [0004] Conventional opioids, such as morphine, have a good action in the treatment of severe to very severe pain. However, their use is limited by their known side effects, e.g. respiratory depression, vomiting, sedation, constipation, addiction, dependency and development of tolerance. They can therefore be administered over a relatively long period of time or in relatively high dosages only if particular safety precautions are taken, such as specific prescription instructions (Goodman, Gilman, The Pharmacological Basis of Therapeutics, Pergamon Press, New York 1990). They furthermore show a lower activity with some states of pain, in particular neuropathic pain. [0005] Tramadol hydrochloride—(1RS,2RS)-2-[(dimethylamino)methyl]-1-(3-methoxyphenyl)cyclohexanol hydrochloride—is another known therapeutic for treatment of severe pain. It occupies a special position among analgesics having an action on the central nervous system, inasmuch as this active compound brings about potent inhibition of pain without the side effects known of opioids (J. Pharmacol. Exptl. Ther. 267, 33 (1993)), both the enantiomers of tramadol and the enantiomers of tramadol metabolites participating in the analgesic action (J. Pharmacol. Exp. Ther. 260, 275 (1992)). Needless to say, tramadol is also not without side effects. [0006] There is thus a need to provide substances which have an analgesic action and are suitable for treatment of pain. These substances should furthermore have as few side effects as possible, such as nausea, dependency, respiratory depression or constipation. DETAILED DESCRIPTION OF THE INVENTION [0007] This object is achieved by the substituted aminomethyl-phenyl-cyclohexane derivatives according to the invention. The invention therefore provides substituted aminomethyl-phenyl-cyclohexane derivatives of the general formula I and Ia, also in the form of their diastereomers or enantiomers and of their free bases or of a salt formed with a physiologically tolerated acid, in particular the hydrochloride salt. [0008] wherein [0009] R 1 and R 1 ′ independently of one another are [0010] H, C 1 -C 10 -alkyl, C 2 -C 10 -alkenyl or C 2 -C 10 -alkinyl, in each case branched or unbranched and mono- or polysubstituted or unsubstituted; F; Cl; Br; I; NR 6 R 6 ′; NO 2 ; CN; OR 6 ; SR 6 ; OC(O)R 6 ; C(O)OR 6 ; C(O)R 6 or C(O)NR 6 R 6 , wherein R 6 and R 6 ′ are [0011] H; C 1 -C 10 -alkyl, C 2 -C 10 -alkenyl or C 2 -C 10 -alkinyl, in each case branched or unbranched and mono- or polysubstituted or unsubstituted; C 3 -C 7 -cycloalkyl, saturated or unsaturated and mono- or polysubstituted or unsubstituted, or a corresponding heterocyclic radical, in which one C atom in the ring is replaced by N, S or O; alkylaryl, saturated or unsaturated and mono- or polysubstituted or unsubstituted; or aryl or heteroaryl, in each case mono- or polysubstituted or unsubstituted; or [0012] R 1 and R 1 together form —CH═CH—CH═CH— resulting in a naphthyl system which can be mono- or polysubstituted, [0013] X is [0014] H, F, Cl, Br, I, CF 3 , OS(O 2 )C 6 H 4 -pCH 3 , OR 7 or OC(O)R 7 , wherein R 7 is [0015] H; C 1 -C 10 -alkyl, C 2 -C 10 -alkenyl or C 2 -C 10 -alkinyl, in each case branched or unbranched and mono- or polysubstituted or unsubstituted; C 3 -C 7 -cycloalkyl, saturated or unsaturated and mono- or polysubstituted or unsubstituted, or a corresponding heterocyclic radical, in which one C atom in the ring is replaced by N, S or O; alkylaryl, saturated or unsaturated and mono- or polysubstituted or unsubstituted; or aryl or heteroaryl, in each case mono- or polysubstituted or unsubstituted; or [0016] if the compound contains no X, according to formula Ia a double bond is formed between C atom A and C atom B or C atom B and C atom C, [0017] R 4 , R 5 independently of one another are [0018] H; C 1 -C 10 -alkyl, C 2 -C 10 -alkenyl or C 2 -C 10 -alkinyl, in each case branched or unbranched and mono- or polysubstituted or unsubstituted; C 3 -C 7 -cycloalkyl, saturated or unsaturated and mono- or polysubstituted or unsubstituted, or a corresponding heterocyclic radical, in which one C atom in the ring is replaced by N, S or O; alkylaryl, saturated or unsaturated and mono- or polysubstituted or unsubstituted; or aryl or heteroaryl, in each case mono- or polysubstituted or unsubstituted; or [0019] R 4 and R 5 together form a C 3 -C 7 -cycloalkyl, saturated or unsaturated and mono- or polysubstituted or unsubstituted, or a corresponding heterocyclic radical, in which one C atom in the ring is replaced by S, O or NR 8 , wherein R 8 is H; or C 1 -C 10 -alkyl, C 2 -C 10 -alkenyl or C 2 -C 10 -alkinyl, in each case branched or unbranched and mono- or polysubstituted or unsubstituted; [0020] and [0021] R 2 , R 3 independently of one another are [0022] R 9 or YR 9 , wherein Y is C 1 -C 10 -alkyl, C 2 -C 10 -alkenyl or C 2 -C 10 -alkinyl, branched or unbranched and mono- or polysubstituted or unsubstituted, wherein R 9 is [0023] H; F; Cl; Br; I; CN; NO 2 ; C 1 -C 18 -alkyl, C 2 -C 18 -alkenyl or C 2 -C 18 -alkinyl, in each case branched or unbranched and mono- or polysubstituted or unsubstituted; or C 3 -C 7 -cycloalkyl, saturated or unsaturated and mono- or polysubstituted or unsubstituted, or a corresponding heterocyclic radical, in which one C atom in the ring is replaced by S, O or NR 10 , where R 10 is [0024] H; or C 1 -C 10 -alkyl, C 2 -C 10 —alkenyl or C 2 -C 10 —alkinyl, in each case branched or unbranched and mono- or polysubstituted or unsubstituted; [0025] OR 11 , OC(O)R 11 , OC(O)OR 11 , OC(S)R 11 , C(O)R 11 , C(O)OR 11 , C(S)R 11 , C(S)OR 11 , SR 11 , S(O)R 11 or S(O 2 )R 11 , wherein R 11 is [0026] H; C 1 -C 18 -alkyl, C 2 -C 18 -alkenyl or C 2 -C 18 -alkinyl, in each case branched or unbranched and mono- or polysubstituted or unsubstituted; C 3 -C 7 -cycloalkyl, saturated or unsaturated and mono- or polysubstituted or unsubstituted, or a corresponding heterocyclic radical, in which one C atom in the ring is replaced by S, O or NR 12 , where R 12 is chosen from [0027] H, C 1 -C 10 -alkyl, C 2 -C 10 —alkenyl or C 2 -C 10 —alkinyl, in each case branched or unbranched and mono- or polysubstituted or unsubstituted; [0028] alkylaryl, saturated or unsaturated and mono- or polysubstituted or unsubstituted; or aryl or heteroaryl, in each case mono- or polysubstituted or unsubstituted; [0029] NR 13 R 14 , NR 13 C(O)R 14 , C(O)NR 13 R 14 or S(O 2 )NR 13 R 14 , wherein R 13 and R 14 independently of one another are [0030] H; O; C 1 -C 18 -alkyl, C 2 -C 18 -alkenyl or C 2 -C 18 -alkinyl, in each case branched or unbranched and mono- or polysubstituted or unsubstituted; C 3 -C 7 -cycloalkyl, saturated or unsaturated and mono- or polysubstituted or unsubstituted, or a corresponding heterocyclic radical, in which one C atom in the ring is replaced by S, O or NR 15 , where R 15 is [0031] H, C 1 -C 10 -alkyl, C 2 -C 10 -alkenyl or C 2 -C 10 —alkinyl, in each case branched or unbranched and mono- or polysubstituted or unsubstituted; [0032] alkylaryl, saturated or unsaturated and mono- or polysubstituted or unsubstituted; or aryl or heteroaryl, in each case mono- or polysubstituted or unsubstituted; or [0033] R 13 and R 14 together form a C 3 -C 7 -cycloalkyl, saturated or unsaturated and mono- or polysubstituted or unsubstituted, or a corresponding heterocyclic radical, in which one C atom in the ring is replaced by S, O or NR 1 6 , where R 16 is [0034] H; or C 1 -C 10 -alkyl, C 2 -C 10 -alkenyl or C 2 -C 10 -alkinyl, in each case branched or unbranched and mono- or polysubstituted or unsubstituted; or [0035] alkylaryl, aryl or heteroaryl, in each case mono- or polysubstituted or unsubstituted; in particular [0036] wherein R 17 , R 18 , R 19 and R 20 independently of one another are [0037] R 21 or ZR 21 , whereing Z is C 1 -C 10 -alkyl, C 2 -C 10 -alkenyl or C 2 -C 10 -alkinyl, in each case branched or unbranched and mono- or polysubstituted or unsubstituted, and wherein R 21 is [0038] H; F; Cl; Br; I; CN; NO 2 ; C 1 -C 18 -alkyl, C 2 -C 18 -alkenyl or C 2 -C 18 -alkinyl, in each case branched or unbranched and mono- or polysubstituted or unsubstituted; C 3 -C 7 -cycloalkyl, saturated or unsaturated and mono- or polysubstituted or unsubstituted, or a corresponding heterocyclic radical, in which one C atom in the ring is replaced by S, O or NR 22 , where R 22 is [0039]  H; or C 1 -C 10 -alkyl, C 2 -C 10 —alkenyl or C 2 -C 10 —alkinyl, in each case branched or unbranched and mono- or polysubstituted or unsubstituted; [0040] or alkylaryl, aryl or heteroaryl, in each case mono- or polysubstituted or unsubstituted; [0041] OR 23 , OC(O)R 23 , OC(O)OR 23 , OC(S)R 23 , C(O)R 23 , C(O)OR 23 , C(S)R 23 , C(S)OR 23 , SR 23 , S(O)R 23 or S(O 2 )R 23 , wherein R 23 is [0042]  H; or C 1 -C 18 -alkyl, C 2 -C 18 -alkenyl or C 2 -C 18 -alkinyl, in each case branched or unbranched and mono- or polysubstituted or unsubstituted; C 3 -C 7 -cycloalkyl, saturated or unsaturated and mono- or polysubstituted or unsubstituted, or a corresponding heterocyclic radical, in which one C atom in the ring is replaced by S, O or NR 24 , where R 24 is [0043]  H; or C 1 -C 10 -alkyl, C 2 -C 10 —alkenyl or C 2 -C 10 —alkinyl, in each case branched or unbranched and mono- or polysubstituted or unsubstituted; alkylaryl, saturated or unsaturated and mono- or polysubstituted or unsubstituted; or aryl or heteroaryl, in each case mono- or polysubstituted or unsubstituted; [0044] NR 25 R 26 , NR 25 C(O)R 26 , C(O)NR 25 R 26 or S(O 2 )NR 25 R 26 , wherein R 25 and R 26 independently of one another are [0045]  H; C 1 -C 18 -alkyl, C 2 -C 18 -alkenyl or C 2 -C 18 -alkinyl, in each case branched or unbranched and mono- or polysubstituted or unsubstituted; C 3 -C 7 -cycloalkyl, saturated or unsaturated and mono- or polysubstituted or unsubstituted, or a corresponding heterocyclic radical, in which one C atom in the ring is replaced by S, O or NR 27 , where R 27 is [0046]  H; or C 1 -C 10 -alkyl, C 2 -C 10 -alkenyl or C 2 -C 10 -alkinyl, in each case branched or unbranched and mono- or polysubstituted or unsubstituted; [0047]  alkylaryl, saturated or unsaturated and mono- or polysubstituted or unsubstituted; or aryl or heteroaryl, in each case mono- or polysubstituted or unsubstituted; or [0048] wherein R 25 and R 26 together form a C 3 -C 7 -cycloalkyl, saturated or unsaturated and mono- or polysubstituted or unsubstituted, or a corresponding heterocyclic radical, in which one C atom in the ring is replaced by S, O or NR 27 , where R 27 is [0049]  H; or C 1 -C 10 -alkyl, C 2 -C 10 -alkenyl or C 2 -C 10 -alkinyl, in each case branched or unbranched and mono- or polysubstituted or unsubstituted. [0050] In connection with alkyl, alkenyl, alkinyl and cycloalkyl and the “corresponding heterocyclic radical,” the term substituted in the context of this invention is understood as meaning the replacement of a hydrogen radical by F, Cl, Br, I, NH 2 , SH or OH; and polysubstituted radicals is understood as meaning radicals which are substituted more than once either on different or on the same atom, for example three times on the same C atom, as in the case of CF 3 , or at different places, as in the case of —CH(OH)—CH═CH—CHCl 2 . [0051] Furthermore, —C(O)— denotes [0052] which also applies to —C(S)— or —S(O)— and —S(O 2 )—. [0053] The term “C 1 -C 8 -alkyl” or “C 1 -C 10 -alkyl” in the context of this invention denotes hydrocarbons having 1 to 8, or 1 to 10 carbon atoms respectively. Examples which may be mentioned are methyl, ethyl, propyl, isopropyl, n-butane, sec-butyl, tert-butyl, n-pentane, neopentyl, n-hexane, n-heptane, n-octane, n-nonane or n-decane. [0054] The term “C 1 -C 18 -alkyl” in the context of this invention denotes hydrocarbons having 1 to 18 carbon atoms. Examples which may be mentioned are methyl, ethyl, propyl, isopropyl, n-butane, sec-butyl, tert-butyl, n-pentane, neopentyl, n-hexane, n-heptane, n-octane, n-nonane, n-decane, n-undecane, n-dodecane, n-tridecane, n-tetradecane, n-pentadecane, n-hexadecane, n-heptadecane or n-octadecane, unsubstituted or mono or polysubstituted. [0055] The term “C 2 -C 10 -alkenyl” or “C 2 -C 10 -alkinyl” or “C 2 -Cls-alkenyl” or “C 2 -C 18 -alkinyl” in the context of this invention denotes hydrocarbons having 2 to 8 or 2 to 18 carbon atoms respectively. Examples which may be mentioned are propenyl, butenyl, pentenyl, hexenyl, heptenyl or octenyl, unsubstituted or mono or polysubstituted, or propinyl, butinyl, pentinyl, hexinyl, heptinyl or octinyl, unsubstituted or mono or polysubstituted. [0056] The term C 3 -C 7 -cycloalkyl in the context of this invention denotes cyclic hydrocarbons having 3 to 7 carbon atoms in the ring. Examples which may be mentioned are cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclohexenyl or cycloheptenyl, saturated or unsaturated and unsubstituted or mono- or polysubstituted. In the context of the invention a “corresponding heterocyclic radical” is understood as meaning a C 3 -C 7 -cycloalkyl in which one C atom in the ring is replaced by S, O or N. Examples which may be mentioned for this are pyrrolidine, pyran, thiolane, piperidine or tetrahydrofuran. [0057] The term “aryl” in the context of this invention denotes phenyls or naphthyls. [0058] The term “alkylaryl” in the context of this invention denotes aryls substituted by at least a C 1 -C 10 -alkylene, the terms aryl and alkyl having the same meaning as above. In this group benzaryl may be mentioned in particular. [0059] The term “heteroaryl” in the context of this invention denotes a 5- or 6-membered aromatic compound which is optionally provided with a fused-on ring system and contain one or two heteroatoms selected from the groups consisting of nitrogen, oxygen and sulfur. Examples which may be mentioned in this group are furan, thiophene, pyrrole, pyridine, pyrimidine, quinoline, isoquinoline, phthalazine or quinazoline. [0060] In respect of aryl, alkylaryl or heteroaryl, mono- or polysubstituted in the context of this invention is understood as meaning substitution of the ring system on one or more atoms by F; Cl; Br; I; NH 2 ; SH; OH; CF 3 ; or mono- or polysubstituted or unsubstituted C 1 -C 6 -alkyl, C 1 -C 6 -alkoxy, C 2 -C 8 -alkenyl, C 2 -C 8 -alkinyl; or aryl, in particular phenyl. [0061] The phrase “Salt formed with a physiologically tolerated acid” in the context of this invention is understood as meaning salts of the particular active compound with inorganic or organic acids which are physiologically tolerated—in particular when used in humans and/or other mammals. Hydrochloride salts are particularly preferred. [0062] Preferably, in formula I or Ia, R 2 and R 3 have different meanings and/or R 3 is H or CH 3 , preferably H, while R 1 , R 1 ′, R 2 , R 4 , R 5 and X are as defined above. [0063] More preferably, in formula I or Ia, R 2 is [0064] wherein R 17 , R 18 , R 19 and R 20 , as well as R 1 , R 1 ′, R 3 , R 4 , R 5 and X have meanings as defined above. [0065] Preferably R 2 is a C 1-3 -alkyl. [0066] In another preferred embodiment in formula I or Ia, R 2 is [0067] and R 19 and R 20 are H, while R 1 , R 1 ′, R 3 , R 4 , R 5 , X and R 17 and R 18 are as defined above. [0068] In a further preferred embodiment, aminomethyl-phenyl-in formula I or Ia according to the invention, R 2 is [0069] wherein R 17 and R 18 have a different meaning and/or R 18 is R 21 , wherein R 21 is [0070] H, F, Cl, Br, I, CF 3 or OR 23 , where R 23 is H, methyl ethyl, propyl, isopropyl, butyl or isobutyl, [0071] while R 1 , R 1 ′, R 3 , R 4 , R 5 and X, as well as R 17 , R 19 and R 20 have one of the meanings defined above. [0072] More preferably, in formula I or Ia according to the invention, R 2 is [0073] wherein R 17 is [0074] R 21 , wherein R 21 is 'H, F, Cl, Br, I, CF 3 , OR 23 , OC(O)R 23 , C(O)R 23 or C(O)OR 23 , preferably H, F, Cl, C(O)OR 23 , wherein R 23 is [0075] H; or C 1 -C 6 -alkyl, C 2 -C 8 -alkenyl or C 2 -C 8 -alkinyl, in particular C 1 -C 4 -alkyl, branched or unbranched and mono- or polysubstituted or unsubstituted; preferably H, methyl ethyl, propyl, isopropyl, butyl or isobutyl, in particular H, CH 3 , C 2 H 5 or isobutyl; [0076] or C(O)NR 25 R 26 , wherein R 25 and R 26 independently of one another are [0077] H; 0; or C 1 -C 18 -alkyl, in particular C 1 -C 4 -alkyl, branched or unbranched, saturated or unsaturated and mono- or polysubstituted or unsubstituted; preferably H, methyl, ethyl, propyl, isopropyl, butyl or isobutyl, in particular C 2 H 5 ; or [0078] ZR 21 , where Z is CH 2 or C 2 H 4 , preferably CH 2 , wherein R 21 is [0079] OR 23 , OC(O)R 23 , C(O)R 23 or C(O)OR 23 , preferably OR 23 , wherein R 23 is [0080] H; or C 1 -C 6 -alkyl, C 2 -C 8 -alkenyl or C 2 -C 8 -alkinyl, in particular C 1 -C 4 -alkyl, branched or unbranched and mono- or polysubstituted or unsubstituted, preferably H, methyl, ethyl, propyl, isopropyl, butyl or isobutyl, in particular H; [0081] C(O)NR 25 R 26 , wherein R 25 and R 26 independently of one another are chosen from [0082] H, O, C 1 -C 18 -alkyl, in particular C 1 -C 4 -alkyl, branched or unbranched, saturated or unsaturated and mono- or polysubstituted or unsubstituted, preferably H, methyl ethyl, propyl, isopropyl, butyl or isobutyl; [0083] while R 1 , R 1 ′, R 3 , R 4 , R 5 and X and R 18 , R 19 and R 20 are as defined above. [0084] In a particularly preferred embodiment in formula I or Ia according to the invention [0085] R 1 is [0086] H, F, Cl, Br, I, CF 3 , SCH 3 or OR 6 , preferably OR 6 , wherein R 6 is [0087] H; or C 1 -C 4 -alkyl, branched or unbranched and mono- or polysubstituted or unsubstituted; preferably H or CH 3 ; and/or [0088] R 1 is [0089] H, F, Cl, SCH 3 or OCH 3 , preferably H and/or [0090] X is [0091] H, F, Br, I, Cl or OR 7 , preferably H, F, Cl or OR 7 , where R 7 is H or CH 3 , preferably H; or [0092] if the compound contains no X, according to formula Ia a double bond is formed between C atom A and C atom B or C atom B and C atom C; and/or [0093] R 4 and R 5 independently of one another are [0094] C 1 -C 4 -alkyl, branched or unbranched and mono- or polysubstituted or unsubstituted, preferably CH 3 , [0095] while R 2 and R 3 have one of the above-defined meanings. [0096] The following substituted aminomethyl-phenyl-cyclohexane derivatives according to the invention are particularly preferred: [0097] rac-cis-E-[-4-benzylidene-2-(3-methoxy-phenyl)-cyclohexylmethyl]-dimethylamine, [0098] rac-trans-E-[4-benzylidene-2-(3-methoxy-phenyl)-cyclohexylmethyl]-dimethylamine, [0099] rac-trans-Z-[4-benzylidene-2-(3-methoxy-phenyl)-cyclohexylmethyl]-dimethylamine, [0100] rac-cis-Z-[4-benzylidene-2-(3-methoxy-phenyl)-cyclohexylmethyl]-dimethylamine, [0101] rac-cis-E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester, [0102] rac-cis-Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester, [0103] rac-trans-Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester, [0104] rac-trans-E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester, [0105] Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-2-methyl-cyclohex-2-enylidenemethyl]-benzoic acid methyl ester, [0106] E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-2-methyl-cyclohex-2-enylidenemethyl]-benzoic acid methyl ester, [0107] Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-2-methyl-cyclohex-2-enylidenemethyl]-naphthalene-1-carboxylic acid ethyl ester, [0108] E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-2-methyl-cyclohex-2-enylidenemethyl]-naphthalene-1-carboxylic acid ethyl ester, [0109] Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-2-fluoro-benzoic acid ethyl ester, [0110] Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid, [0111] E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid, [0112] E-{3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-phenyl}-methanol, [0113] rac-trans-Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid, [0114] rac-trans-E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid, [0115] rac-trans-E-[3-(2-dimethylaminomethyl-5-(3-hydroxymethyl-benzylidene)-cyclohexyl) -phenol, [0116] rac-trans-E-3-(5-benzylidene-2-dimethylaminomethyl-cyclohexyl)-phenol, [0117] E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid tert-butyl ester, [0118] E-3-[6-dimethylaminomethyl-3-(3-hydroxymethyl-benzylidene)-cyclohex-1-enyl]-phenol, [0119] rac-trans-Z-3-(5-benzylidene-2-dimethylaminomethyl-cyclohexyl)-phenol, [0120] Z-3-[2-dimethylaminomethyl-5-(3-hydroxymethyl-benzylidene)-cyclohex-1-enyl]-phenol, [0121] Z-{3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-phenyl}-methanol, [0122] rac-cis-E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid, [0123] rac-cis-Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid, [0124] rac-trans-E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid tert-butyl ester, [0125] rac-trans-E-[3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl) -phenyl)-methanol], [0126] rac-cis-Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid ethyl ester, [0127] E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-N,N-diethyl-benzamide rac-trans-E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-N,N-diethyl-benzamide, [0128] E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid ethyl ester, [0129] Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-N,N-diethyl-benzamide, [0130] rac-cis-E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-N,N-diethyl-benzamide, [0131] rac-trans-Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-N,N-diethyl-benzamide, [0132] E-3-[4-dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid methyl ester, [0133] Z-3-[4-dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid methyl ester, [0134] Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid isobutyl ester, [0135] Z-3-[6-dimethylaminomethyl-3-(3-hydroxymethyl-benzylidene)-cyclohex-1-enyl]-phenol, [0136] Z-[4-(4-chloro-benzylidene)-2-(3-methoxy-phenyl)-cyclohex-2-enylmethyl]-dimethyl-amine, [0137] E-[4-(4-fluoro-benzylidene)-2-(3-methoxy-phenyl)-cyclohex-2-enylmethyl]-dimethyl-amine, [0138] Z-[4-(4-fluoro-benzylidene)-2-(3-methoxy-phenyl)-cyclohex-2-enylmethyl]-dimethyl-amine, [0139] E-3-[6-dimethylaminomethyl-3-(4-fluoro-benzylidene)-cyclohex-1-enyl]-phenol, [0140] Z-3-[6-dimethylaminomethyl-3-(4-fluoro-benzylidene)-cyclohex-1-enyl]-phenol, [0141] E-[4-(4-chloro-benzylidene)-2-(3-methoxy-phenyl)-cyclohex-2-enylmethyl]-dimethyl-amine, [0142] E-3-[3-(4-chloro-benzylidene)-6-dimethylaminomethyl-cyclohex-1-enyl]-phenol, [0143] Z-3-[4-dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid methyl ester, [0144] E-3-[4-dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid, [0145] rac-cis-E-3-[4-dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester, [0146] rac-cis-Z-3-[4-dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester, [0147] rac-trans-Z-3-[4-dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohexylidenemethyl]-benzoic acid, [0148] rac-trans-E-[4-dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohexylidenemethyl]-benzoic acid, [0149] rac-cis-Z-3-[4-dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohexylidenemethyl]-benzoic acid, [0150] rac-cis-Z-3-[4-dimethylaminomethyl-3-hydroxy-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester, [0151] rac-cis-E-3-[3-chloro-4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester, [0152] rac-cis-E-3-[4-dimethylaminomethyl-3-hydroxy-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester, [0153] rac-cis-Z-3-[4-dimethylaminomethyl-3-hydroxy-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester, [0154] (+)-trans-E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid, [0155] (−)-trans-E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid, [0156] rac-trans-E-3-(4-dimethylaminomethyl-3-phenyl-cyclohexylidenemethyl)-benzoic acid methyl ester, [0157] rac-trans-Z-3-(4-dimethylaminomethyl-3-phenyl-cyclohexylidenemethyl)-benzoic acid methyl ester, [0158] rac-cis-E-3-(4-dimethylaminomethyl-3-phenyl-cyclohexylidenemethyl)-benzoic acid, [0159] rac-cis-E-3-(4-dimethylaminomethyl-3-phenyl-cyclohexylidenemethyl)-benzoic acid, [0160] rac-trans-Z-3-(4-dimethylaminomethyl-3-phenyl-cyclohexylidenemethyl)benzoic acid, [0161] rac-trans-E-3-(4-dimethylaminomethyl-3-phenyl-cyclohexylidenemethyl)-benzoic acid, [0162] rac-trans-E-3-[4-dimethylaminomethyl-3-(3-triflluoromethyl-phenyl)-cyclohexylidenemethyl]-benzoic acid, [0163] rac-trans-Z-3-[4-dimethylaminomethyl-3-(3-trifluoromethyl-phenyl)-cyclohexylidenemethyl]-benzoic acid, [0164] rac-trans-E-3-[4-dimethylaminomethyl-3-(3-fluoro-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester, [0165] rac-trans-Z-3-[4-dimethylaminomethyl-3-(3-fluoro-phenyl)-cyclohexylidenemethyl]benzoic acid methyl ester, [0166] rac-cis-E-3-[4-dimethylaminomethyl-3-(3-fluoro-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester, [0167] rac-trans-E-3-[4-dimethylaminomethyl-3-(3-fluoro-phenyl)-cyclohexylidenemethyl]-benzoic acid, [0168] rac-trans-Z-3-[4-dimethylaminomethyl-3-(3-fluoro-phenyl)-cyclohexylidenemethyl]-benzoic acid, [0169] rac-cis-E-3-[4-dimethylaminomethyl-3-(3-fluoro-phenyl)-cyclohexylidenemethyl]-benzoic acid E-[4-ethylidene-2-(3-methoxy-phenyl)-cyclohex-2-enylmethyl]-dimethylamine [0170] [4-isopropylidene-2-(3-methoxy-phenyl)-cyclohex-2-enylmethyl]-dimethylamine, [0171] E-[2-(3-methoxy-phenyl)-4-propylidene-cyclohex-2-enylmethyl]-dimethylamine, [0172] E-[4-butylidene-2-(3-methoxy-phenyl)-cyclohex-2-enylmethyl]-dimethylamine [0173] and salts thereof, in particular hydrochloride salts. [0174] The invention also provides a process for the preparation of substituted aminomethyl-phenyl-cyclohexane derivatives of the formula I or Ia [0175] in which R 1 , R 1 ′, R 2 , R 3 , R 4 , R 5 and X are as previously defined. According to the present invention cyclohexanones of the formula II or Iia [0176] in which R 4 , R 5 and X are as defined above, R 28 is as defined in the definition of R 1 , and R 28 is as defined in the definition of R 1 ′, are reacted in a Wittig reaction in an organic solvent in the presence of a base with alkyltriphenylphosphonium salts of the formula III [0177] wherein A denotes chloride or bromide and, independently of one another, R 29 is as defined in the above definition of R 2 and R 30 is as defined in the above definition of R 3 . [0178] Preferred organic solvents here are benzene, toluene or a chlorinated hydrocarbon, and potassium tert-butylate or sodium hydride are preferably used as the base. Furthermore, the reaction temperature, in particular during the Wittig reaction, is preferably kept between 50° C. and 90° C. [0179] OH, SH and NH 2 groups can undergo undesirable side reactions under the reaction conditions mentioned. It is therefore preferable to provide these with protective groups, or in the case of NH 2 to replace it by NO 2 , and to remove the protective group or reduce the NO 2 group after the Wittig reaction. The present invention therefore also provides a modification of the process described above in which in R 28 and/or R 28 ′ according to formula II or Ia and/or R 29 and/or R 30 according to formula III at least one OH group has been replaced by an OSi(Ph) 2 tert-but group, at least one SH group has been replaced by an S-p-methoxybenzyl group and/or at least one NH 2 group has been replaced by an NO 2 group and, after conclusion of the Wittig reaction, at least one OSi(Ph) 2 tert-but group is split off with tetrabutylammonium fluoride in tetrahydrofuran and/or at least one p-methoxybenzyl group is split off with a metal amine, preferably sodium amine, and/or at least one NO 2 group is reduced to NH 2 . [0180] Furthermore, carboxylic acid or thiocarboxylic acid groups are not stable under certain circumstances under the conditions of the Wittig reaction, so that it is preferable to react methyl esters thereof in the Wittig reaction and then to hydrolyse the process product from the Wittig reaction with KOH solution or NaOH solution in methanol at 40° C.-60° C. The invention therefore also provides a modification of the processes described above in which, after the Wittig reaction, a process product with at least one C(O)OCH 3 , OC(O)OCH 3 and/or C(S)OCH3 group is hydrolyzed with KOH solution or NaOH solution in methanol at 40° C.-60° C. [0181] The reactions proceed specifically and with high yields. Nevertheless, purification of the compounds obtained in the individual reaction sequences, in particular of the end product, is usually necessary. The purification is preferably carried out via crystallization or chromatographic methods, in particular column chromatography. [0182] The compounds of formula I or Ia can be converted into their salts in a manner well-known to those of ordinary skill in the art with physiologically tolerated acids, such as hydrochloric acid, hydrobromic acid, sulfuric acid, methanesulfonic acid, formic acid, acetic acid, oxalic acid, succinic acid, tartaric acid, mandelic acid, fumaric acid, lactic acid, citric acid, glutamic acid and/or aspartic acid. The salt formation is preferably carried out in a solvent, such as diisopropyl ether, acetic acid alkyl esters, acetone and/or 2-butanone. Trimethylchlorosilane in aqueous solution is particularly suitable for preparation of the hydrochlorides. [0183] The cyclohexanones of formulae II and Ia are prepared by first reacting 3,3-dimethyl-1,5-dioxa-spiro[5.5]undecan-8-one with immonium salts of the formula IV or with formaldehyde and an amine of the formula V. The Mannich bases obtained in this way are then reacted with an organometallic compound of the formula VI, in which Z denotes MgCl, MgBr, MgI or lithium. The reaction of the Mannich bases with a Grignard compound of the formula VI, in which Z denotes MgCl, MgBr or MgI, or with an organolithium compound of the formula VI, in which Z is Li, can be carried out in an aliphatic ether, for example diethyl ether and/or tetrahydrofuran, at temperatures of between −70° C. and 60° C. The reaction with a Grignard compound of the formula VI can be carried out with or without the addition of an entraining reagent. If an entraining reagent is employed, 1,2-dibromoethane is preferred. [0184] Products of the general formula VII are first obtained in this way. [0185] Compounds of the formula IIa are obtained by reacting products of the general formula VII with an acid, for example hydrochloric acid, formic acid or acetic acid, at room temperature. Subsequent hydrogenation of the products obtained in this way with catalytically activated hydrogen, platinum or palladium absorbed on a support material, such as active charcoal, serving as the catalyst, leads to compounds of the formula II where X is H. The hydrogenation is carried out in a solvent, such as ethyl acetate or a C 1 -C 4 -alkyl alcohol, under pressures of 0.1 to 10 bar and at temperatures of 20° C. to 80° C. [0186] Compounds of the general formula II where X is OH are obtained by reacting products of the general formula VII with acids, for example hydrochloric acid, at temperatures of between 5° C. and 10C. [0187] Compounds of the general formula II where X is F, Cl, Br, I or CF 3 are obtained by replacement of OH by F or Cl or Br or I or CF 3 by processes well known to those ordinarily skilled in the art. [0188] Compounds of the general formula II where X is OR 7 are obtained by etherification of the OH group with a halide of the formula VIII; R 7 Cl  VIII. [0189] Compounds of the general formula II where X is OC(O)R 7 are obtained by esterification of the OH group with an acid chloride of the formula IX; R 7 COCl  IX. [0190] Most of the substituted alkyltriphenylphosphonium salts used in the preparation process are commercially obtainable. However, in some exceptional cases these must be synthesized. 3-(Benzoic acid methyl ester)-methyltriphenylphosphonium bromide may be mentioned as an example of the synthesis of the substituted alkyltriphenylphosphonium salts: [0191] This is prepared as follows: 3-Toluic acid is converted with methanol in the presence of sulfuric acid into 3-toluic acid methyl ester, which reacts with N-bromosuccinimide to give 3-bromomethyl-benzoic acid methyl ester. Reaction of bromomethyl-benzoic acid methyl ester with triphenylphosphane finally leads to 3-(benzoic acid methyl ester)-methyltriphenylphosphonium bromide. [0192] The substituted aminomethyl-phenyl-cyclohexane derivatives according to the invention are toxicologically acceptable so that they are suitable as a pharmaceutical active compound in medicaments. [0193] The invention therefore also provides medicaments which comprise, as the active compound, at least one substituted aminomethyl-phenyl-cyclohexane derivative of the general formula I or Ia [0194] in which R 1 , R 1 , R 2 , R 3 , R 4 , R 5 and X have one of the meanings mentioned in claim 1 , in the form of its diastereomers or enantiomers and of its free base or of a salt formed with a physiologically tolerated acid, in particular a hydrochloride salt. [0195] Medicaments which comprise as the active compound at least one substituted aminomethyl-phenyl-cyclohexane derivative chosen from the following group are particularly preferred here: [0196] rac-cis-E-[-4-benzylidene-2-(3-methoxy-phenyl)-cyclohexylmethyl]-dimethylamine, [0197] rac-trans-E-[4-benzylidene-2-(3-methoxy-phenyl)-cyclohexylmethyl]-dimethylamine, [0198] rac-trans-Z-[4-benzylidene-2-(3-methoxy-phenyl)-cyclohexylmethyl]-dimethylamine, [0199] rac-cis-Z-[4-benzylidene-2-(3-methoxy-phenyl)-cyclohexylmethyl]-dimethylamine, [0200] rac-cis-E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester, [0201] rac-cis-Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester, [0202] rac-trans-Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester, [0203] rac-trans-E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester, [0204] Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-2-methyl-cyclohex-2-enylidenemethyl]-benzoic acid methyl ester, [0205] E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-2-methyl-cyclohex-2-enylidenemethyl]-benzoic acid methyl ester, [0206] Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-2-methyl-cyclohex-2-enylidenemethyl]-naphthalene-1-carboxylic acid ethyl ester, [0207] E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-2-methyl-cyclohex-2-enylidenemethyl]-naphthalene-1-carboxylic acid ethyl ester, [0208] Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-2-fluoro-benzoic acid ethyl ester, [0209] Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid, [0210] E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid, [0211] E-{3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-phenyl}-methanol, [0212] rac-trans-Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid, [0213] rac-trans-E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid, [0214] rac-trans-E-[3-(2-dimethylaminomethyl-5-(3-hydroxymethyl-benzylidene)-cyclohexyl) -phenol, [0215] rac-trans-E-3-(5-benzylidene-2-dimethylaminomethyl-cyclohexyl)-phenol, [0216] E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid tert-butyl ester, [0217] E-3-[6-dimethylaminomethyl-3-(3-hydroxymethyl-benzylidene)-cyclohex-1-enyl]-phenol, [0218] rac-trans-Z-3-(5-benzylidene-2-dimethylaminomethyl-cyclohexyl)-phenol, [0219] Z-3-[2-dimethylaminomethyl-5-(3-hydroxymethyl-benzylidene)-cyclohex-1-enyl]-phenol, [0220] Z-{3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-phenyl}-methanol, [0221] rac-cis-E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid, [0222] rac-cis-Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid, [0223] rac-trans-E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid tert-butyl ester, [0224] rac-trans-E-[3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl) -phenyl) -methanol], [0225] rac-cis-Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid ethyl ester, [0226] E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-N,N-diethyl-benzamide rac-trans-E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-N,N-diethyl-benzamide, [0227] E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid ethyl ester, [0228] Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-N,N-diethyl-benzamide, [0229] rac-cis-E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-N,N-diethyl-benzamide, [0230] rac-trans-Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-N,N-diethyl-benzamide, [0231] E-3-[4-dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid methyl ester, [0232] Z-3-[4-dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid methyl ester, [0233] Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid isobutyl ester, [0234] Z-3-[6-dimethylaminomethyl-3-(3-hydroxymethyl-benzylidene)-cyclohex-1-enyl]-phenol, [0235] Z-[4-(4-chloro-benzylidene)-2-(3-methoxy-phenyl) -cyclohex-2-enylmethyl]-dimethyl-amine, [0236] E-[4-(4-fluoro-benzylidene)-2-(3-methoxy-phenyl)-cyclohex-2-enylmethyl]-dimethyl-amine, [0237] Z-[4- (4-fluoro-benzylidene)-2-(3-methoxy-phenyl) -cyclohex-2-enylmethyl]-dimethyl-amine, [0238] E-3-[6-dimethylaminomethyl-3-(4-fluoro-benzylidene) -cyclohex-1-enyl]-phenol, [0239] Z-3-[6-dimethylaminomethyl-3- (4-fluoro-benzylidene)-cyclohex-1-enyl]-phenol, [0240] E-[4-(4-chloro-benzylidene)-2-(3-methoxy-phenyl)-cyclohex-2-enylmethyl]-dimethyl-amine, [0241] E-3-[3-(4-chloro-benzylidene)-6-dimethylaminomethyl-cyclohex-1-enyl]-phenol, [0242] Z-3-[4-dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid methyl ester, [0243] E-3-[4-dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid, [0244] rac-cis-E-3-[4-dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester, [0245] rac-cis-Z-3-[4-dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester, [0246] rac-trans-Z-3-[4-dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohexylidenemethyl]-benzoic acid, [0247] rac-trans-E-[4-dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohexylidenemethyl]-benzoic acid, [0248] rac-cis-Z-3-[4-dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohexylidenemethyl]-benzoic acid, [0249] rac-cis-Z-3-[4-dimethylaminomethyl-3-hydroxy-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester, [0250] rac-cis-E-3-[3-chloro-4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester, [0251] rac-cis-E-3-[4-dimethylaminomethyl-3-hydroxy-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester, [0252] rac-cis-Z-3-[4-dimethylaminomethyl-3-hydroxy-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester, [0253] (+)-trans-E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid, [0254] (−)-trans-E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid, [0255] rac-trans-E-3-(4-dimethylaminomethyl-3-phenyl-cyclohexylidenemethyl)-benzoic acid methyl ester, [0256] rac-trans-Z-3-(4-dimethylaminomethyl-3-phenyl-cyclohexylidenemethyl)-benzoic acid methyl ester, [0257] rac-cis-E-3-(4-dimethylaminomethyl-3-phenyl-cyclohexylidenemethyl)-benzoic acid, [0258] rac-cis-E-3-(4-dimethylaminomethyl-3-phenyl-cyclohexylidenemethyl)-benzoic acid, [0259] rac-trans-Z-3-(4-dimethylaminomethyl-3-phenyl-cyclohexylidenemethyl)benzoic acid, [0260] rac-trans-E-3-(4-dimethylaminomethyl-3-phenyl-cyclohexylidenemethyl)-benzoic acid, [0261] rac-trans-E-3-[4-dimethylaminomethyl-3-(3-triflluoromethyl-phenyl)-cyclohexylidenemethyl]-benzoic acid, [0262] rac-trans-Z-3-[4-dimethylaminomethyl-3-(3-trifluoromethyl-phenyl)-cyclohexylidenemethyl]-benzoic acid, [0263] rac-trans-E-3-[4-dimethylaminomethyl-3-(3-fluoro-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester, [0264] rac-trans-Z-3-[4-dimethylaminomethyl-3-(3-fluoro-phenyl)-cyclohexylidenemethyl]benzoic acid methyl ester, [0265] rac-cis-E-3-[4-dimethylaminomethyl-3-(3-fluoro-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester, [0266] rac-trans-E-3-[4-dimethylaminomethyl-3-(3-fluoro-phenyl)-cyclohexylidenemethyl]-benzoic acid, [0267] rac-trans-Z-3-[4-dimethylaminomethyl-3-(3-fluoro-phenyl)-cyclohexylidenemethyl]-benzoic acid, [0268] rac-cis-E-3-[4-dimethylaminomethyl-3-(3-fluoro-phenyl)-cyclohexylidenemethyl]-benzoic acid, [0269] E-[4-ethylidene-2-(3-methoxy-phenyl)-cyclohex-2-enylmethyl]-dimethylamine, [0270] [4-isopropylidene-2-(3-methoxy-phenyl)-cyclohex-2-enylmethyl]-dimethylamine, [0271] E-[2-(3-methoxy-phenyl)-4-propylidene-cyclohex-2-enylmethyl]-dimethylamine, and [0272] E-[4-butylidene-2-(3-methoxy-phenyl)-cyclohex-2-enylmethyl]-dimethylamine, [0273] as a free base or in the form of a salt formed with a physiologically tolerated acid, in particular a hydrochloride salt. [0274] The medicaments according to the invention comprise, in addition to at least one substituted aminomethyl-phenyl-cyclohexane derivative according to the invention, carrier materials, fillers, solvents, diluents, dyestuffs and/or binders and can be administered as liquid formulations such as injection solutions, drops or juices, or as semi-solid formulations, or as granules, tablets, pellets, patches, capsules, plasters or aerosols. The choice of auxiliary substances and the amounts thereof to be employed depends on whether the medicament is to be administered orally, perorally, parenterally, intravenously, intraperitoneally, intradermally, intramuscularly, intranasally, buccally, rectally or locally, for example on infections of the skin, the mucous membranes and the eyes. Formulations in the form of tablets, coated tablets, capsules, granules, drops, juices and syrups are suitable for oral administration, and solutions, suspensions, easily reconstitutable dry formulations and sprays are suitable for parenteral, topical and inhalatory administration. Substituted aminomethyl-phenyl-cyclohexane derivatives according to the invention in a depot in dissolved form or in a patch, optionally with the addition of agents which promote penetration through the skin, are suitable formulations for percutaneous administration. Formulation forms which can be used orally or percutaneously can release the substituted aminomethyl-phenyl-cyclohexane derivatives according to the invention in a delayed manner. The amount of active compound to be administered to the patient varies according to the body weight of the patient, the mode of administration, the indication and the severity of the disease. 50 to 500 mg/kg of at least one substituted aminomethyl-phenyl-cyclohexane derivative according to the invention are usually administered. [0275] The substituted aminomethyl-phenyl-cyclohexane derivatives according to the invention are preferably employed for treatment of pain, so that the invention also provides the use of at least one substituted aminomethyl-phenyl-cyclohexane derivative of the general formula I or Ia [0276] in which R 1 , R 1 , R 2 , R 3 , R 4 , R 5 and X are as defined above, in the form of its diastereomers or enantiomers and of its free base or of a salt formed with a physiologically tolerated acid, in particular the hydrochloride salt, for the preparation of a medicament or a pharmaceutical composition for treatment of pain. [0277] It has been found, surprisingly, that the substituted aminomethyl-phenyl-cyclohexane derivatives according to the invention are very suitable for further indications, in particular for treatment of urinary incontinence, itching and/or diarrhoea, and also in other indications. The present invention therefore also provides the use of at least one substituted aminomethyl-phenyl-cyclohexane derivative of the general formula I or Ia [0278] in which R 1 , R 1 ′, R 2 , R 3 , R 4 , R 5 and X are as defined above, in the form of its diastereomers or enantiomers and of its free base or of a salt formed with a physiologically tolerated acid, in particular the hydrochloride salt, for the preparation of a medicament for treatment of inflammatory and allergic reactions, depression, drug and/or alcohol abuse, gastritis, cardiovascular diseases, respiratory tract diseases, coughing, mental illnesses and/or epilepsy, and in particular urinary incontinence, itching and/or diarrhoea. [0279] The invention is explained further by examples in the following, without limiting it thereto. EXAMPLES [0280] The following examples show compounds according to the invention and the preparation thereof, and activity studies carried out therewith. [0281] [0281] [0282] The following information generally applies: [0283] The yields of the compounds prepared are not optimized. [0284] All temperatures are uncorrected. [0285] Silica gel 60 (0.040-0.063 mm) from E. Merck, Darmstadt was employed as the stationary phase for the column chromatography. [0286] The thin layer chromatography studies were carried out with HPTLC precoated plates, silica gel 60 F 254 from E. Merck, Darmstadt. [0287] The mixing ratios of the mobile phases for all the chromatographic studies are always stated in volume/volume. [0288] The term ether means diethyl ether. [0289] Unless stated otherwise, petroleum ether with the boiling range of 50° C.-70° C. was used. [0290] The compounds are numbered, and the figures in parentheses correspond to the number of the allocated compound. Example 1 [0291] Z-3-[4-Dimethylaminomethyl-3-(3-methoxy-phenyl)-2-methyl-cyclohex-2-enylidenemethyl]-benzoic acid methyl ester hydrochloride (9) and E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-2-methyl-cyclohex-2-enylidenemethyl]-benzoic acid methyl ester hydrochloride (10) [0292] 42.6 g potassium tert-butylate and 169.8 g 3-(benzoic acid methyl ester)-methyltriphenylphosphonium chloride were suspended in 1.5 1 analytical grade toluene under a nitrogen atmosphere at room temperature and the suspension was then stirred at 70° C. for one hour. 10 g 4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enone in 100 ml analytical grade toluene were added at this temperature and the mixture was stirred at 70° C. for 3 days. The mixture was quenched with 500 ml water. The phases were separated and the aqueous phase was washed 3 times with 200 ml ethyl acetate each time. The combined organic phases were dried over magnesium sulfate and then freed from solvent in vacuo. The residue obtained in this way was taken up in a mixture of 150 ml ethyl acetate and 150 ml diiso-ether. The solid which had precipitated out was filtered off and washed with diiso-ether. The combined organic phases were freed from the solvent in vacuo. The residue was purified by column chromatography on silica gel with ethyl acetate/methanol=9/1. 5.3 g E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-2-methyl-cyclohex-2-enylidenemethyl]-benzoic acid methyl ester were obtained as the first product fraction in the form of an orange-yellow oil. To prepare the hydrochloride, the oil was dissolved in 100 ml acetone, and an equimolar amount of trimethylchlorosilane and water was added. 5 g (30.7% of theory) of the title compound 10 were obtained in this way in the form of white crystals. 4 g Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-2-methyl-cyclohex-2-enylidenemethyl]-benzoic acid methyl ester were obtained as the second product fraction, likewise in the form of an orange-yellow oil. To liberate the hydrochloride, the oil was dissolved in 100 ml acetone, and an equimolar amount of trimethylchlorosilane and water was added. 3.5 g (21.5% of theory) of the title compound were obtained in this way in the form of white crystals. Example 2 [0293] rac-trans-Z-3-[4-Dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester hydrochloride (7) and rac-trans-E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester hydrochloride (8) [0294] Employing: [0295] rac-trans-4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexanone [0296] instead of dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enone in example 1, the procedure described in example 1 gave: [0297] rac-trans-E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester hydrochloride (8), and [0298] rac-trans-Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester hydrochloride (7). Example 3 [0299] rac-cis-Z-3-[4-Dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester hydrochloride (6) and rac-cis-E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester; hydrochloride (5) [0300] Employing rac-cis-4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexanone instead of dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enone in example 1, the procedure described in example 1 gave: [0301] rac-cis-E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester hydrochloride (5), and [0302] rac-cis-Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester hydrochloride (6). Example 4 [0303] Z-3-[4-Dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid hydrochloride (14) [0304] 3 g of the Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-2-methyl-cyclohex-2-enylidenemethyl]-benzoic acid methyl ester, as the base, prepared according to example 1 were dissolved in 30 ml methanol, and 30 ml 1 N potassium hydroxide solution were added. The mixture was stirred at 60° C. for 2 hours. After the reaction mixture had cooled to room temperature, 1 N hydrochloric acid was added to the mixture until a pH of 4 was established. The phases were separated and the aqueous phase was washed 3 times with 20 ml ethyl acetate each time. The combined organic phases were dried over magnesium sulfate and freed from the solvent in vacuo. 2.7 g Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl) -cyclohex -2-enylidenemethyl]-benzoic acid base were obtained in this way in the form of an orange-yellow oil. To prepare the hydrochloride, the base was dissolved in 10 ml acetone, and an equimolar amount of trimethylchlorosilane and water was added. 2.4 g (77% of theory) Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid hydrochloride (14) were obtained in this way in the form of white crystals. Example 5 [0305] E-3-[4-Dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid hydrochloride (15) [0306] Employing: [0307] E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-2-methyl-cyclohex-2-enylidenemethyl]-benzoic acid methyl ester base, which was prepared according to example 1, [0308] instead of Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-2-methyl-cyclohex -2-enylidenemethyl]-benzoic acid methyl ester base in example 4, the procedure described in example 4 gave E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid hydrochloride (15). Example 6 [0309] rac-trans-Z-3-[4-Dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid; hydrochloride (17) [0310] Employing: [0311] rac-trans-Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester base, which was prepared according to example 2, [0312] instead of Z-3-[4-Dimethylaminomethyl-3-(3-methoxy-phenyl)-2-methyl-cyclohex -2-enylidenemethyl]-benzoic acid methyl ester base in example 4, the procedure described in example 4 gave rac-trans-Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid hydrochloride (17). Example 7 [0313] rac-trans-E-3-[4-Dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid hydrochloride (18) [0314] Employing [0315] rac-trans-E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester base, which was prepared according to example 2, [0316] instead of Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-2-methyl-cyclohex -2-enylidenemethyl]-benzoic acid methyl ester base in example 4, the procedure described in example 4 gave rac-trans-E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid hydrochloride (18). Example 8 [0317] rac-cis-Z-3-[4-Dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid hydrochloride (27) [0318] Employing [0319] rac-cis-Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester base, which was prepared according to example 3, [0320] instead of Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-2-methyl-cyclohex -2-enylidenemethyl]-benzoic acid methyl ester base in example 4, the procedure described in example 4 gave rac-cis-Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl) -cyclohexylidenemethyl]-benzoic acid hydrochloride (27). Example 9 [0321] rac-cis-E-3-[4-Dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid hydrochloride (26) [0322] Employing: [0323] rac-cis-E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester base, which was prepared according to example 3, [0324] instead of Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-2-methyl-cyclohex -2-enylidenemethyl]-benzoic acid methyl ester base in example 4, the procedure described in example 4 gave rac-cis-E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl) -cyclohexylidenemethyl]-benzoic acid hydrochloride (26). Example 10 [0325] Z-3-[4-Dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-N,N-diethyl-benzamide hydrochloride (34) [0326] 1.8 g of the Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid base prepared according to example 4 were dissolved in 50 ml analytical grade dimethylformamide, and 2 g DCC and 1.1 g hydroxysuccinimide were added at 0° C. to 15° C. The mixture was stirred at 0° C. for one hour and 2 ml diethylamine were then added dropwise at this temperature. The mixture was stirred at 0° C. for an additional hour and then at room temperature for four days. The reaction mixture was poured on to 300 ml saturated sodium chloride solution and the mixture was then extracted 3 times with 250 ml ethyl acetate each time. The organic phases were washed with 50 ml saturated sodium chloride solution and then dried over magnesium sulfate. The solvent was removed in vacuo. The residue was chromatographed on silica gel with ethyl acetate/methanol=6/5. 0.87 g Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl) -cyclohex-2-enylidenemethyl]-N,N-diethyl-benzamide base was obtained in this way in the form of an orange-yellow oil. To liberate the hydrochloride, the oil was dissolved in 5 ml acetone, and an equimolar amount of trimethylchlorosilane and water was added. 0.52 g (22.1% of theory) of the title compound 34 was obtained in this way in the form of white crystals. Example 11 [0327] E-3-[4-Dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-N,N-diethyl-benzamide hydrochloride (31) [0328] Employing: [0329] E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid as the base, which was prepared according to example 5, [0330] instead of Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid in example 10, the procedure described in example 10 gave E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-N,N-diethyl-benzamide hydrochloride (31). Example 12 [0331] rac-trans-Z-3-[4-Dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-N,N-diethyl-benzamide hydrochloride (36) [0332] Employing: [0333] rac-trans-Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid as the base, which was prepared according to example 6, [0334] instead of Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid in example 10, the procedure described in example 10 gave rac-trans-Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-N,N-diethyl-benzamide hydrochloride (36). Example 13 [0335] rac-trans-E-3-[4-Dimethylaminomethyl-3-(3-methoxy-phenyl) -cyclohex-2-enylidenemethyl]-N,N-diethyl-benzamide hydrochloride (32) [0336] Employing: [0337] rac-trans E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid as the base, which was prepared according to example 7, [0338] instead of Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid in example 10, the procedure described in example 10 gave rac-trans-E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-N,N-diethyl-benzamide hydrochloride (32). Example 14 [0339] rac-cis-E-3-[4-Dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-N,N-diethyl-benzamide; hydrochloride (35) [0340] Employing: [0341] rac-cis-E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid as the base, which was prepared according to example 9, [0342] instead of Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid in example 10, the procedure described in example 10 gave rac-cis-E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-N,N-diethyl-benzamide hydrochloride (35). Example 15 [0343] Z-{3-[4-Dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-phenyl}-methanol; hydrochloride (25) [0344] 50 ml diisobutylaluminium hydride solution (25 wt. % soln. in toluene) were initially introduced into the reaction vessel under a nitrogen atmosphere. 1 g Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-2-methyl-cyclohex-2-enylidenemethyl]-benzoic acid methyl ester base, which was prepared according to example 1, dissolved in 100 ml analytical grade toluene, were then added dropwise at room temperature. The mixture was heated under reflux for two hours. When the reaction had ended the mixture was cooled to 0° C. and quenched with a mixture of 25 ml ethanol and 20 ml water. The precipitate which had precipitated out was filtered off with suction and washed with ethyl acetate. The organic phase was dried over magnesium sulfate and then freed from the solvent in vacuo. The residue was purified by column chromatography on silica gel with ethyl acetate/methanol=9/1. 580 mg of the title compound as the base were obtained in this way. To liberate the hydrochloride, the base was dissolved in 20 ml acetone, and an equimolar amount of trimethylchlorosilane and water was added. 550 mg (52.9% of theory) Z-(3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-phenyl)-methanol; hydrochloride (25) were obtained in this way in the form of white crystals. Example 16 [0345] E-{3-[4-Dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-phenyl]-methanol hydrochloride (16) [0346] Employing: [0347] E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-2-methyl-cyclohex-2-enylidenemethyl]-benzoic acid methyl ester base, which was prepared according to example 1, [0348] instead of Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-2-methyl-cyclohex -2-enylidenemethyl]-benzoic acid methyl ester base in example 15, the procedure described in example 15 gave E-{3-[4-dimethylaminomethyl -3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-phenyl}-methanol; hydrochloride (16). Example 17 [0349] Z-3-[6-Dimethylaminomethyl-3- (3-hydroxymethyl-benzylidene) -cyclohex-1-enyl]-phenol; hydrochloride (40) and Z-3-[2-dimethylaminomethyl-5-(3-hydroxymethyl-benzylidene)-cyclohex-1-enyl]-phenol; hydrochloride (24) [0350] 100 ml diisobutylaluminium hydride solution (25 wt. % soln. in toluene) were initially introduced into the reaction vessel under a nitrogen atmosphere. 1 g Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-2-methyl-cyclohex-2-enylidenemethyl]-benzoic acid methyl ester base, which was prepared according to example 1, dissolved in 100 ml analytical grade toluene, were then added dropwise at room temperature. The mixture was heated under reflux for six hours. When the reaction had ended the mixture was cooled to 0° C. and quenched with a mixture of 25 ml ethanol and 20 ml water. The precipitate which had precipitated out was filtered off with suction and washed with ethyl acetate. The organic phase was dried over magnesium sulfate and then freed from the solvent in vacuo. The residue was purified by column chromatography on silica gel with ethyl acetate/methanol=9/1. 200 mg Z-3-[2-dimethylaminomethyl-5-(3-hydroxymethyl-benzylidene)-cyclohex-1-enyl]-phenol base were obtained as the first product fraction. To liberate the hydrochloride, the base was dissolved in 20 ml acetone, and an equimolar amount of trimethylchlorosilane and water was added. 180 mg (17.9% of theory) Z-3 [2-dimethylaminomethyl-5-(3-hydroxymethyl-benzylidene)-cyclohex-1-enyl]-phenol; hydrochloride (24) were obtained in this way in the form of white crystals. 440 mg Z-3-[6-dimethylaminomethyl-3-(3-hydroxymethyl-benzylidene)-cyclohex -1-enyl]-phenol base were obtained as the second product fraction. To liberate the hydrochloride, the base was dissolved in 20 ml acetone, an equimolar amount of trimethylchlorosilane and water was added and 410 mg (40.9% of theory) Z-3-[6-Dimethylaminomethyl-3-(3-hydroxymethyl-benzylidene)-cyclohex-1-enyl]-phenol; hydrochloride (40) were obtained in this way in the form of white crystals. Example 18 [0351] E-3-[6-Dimethylaminomethyl-3-(3-hydroxymethyl-benzylidene)-cyclohex-1-enyl]-phenol; hydrochloride (22) [0352] Employing: [0353] E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-2-methyl-cyclohex-2-enylidenemethyl]-benzoic acid methyl ester base, which was prepared according to example 1, [0354] instead of Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-2-methyl-cyclohex -2-enylidenemethyl]-benzoic acid methyl ester base in example 17, the procedure described in example 17 gave exclusively E-3-[6-dimethylaminomethyl-3-(3-hydroxymethyl-benzylidene)-cyclohex-1-enyl]-phenol; hydrochloride (22). Example 19 [0355] rac-trans-E-[3-(2-Dimethylaminomethyl-5-(3-hydroxymethyl-benzylidene)-cyclohexyl)-phenol, hydrochloride (19) [0356] Employing: [0357] rac-trans-E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester base, which was prepared according to example 2, [0358] instead of Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-2-methyl-cyclohex -2-enylidenemethyl]-benzoic acid methyl ester base in example 17, the procedure described in example 17 gave exclusively rac-trans-E-3-[2-dimethylaminomethyl-5-(3-hydroxymethyl-benzylidene) -cyclohexyl]-phenol hydrochloride (19). Example 20 [0359] Z-3-[4-Dimethylaminomethyl-3-(3-methoxy-phenyl)-2-methyl-cyclohex-2-enylidenemethyl]-naphthalene-1-carboxylic acid ethyl ester; hydrochloride (11) and E-3-[4-dimethylaminomethyl-3-(-methoxy-phenyl)-2-methyl-cyclohex -2-enylidenemethyl]-naphthalene-1-carboxylic acid ethyl ester hydrochloride (12) [0360] Employing: [0361] 3-(naphthyl-1-carboxylic acid ethyl ester)-methyl-triphenylphosphonium chloride [0362] instead of 3-(benzoic acid methyl ester)-methyltriphenylphosphonium chloride in example 1, the procedure described in example 1 gave [0363] Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-2-methyl-cyclohex-2-enylidenemethyl]-naphthalene-1-carboxylic acid ethyl ester; hydrochloride (11) and E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-2-methyl-cyclohex -2-enylidenemethyl]-naphthalene-1-carboxylic acid ethyl ester hydrochloride (12). Example 21 [0364] Z-3-[4-Dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-2-fluoro-benzoic acid ethyl ester hydrochloride (13) [0365] Employing: [0366] (2-fluoro-3-benzoic acid ethyl ester)-methyl-triphenylphosphonium chloride instead of 3-(benzoic acid methyl ester)-methyltriphenylphosphonium chloride in example 1, the procedure described in example 1 gave exclusively Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-2-fluoro-benzoic acid ethyl ester hydrochloride (13). Example 22 [0367] E-3-[4-Dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid tert-butyl ester; hydrochloride (21) [0368] Employing: [0369] (3-benzoic acid tert-butyl ester)-methyl-triphenylphosphonium chloride) [0370] instead of 3-(benzoic acid methyl ester)-methyltriphenylphosphonium chloride in example 1, the procedure described in example 1 gave exclusively E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid tert-butyl ester; hydrochloride (21). Example 23 [0371] E-3-[4-Dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid ethyl ester; hydrochloride (33) [0372] Employing: [0373] (3-benzoic acid ethyl ester)-methyltriphenylphosphonium chloride [0374] instead of 3-(benzoic acid methyl ester)-methyltriphenylphosphonium chloride in example 1, the procedure described in example 1 gave exclusively E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid ethyl ester; hydrochloride (33). Example 24 [0375] Z-3-[4-Dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid isobutyl ester; hydrochloride (39) [0376] Employing: [0377] (3-benzoic acid isobutyl ester)-methyl-triphenylphosphonium chloride [0378] instead of 3-(benzoic acid methyl ester)-methyltriphenylphosphonium chloride in example 1, the procedure described in example 1 gave exclusively Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid isobutyl ester; hydrochloride (39). Example 25 [0379] rac-trans-E-3-[4-Dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid tert-butyl ester; hydrochloride (28) [0380] Employing: [0381] (3-benzoic acid tert-butyl ester)-methyl-triphenylphosphonium chloride [0382] instead of 3-(benzoic acid methyl ester)-methyltriphenylphosphonium chloride in example 2, the procedure described in example 2 gave exclusively rac-trans-E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid tert-butyl ester; hydrochloride (28). Example 26 [0383] rac-cis-Z-3-[4-Dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid ethyl ester; hydrochloride (30) [0384] Employing: [0385] (3-benzoic acid ethyl ester)-methyl-triphenylphosphonium chloride [0386] instead of 3-(benzoic acid methyl ester)-methyltriphenylphosphonium chloride in example 3, the procedure described in example 3 gave exclusively rac-cis-Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid ethyl ester; hydrochloride (30). Example 27 [0387] Z-[4-(4-Chloro-benzylidene)-2-(3-methoxy-phenyl)-cyclohex-2-enylmethyl]-dimethyl-amine; hydrochloride (41) and E-[4-(4-chloro-benzylidene)-2-(3-methoxy-phenyl)-cyclohex-2-enylmethyl]-dimethyl-amine; hydrochloride (46) [0388] 21.6 g potassium tert-butylate and 65 g 4-chlorobenzyltriphenylphosphonium chloride were suspended in 800 ml analytical grade toluene under a nitrogen atmosphere at room temperature and the suspension was then stirred at 70° C. for one hour. 11.5 g 4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enone in 100 ml analytical grade toluene were added at this temperature and the mixture was stirred at 70° C. for 3 days. The mixture was quenched with 500 ml water. The phases were separated and the aqueous phase was washed 3 times with 200 ml ethyl acetate each time. The combined organic phases were dried over magnesium sulfate and then freed from the solvent in vacuo. The solid which had precipitated out was filtered off and washed with diiso-ether. The combined organic phases were freed from the solvent in vacuo. The residue was purified by column chromatography on silica gel with ethyl acetate/methanol=9/1. 5.2 g E-[4-(4-chloro-benzylidene)-2-(3-methoxy-phenyl)-cyclohex-2-enylmethyl]-dimethyl-amine base were obtained as the first product fraction. To prepare the hydrochloride, the base was dissolved in 50 ml acetone, and an equimolar amount of trimethylchlorosilane and water was added. 4.7 g (27.6% of theory) of the title compound 46 were obtained in this way in the form of white crystals. 3.5 g Z-[4-(4-chloro-benzylidene)-2-(3-methoxy-phenyl)-cyclohex-2-enylmethyl]-dimethyl-amine base were obtained as the second product fraction. To liberate the hydrochloride, the base was dissolved in 50 ml acetone, and an equimolar amount of trimethylchlorosilane and water was added. 3 g (17.6% of theory) of the title compound 41 were obtained in this way in the form of white crystals. Example 28 [0389] E-3-[3-(4-Chloro-benzylidene)-6-dimethylaminomethyl-cyclohex-1-enyl]-phenol; hydrochloride (47) [0390] 850 mg E-[4-(4-chloro-benzylidene)-2-(3-methoxy-phenyl)-cyclohex-2-enylmethyl]-dimethyl-amine base, which was prepared according to example 27, dissolved in 50 ml analytical grade toluene, were added to 50 ml diisobutylaluminium hydride solution (25 wt. % soln. in toluene). The mixture was heated under reflux for 8 hours. The reaction solution was subsequently quenched with 100 ml ethanol and then with 100 ml water. The precipitate which had precipitated out was filtered off with suction and washed with toluene. The combined organic phases were dried over magnesium sulfate and the solvent was then evaporated in vacuo. The residue was purified on silica gel with ethyl acetate/methanol=9/1. 500 mg of the title compound 47 as the base were obtained in this way. To liberate the hydrochloride, the title compound was dissolved in 50 ml acetone, and an equimolar amount of trimethylchlorosilane and water was added. 430 mg (52.5% of theory) E-3-[3-(4-chloro-benzylidene)-6-dimethylaminomethyl-cyclohex-1-enyl]-phenol; hydrochloride (47) were obtained in this way in the form of white crystals. Example 29 [0391] Z-[4-(4-Fluoro-benzylidene)-2-(3-methoxy-phenyl)-cyclohex-2-enylmethyl]-dimethyl-amine; hydrochloride (43) and E-[4-(4-fluoro-benzylidene)-2-(3-methoxy-phenyl)-cyclohex-2-enylmethyl]-dimethyl-amine; hydrochloride (42) [0392] 21.6 g potassium tert-butylate and 70 g 4-fluorobenzyltriphenylphosphonium chloride were suspended in 800 ml analytical grade toluene under a nitrogen atmosphere at room temperature and the suspension was then stirred at 70° C. for one hour. 11.5 g 4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enone in 100 ml analytical grade toluene were added at this temperature and the mixture was stirred at 70° C. for 3 days. The mixture was quenched with 500 ml water. The phases were separated and the aqueous phase was washed 3 times with 200 ml ethyl acetate each time. The combined organic phases were dried over magnesium sulfate and then freed from the solvent in vacuo. The solid which had precipitated out was filtered off and washed with diiso-ether. The combined organic phases were freed from the solvent in vacuo. The residue was purified by column chromatography on silica gel with ethyl acetate/methanol=9/1. 5.4 g E-[4-(4-fluoro-benzylidene)-2-(3-methoxy-phenyl)-cyclohex-2-enylmethyl]-dimethyl-amide were obtained as the first product fraction. To prepare the hydrochloride, the base was dissolved in 50 ml acetone, and an equimolar amount of trimethylchlorosilane and water was added. 5.1 g (30% of theory) of the title compound 42 were obtained in this way in the form of white crystals. 4.2 g Z-[4-(4-fluoro-benzylidene)-2-(3-methoxy-phenyl) -cyclohex-2-enylmethyl]-dimethyl-amine were obtained as the second product fraction. To liberate the hydrochloride, the base was dissolved in 50 ml acetone, and an equimolar amount of water and trimethylchlorosilane was added. 3.9 g (22.9% of theory) of the title compound 43 were obtained in this way in the form of white crystals. Example 30 [0393] Z-3-[6-Dimethylaminomethyl-3-(4-fluoro-benzylidene)-cyclohex-1-enyl]-phenol; hydrochloride (45) [0394] Employing: [0395] Z-[4-(4-fluoro-benzylidene)-2-(3-methoxy-phenyl)-cyclohex-2-enylmethyl]-dimethyl-amine base [0396] instead of E-[4-(4-chloro-benzylidene)-2-(3-methoxy-phenyl)-cyclohex-2-enylmethyl]-dimethyl-amine base in example 28, the procedure described in example 28 gave Z-3-[6-dimethylaminomethyl-3-(4-fluoro-benzylidene)-cyclohex-1-enyl]-phenol; hydrochloride (45). Example 31 [0397] E-3-[6-Dimethylaminomethyl-3- (4-fluoro-benzylidene) -cyclohex-1-enyl]-phenol; hydrochloride (44) [0398] Employing: [0399] E-[4-(4-fluoro-benzylidene)-2-(3-methoxy-phenyl)-cyclohex-2-enylmethyl]-dimethyl-amine base [0400] instead of E-[4-(4-chloro-benzylidene)-2-(3-methoxy-phenyl)-cyclohex-2-enylmethyl]-dimethyl-amine base in example 28, the procedure described in example 28 gave E-3-[6-dimethylaminomethyl-3-(4-fluoro-benzylidene)-cyclohex-1-enyl]-phenol; hydrochloride (44). Example 32 [0401] Z-3-[4-Dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid methyl ester hydrochloride (38) and E-3-[4-dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid methyl ester hydrochloride (37) [0402] 8.1 g potassium tert-butylate and 35.4 g 3-(benzoic acid methyl ester)-methyltriphenylphosphonium chloride were suspended in 800 ml analytical grade toluene under a nitrogen atmosphere at room temperature and the suspension was then stirred at 70° C. for one hour. 7 g 3-(3-(tert-butyl-diphenyl-silanyloxy)-cyclohex-2-enone in 100 ml analytical grade toluene were added at this temperature and the mixture was stirred at 70° C. for 3 days. The mixture was quenched with 500 ml water. The phases were separated and the aqueous phase was washed 3 times with 200 ml ethyl acetate each time. The combined organic phases were dried over magnesium sulfate and then freed from solvent in vacuo. The residue obtained in this way was taken up in a mixture of 150 ml ethyl acetate and 150 ml diiso-ether. The solid which had precipitated out was filtered off and washed with diiso-ether. The combined organic phases were freed from the solvent in vacuo. The residue (16.7 g) was dissolved in 70 ml tetrahydrofuran, and 16.7 ml tetrabutylammonium fluoride were added. After a reaction time of 10 minutes the reaction solution was quenched with 50 ml water and extracted three times with 50 ml ethyl acetate each time. The combined organic phases were dried over magnesium sulfate and then freed from the solvent in vacuo. The residue was purified by column chromatography on silica gel with ethyl acetate/methanol=9/1. 2.5 g E-3-[4-dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid methyl ester base were obtained as the first product fraction. To liberate the hydrochloride, the base was dissolved in 50 ml acetone, and an equimolar amount of trimethylchlorosilane and water was added. 2 g (36.8% of theory) E-3-[4-dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid methyl ester hydrochloride (37) were obtained in this way. 1.8 g (27.6% of theory) Z-3 [4-Dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid methyl ester were obtained as the second product fraction. To liberate the hydrochloride, the base was dissolved in 50 ml acetone, and an equimolar amount of trimethylchlorosilane and water was added. 1.5 g (27.6% of theory) Z-3-[4-dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid methyl ester hydrochloride (38) were obtained in this way. Example 33 [0403] rac-cis-Z-3-[4-Dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohexylidenmethyl]-benzoic acid methyl ester; hydrochloride (51) and rac-cis-E-3-[4-dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohexylidenmethyl]-benzoic acid methyl ester; hydrochloride (50) [0404] Employing: [0405] rac-cis-3-(3-(tert-butyl-diphenyl-silanyloxy)-phenyl)-cyclohexanone [0406] instead of 3-(3-(tert-butyl-diphenyl-silanyloxy)-cyclohex-2-enone in example 32, the procedure described in example 32 gave rac-cis-Z-3-[4-dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohexylidenmethyl]-benzoic acid methyl ester; hydrochloride (51) and rac-cis-E-3-[4-dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohexylidenmethyl]-benzoic acid methyl ester; hydrochloride (50). Example 34 [0407] Z-3-[4-Dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid hydrochloride (48) [0408] 3 g of the Z-3-[4-Dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohex-2-enylidenmethyl]-benzoic acid methyl ester, as the base, prepared according to example 32 were dissolved in 30 ml methanol, and 30 ml 1 N potassium hydroxide solution were added. The mixture was stirred at 60° C. for 2 hours. After the reaction mixture had cooled to room temperature, 1 N hydrochloric acid was added to the mixture until a pH of 4 was established. The phases were separated and the aqueous phase was washed 3 times with 20 ml ethyl acetate each time. The combined organic phases were dried over magnesium sulfate and freed from the solvent in vacuo. Z-3-[4-Dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohex-2-enylidenmethyl]-benzoic acid, 2.7 g in the form of an orange-yellow oil, was obtained in this way. To prepare the hydrochloride, the base was dissolved in 10 ml acetone, and an equimolar amount of trimethylchlorosilane and water was added. 2.4 g (77.7% of theory) Z-3-[4-dimethylaminomethyl-3-(3-hydroxy-phenyl) -cyclohex-2-enylidenmethyl]-benzoic acid hydrochloride were obtained in this way. Example 35 [0409] E-3-[4-Dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid; hydrochloride (49) [0410] Employing: [0411] E-3-[4-dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid methyl ester as the base, which was prepared according to example 32, [0412] instead of Z-3-[4-dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid methyl ester base in example 34, the procedure described in example 34 gave E-3-[4-dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid; hydrochloride (49). Example 36 [0413] rac-trans-Z-3-[4-Dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohexylidenemethyl]-benzoic acid; hydrochloride (52) [0414] Employing: [0415] rac-trans-Z-3-[4-dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid methyl ester as the base [0416] instead of Z-3-[4-dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid methyl ester base in example 34, the procedure described in example 34 gave rac-trans-Z-3-[4-dimethylaminomethyl-3-(3-hydroxy-phenyl) -cyclohexylidenemethyl]-benzoic acid; hydrochloride (52). Example 37 [0417] rac-trans-E-3-[4-Dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohexylidenemethyl]-benzoic acid hydrochloride (53) [0418] Employing: [0419] rac-trans-E-3-[4-dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid methyl ester as the base [0420] instead of Z-3-[4-dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid methyl ester base in example 34, the procedure described in example 34 gave rac-trans-E-3-[4-dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohexylidenemethyl]-benzoic acid; hydrochloride (53). Example 38 [0421] rac-trans-Z-[4-Benzylidene-2-(3-methoxy-phenyl)-cyclohexylmethyl]-dimethylamine hydrochloride (3) and rac-trans-E-[4-benzylidene-2-(3-methoxy-phenyl)-cyclohexylmethyl]-dimethylamine hydrochloride (2) [0422] Employing: [0423] rac-trans-4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexanone instead of dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enone in example 1 [0424] and benzyltriphenylphosphonium chloride instead of 3-(benzoic acid methyl ester)-methyltriphenylphosphonium chloride in example 1 [0425] the procedure described in example 1 gave: [0426] rac-trans-Z-[4-benzylidene-2-(3-methoxy-phenyl)-cyclohexylmethyl]-dimethylamine hydrochloride (3) and rac-trans-E-[4-benzylidene-2-(3-methoxy-phenyl)-cyclohexylmethyl]-dimethylamine hydrochloride (2). Example 39 [0427] rac-trans-Z-3-(5-Benzylidene-2-dimethylaminomethyl-cyclohexyl)-phenol; hydrochloride (23) [0428] 140 ml diisobutylaluminium hydride solution (25 wt. % soln. in toluene) were initially introduced into the reaction vessel under a nitrogen atmosphere. 2.4 g rac-trans-Z-[4-benzylidene-2-(3-methoxy-phenyl)-cyclohexylmethyl}-dimethylamine base, which was prepared according to example 39, dissolved in 20 ml analytical grade toluene, were then added dropwise at room temperature. The mixture was heated under reflux for two hours, When the reaction had ended the mixture was cooled to 0° C. and quenched with a mixture of 25 ml ethanol and 20 ml water. The precipitate which had precipitated out was filtered off with suction and washed with ethyl acetate. The organic phase was dried over magnesium sulfate and then freed from the solvent in vacuo. The residue was purified by column chromatography on silica gel with ethyl acetate/methanol=9/1. 1 g of the title compound as the base was obtained in this way. To liberate the hydrochloride, the base was dissolved in 20 ml acetone, and an equimolar amount of trimethylchlorosilane and water was added. 300 mg (17.1% of theory) rac-trans-Z-3-(5-benzylidene-2-dimethylaminomethyl-cyclohexyl)-phenol; hydrochloride (23) was obtained in this way in the form of white crystals. Example 40 [0429] rac-trans-E-3-[5-Benzylidene-2-dimethylaminomethyl-cyclohexyl)-phenol; hydrochloride (20) [0430] Employing: [0431] rac-trans-E-[4-benzylidene-2-(3-methoxy-phenyl)-cyclohexylmethyl]-dimethylamine base [0432] instead of rac-trans-Z-[4-benzylidene-2-(3-methoxy-phenyl)-cyclohexylmethyl]-dimethylamine base in example 39, the procedure described in example 39 gave rac-trans-E-3-(5-benzylidene-2-dimethylaminomethyl-cyclohexyl)-phenol; hydrochloride (20). Example 41 [0433] rac-cis-Z-[-4-Benzylidene-2-(3-methoxy-phenyl)-cyclohexylmethyl]-dimethylamine hydrochloride (4) and rac-cis-E-[4-benzylidene-2-(3-methoxy-phenyl)-cyclohexylmethyl]-dimethylamine hydrochloride (1) [0434] Employing: [0435] rac-cis-4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexanone instead of dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enone in example 1 [0436] and benzyltriphenylphosphonium chloride instead of 3-(benzoic acid methyl ester)-methyltriphenylphosphonium chloride in example 1 [0437] the procedure described in example 1 gave [0438] rac-cis-Z-[4-benzylidene-2-(3-methoxy-phenyl)-cyclohexylmethyl]-dimethylamine hydrochloride (4) and rac-cis-E-[-4-Benzylidene-2-(3-methoxy-phenyl)-cyclohexylmethyl]-dimethylamine hydrochloride (1). Example 42 [0439] rac-trans-E-[3-[4-Dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl)-phenyl)-methanol]; hydrochloride (29) [0440] Employing [0441] rac-trans-E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester, which was prepared according to example 2, [0442] instead of Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-2-methyl-cyclohex-2-enylidenemethyl]-benzoic acid methyl ester in example 15, the procedure described in example 15 gave rac-trans-E-[3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl)-phenyl)-methanol]; hydrochloride (29). Example 43 [0443] The following compounds were prepared in accordance with the instructions described above. The particular structure is demonstrated by NMR: [0444] rac-cis-Z-3-[4-dimethylaminomethyl-3-(3-hydroxy-phenyl)-cyclohexylidenemethyl]-benzoic acid, [0445] rac-cis-Z-3-[4-dimethylaminomethyl-3-hydroxy-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester, [0446] rac-cis-E-3-[3-chloro-4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester, [0447] rac-cis-E-3-[4-dimethylaminomethyl-3-hydroxy-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester, [0448] rac-cis-Z-3-[4-dimethylaminomethyl-3-hydroxy-3-(3-methoxy-phenyl)cyclohexylidenemethyl]-benzoic acid methyl ester, [0449] (+)-trans-E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid, [0450] (−)-trans-E-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohexylidenemethyl]-benzoic acid, [0451] rac-trans-E-3-(4-dimethylaminomethyl-3-phenyl-cyclohexylidenemethyl)-benzoic acid methyl ester, [0452] rac-trans-Z-3-(4-dimethylaminomethyl-3-phenyl-cyclohexylidenemethyl)-benzoic acid methyl ester, [0453] rac-cis-E-3-(4-dimethylaminomethyl-3-phenyl-cyclohexylidenemethyl)-benzoic acid, [0454] rac-cis-E-3-(4-dimethylaminomethyl-3-phenyl-cyclohexylidenemethyl)-benzoic acid, [0455] rac-trans-Z-3-(4-dimethylaminomethyl-3-phenyl-cyclohexylidenemethyl)benzoic acid, [0456] rac-trans-E-3-(4-dimethylaminomethyl-3-phenyl-cyclohexylidenemethyl)-benzoic acid, [0457] rac-trans-E-3-[4-dimethylaminomethyl-3-(3-triflluoromethyl-phenyl)-cyclohexylidenemethyl]-benzoic acid, [0458] rac-trans-Z-3-[4-dimethylaminomethyl-3-(3-trifluoromethyl-phenyl)-cyclohexylidenemethyl]-benzoic acid, [0459] rac-trans-E-3-[4-dimethylaminomethyl-3-(3-fluoro-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester, [0460] rac-trans-Z-3-[4-dimethylaminomethyl-3-(3-fluoro-phenyl)-cyclohexylidenemethyl]benzoic acid methyl ester, [0461] rac-cis-E-3-[4-dimethylaminomethyl-3-(3-fluoro-phenyl)-cyclohexylidenemethyl]-benzoic acid methyl ester, [0462] rac-trans-E-3-[4-dimethylaminomethyl-3-(3-fluoro-phenyl)-cyclohexylidenemethyl]-benzoic acid, [0463] rac-trans-Z-3-[4-dimethylaminomethyl-3-(3-fluoro-phenyl)-cyclohexylidenemethyl]-benzoic acid, [0464] rac-cis-E-3-[4-dimethylaminomethyl-3-(3-fluoro-phenyl)-cyclohexylidenemethyl]-benzoic acid, [0465] E-[4-ethylidene-2-(3-methoxy-phenyl)-cyclohex-2-enylmethyl]-dimethylamine [0466] [4-isopropylidene-2-(3-methoxy-phenyl)-cyclohex-2-enylmethyl]-dimethylamine, [0467] E-[2-(3-methoxy-phenyl)-4-propylidene-cyclohex-2-enylmethyl]-dimethylamine, and [0468] E-[4-butylidene-2-(3-methoxy-phenyl)-cyclohex-2-enylmethyl]-dimethylamine. Example 44 [0469] Pharmacological Studies: [0470] Writhing Test [0471] The antinociceptive activity of the compounds according to the invention was investigated in mice in the phenylquinone-induced writhing test, modified by I.C. Hendershot, J. Forsaith, J. Pharmacol. Exp. Ther. 125, 237-240 (1959). Male NMRI mice weighing 25-30 g were used. Groups of 10 animals per substance dose received 0.3 ml/mouse of a 0.02% aqueous solution of phenylquinone (phenylbenzoquinone, Sigma, Deisenhofen; preparation of the solution with the addition of 5% ethanol and storage in a water bath at 45° C.) administered intraperitoneally 10 minutes after intravenous administration of a compound according to the invention. The animals were placed individually in observation cages. The number of pain-induced stretching movements (so-called writhing reactions, that is straightening of the body with stretching of the hind extremities) was counted by means of a push-button counter for 5-20 minutes after the administration of phenylquinone. Animals which received physiological saline solution i.v. and phenylquinone i.v. were also run as a control. [0472] All substances were tested in the standard dose of 10 mg/kg. The percentage inhibition (% inhibition) of the writhing reactions by a substance was calculated according to the following equation: % inhibition=100−(WR treated animals /WR control ×100) [0473] All compounds according to the invention investigated showed a moderate to potent analgesic action. [0474] The results of selected writhing investigations are summarized in Table 1. TABLE 1 Analgesia Effect in Mouse Writhing Test % inhibition of the writhing reactions Compound (10 mg/kg i.v.) 8 98 10 84 13 85 14 94 15 100 16 98 17 85 18 100 19 82 20 84 21 79 22 93 23 88 24 100 25 100 26 87 28 100 29 94 30 84 32 100 33 90 34 78 35 100 36 100 37 91 39 78 48 98

A substituted aminomethyl-phenyl-cyclohexane derivative of formula I or Ia, and their a diastereomer, enantiomer, or of a salt formed with a physiologically tolerated acid. Also disclosed are method for preparing the substituted aminomethyl-phenyl-cyclohexane derivative, pharmaceutical compositions comprising the same and method of using the same for treating pain, urinary incontinence, itching, diarrhea, inflammatory and allergic reactions, depression, drug or alcohol abuse, gastritis, cardiovascular diseases, respiratory tract diseases, coughing, mental illnesses and epilepsy.

BACKGROUND OF THE INVENTION [0001] This invention relates to a connector, such as a waterproof connector, in which a wire, connected to a terminal received in a chamber in a connector housing, is sealed by a rubber plug. [0002] [0002]FIG. 10 shows a related connector of the type described. This connector 1 comprises a housing 2 having chambers 3 for respectively receiving terminals 7 each press-clamping a wire 5 and a rubber plug 6 . A cantilever-type elastic arm (so-called lance) 4 for retaining the terminal 7 is integrally formed on and projects upwardly from a bottom wall of the chamber 3 . [0003] When the terminal 7 is inserted into the chamber 3 in the housing 2 from the rear side thereof, the elastic arm 4 is elastically deformed, and retains the terminal 3 in the chamber 3 . A lower portion of the terminal 7 , retained in the chamber 3 by the elastic arm 4 , is supported by a spacer 8 , inserted into the chamber 3 from the front side thereof. [0004] In the related connector 1 , the terminal 7 is received in the chamber 3 , and is retained therein by the elastic arm 4 , and besides the terminal 7 is supported by the rattle-preventing spacer 8 . However, since the clearance (Δd) of the terminal 7 is formed as a result of accumulation of dimensional irregularities (tolerances) of three dimensions, that is, a height A of the chamber 3 in the housing 2 , a thickness C of the spacer 8 and a height B of the terminal 7 (Δd=A−C−B), it tends to be enlarged. As a result, there is probability that the durability of the terminal was adversely affected by vibrations and others. SUMMARY OF THE INVENTION [0005] Therefore, this invention has been made in order to solve the above problem, and an object of the invention is to provide a connector in which the clearance of a terminal is suppressed so as to enhance the durability against vibrations and others. [0006] In order to achieve the above object, according to the present invention, there is provided a connector comprising: [0007] a terminal fitting, connected to an electric wire; [0008] at least one pair of positioning members, provided on both side faces of the terminal fitting; and [0009] a housing, including a chamber for accommodating the terminal fitting therein, and a pair of guide members engaged with the associated positioning members to guide the terminal fitting inserted into the chamber to a predetermined position. [0010] In this configuration, the clearance of the terminal fitting within the chamber is suppressed, and the durability against vibrations and others is enhanced. Therefore, wear of that portion of the terminal, disposed in contact with a mating terminal, which would be caused by the clearance, is positively prevented, so that the contact reliability of the terminal is further enhanced. [0011] Preferably, the positioning members are protrusions integrally formed with the both side walls of the terminal fitting, and the guide members are a pair of grooves each formed on both side walls of the chamber for receiving the associated protrusions therein. [0012] In this configuration, the clearance of the terminal in the chamber is suppressed easily and positively with this simple construction, and the connector of a high reliability can be produced at low costs. BRIEF DESCRIPTION OF THE DRAWINGS [0013] The above objects and advantages of the present invention will become more apparent by describing in detail preferred exemplary embodiments thereof with reference to the accompanying drawings, wherein like reference numerals designate like or corresponding parts throughout the several views, and wherein: [0014] [0014]FIG. 1 is a vertical cross-sectional view of one preferred embodiment of a connector of the invention, showing a condition before this connector is assembled; [0015] [0015]FIG. 2 is a vertical cross-sectional view of the connector, showing a condition in which an inner housing is provisionally fitted in an outer housing, with terminals not yet inserted; [0016] [0016]FIG. 3 is a vertical cross-sectional view of the connector in the above provisionally-fitted condition, showing a condition during the insertion of the terminals; [0017] [0017]FIG. 4 is a vertical cross-sectional view of the connector in the provisionally-fitted condition, showing a condition in which the terminals are primarily retained; [0018] [0018]FIG. 5 is a vertical cross-sectional view of the connector in a completely-assembled condition in which the inner housing is completely fitted in the outer housing; [0019] [0019]FIG. 6 is a front-elevational view of the connector in its completely-assembled condition; [0020] [0020]FIG. 7 is a perspective view of the terminal to be received in a chamber in the inner housing, according to a first embodiment of the invention; [0021] [0021]FIG. 8 is a cross-sectional view of the terminal of FIG. 7 in its received condition; [0022] [0022]FIG. 9 is a perspective view of a terminal to be received in the chamber, according to a second embodiment of the invention; [0023] [0023]FIG. 10 is a cross-sectional view of a related connector; and [0024] [0024]FIG. 11 is a cross-sectional view showing a terminal in its received condition, which is used in the related connector. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0025] One preferred embodiment of the present invention will now be described with reference to the drawings. [0026] As shown in FIGS. 1 to 6 , a connector housing 11 of the connector 10 comprises the inner housing 12 , made of a synthetic resin, and the outer housing 21 of a synthetic resin to be fitted with the inner housing 12 . The inner housing 12 has a pair of right and left chambers 13 formed integrally therewith for respectively receiving terminals 32 each press-clamping a wire 30 and a rubber plug 31 . The outer housing 21 has a pair of right and left insertion paths 23 of a substantially cylindrical shape each formed integrally therewith for receiving the wire 30 , the rubber plug 21 and the terminal 32 . A waterproof packing 20 is provided between the inner housing 12 and the outer housing 21 . [0027] The inner housing 12 includes an inner peripheral wall portion 14 of a substantially square shape (having an open rear end) for fitting in an inner peripheral wall portion 24 of the outer housing 21 , an outer peripheral wall portion 15 of a substantially square shape, which extends rearwardly in surrounding relation to the inner peripheral wall portion 14 , and can be fitted on the inner peripheral wall portion 24 of the outer housing 21 , and a front wall portion 16 from which the inner and outer peripheral wall portions 14 and 15 extend rearwardly. Within the inner peripheral wall portion 14 , the pair of right and left chambers 13 are formed respectively on opposite sides of a partition wall 14 a serving also as a central side wall of the inner peripheral wall portion 14 . [0028] Cantilevered flexible retainers 17 each for retaining the terminal 32 received in the chamber 13 are formed integrally on an inner face of an upper portion of the inner peripheral wall portion 14 of the inner housing 12 , and are opposed to the chambers 13 , respectively, the flexible retainers 17 extending from the front portion to the rear end. A retaining projection 17 a for retaining engagement with a retained portion 33 a of the terminal 32 is formed integrally on a lower face of a free end of each flexible retainer 17 , and a cancellation projection 17 b is formed integrally on a rear portion of the flexible retainer 17 near to the free end thereof. A flexure-allowing space 18 is formed between each flexible retainer 17 and an upper wall of the inner peripheral wall portion 14 . A recessed groove 14 c serving as a positioning guide portion, is formed in each of opposed side walls 14 a and 14 b of each chamber 13 in the inner peripheral wall portion 14 , and extends horizontally, the groove 14 c being disposed substantially centrally of the height of the wall 14 a, 14 b. [0029] A provisional fitting claw (provisional fitting member) 19 a is formed integrally on a lower outer face of the inner peripheral wall portion 14 of the inner housing 12 at a rear portion thereof, and this claw 19 a can be engaged in an engagement hole 27 , formed in the inner peripheral wall portion 24 of the outer housing 21 , to hold the two housings 12 and 21 in a provisionally-fitted condition. A complete fitting claw (complete fitting member) 19 b is formed integrally on the lower outer face of the inner peripheral wall portion 14 at a front portion thereof, and this claw 19 b can be engaged in the engagement hole 27 in the outer housing 21 to hold the two housings 12 and 21 in a completely-fitted condition. [0030] In the above provisionally-fitted condition, when each terminal 32 is inserted into the corresponding insertion path 23 of a substantially cylindrical shape from the rear side thereof, and is received in the corresponding chamber 13 , the terminal 32 is retained by the flexible retainer 17 . In the provisionally-fitted condition, the front wall portion 16 of the inner housing 12 forwardly projects a predetermined distance from the front side of the outer housing 21 (This projection distance is indicated by reference character Y in FIG. 2). The rubber plug 31 , press-clamped by a plug damper 35 formed at a rear end portion of the terminal 32 , serves also as a visual confirmation member. When the connector is shifted from the provisionally-fitted condition to the completely-fitted condition, each rubber plug (visual confirmation member) 31 moves into the corresponding insertion path 23 , and this movement of the rubber plug 31 can be visually confirmed from the rear side of the outer housing 21 (The amount of movement of each rubber plug 31 is indicated by reference character Z in FIG. 4). [0031] A distal end 15 a of the outer peripheral wall portion 15 of the inner housing 12 is formed into a tapering shape, so that when the inner housing 12 and the outer housing 21 are completely fitted together, the distal end 15 a of the outer peripheral wall portion 15 of the inner housing 12 and a packing support portion 28 , formed on the inner peripheral wall portion 24 of the outer housing 21 , hold the waterproof packing 20 therebetween in closely-contacted relation thereto. [0032] Through holes 16 a each for passing a mating terminal of a mating connector (not shown) therethrough are formed respectively through those portions of the front wall portion 16 of the inner housing 12 substantially aligned respectively with the chambers 13 . A tapering guide face 16 b is formed at a front peripheral edge portion of each through hole 16 a. Jig insertion holes 16 c each for inserting a bar-like terminal-withdrawing jig (not shown) therethrough are formed through the front wall portion 16 of the inner housing 12 , and are disposed above the through holes 16 a, respectively. [0033] When a distal end portion of the terminal-withdrawing jig is inserted into the jig insertion hole 16 c in the same direction as a mating connector-inserting direction, the distal end portion of this terminal-withdrawing jig is brought into abutting engagement with a slanting face of the cancellation projection 17 b of the flexible retainer 17 to move the retaining projection 17 a upward. More specifically, in the provisionally-fitted condition of the inner and outer housings 12 and 21 , the cancellation projection 17 b of the flexible retainer 17 is pressed by the distal end portion of the terminal-withdrawing jig, inserted through the jig insertion hole 16 c, so that the retaining projection 17 a of the flexible retainer 17 is displaced out of engagement with the retained portion 33 a of the terminal 32 in the flexure-allowing space 18 . [0034] The waterproof packing 20 is made of rubber, and has an annular shape. Front and rear convex portions 20 a of a substantially triangular cross-section are formed integrally on the outer peripheral face of the waterproof packing 20 . The front and rear convex portions 20 a are held between the distal end 15 a of the outer peripheral wall portion 15 of the inner housing 12 and the packing support portion 28 , formed on the inner peripheral wall portion 24 of the outer housing 21 , in closely-contacted relation thereto. [0035] The outer housing 21 includes the pair of insertion paths 23 of a substantially cylindrical shape, integrally formed on and extending rearwardly from a central partition wall 22 , the inner peripheral wall portion 24 of a substantially square shape, which is integrally formed on and extends forwardly from the partition wall 22 , and serves as a insertion path communicating with the insertion paths 23 , and the outer peripheral wall portion 25 of a substantially square shape surrounding the inner peripheral wall portion 24 . Thus, the outer housing 21 has a double-wall construction having open front and rear ends. The rubber plug (waterproof plug) 31 , which is press-clamped to the terminal 32 , and is closely fitted on the wire 30 , is inserted into the insertion path 23 by press-fitting or other means. Namely, in the completely-fitted condition of the connector, the rubber plug 31 , which is fitted on the wire 30 , and is secured to the terminal 32 , is held between the wire 30 and the insertion path 23 of a substantially cylindrical shape in closely-contacted relation thereto. [0036] Plate-shaped flexure-preventing members 26 are formed integrally on the partition wall 22 of the outer housing 21 , and extend therefrom into the interior of the inner peripheral wall portion 24 , and these flexure-preventing members 26 are opposed respectively to the flexure-allowing spaces 18 for the flexible retainers 17 of the inner housing 12 . In the completely-fitted condition of the inner and outer housings 12 and 21 , each of the flexure-preventing members 26 is inserted in the flexure-allowing space 18 to prevent the flexing (or elastic deformation) of the flexible retainer 17 . [0037] The engagement hole 27 is formed through the lower wall of the inner peripheral wall portion 24 of the outer housing 21 , and the provisional fitting claw 19 a and the complete fitting claw 19 b, formed on the inner peripheral wall portion 14 of the inner housing 12 , can be releasably engaged with this engagement hole 27 . A tapered packing support portion 28 is formed integrally at the proximal end of the inner peripheral wall portion 24 of the outer housing 21 at which the partition wall 22 is provided. The tapered face is so formed as to be along with a surface of the convex portion 20 a of the annular waterproof packing 20 of rubber. [0038] Recesses 25 d for respectively guiding convex portions, formed respectively on opposite sides of the mating connector (not shown), are formed respectively in inner faces of the opposite side walls of the outer peripheral wall portion 25 of the outer housing 21 , each of the recesses 25 d being disposed substantially centrally of the height of the side wall. A retaining hole 29 is formed through a front portion of the upper wall of the outer peripheral wall portion 25 of the outer housing 21 , and an elastic retaining arm on the mating connector (not shown) is releasably engageable in this retaining hole 29 . In an assembled condition of the inner and outer housings 12 and 21 , a clearance t is formed between the inner peripheral wall portion 14 of the inner housing 12 and the inner peripheral wall portion 24 of the outer housing 21 , as shown in FIG. 5. [0039] As shown in FIGS. 1, 2, 7 and 8 , the terminal 32 has a female terminal body 33 of a square tubular shape, and convex portions 33 c, each serving as a positioning member, are integrally formed respectively on opposite side faces of the terminal body 33 , and extend horizontally, each of the convex portions 33 c being disposed substantially centrally of the height of the side face. The convex portions 33 c are engaged respectively in the grooves 14 c, formed respectively in the opposed side walls of the chamber 13 , thereby properly positioning the terminal 32 received in the chamber 13 . When the terminal is thus received in the chamber, the upper edge (retained portion) 33 a of the rear end of the terminal body 33 , which serves as the retaining portion, is retained by the retaining projection 17 a of the flexible retainer 17 . A conductor 30 a of the wire 30 is press-clamped by a conductor damper 34 of the terminal 32 , and the front end portion of the rubber plug 31 is press-clamped by the plug clamper 35 of the terminal 32 . [0040] For assembling the connector 10 of this embodiment, the waterproof packing 20 is fitted in the packing support portion 28 of the inner peripheral wall portion 24 of the outer housing 21 forming the outer portion of the connector housing 11 , as shown in FIG. 2. Then, the inner peripheral wall portion 14 of the inner housing 12 , forming the inner portion of the connector housing 11 , is fitted into the inner peripheral wall portion 24 of the outer housing 21 , and the provisional fitting claw 19 a, formed on the inner peripheral wall portion 14 of the inner housing 12 , is engaged with the engagement hole 27 in the inner peripheral wall portion 24 of the outer housing 21 , thereby provisionally fitting the inner housing 12 in the outer housing 21 . In this provisionally-fitted condition, the front wall portion 16 of the inner housing 12 forwardly projects a distance Y from the outer housing 21 . [0041] Then, in the provisionally-fitted condition, when each terminal 32 , press-clamping the wire 30 and the rubber plug 31 , is inserted into the insertion path 23 in the outer housing 21 , and is received in the chamber 13 in the inner housing 12 as shown in FIG. 3, the rear upper edge 33 a of the terminal body 33 of the terminal 32 is retained by the retaining projection 17 a of the flexible retainer 17 as shown in FIG. 4, so that the terminal 32 is primarily retained by the flexible retainer 17 . [0042] Here, the rear end portion of the rubber plug 31 is pulled into the insertion path 23 by a distance Z from the rear end face of the outer housing 21 . The distance Z is so selected as to become smaller than the distance Y. [0043] Then, when the inner peripheral wall portion 14 of the inner housing 12 is further fitted into the inner peripheral wall portion 24 of the outer housing 21 as shown in FIG. 5, the complete fitting claw 19 b, formed on the inner peripheral wall portion 14 of the inner housing 12 , is retainingly engaged in the engagement hole 27 in the inner peripheral wall portion 24 of the outer housing 21 , and the inner housing 12 is completely fitted in the outer housing 21 , thus completing the assembling of the connector 10 . [0044] In accordance with the fitting operation of the inner housing 12 , the terminal 32 and the rubber plug 31 are moved backwards within the insertion path 23 . Since the distance Z is so selected as to become the distance Y, the rear end portion of the rubber plug 31 is projected outside from the rear end face of the outer housing 21 , when the inner housing 12 is in the completely-fitted condition. [0045] When the inner housing 12 is completely fitted into the outer housing 21 , each flexure-preventing member 26 of the outer housing 21 is inserted into the flexure-allowing space 18 for the flexible retainer 17 of the inner housing 12 . As a result, the flexure-preventing member 26 positively prevents the flexible retainer 17 , primarily retaining the terminal 32 , from being elastically deformed away from the terminal 32 . Therefore, the terminal 32 is retained by the retaining projection 17 a of the flexible retainer 17 , and also is indirectly retained by the flexure-preventing member 26 which prevents the elastic deformation of the flexible retainer 17 . Thus, each terminal is easily and positively retained in a double manner. [0046] The completion of the double-retaining of each terminal 32 by the flexible retainer 17 of the inner housing 12 and the flexure-preventing member 26 of the outer housing 21 can be easily confirmed from the rearward movement (i.e., the movement over the distance Y in FIG. 2) of the inner housing 12 at the front side of the outer housing 21 at the time of shifting of the inner housing 12 from the provisionally-fitted condition to the completely-fitted condition, and also from the rearward movement (i.e., the movement over a distance Z in FIG. 4) of the rubber plug 31 in the substantially-cylindrical insertion path 23 at the rear portion of the outer housing 21 [0047] Namely, the rearward movement of the inner housing 12 at the front side of the outer housing 21 at the time of shifting of the inner housing 12 from the provisionally-fitted condition to the completely-fitted condition and the rearward movement of the rubber plug 31 (occurring simultaneously with the above rearward movement of the inner housing 12 ) in the substantially-cylindrical insertion path 23 at the rear portion of the outer housing 21 can be confirmed at the front and rear sides of the connector housing 11 , respectively. Therefore, in a wire harness-producing process, the movement of the operator for inspection and confirmation purposes is much less as compared with the related construction, and the efficiency of the operation is much enhanced. [0048] When the inner housing 12 and the outer housing 21 are completely fitted together, the slanting face of the distal end 15 a of the outer peripheral wall portion 15 of the inner housing 12 and the packing support portion 28 hold the waterproof packing 20 therebetween in closely-contacted relation thereto. In this completely-fitted condition, the rubber plug 31 , which is fitted on the wire 30 , and is secured to the terminal 32 , is received in the insertion path 23 in the outer housing 21 in closely-contacted relation thereto. With these effects, the waterproof performance of the assembled connector 10 is much enhanced. [0049] Thus, in the completely-fitted condition of the inner housing 12 and the outer housing 21 , the convex portions 20 a and 20 b of the waterproof packing 20 , made of rubber, are disposed between and held in intimate contact respectively with the slanting surface of the distal end 15 a of the outer peripheral wall portion 15 of the inner housing 12 and the packing support portion 28 of a V-shaped cross-section formed at the proximal end of the inner peripheral wall portion 24 of the outer housing 21 . Therefore, vibrations, applied to the outer housing 21 , can be absorbed by the waterproof rubber packing 20 . [0050] As shown in FIG. 8, the convex portions 33 c are integrally formed respectively on the opposite side surfaces 33 b of the terminal body 33 of the terminal 32 , and the grooves 14 c of a channel-shaped cross-section, in which the convex portions 33 c can be engaged, respectively, are formed respectively in the opposed side walls 14 a and 14 b of each chamber 13 (which are to be opposed respectively to the convex portions 33 c ) in the inner housing 12 , and thanks to the provision of the convex portions 33 c and the grooves 14 c, the clearance of the terminal 32 in the chamber 13 is reduced. Namely, as shown in FIG. 8, the clearance (Δd′) of the terminal 32 is formed as a result of accumulation of dimensional irregularities (tolerances) of two dimensions, that is, a height A′ from the bottom surface of the chamber 13 to the upper surface of each groove 14 c and a height B′ from the bottom surface of the terminal body 33 of the terminal 32 to the upper surface of each convex portion 33 c (Δd′=A′−B′), and therefore the durability against vibrations and others is enhanced. Therefore, wear of that portion of the terminal 32 , disposed in contact with the mating terminal, which would be caused by the clearance, is positively prevented, so that the contact reliability of the terminal 32 is further enhanced. [0051] The convex portions 33 c are integrally formed respectively on the opposite side surfaces 33 b of the terminal body 33 , and the grooves 14 c of a channel-shaped cross-section are formed respectively in the opposed side walls 14 a and 14 b of each chamber 13 , and with these simple configurations, the clearance of the terminal 32 in the chamber 13 is suppressed easily and positively, and the connector 10 of a high reliability can be produced at low costs. [0052] In the above embodiment, as shown in FIG. 7, the convex portions 33 c are integrally formed respectively on the opposite side surfaces 33 b of the terminal body 33 of the terminal 32 by pressing or the like, and extend horizontally over a predetermined span L entirely. However, as shown in FIG. 9, a pair of discrete convex portions 33 c′ may be integrally formed respectively on front and rear portions of each side surface 33 b of a terminal body 33 of a terminal 32 in such a manner that the span of the two discrete convex portions 33 c′ constitutes both ends of the span L. Although the terminals, each press-clamping the rubber plug at its rear end portion, are used, there may be used the type of terminals to which a rubber plug is not press-clamped, in which case the rubber plug is mounted on the wire. [0053] Although the present invention has been shown and described with reference to specific preferred embodiments, various changes and modifications will be apparent to those skilled in the art from the teachings herein. Such changes and modifications as are obvious are deemed to come within the spirit, scope and contemplation of the invention as defined in the appended claims.

At least one pair of positioning members are provided on both side faces of a terminal fitting connected to an electric wire. A housing includes a chamber for accommodating the terminal fitting therein, and a pair of guide members engaged with the associated positioning members to guide the terminal fitting inserted into the chamber to a predetermined position. The positioning members are protrusions integrally formed with the both side walls of the terminal fitting. The guide members are a pair of grooves each formed on both side walls of the chamber for receiving the associated protrusions therein.

CROSS-REFERENCE TO RELATED APPLICATIONS This is a continuation-in-part of application Ser. No. 08/591,081, filed Jan. 25, 1996, now abandoned, which is a continuation-in-part of application Ser. No. 08/422,605 filed Apr. 12, 1995, now U.S. Pat. No. 5,598,732, which is a continuation of Ser. No. 08/215,969 filed Mar. 17, 1994, now abandoned, which is a continuation of Ser. No. 07/914,237 filed Jul. 17, 1992, now abandoned, which is a continuation-in-part of Ser. No. 07/679,943 filed Apr. 3, 1991, now U.S. Pat. No. 5,148,698. BACKGROUND OF THE INVENTION The invention concerns a compression tool, in particular for joining tubular workpieces, with more than two arcuate compression jaws so movable relative to each other that they can open in order to be placed on the workpiece and that they complement one another into a closed compression space toward the end of compression, and also comprising at least one drive system to move the compression jaws towards the workpiece for compression therebetween. Metal coupling sleeves, preferably steel, and plastically deforming, are employed to join pipe ends. The sleeve inside diameter exceeds the outside diameter of the pipe ends to be joined by an amount such that when being radially compressed, they remain deformed until coming to rest against the outside of the pipe ends. As disclosed by the German Patent No. 1,187,870, such coupling sleeves additionally may comprise an annular groove near each end which receives an elastic sealing ring. Radial compression may be implemented by compression tools, such as illustratively known from the German Patent No. 21 36 782. This compression tool comprises two clamping jaws, each with two arms and at least one clamping jaw being pivotally supported on the compression tool. The compression jaws comprise compression surfaces forming arcs of circle of equal radii, enclosing a compression space. Instead of being arcs of circle, the compression surfaces also may be contoured, for instance to form a polygonal or oval compression space. The arms of the compression jaws away from the compression space can be spread apart against the force of a spring, whereby the compression jaws move relative to each other in the region of the compression space. The spreading apart takes place by means of adjacent and abutting pressure rollers which are jointly moved by a drive system comprising an operational cylinder between the arms for thereby causing pivoting of the compression jaws. The German Offenlegungsschrift 34 23 283 describes a compression tool of this type. In that compression tool, there are two compression jaws each pivotally supported on a drive lever which is in turn pivotally guided on the compression tool. The drive levers comprise opposite arms which can be spread apart by pressure rollers moved by an operational cylinder into the gap between the arms. Moreover, the compression jaws are guided in slide means so that, upon the drive levers being pivoted into the open position, they will be pivoted up about their linkages at the drive whereby a wide, tong-like aperture is created between the compression jaws, facilitating the seating of the pipe ends to be joined, or of a coupling sleeve. When pivoting the drive levers in the reverse direction, the clamping jaws again are so pivoted so that the mid-perpendiculars to their arcs of circle approximately coincide, and upon further pivoting motion of the drive levers the clamping jaws are displaced relative to one another in parallel manner. The clamping jaws are further displaced during compression until at the end of this compression they enclose a circular surface, whereby they have deformed the pipe ends or the coupling sleeve by a corresponding reduction in diameter. This compression tool has been found practically useful, provided that a comparatively modest reduction in diameter or squeeze depth is required. Where the squeeze depths are more substantial--which shall be the case when the pipe connection must withstand higher internal pressures, more than two compression jaws must be provided to prevent beads from being formed between the end faces of the compression jaws, or else complete closure will not take place. Such compression tools are known for instance from the German Offenlegungsschriften 21 28 782; 35 13 129; and the German Auslegeschriften 25 11 942 and 19 07 956. All the compression tools described therein share in common the feature that all the clamping jaws are displaceable and are guided in the radial direction. This entails complex guide means and drive systems, with the result that the compression tools become heavy and hard to handle, and also expensive. SUMMARY OF THE INVENTION The object of the invention is to design a compression tool of the initially cited kind that, in spite of the presence of more than two compression jaws, can be as simple as possible and therefore easily handled and economical to manufacture. The problem is solved by the invention in that one of the compression jaws is a rest which can be placed on the workpiece, and the other compression jaws are displaceable by means of the drive system(s) and are guided so that during compression they always move toward the center of the compression space achieved by the compression tool when in the closed state. Appropriately, the compression jaws are displaced relative to each other so that their adjacent and opposite end faces are equal distances apart at the beginning of compression. The compression tool of the invention is achieved by its simple design having one of the compression jaws being a rest and therefore not requiring a guide or drive. The remaining compression jaws are guided and driven so that during compression they move in very specific directions, namely toward the center of the compression chamber achieved by the compression tool when in the closed state. This is an important condition so that equal forces act from all sides on the workpiece. In one embodiment of the invention, the compression jaws evince equal arcs of circle at their periphery, so that any gaps between the opposite end faces of the compression jaws are evenly distributed over the periphery. Where three compression jaws are present, the directions of motion of the two displaceable compression jaws should subtend between them an angle of 60° which is symmetrical to the mid-perpendicular of the rest and which angle opens away from this rest. Where four compression jaws are involved, the directions of motion of the two compression jaws adjacent to the rest subtend an angle of 90° during compression, this 90° angle being symmetrical to the mid-perpendicular of the rest and opening away from it. In a further feature of the invention, the rest is designed as a rest-yoke at the free end of the compression tool, and pivotally supported on one side while being detachable or lockable at the opposite side. This rest-yoke can be pivoted open when the compression tool is to be placed on the pipe ends to be joined, i.e. on the coupling sleeve. After being pivoted back and locked, the displaceable compression jaws can then be moved by the drive system toward the rest. In a further embodiment of the invention, the displaceable compression jaws on one hand rest against the guide means which determines the displacement directions, and on the other hand rest against a compression force which is displaceable toward the rest and connected to the drive system(s) and which supports in displaceable manner the compression jaws adjacent to the rest. It is possible in this respect to install a further compression jaw at, or connect it with the compression force between, the compression jaws so that the jaws are displaceable relative to this force, where this further jaw is opposite the rest. The compression force is part of the drive system and illustratively may be a hydraulic actuator or be connected to such. Instead of such a compression force, each displaceable compression jaw may be fitted with its own drive system, for instance with a hydraulic actuator. Such an actuator may be a pressure or a traction force. In a modification or deviation from the above, however, at least part of the displaceable compression jaws may be seated on pivot levers pivoted by the drive system(s). Such assemblies of pivot levers already are known from the German Offenlegungsschrift 34 23 283. They may be stationary on the compression tool, at least as regards the actuation of the compression jaws near the rest. There is the possibility, similarly to the compression tool of the German Offenlegungsschrift 34 23 283, of mounting the compression jaws in compression-jaw supports pivotally resting on the pivot levers. To control the displacement of the compression-jaw holders, a slide means may be used, again as already disclosed in the German Auslegeschriften 34 23 283. The invention furthermore provides that the rest may be part of a compression-ring having hinged compression jaws, which is open between two compression jaws, the compression ring being closed when called for by the drive system(s). For that purpose, the drive system(s) may act on the free ends of the compression ring. This embodiment mode makes it possible to design the compression-ring drive system(s) separately, and for the drive system(s) and the compression ring to include coupling components so that they may be operationally coupled. In that case, the compression tool is in two parts, with the compression ring first being laid around the workpiece while the compression jaw acting as a rest against which the workpiece was abut, and then secondly the compression tool being placed against the compression ring. This embodiment permits very easy handling because the individual components are substantially more lightweight, and can be handled independently from each other. The compression ring may comprise at least one traction belt resting externally against at least the displaceable compression jaws in order to make the compression jaws move relative to each other, and two traction belts also may be provided for that purpose too. This design is especially lightweight and economical. To assure that the end-face gaps between the compression jaws are precisely identical at the beginning of compression, a further feature of the invention provides that at least part of the compression jaws in the compression-jaws supports are displaceable relative to these, with corresponding guide systems being present to ensure such equal gaps between the compression jaws at the beginning of compression. Essentially, the compression jaws can be guided displaceably along the periphery. Slide guides are applicable as guide systems, however spring-loading toward stops also may be used. In yet another feature of the invention, the pressing jaws mounted to the compression ring are fixed thereto so that they essentially move only radially. This feature is particularly useful for workpieces of relatively small diameter. In addition, the press jaws, which can assume essentially any configuration in the compressed position, may be integral with and form a portion of the components of the hingedly interconnected compression ring. DESCRIPTION OF THE DRAWINGS The drawings more closely illustrate embodiments of the invention. FIG. 1 is a compression tool in the open position; FIG. 2 is the compression tool of FIG. 1 in the closed position; FIG. 3 is another compression tool in the open position; FIG. 4 the compression tool of FIG. 3 in the closed position; FIG. 5 further compression tool in the open position; FIG. 6 is the compression tool of FIG. 5 in the closed position; FIG. 7 is a half-representation of two further compression tools in the open position; FIG. 8 shows the compression tools of FIG. 7 in the closed position; FIG. 9 discloses a further embodiment based upon the tool of FIG. 1, with the tool in the open position; FIG. 10 dicloses the embodiment of FIG. 9 in the closed position; FIG. 11 discloses a further embodiment of the tool of FIGS. 7 and 8, with the tool in the open position; FIG. 12 discloses the tool of FIG. 11 in the closed position; FIG. 13 shows a side view of a pressing device with a compression molding die and a separate closing device in an initial position prior to compression; FIG. 14 shows a side view of the pressing device according to FIG. 13 in the final pressing position;, FIG. 15 shows a cross section through the pressing device according to FIG. 14 in the plane A--A; FIG. 16 shows a cross section through the pressing device according to FIG. 14 in the plane B--B; FIG. 17 shows a side view of another pressing device with a compression molding die and a closing device linked on one side in the starting position; FIG. 18 shows a side view of another pressing device with a compression molding die and a closing device linked on both sides in the starting position; and FIG. 19 is an elevational view, with portions shown in phantom, of another embodiment of the invention. DESCRIPTION OF THE INVENTION FIGS. 1 and 2 show only the upper head part of a compression tool 1. It comprises a tool housing 2 hollow on the inside and which first flares upward and then tapers conically. A U-shaped clearance 3 is present at the middle. The free ends of the clearance 3 are connected by a rest-yoke 4. The rest-yoke 4 is pivotally supported by a support bolt 5 shown on the right in this view. On the left side, the rest-yoke 4 is fixed in the shown position by a locking bolt 6. This locking bolt 6 passes through matching clearances in the tool housing 2 and in the rest 4, and is easily removed. After it has been removed, the rest-yoke 4 can be pivoted about the support bolt 5 in the direction of the double arrow A, namely clockwise until the clearance 3 is totally open in the upward direction. On its inside the rest-yoke 4 comprises an arcuate compression surface 7 subtending an angle of 120° symmetrical to the longitudinal axis of the compression tool 1. The compression surface 7 comprises a peripheral groove which opens inward. It can be exchangeably mounted to rest-yoke 4. Oblique guide surfaces 8, 9 extend inside the tool housing 2 and subtend an angle of 60° and are mirror-symmetrical with respect to the longitudinal axis of the compression tool 1. One compression jaw 10, 11 rests against the guide surfaces 8, 9 across correspondingly oblique support surfaces 12, 13. The compression jaws 10, 11 also are mirror-symmetrical with respect to the longitudinal axis of the compression tool 1 and each has a compression surface 14, 15 in the form of arcs of circle of 120°. They too have a peripheral groove on the inside. The arcs of circle of all the compression surfaces 7, 14, 15 evince the same radii. The compression jaws 10, 11 enter at the bottom a guide groove 16 which is horizontal and transverse to the longitudinal axis of the compression tool 1, the groove being formed in the head 17 of a compression force 18. The lower sides of the compression jaws 10, 11 also are horizontal, whereby the compression jaws 10, 11 are displaceably guided in the groove 16 transversely to the longitudinal axis of the compression tool 1, namely in geometrically locking manner as in a dovetail guide. Transverse and coaxial blind holes 19, 20 are present in the lower segments of the compression jaws 10, 11. A compression spring 21 is set into these blind holes 19, 21 and biases the compression jaws 10, 11 outward and thereby, on account of the support surfaces 12, 13, against the guide surfaces 8, 9. The compression force 18 is supported in vertically and linearly displaceable manner in the direction of the longitudinal axis of the compression tool 1 (double arrow B). It is actuated by a pneumatically or hydraulically loaded actuator not shown herein in further detail. When the compression tool 1 is being used, first the lock of the rest-yoke 4 is loosened by means of the locking bolt 6, i.e. the locking bolt 6 is pulled out and the rest-yoke 4 is pivoted clockwise until the fork-shaped aperture 3 is entirely cleared. Simultaneously, the compression force of actuator 18 is disposed in the downwardly retracted position. The compression tool 1 thereupon can be set on a coupling sleeve 22, so that the sleeve extends perpendicularly to the plane of the drawing through the clearance 3 in which it is received. Thereupon the rest 4 is pivoted back about the coupling sleeve 22, and locked by inserting the locking bolt 6. Now the coupling sleeve 22 has been enclosed by the compression tool 1. Thereupon the compression jaws 10, 11 are made to rest against the coupling sleeve 22 by raising the compression force 18. Because their radius is less than the anticipated squeeze depth of the radius of the coupling sleeve 22 prior to the compression, the compression surfaces 7, 14, 15 rest by their outer transverse edges against the periphery of the coupling sleeve 22. Free gaps 23, 24, 25 of equal size are disposed between the end faces of the compression jaws 10, 11 and the rest-yoke 4. The radii of the arcs of circle of the compression surfaces 7, 14, 15 originate at centers located on the apices of an isosceles triangle. The compression force 18 is raised upon further application of pressure. In the process, the compression jaws 10, 11 slide by means of their support surfaces 12, 13 over the guide surfaces 8, 9, whereby a motion in the directions of the arrows C, D is imparted to them. The two directions of motion subtend the same angle as the guide surfaces 8, 9, namely 60°. In this process the compression jaws 10, 11 slide simultaneously and horizontally inside the groove 16 of the compression force 18 toward one another and against the opposition of the compression spring 21. The coupling sleeve 22 is swaged radially in this manner, that is, its diameter is reduced by the desired squeeze depth. At the end of compression, the compression surfaces 7, 14, 15 enclose a circular compression space and the gaps 23, 24, 25 have become eliminated. To remove the compression tool 1 from the coupling sleeve 22, then the compression force 18 is moved back again. Following removal of the locking bolt 6, the rest-yoke 4 is pivoted away whereby the compression tool 1 can be removed. Again FIGS. 3 and 4 shown a compression tool 31 only in part, namely its head region. The compression tool 31 comprises a tool housing 32 which is hollow on the inside and which extends downward to receive a drive and to allow handling, though this is not shown herein in further detail. Two drive levers 34, 35 in the tool housing 32 extend in mirror-symmetry to the longitudinal axis 33 and are supported pivotally on pivot bolts 36, 37 perpendicular to the plane of the drawing. The downward arms 38, 39 of the drive levers 34, 35 are spread apart in the directions of the arrows E, F in order to pivot against the opposition of a spring, not shown here in further detail, which pulls together the arms 38, 39. A pair of pressure rollers is used to spread apart the arms 38, 39, the pair being moved by a pneumatically or hydraulically driven linear actuator into the gap between the arms 38, 39. Such a drive is known per se from the German Patent 21 36 782 and from the German Offenlegungsschrift 34 23 382. Compression jaws 42, 43 are seated in the arms 40, 41 of the drive levers 34, 35 that extend upward from the pivot bolts 36, 37. Each compression jaw 42, 43 has inside compression surfaces 44, 45 forming arcs of circle of 120°. Both compression jaws 42, 43 are displaceably supported on the arms 40, 41 of the drive levers 34, 35 so that they move in the circumferential directions shown by the arrows G, H. For such purpose they rest by their outsides against corresponding arcuate guide surfaces 46, 47 of the arms 40, 41 coaxial with the arcs-of-circle segments of the particular compression surfaces 44, 45. The compression jaws 42, 43 comprise laterally and externally projecting beaks 48, 49 on both sides of the guide surfaces 46, 47. The beaks 48, 49 comprise guide projections 50, 51 entering, in geometrically constrained manner, slides 52, 53 inside the tool housing 32. Thus, the compression jaws 42, 43 are guided in constrained manner in the circumferential direction G, H while the drive levers 34, 35 are being pivoted. A further compression jaw is formed by a stationary rest 54 inside the tool housing 32 and having a compression surface 55 at the top in the form of an arc of circle of 120°. The radius of the arc of circle is the same as that of the remaining compression surfaces 44, 45. In order to use the compression tool 31, first the arms 38, 39 of the drive levers 34, 35 are manually pushed together, that is opposite the directions E, F. The arms 40, 41 thereby open like tongs and provide access to the space between the end faces of the compression jaws 42, 43, so that the compression tool 31 can be slipped over a coupling sleeve 56 transversely to the sleeve's longitudinal axis. The compression jaws 42, 43 are closed after the coupling sleeve 56 has been placed against the compression surface 55 of the rest 54. This takes place by spreading apart the lower arms 38, 39 of the drive lever 34, 35 by means of a drive system not shown in further detail herein. Thereupon the compression jaws 42, 43 come to rest against the outside surface of the coupling sleeve 56. Because, before compression, the radii of the compression surfaces 44, 45, 55 are less by the anticipated squeeze depth than the radius of the coupling sleeve 56, the compression surfaces 44, 45, 55 rest on the periphery of the coupling sleeve 56 only by their external transverse edges. In order that equal gaps 57, 58, 59 exist between the end faces of the compression jaws 42, 43 and of the rest 54, the slides 52, 53 are shaped so that the compression jaws 42, 43 are correspondingly circumferentially displaced relative to the arms 40, 41 of the drive levers 34, 35, that is, the left compression jaw 42 moves clockwise and the right compression jaw 43 counterclockwise. The radii of the arcs of circle of the compression surfaces 44, 45, 55 start from origins located on the apices of an isosceles triangle. The lower arms 38, 39 of the drive levers 34, 35 are spread apart additionally by increasing the pressure-loading on the drive system. As a result, the compression jaws 42, 43 are moved further inward, the two directions of motion substantially subtending an angle of 60° which is symmetrical to the longitudinal axis 33 and which opens away from the rest 54. This is due to the pivot bolts 36, 37 each being on straight lines starting from the origin of the arc of circle of the rest 54 and subtending an angle twice as large as that subtended by the directions of motion of the compression jaws 42, 43, ie 120°. Because the upper gap 57 between the end faces of the compression jaws 42, 43 would be reduced faster during compression than the gap between the compression jaws 42, 43 and the rest 54, the slides 52, 53 curve inward and downward in such manner that the compression jaws 42, 43 are circumferentially displaced relative to the arms 40, 41, namely the left compression jaw 42 counterclockwise and the right compression jaw 43 clockwise. The guidance of the slides 52, 53 is such that the gaps 57, 58, 59 remain constant during the entire compression until the end faces of the compression jaws 42, 43 and of the rest 54 make contact at the end of compression. The coupling sleeve 56 is radially swaged in this process and its diameter is reduced by the desired squeeze depth. In order to remove the compression tool 31 from the coupling sleeve 56, then the lower arms 38, 39 of the drive lever 34, 35 are pushed together so that the upper arms 40, 41 open like tongs. The compression tool 31 thereupon can be removed from the coupling sleeve 56. FIGS. 5 and 6 show a compression tool 61, again only in part, which is quite similar to the compression tool 31 of FIGS. 3 and 4. It comprises an internally hollow tool housing 62 extending downwardly to receive a drive system and to allow handling, and is not shown herein in further detail. Two drive levers 64, 65 are rotatably supported in the tool housing 62 and in mirror-image manner relative to the longitudinal axis 63 on pivot bolts 66, 67 perpendicular to the plane of the drawing. The downward arms 68, 69 of the drive levers 64, 65 are spread apart in the directions of the arrows I, J for purposes of pivoting and against the opposition of a spring, not shown in further detail, pulling together the lower arms 68, 69. A pair of pressure rollers is used to spread apart the arms 68, 69 in the manner already described in relation to the compression tool 31 of FIGS. 3 and 4. Compression jaws 72, 73 are seated in the arms 70, 71 of the drive levers 64, 65, where the arms extend upward from the pivot bolts 66, 67. These compression jaws each comprise inside compression surfaces 74, 75, each forming arcs of circle of 120°. Both compression jaws 72, 73 are supported on the upper arms 70, 71 of the drive levers 64, 65 so as to be circumferentially displaceable in the directions of the arrows K, L. For that purpose they rest by their outsides against corresponding arcuate guide surfaces 76, 77 in the arms 70, 71 which are coaxial with the arcs of circle of the particular compression surfaces 74, 75. The compression jaws 72, 73 have notches 78, 79 at their external peripheries which are engaged by pins 80, 81 axially displaceably seated in the upper arms 70, 71. These pins 80, 81 are biased by compression springs 82, 83 toward the notches 78, 79. The pins 80, 81 and the notches 78, 79 are arranged in such a way that the pins 80, 81 tend to move the compression jaws 72, 73 circumferentially toward each other, namely the left compression jaw 74 clockwise and the right compression jaw 73 counter-clockwise. Stops, not shown in further detail herein, assure that the compression jaws 72, 73 cannot be displaced beyond a maximum distance in these two directions. Obviously the guidance of the compression jaws 72, 73 is such that they cannot drop out of their seats in the arms 70, 71, and inward, ie, constrained guidance is provided. A further compression jaw is formed by a rest 84 mounted in stationary manner inside the tool housing 62 and having at its top a squeezing surface 85 in the form of a 120° arc of circle. The arc of circle has the same radius as that of the other compression surfaces 74, 75. When the compression tool 61 is put to use, first the lower arms 68, 69 of the drive levers 64, 65 are manually forced together, that is opposite the directions of the arrows I, J. As a result, the upper arms 70, 71 open like tongs and provide a space between the end faces of the compression jaws 72, 73 whereby the compression tool 61 can be slipped over a coupling sleeve 86 transversely to the latter's longitudinal axis. When the coupling sleeve 86 makes contact with the compression surface 85 of the rest 84, the compression jaws 72, 73 can be closed by a spreading apart the lower arms 68, 69 using a drive system not shown herein in further detail. The compression jaws 72, 73 then come to rest against the outer surface of the coupling sleeve 86. Because the radii of the compression surfaces 74, 75, 85 are less by the anticipated squeeze depth than the radius of the coupling sleeve 86 prior to compression, the compression surfaces 74, 75, 85 rest against the periphery of the coupling sleeve 86 by their outer transverse edges. In order that equal-size gaps 87, 88, 89 exist between the end faces of the compression jaws 72, 73 and of the rest 84, then stops limiting the circumferential motion of the compression jaws 72, 73 are mounted accordingly. The radii of the arcs of circle of the compression surfaces 74, 75, 85 start from centers located on the apices of an isosceles triangle. By further loading the drive system, the lower arms 68, 69 of the drive levers 64, 65 are spread apart even more. As a result, the compression jaws 72, 73 are moved further inward, the two directions of motion essentially subtending an angle of 60° symmetrical in relation to the longitudinal axis 63 and opening away from the rest 84. Again the reason is that the pivot bolts 66, 67 each are located on straight lines starting from the center of the arc of circle of the rest 84 and subtending an angle of 120°. During compression, the compression jaws 72, 73 automatically shift circumferentially relative to the upper arms 70, 71, namely the left compression jaw 72 counter-clockwise and the right compression jaw 73 clockwise. It was found that the gaps 87, 88, 89 in this embodiment remained essentially equal, in spite of the inaccurate guidance during the entire compression procedure, until the end faces of the compression jaws 72, 73 and of the rest 84 come to touch at the end of compression, as shown in FIG. 6. In the process, the coupling sleeve 86 is radially swaged and its diameter is reduced by the desired squeeze depth. FIGS. 7 and 8 show two compression tools 91, 92 each by its half. The left half of FIGS. 7 and 8 as regards the axis of symmetry shows the compression tool 91 and the right half the compression tool 92. Both compression tools 91, 92 are mirror-symmetrical and their design already is known from their half-representations. The compression tool 91 shown on the left in FIGS. 7 and 8 comprises a compression ring 93 consisting of a total of three compression jaws 94, 95; on account of the half-representation the compression jaw 94 appears only in part--and one compression jaw, namely the one on the right hand side, not at all. A flexible traction belt 97 made of spring steel is affixed by means of a screw 96 to the upper compression jaw 94 and extends over the periphery of the upper compression jaw 94 and the left compression jaw 95. A corresponding traction belt is present on the other side (omitted) of the compression ring 93. The lower compression jaws 95 are guided on the traction belt 97 so as to be circumferentially displaceable in the direction K. One rubber spring 98 enters each clearance in the opposite end faces of the compression jaws 94, 95 and is vulcanized onto them. In the unloaded state, the compression jaws 94, 95 are forced apart to a given extent by the rubber springs 98 and as a result equally wide gaps 99, 100 are created between the opposite end faces of the compression jaws 94, 95 when these rest externally against a coupling sleeve 101. External connection fittings 102 are mounted on the free ends of the traction belts 97. A drive system 103 separate from the compression ring 93, and indicated here merely schematically and in dash-dot lines, can be linked to these connection fittings 102. Accordingly the compression tool 91 consists of two independent parts that can be hooked up together. The drive system 103 comprises two drive levers 104, of which only the left one is shown. They are rotatably supported on pivot bolts 105 which are perpendicular to the plane of the drawing. The downward arms 106 are spread in the direction of the arrow L for purposes of pivoting, and this against the opposition of a tension spring, not shown in further detail, which pulls on the lower arms 106. In order to spread apart the arms 106, a pair of pressure rollers is used as described already in relation to the compression tool 31 and FIGS. 3 and 4. The arms 107 rising from the pivot bolts 105 are shaped in such a way that they can engage the connection fittings 102 from behind. When using the compression tool 91, first the compression ring 93 is opened, whereby the lower compression jaws 95 are externally out of the way in the manner indicated by dash-dot lines. Thereupon the compression ring 93 can be slipped over the combination of coupling sleeve 101 and pipe end 108 transverse to the longitudinal axis. Because of the spring action of the traction belts 97, the compression jaws 94, 95 come to rest against the periphery of the coupling sleeve 101, and again only by their external transverse edges. Thereupon the drive system 103 is made to contract in such manner that the upper arms 107 of the drive levers 104 externally engage the connection fittings 102 from behind in the manner shown by FIG. 7. The drive levers 104 then are spread apart in the manner previously described, whereby the traction belts 97 are pressed together at their free ends. As a result, the coupling sleeve 101 and the pipe end 108 are radially swaged, the lower compression jaws 95 automatically moving circumferentially, namely the left lower compression jaw 95 clockwise and the right lower compression jaw counter-clockwise. This takes place until the end faces of the compression jaws 94, 95 come to rest against each other, the rubber springs 98 being compressed. This state is shown in FIG. 8. The compression tool 92 is designed similarly as regards operation as the tool 91. It also comprises a compression ring 109 with three compression jaws 110, 111 of equal lengths. The upper compression jaw 110 is rigidly joined to a compression-jaw support 112, and the two lower compression jaws 111 are circumferentially and displaceably guided on compression-jaw supports 113. The compression-jaw supports 113 are linked by pivot links 114 to the upper compression jaw support 112. The lower compression jaws 111 comprises notches 115 at their outer peripheries, the notches being entered by axially displaceable pins 116 resting in the lower compression jaw supports 113. These pins 116 are spring-loaded by compression springs 117 toward the notches 115. The pins 116 and the notches 115 are arranged in such manner that the pins are biased to move the lower compression jaws 111 toward each other, namely the shown right lower compression jaw 111 clockwise and the omitted compression jaw counter-clockwise. Stops, not shown in further detail, assure that the lower compression jaws 111 cannot go beyond maximum distances in these two directions. Drive bolts 118 projecting vertically from the plane of the drawing and assume the function of the connection fittings 102 of the compression tool 91 and are mounted to the free ends of the lower compression jaws supports 113. The drive system 103 shown in the left half of FIGS. 7 and 8 can be hooked-up to these drive bolts 118 by placing the upper arms 107 of the drive levers 104 against the outsides of the drive bolts 118. The handling of the compression tool 92 is the same as for the compression tool 91. Initially the compression ring 109 is slipped over the coupling sleeve 101 and the pipe end 108 transversely to their longitudinal axis, the two lower compression jaw supports 113 being open, ie being pivoted outward as indicated by the dash-dot lines. Then the lower compression jaw supports 113 are made to rest against the outer periphery of the coupling sleeve 101. The previously mentioned circumferential motion stops for the lower compression jaws 111 are mounted in such a way that upon contact with the coupling sleeve 101, equal-size gaps 119, 120 arise between the end faces of the compression jaws 110, 111. By further spreading apart the lower arms 106 of the drive levers 104, the lower compression jaws 113 are pivoted inward, the lower compression jaws 111 automatically moving in the circumferential direction M, namely the shown right compression jaw 111 counter-clockwise and the left, omitted compression jaw clockwise. This goes on until the end faces of the compression jaws 110, 111 come into contact at the end of compression. This state is shown in the right half of FIG. 8. The compression tool 92 does not differ kinematically and hence not in principle from that of FIGS. 5 and 6 nor from the compression tool 31 of FIGS. 3 and 4 because in those compression tools 61, 31 also the compressing motion of the compression jaws 72, 73 and 42, 43 resp. may be implemented by contracting the upper arms 70, 71 and 40, 41 of the drive levers 64, 65 and 34, 35 operating as compression jaw supports in the region of the upper gap 87 and 57 by making use of a correspondingly designed and separate drive system. In that case the lower arms 68, 69 and 38, 39 of the drive levers 64, 65 and 34, 35 are not needed. Obviously the compression tools 91, 92 also may be made integral, that is the drive system 103 may be connected by an appropriate housing component with one of the compression jaws 94, 95, 110, 111. In that case this compression jaw 94, 95, 110, 111 would be comparable to the rests 4, 54, 84 in the embodiments of FIGS. 1 through 6. Also, one of the lower compression jaws 95, 111 which is fixed to the compression tool 91, 92 may assume the function of the compression jaw 95, 111 acting as a rest. In this case only one drive lever 104 is required to pull together the compression jaws 94, 95, 110, 111. The tool T 1 of FIGS. 9 and 10 includes a tool housing 122 to which rest yoke 124 is attached. Housing 122 includes supports 126, 127, and 128. Yoke 124 has a compression surface 130 which is arcuate and forms a circle with the cooperating arcuate compression surfaces 132, 133, and 134 of supports 126, 127, and 128, respectively, when the tool T 1 is in the closed or compressed orientation. Yoke 124 is connected by pivot pin 136 to housing 122. The opposite end of yoke 124 is secured by removable pin 128. Removal of pin 138 permits the yoke 124 to be pivoted about pin 136 in the directions of arrow 140. Removal of pin 138 and pivoting of yoke 124 thereby permits access to the U-shaped clearance 142 formed in the housing 122. Housing 122 has internal supports 144 and 145, each with a guide surface 146 and 147, respectively. Each of supports 126 and 127 likewise has a guide surface 148 and 149, respectively, so that supports 126 and 127 may slide relative to the supports 144 and 145 when the tool T 1 is shifted between the open position of FIG. 9 and the closed position of FIG. 10. Support 126 has a bore 150 and support 128 has a bore 151 axially aligned with bore 150. Compression spring 152 is received within bores 150 and 151 in order to bias the support 126 toward the closed position. Similarly, support 127 has a bore 154 axially aligned with bore 156 of support 128. Bores 154 and 156 have compression spring 158 received therein for biasing support 127 to the closed position. The bores 150 and 151 are, preferably, disposed transverse to the bores 164 and 156. Gap 160 separates support 124 from support 1126, while a similar gap 162 separates support 124 from support 127. Likewise, gap 164 separates support 126 from support 128, while gap 166 separates support 128 from support 127. The gaps 160, 162, 164 and 166 are of uniform dimension as best shown in FIG. 9, so that the supports 124, 126, 127, and 128 are uniformly circumferentially spaced as the tool T 1 is shifted by driver 168 between the open and closed positions. It can be noted in FIG. 10 that the gaps 160, 162, 164, and 166 have been eliminated as a result of movement of drive 168 and corresponding movement of supports 126, 127, and 128 relative to yoke 124. In the closed position of FIG. 10, compression surface 134 of support 128 has moved into clearance 142. The supports 126 and 127 each have a side surface 170 and 172, respectively, to which a cooperating surface 174 and 176 of the support 128 is keyed. In this way, upward movement of drive 168, as viewed in FIGS. 9 and 10, causes corresponding movement of support 128 and thereby movement of supports 126 and 127 along guide surfaces 146 and 147. The tool T 2 of FIGS. 11 and 12 has supports 180, 182, 184, 186, and 188. Links 190 pivotally interconnect each of the supports 180 and 182, 182 and 184, 184 and 186, and 186 and 188 through pins 192. Drive bolts 194 are secured to supports 180 and 188 and extend outwardly and transversely thereto in order to be engaged by a driver (not shown) for causing the bolts 194 to approach and withdraw for thereby shifting the tool T 2 between the open position of FIG. 11 and the closed position of FIG. 12. Each of the supports carries a cooperating jaw 196, 198, 200, 202, and 204, respectively, and each jaw has an associated compression surface 206, 208, 210, 212, and 214, respectively. The compression surfaces form a circle when the tool T 2 is in the closed position in order to uniformly squeeze the object. Jaw 200 is fixed to support 184 by pins 216, while each of the other jaws 196, 198, 202, and 204 is movable along its associated support 180, 182, 186, and 188, respectively. Gap 218 separates jaws 196 and 198, while gap 220 separates jaws 198 and 200. Similarly, gap 222 separates jaws 200 and 208, and gap 224 separates jaws 202 and 204. The gaps are uniformly spaced, as best shown in FIG. 11, with the result that the jaws remain uniformly spaced as the tool T 2 is shifted between the open and closed positions. Each of supports 180, 182, 186, and 188 has a clearance area 226 of generally frustoconical configuration. Each clearance area 226 has a link 228 pivotal therein with respect to pivot pin 230. The links 228 of supports 182 and 186 are disposed between the pins 216 of their associated jaws 198 and 202, while the links 228 of the supports 180 and 188 are in contact with one of the pins 216 of the associated jaws 196 and 204. Movement of the drive bolts 194 toward each other, as indicated by the arrows 232, causes the tool T 2 to shift from the open position of FIG. 11 to the closed position of FIG. 12. As a result of movement of the drive bolts 194 toward each other, then each of the movable jaws 196, 198, 202, and 204 moves relative to its likewise pivoting support 180, 182, 186, and 188, respectively, as a result of which each of the links 228 is moved within its associated clearance 226 relative to its pin 230. Movement of the drive bolts 194 thereby causes the gaps 218, 220, 222, and 224 to uniformly close until edge surfaces of adjacent jaws contact each other at the closed position. Movement of the drive bolts 194 away from each other, opposite to the direction of arrows 232, causes the gaps to open until the configuration of FIG. 11 is reached. The pressing device 300 is shown in FIGS. 13 through 16 and is comprised of a press ring 302, which constitutes the compression molding die, and a respective closing device 304. The press ring 302 is comprised of three compression jaws 306, 308, and 310, although a greater number may be provided as needed. The compression jaws on the left and right 306, 310 are coupled in a pivot-like manner to the upper compression jaw 308 by means of hinge pins 312, 314. The upper compression jaw 308 contains two recesses 357, 359 to allow for pivoting of the right and left compression jaws 306, 310. The compression jaws 306, 308, and 310 when in the initial or non-press position ensure that there is a closing gap 316 between the adjacent end faces of the left and right side compression jaws 306, 310, as best shown in FIG. 13. Each of the jaws has a press surface 307, 309, and 311, respectively. The press surfaces preferably are integral with and form a part of the associated compression jaw, thus increasing strength and reducing complexity and manufacturing costs. The press surfaces 307, 309, and 311 may have essentially any configuration, provided that they define a wholly closed space when the compression jaws 306, 308, and 310 are in the closed position of FIG. 14. The press ring 302 encloses a pipe connection provided by an end area of pipe 318 and a press fitting 320 pushed on top of it. The connection between pipe 318 and press fitting 320 can best be seen in FIG. 16, in which press fitting 320 can be seen in fragmentary form. It has a cylinder section 322, with a reduced diameter portion providing a constriction 324 which acts as a limit stop for the end of the pipe 318. At the free end, the press fitting 320 has an annular ring 326 which bulges radially outwardly and into which an elastomer sealing ring 328 is inserted on the inside. The other end of the press fitting 320, which is not shown, is identical. The compression jaws 306, 310 are located on the outside of the press fitting 320 in the area of the annular ring 326. As can be seen in FIGS. 15 and 16, the compression jaws 306, 308, and 310 provide a compression die with centered, ring-shaped compression grooves 330, 332, 334 and shaping webs 336, 338, 340, 342, 344, and 346 which are at a preselected distance from each other. The compression grooves 330, 332, and 334 engage the annular ring 326 of the press fitting 320 in the position shown in FIG. 16, while the left channel webs 336, 340, and 344 each are applied to the outer circumference of the cylinder of the cylinder section 322. Coupling pins or drive bolts 348, 350 extend from end portions of the compression jaws 306, 310. The jaws 306 and 308 face each other, and provide a closing gap 316 therebetween when in the open configuration of FIG. 13. As can best be seen in FIG. 15, two channels are formed in the area of the coupling pins 348, 350, whose extensions are marked by means of dash-dot curved lines 356, 358 in FIG. 13. The closing device 304 is connectable to the press ring 302. It has a T-shaped lever bearing plate 360 to which two adjacent closing levers 362, 364 are linked by means of pivot pins 366, 368. The closing levers 362, 364 are two-armed, symmetrical, and have closing arms 370, 372 which extend upwardly and drive arms 374, 376 which extend downwardly. In the section of the lever bearing plate 360 which points downwardly, a drive device 378 is provided which is attached by means of a connecting pin 380. The drive device 378 has a plate 382 which encloses the connecting pin 380 and which extends into an hydraulic cylinder 384, which is only partially shown and which has the customary structure. A piston rod 386 can move axially inside the hydraulic cylinder 384, that is, it can be moved vertically, as viewed in the figure. The piston rod 386 is connected in the hydraulic cylinder 384 to a piston which is not shown and to which hydraulic pressure may be applied so that the piston rod 386 is moved. At the upper end of the piston rod 386 there are two opposing, adjacent spread rollers 388, 390 which roll freely. Each of closing arms 370, 372 is forked in the upper end portion, as can be seen in FIG. 15 from tines 371 and 373. The forking is such that the closing arms 370, 372 can be pushed into the channels 352, 354, with the tines positioned within and dimensioned to correspond to the channels as can be seen in FIG. 15. The closing arms 370, 372 have opposing coupling recesses 392, 394, as best shown in FIG. 13, which are securable to the coupling pins 348, 350, as best shown in FIG. 14. Press ring 302 and closing device 304 are in FIG. 13 separated. The press ring 302 sits loosely on the press fitting 320. In order to carry out the pressing process, the closing device 304 is connected to the press ring 302, so that the tines 371 and 373 of the forked end areas of the closing arms 370, 372 slide into the channels 352 and 354 until the coupling recesses 392, 394 are at the level of the coupling pins 348 and 350. Hydraulic pressure is then applied to cylinder 384, so that the piston rod 386 advances and thereby moves the spread rollers 388, 390. During this process, the spread rollers 388, 390 contact the opposite drive surfaces 396, 398 of the drive arms 374, 376 and cause the closing levers 362 and 364 to pivot about pins 366 and 368. The result is that the closing arms 370, 372 approach each other and engage the coupling pins 348, 350, and position them within the outside with the coupling recesses 392, 394. As the piston rod 386 advances further, the drive arms 374, 376 are spread further apart, so that the opposing compression jaws 306, 310 move toward each other and the closing gap 316 is reduced. Because press surfaces 307, 309, and 311 are integral with the associated jaws, they move with the jaws and not relative thereto. The press ring 302 is constricted in this manner until the final shaping position shown in FIG. 14 is reached, in which the left and right compression jaws 306, 310 have made contact and thus their end faces 359 and 361 are engaged. During this compression closing process, the annular ring 326 and the immediately adjacent area of the cylinder section 322 of the press fitting 320 are plastically deformed radially toward the inside, whereby the end area of the pipe 318 is constricted radially toward the inside as well. Due to the shape of the inside surfaces 307, 309, and 311 of the compression jaws 306, 308, and 310, respectively, the result is a hexagon shape. In this manner, the press fitting 320 and the end area of the pipe 318 are connected in a tight and close manner. FIG. 17 shows a pressing device 400 which is slightly modified with regard to the pressing device 300 of FIGS. 13 through 16. Its basic structure is identical to that of pressing device 300, so that corresponding parts in FIG. 17 have the same reference numbers. Please refer to the description of pressing device 300 for the description of these parts. The pressing device 400 has the following modifications, however. The closing device 304 has a closing lever 362 on its left side whose closing arm 370 does not have a coupling recess, but instead completely encloses the coupling pin 348 in the area of the fork. Compression jaw 306 may pivot freely about pin 348. This is how the closing device 304 is connected with the press ring 302 in a pivoting manner. The pin 350 of the compression jaw 310 is remote from coupling recess 394. For the pressing process, the press ring 302 is placed around the press fitting 320. This is continued until the press ring 302 is approximately in the position which is shown in FIG. 13, and until the forked area of the right closing lever 364 can recess into the channel area 358 of the compression jaw 310. Once the coupling recess 394 is on the level of the coupling pin 350, then the press ring 302 can be constricted as described for pressing device 300, that is, hydraulic pressure is applied to hydraulic cylinder 384 so that the piston rod 386 thereby moves the spread rollers 388, 390 which contact the opposite drive surfaces 396, 398, thus spreading the drive arms 374, 376. In this manner, the compression jaws 306, 308 are gradually brought into the final pressing position. In this position, the pressing device 400 is identical to pressing device 300 shown in FIG. 14, with the exception of the above discrepancy with regard to the shape of the upper end area of the closing arm 370. Another deviation from the pressing device 300 according to FIG. 13 is the fact that the connecting pin 380 of the drive device 304 can easily be removed. This makes it possible to separate the drive device 378 from the lever bearing plate 360. This simplifies the operation of placing the press ring 302 around the press fitting 320, because the is weight of the driving device 378 is no longer existent. Once the press ring 302 is fitted around the press fitting 320 and once the coupling recess 394 has engaged the coupling pin 350, the drive device 378 can be attached to the lever bearing plate 360 by connecting pin 380. FIG. 18 shows the pressing device 402, another modification of the pressing device 300. Again, the basic structure of pressing device 402 is identical to that of pressing device 300. Thus, the same reference numbers are used for the corresponding parts and the pressing device 300 is referred to for the description of these parts. The pressing device 402 is different from pressing devices 300, 400 in the following aspects. Compared to pressing device 400, the upper area of the right closing arm 372 has the same structure as the closing arm 370 in pressing device 400. That is, both fork-shaped end areas of the closing arm 370, 372 completely enclose the respective coupling pin 348, 350. The compression jaws 306, 310 are linked to the closing levers 362, 364 via the coupling pins 348, 350, and may rotate about those pins. In order to ensure that the press ring 302 can be placed over the press fitting 320 and the end area of the pipe 318, the hinge pin 314 can be removed. In this manner, it is possible to separate the upper compression jaw 308 from the right compression jaw 310 and to pivot it up and to the outside, so that the press ring 302 is open and can be placed around the press fitting 320 as can be seen in FIG. 18. Then, the upper compression jaw 308 is pivoted into the direction of the right compression jaw 310 again until the openings 404, 406 intended for the hinge pins 314 are aligned. After the hinge pin 314 is placed, the pressing process can start in the same manner as described for the pressing devices 300, 400. The final pressing position of the pressing device 402 is identical to the final pressing position of the pressing device 300 shown in FIG. 14. FIG. 19 discloses press device 500 having a press ring provided by pivotally interconnected press jaws 502, 504, and 506. The press jaws have cooperating press surfaces 508, 510, and 512, respectively, that form, when in the closed orientation of FIG. 19, an essentially closed pressing area 514. The press jaws may have separate pressing surfaces that are fixed or slidable, or the press surfaces may be integral as shown. Pressing area 514 may have essentially any closed shape, and need not be circular. Preferably press jaw 504 has recessed portions 516 and 518 at its lateral ends, in which pins 520 and 522 are secured for pivotally receiving press jaws 502 and 506, respectively. Recessed portions 516 and 518 may be configured to act as tongues received between opposed grooves formed by press jaws 502 and 504, or press jaws 502 and 504 may rest against the recessed portions, in order to provide support for the press jaws. The support, during pivoting motion between the closed position of FIG. 19, and the open position (not shown) in which pieces to be pressed may be placed within press area 514 or already pressed pieces removed therefrom, prevents the press tool 500 from being deformed during pressing operation. Lugs 524 and 526 are carried by press jaws 502 and 506, respectively, and preferably extend from opposite major surfaces thereof Lugs 524 and 526 are received within arcuate catches 528 and 530 at the distal ends of operating levers 532 and 534, respectively. Levers 532 and 534 pivot about pins 536 and 538, respectively, carried by support block 540. T-shaped lever bearing plate 540 cooperates with a drive unit, such as an hydraulic actuator, pneumatic actuator, or electric actuator, for causing levers 532 and 534 to pivot in order to shift press device 500 between the closed position and the open position. The drive unit may be such as disclosed in FIGS. 17 and 18, and which correspondingly operates on the T-shaped lever bearing plate 540. Each of the operating levers 532 and 534 has an interior contoured surface 542 and 544, respectively. The operating levers and their interior surfaces may be identical, in order to minimize manufacturing costs and to increase the ease of assembly. Each of the interior surfaces 542 and 544 has a protruding apex 546 and 548, respectively. The apexes 546 and 548 engage when the press device 500 is in the closed position of FIG. 19, and thus act as stops preventing overtravel of the operating levers 532 and 534. Each of the apexes 546 and 548 is formed as a surface having a not insignificant thickness, in order to provide strength during closing of the press jaws 502, 504, and 506 by the action of the operating levers 532 and 534. The cooperating stopping action provided by the abutting surfaces of apexes 546 and 548 is similar to the stopping action achieved by engagement of lateral end surfaces of the pressing jaws and lateral end surfaces of the press ring components. Because of the positive stopping action that is achieved by engagement of the respective stopping surfaces, then a high strength drive unit may be utilized in order to maximize the connection between the tubular coupling and the pipe end components forming the workpieces. Additionally, a high-speed drive unit may be utilized, because engagement of the stopping surfaces assures that a highly accurate drive control mechanism need not be utilized. Rather, a relatively simple control mechanism is provided by the stopping surfaces, but yet one that assures that the drive unit may remain actuated until the pressing operation is completed. Additionally, in part because of the precise stopping action achieved, it in some instances is permissible that edge surfaces 509 and 513 not be in engagement when the press ring is in the closed orientation of FIG. 19. While I prefer that the stop surfaces be provided by cooperating edge or end surfaces of the press jaws, or of the press ring components, or of the operating levers, those skilled in the art will appreciate that the precise positioning of the surfaces is a function of the particular press tool. It is important merely that the cooperating stop surfaces be located somewhere between the press ring and the drive unit. Moreover, the stop surfaces must be juxtaposed for engagement, so that one stop surface faces another stop surface and these surfaces may thus engage to stop the press tool precisely as desired. Engagement of the stop surfaces may be used as a control mechanism, triggering shifting of the drive unit into the opposite direction in order to maximize efficiency of operation. While this invention has been described as having a preferred design, it is understood that the it is capable of further modifications, uses, and/or adaptations which follow in general the principle of the invention and includes such departures from the present disclosure as come within known or customary practice in the art to which the invention pertains and that may be applied to the central features hereinbefore set forth and fall within the scope of the limits of the appended claims.

A pressing device comprises a press ring having at least three pivotally interconnected compression jaws. The press ring has a first open configuration, and a second closed configuration. A coupling element extends from each of two jaws for operable connection to a closing device. The closing device shifts the press ring between the configurations, and includes two oppositely disposed pivotal levers. A drive device is operably engageable with each of the levers, for pivoting the levers and thereby causing the ring to be shifted between the configurations.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mixed ionic conductor and an electrochemical device, such as a fuel cell or a gas sensor, using the same. 2. Description of the Prior Art The applicant has long been actively developing mixed conductors of protons and oxide ions (see for example Publication of Unexamined Japanese Patent Application (Tokkai) No. H5-28820 or H6-231611). These mixed ionic conductors are basically perovskite oxides containing barium and cerium wherein a portion of the cerium has been substituted by the substitute element M, so as to achieve a high ionic conductivity (chemical formula: BaCe 1−p M p O 3−α ). Especially, when the substitution amount p of the substitution element M is 0.16 to 0.23, the mixed ionic conductor has a high conductivity, higher even than zirconia-based oxides (YSZ: yttrium-stabilized zirconia), which conventionally have been used as oxide ionic conductors. As the substitution element M, rare earth elements are suitable, in particular heavy rare earth elements, because of their atomic radius and charge balance. New fuel cells, sensors and other electrochemical devices using such materials as a solid electrolyte have been developed. The sensor characteristics and the discharge characteristics of fuel cells using such materials have been shown to be superior to prior devices. Other patent applications related to these materials are Tokkai H5-234604, Tokkai H5-290860, Tokkai H6-223857, Tokkai H6-290802, Tokkai H7-65839, Tokkai H7-136455, Tokkai H8-29390, Tokkai H8-162121, and Tokkai H8-220060. However, these materials show some problems with regard to their chemical stability. For example, barium tends to precipitate in CO 2 gas. To solve these problems, the applicant has proposed a counter-strategy in Tokkai H9-295866. However, even this counter-strategy is not perfect, and for example at low temperatures of 85° C. and 85% humidity, precipitation can be observed in shelf tests and boiling tests in water. Moreover, under high water vapor pressures as during discharge of the fuel cells, barium can be seen to precipitate near the platinum electrodes. Furthermore, with gas sensors, there is the problem of maintaining high ion conductivity at lower temperatures over a long time and the problem of raising the acid resistance of the oxide itself. SUMMARY OF THE INVENTION To solve these problems, it is an object of the present invention to improve the chemical stability of the mixed ionic conductors. The main cause for decomposition of the oxides due to humidity is believed to be the fact that the segregated barium turning into barium hydroxide reacts with the carbon dioxide, and forms stable barium carbonate. To increase the moisture resistance, the present invention uses a mixed ionic conductor including the following perovskite structure oxide. A mixed ionic conductor of one embodiment of the present invention (a first ionic conductor) includes an ion conductive oxide having a perovskite structure of the formula Ba a (Ce 1−b M 1 b )L c O 3−α , wherein M 1 is at least one trivalent rare earth element other than Ce; L is at least one element selected from the group consisting of Zr, Ti, V, Nb, Cr, Mo, W, Fe, Co, Ni, Cu, Ag, Au, Pd, Pt, Bi, Sb, Sn, Pb and Ga;  with 0.9≦a≦1; 0.16≦b≦0.26; 0.01≦c≦0.1;  and (2+b−2a)/2≦α<1.5. In this mixed ionic conductor it is preferable that M 1 is at least one element selected from the group consisting of La, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Y and Sc. More preferably, M 1 is Gd and/or Y. It is also preferable that L is at least one element selected from the group consisting of Zr, Ti, Fe, Co, Ni, Cu, Bi, Sn, Pb and Ga. More preferably, L is at least one element selected from the group consisting of Zr, Ti, Bi, Pb and Ga. A mixed ionic conductor of another embodiment of the present invention (a second ionic conductor) includes an ion conductive oxide having a perovskite structure of the formula Ba e Zr 1−z M 2 z O 3−β , wherein 0.9≦e≦1; M 2 is at least one element selected from the group consisting of trivalent rare earth elements, Bi, Ga, Sn, Sb and In;  with 0.01≦z≦0.3;  and (2+z−2e)/2≦β<1.5. In this mixed ionic conductor it is preferable that 0.16≦z≦0.3. It is also preferable that M 2 is at least one element selected from the group consisting of trivalent rare earth elements and In, especially elements selected from the group consisting of Pr, Eu, Gd, Yb, Sc and In. A mixed ionic conductor of yet another embodiment of the present invention (a third ionic conductor) includes an ion conductive oxide having a perovskite structure of the formula Ba d Zr 1−x−y Ce x M 3 y O 3−γ wherein M 3 is at least one element selected from the group consisting of trivalent rare earth elements, Bi and In;  with 0.98≦d≦1; 0.01≦x≦0.5; 0.01≦y≦0.3;  and (2+y−2d)/2≦γ<1.5. In this third mixed ionic conductor, it is preferable that M 3 is at least one element selected from the group consisting of Nd, Sm, Eu, Gd, Tb, Yb, Y, Sc and In. More preferably, M 3 is at least one element selected from the group consisting of Gd, In, Y and Yb. The mixed ionic conductors of the present invention have not only the necessary conductivity for electrochemical devices such as fuel cells, but also superior moisture resistance. Throughout this specification, “rare earth element” means Sc, Y, and the lanthanides (elements 57 La through 71 Lu). In the above formulas, α, β and γ are determined by the absent amount of disproportionate oxygen. The present invention also provides devices using such a mixed ionic conductor. A fuel cell in accordance with the present invention includes as a solid-state electrolyte a mixed ionic conductor as described above. A gas sensor in accordance with the present invention includes as a solid-state electrolyte a mixed ionic conductor as described above. Using the mixed ionic conductors of the present invention provides electric devices, such as fuel cells and gas sensors, with high moisture resistance, high performance, and long lifetimes. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective cross-sectional view of an embodiment of a fuel cell using a mixed ionic conductor in accordance with the present invention. FIG. 2 is a cross-sectional view of an embodiment of a gas sensor using a mixed ionic conductor in accordance with the present invention. FIG. 3 is a graph showing the conductivity of mixed ionic conductors in accordance with the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS The following is an explanation of the preferred embodiments of the present invention. As the applicant has pointed out in the above-noted publications, the high conductivity of mixed ionic conductors in accordance with the present invention stems from the mixed ion conductivity of oxygen ions and protons. In order to improve the moisture resistance of such mixed ionic conductors, a suitable substitute element is introduced into the above-mentioned first ionic conductor so as to reduce the amount of barium in the perovskite oxide to less than the stochiometric ratio. In the following, such a mixed ionic conductor also is referred to as “additive system” conductor. The second and the third ionic conductors in accordance with the present invention are also mixed ionic conductors with high moisture resistance. In the following, these mixed ionic conductors are referred to as “barium-zirconium system” conductors and “barium zirconium cerium system” conductors, respectively. While these systems are mixed ionic conductors exhibiting proton conductivity, they still provide high moisture resistance. These systems of mixed ionic conductors can be obtained with conventional raw materials and manufacturing methods. Specific examples of manufacturing methods are explained along with the examples further below. The following is an explanation of a device using a mixed ionic conductor in accordance with the present invention. FIG. 1 is a cross-sectional perspective view of an embodiment of a fuel cell in accordance with the present invention. This planar fuel cell has several layered units 7 , which include a cathode (fuel electrode) 3 , a solid electrolyte 2 layered on the cathode 3 , and an anode (air electrode) 1 on the solid electrolyte 2 . Separators 4 are arranged between the layered units 7 . When generating power, an oxidation gas 6 (such as air) is supplied to the anodes 1 , and a fuel gas 5 (a reduction gas such as hydrogen or natural gas) is supplied to the cathodes 3 . The oxidation-reduction reaction at the electrodes generates electrons, so that the fuel cell serves as an electric power source. FIG. 2 is a cross-sectional view of an embodiment of a gas sensor in accordance with the present invention. This HC sensor (hydrocarbon sensor) includes an anode 15 , a solid electrolyte 14 on the anode 15 , and a cathode 16 on the solid electrolyte 14 . This layered structure is attached with an inorganic adhesive 18 to a (ceramic) substrate 17 , providing a space 20 between the substrate and the layered structure. This space 20 is in communication with the outside via a diffusion limiting hole 13 . When a certain voltage (for example 1.2V) is applied steadily between the two electrodes 15 and 16 , a current that is proportional to the concentration of hydrocarbons in the space adjacent to the anode 15 is attained as output. During the measurement, the sensor is kept at a certain temperature with a heater 19 attached to the substrate. To provide the diffusion limiting hole 13 is advantageous to limit the inflow of the material to be measured (here, hydrocarbons) into the space 20 . This embodiment has been explained for a HC sensor, but an oxygen sensor is also possible by exchanging anode and cathode in the structure shown in FIG. 2 . Furthermore, the mixed ionic conductor of the present invention is not limited the above, but also can be applied to all kinds of other electrochemical devices. EXAMPLES The following is a more detailed description of specific examples of the present invention. It should be noted that the present invention is in no way limited to these examples. As examples of the present invention, oxides as shown in Tables 1 to 6 have been synthesized. These oxides were synthesized by solid state sintering. An oxide powder of barium, cerium, zirconium, and rare earth elements was weighed to the composition ratio listed in the tables, and crushed and mixed with ethanol in an agate mortar. After sufficient mixing, the solvent was removed, defatted with a burner, and crushing and mixing were repeated in the agate mortar. Then, the samples were pressed into columnar shape and fired for 10 hours at 1300° C. After the firing, granules of about 3 μm were produced by coarse crushing, with further crushing in a benzene solution with a planetary ball mill. The resulting powder was vacuum-dried at 150° C., and columns were formed with a hydrostatic press at 2 tons/cm 2 , which were immediately fired for 10 hours at 1650° C. to synthesize a sintered product. For almost all samples, a very compact single-phase perovskite oxide was attained. The resulting samples were then evaluated as follows: Boiling Test As an accelerated test of moisture resistance, the samples were introduced into boiling water of 100° C., and the level of Ba precipitation was evaluated after 10 hours by measuring the pH value. This evaluation utilizes the fact that the pH value in the aqueous solution rises proportionally with the precipitation of barium. For a pH change of not more than 2, the moisture resistance was taken to be excellent (A), for more than 2 and not more than 3.5, it was taken to be good (B), for more than 3.5 and not more than 4, it was taken to be adequate (C), and for more than 4, it was taken to be poor (D). Conductivity After the above-mentioned boiling test, disks of 0.5 mm thickness and 13 mm diameter were made of the columnar sintered product samples, both sides of the disks were coated with a platinum paste on an area of 0.5 cm 2 each, which was baked onto the samples, and the ion conductivity was measured. In this experiment, the conductivity was calculated from the resistance with the alternating current impedance method in air. The measurement temperature was 500° C. The resistance of the leads of the measurement device was subtracted. When the conductivity (in S/cm) was at least 0.007, it was taken as A, for at least 0.001 and less than 0.007 it was taken as B, and for less than 0.001 it was taken as C. FIG. 3 is an arrhenius plot showing the conductivity of materials in accordance with the present invention. Crystallinity When the sintered product was single-phase it was taken as A, when it was multi-phase, it was taken as B, and sintering failures were taken as C. The tables show the conductivity at 500° C. and the result of the pH evaluation in the boiling test. TABLE 1 Material Boiling Test Crystallinity Conductivity BaCe 0.8 Gd 0.2 O 3-α D A A Ba 0.99 Ce 0.8 Gd 0.2 O 3-α D A A Ba 0.98 Ce 0.8 Gd 0.2 O 3-60 D A A Ba 0.94 Ce 0.8 Gd 0.2 O 3-α D A B Ba 0.90 Ce 0.8 Gd 0.2 O 3-α D A B TABLE 2 Additive System Material Boiling Test Crystallinity Conductivity BaCe 0.8 Gd 0.2 Zr 0.01 O 3-α B A A BaCe 0.8 Gd 0.2 Zr 0.4 O 3-α B A A BaCe 0.8 Gd 0.2 Zr 0.60 O 3-α B A A BaCe 0.8 Gd 0.2 Zr 0.1 O 3-α B A A BaCe 0.8 Gd 0.2 Zr 0.11 O 3-α D B not measured BaCe 0.9 Gd 0.2 Zr 0.15 O 3-α D C not measured Ba 0.99 Ce 0.8 Gd 0.2 Zr 0.01 O 3-α B A A Ba 0.99 Ce 0.8 Gd 0.2 Zr 0.04 O 3-α B A A Ba 0.99 Ce 0.8 Gd 0.2 Zr 0.06 O 3-α B A B Ba 0.99 Ce 0.8 Gd 0.2 Zr 0.1 O 3-α B A B Ba 0.99 Ce 0.8 Gd 0.2 Zr 0.11 O 3-α B B C Ba 0.98 Ce 0.8 Gd 0.2 Zr 0.01 O 3-α B A A Ba 0.98 Ce 0.8 Gd 0.2 Zr 0.04 O 3-α B A B Ba 0.98 Ce 0.8 Gd 0.2 Zr 0.06 O 3-α B A B Ba 0.98 Ce 0.8 Gd 0.2 Zr 0.1 O 3-α B A B Ba 0.98 Ce 0.8 Gd 0.2 Zr 0.11 O 3-α B B C Ba 0.98 Ce 0.8 Gd 0.16 Zr 0.04 O 3-α B A B Ba 0.98 Ce 0.8 Gd 0.23 Zr 0.04 O 3-α B A B Ba 0.98 Ce 0.8 Gd 0.26 Zr 0.04 O 3-α B A A Ba 0.9 Ce 0.8 Gd 0.2 Zr 0.01 O 3-α B A B Ba 0.9 Ce 0.8 Gd 0.2 Zr 0.04 O 3-α B A C Ba 0.9 Ce 0.8 Gd 0.2 Zr 0.06 O 3-α B A C Ba 0.9 Ce 0.8 Gd 0.2 Zr 0.1 O 3-α A A C Ba 0.9 Ce 0.8 Gd 0.2 Zr 0.11 O 3-α A B D Ba 0.89 Ce 0.8 Gd 0.2 Zr 0.01 O 3-α B A C Ba 0.85 Ce 0.8 Gd 0.2 Zr 0.04 O 3-α B A D TABLE 3 Additive System Material Boiling Test Crystallinity Conductivity Ba 0.98 Ce 0.8 Gd 0.2 Zr 0.04 O 3-α B A B Ba 0.99 Ce 0.8 Gd 0.2 Zr 0.01 O 3-α B A A Ba 0.9 Ce 0.8 Gd 0.2 Zr 001 O 3-α B A C Ba 0.98 Ce 0.8 Gd 0.2 Zr 0.04 O 3-α B A C Ba 0.99 Ce 0.8 Gd 0.2 Zr 0.01 O 3-α B A B Ba 0.9 Ce 0.8 Gd 0.2 Zr 0.01 O 3-α B A C Ba 0.98 Ce 0.8 Gd 0.2 Zr 0.04 O 3-α B A B Ba 0.99 Ce 0.8 Gd 0.2 Zr 0.01 O 3-α B A B Ba 0.9 Ce 0.8 Gd 0.2 Zr 0.01 O 3-α B A C Ba 0.98 Ce 0.8 Gd 0.2 Zr 0.04 O 3-α B A B Ba 0.99 Ce 0.8 Gd 0.2 Zr 0.01 O 3-α B A B Ba 0.9 Ce 0.8 Gd 0.2 Zr 0.1 O 3-α B A C Ba 0.98 Ce 0.8 Pm 0.2 Zr 0.04 O 3-α B A B Ba 0.99 Ce 0.8 Pm 0.2 Zr 0.01 O 3-α B A B Ba 0.9 Ce 0.8 Pm 0.2 Zr 0.1 O 3-α B A C Ba 0.98 Ce 0.8 Sm 0.2 Zr 0.04 O 3-α B A B Ba 0.99 Ce 0.8 Sm 0.2 Zr 0.01 O 3-α B A A Ba 0.9 Ce 0.8 Sm 0.2 Zr 0.1 O 3-α B A C Ba 0.98 Ce 0.8 Eu 0.2 Zr 0.04 O 3-α B A B Ba 0.99 Ce 0.8 Eu 0.2 Zr 0.01 O 3-α B A A Ba 0.9 Ce 0.8 Eu 0.2 Zr 0.1 O 3-α B A C Ba 0.98 Ce 0.8 Tb 0.2 Zr 0.04 O 3-α B A B Ba 0.99 Ce 0.8 Tb 0.2 Zr 0.01 O 3-α B A A Ba 0.9 Ce 0.8 Tb 0.2 Zr 0.1 O 3-α B A C Ba 0.98 Ce 0.8 Dy 0.2 Zr 0.04 O 3-α B A B Ba 0.99 Ce 0.8 Dy 0.2 Zr 0.01 O 3-α B A A Ba 0.9 Ce 0.8 Dy 0.2 Zr 0.1 O 3-α B A C Ba 0.98 Ce 0.8 Ho 0.2 Zr 0.04 O 3-α B A B Ba 0.98 Ce 0.8 Ho 0.2 Zr 0.01 O 3-α B A B Ba 0.9 Ce 0.8 Ho 0.2 Zr 0.1 O 3-α B A C Ba 0.98 Ce 0.8 Er 0.2 Zr 0.04 O 3-α B A B Ba 0.99 Ce 0.8 Er 0.2 Zr 0.01 O 3-α B A A Ba 0.9 Ce 0.8 Er 0.2 Zr 0.1 O 3-α B A C Ba 0.98 Ce 0.8 Tm 0.2 Zr 0.04 O 3-α B A B Ba 0.99 Ce 0.8 Tm 0.2 Zr 0.01 O 3-α B A B Ba 0.9 Ce 0.8 Tm 0.2 Zr 0.1 O 3-α B A C Ba 0.98 Ce 0.8 Yb 0.2 Zr 0.04 O 3-α B A B Ba 0.99 Ce 0.8 Yb 0.2 Zr 0.01 O 3-α B A A Ba 0.9 Ce 0.8 Yb 0.2 Zr 0.1 O 3-α B A C TABLE 4 Additive System Material Boiling Test Crystallinity Conductivity Ba 0.99 Ce 0.8 Gd 0.2 Ti 0.01 O 3-α B A C Ba 0.99 Ce 0.8 Gd 0.2 Ti 0.1 O 3-α B A C Ba 0.98 Ce 0.8 Gd 0.2 Ti 0.04 O 3-α B A C Ba 0.9 Ce 0.8 Gd 0.2 Ti 0.1 O 3-α A A C Ba 0.98 Ce 0.8 Gd 0.16 Ti 0.04 O 3-α B A C Ba 0.99 Ce 0.8 Gd 0.2 Ti 0.01 O 3-α B A A Ba 0.99 Ce 0.8 Gd 0.2 Ti 0.1 O 3-α B A B Ba 0.98 Ce 0.8 Gd 0.2 Ti 0.04 O 3-α B A B Ba 0.9 Ce 0.8 Gd 0.2 Ti 0.1 O 3-α A A C Ba 0.98 Ce 0.8 Gd 0.16 Ti 0.04 O 3-α B A B Ba 0.99 Ce 0.8 Gd 0.2 Pb 0.01 O 3-α B A B Ba 0.99 Ce 0.8 Gd 0.2 Pb 0.1 O 3-α B A C Ba 0.98 Ce 0.8 Gd 0.2 Pb 0.04 O 3-α B A C Ba 0.9 Ce 0.8 Gd 0.2 Pb 0.1 O 3-α A A C Ba 0.98 Ce 0.8 Gd 0.16 Pb 0.04 O 3-α B A C Ba 0.99 Ce 0.8 Gd 0.2 Ga 0.01 O 3-α B A A Ba 0.99 Ce 0.8 Gd 0.2 Ga 0.1 O 3-α B A C Ba 0.98 Ce 0.8 Gd 0.2 Ga 0.04 O 3-α B A B Ba 0.9 Ce 0.8 Gd 0.2 Ga 0.1 O 3-α A A C Ba 0.98 Ce 0.8 Gd 0.2 Ga 0.04 O 3-α B A B Ba 0.98 Ce 0.8 Gd 0.2 V 0.04 O 3-α C A C Ba 0.98 Ce 0.8 Gd 0.2 Nb 0.04 O 3-α C A C Ba 0.98 Ce 0.8 Gd 0.2 Cr 0.04 O 3-α C A C Ba 0.98 Ce 0.8 Gd 0.2 Mo 0.04 O 3-α C A C Ba 0.98 Ce 0.8 Gd 0.2 W 0.04 O 3-α C A C Ba 0.98 Ce 0.8 Gd 0.2 Fe 0.04 O 3-α B A C Ba 0.98 Ce 0.8 Gd 0.2 Co 0.04 O 3-α B A C Ba 0.98 Ce 0.8 Gd 0.2 Ni 0.04 O 3-α B A C Ba 0.98 Ce 0.8 Gd 0.2 Cu 0.04 O 3-α B A B Ba 0.98 Ce 0.8 Gd 0.2 Ag 0.04 O 3-α C A B Ba 0.98 Ce 0.8 Gd 0.2 Au 0.04 O 3-α C A B Ba 0.98 Ce 0.8 Gd 0.2 Pd 0.04 O 3-α C A B Ba 0.98 Ce 0.8 Gd 0.2 Pt 0.04 O 3-α C A B Ba 0.98 Ce 0.8 Gd 0.2 Sb 0.04 O 3-α B A C Ba 0.98 Ce 0.8 Gd 0.2 Sn 0.04 O 3-α B A C TABLE 5 Barium-Zirconium System Material Boiling Test Crystallinity Conductivity BaZr 0.84 Y 0.16 O 3-α A A C BaZr 0.8 Y 0.2 O 3-α A A C BaZr 0.75 Y 0.25 O 3-α A A C BaZr 0.7 Y 0.3 O 3-α A A B BaZr 0.65 Y 0.35 O 3-α B C not measured BaZr 0.8 In 0.2 O 3-α A A C BaZr 0.7 In 0.3 O 3-α A A B BaZr 0.95 Gd 0.05 O 3-α A A C BaZr 0.84 Gd 0.16 O 3-α A A C BaZr 0.8 Gd 0.2 O 3-α A A C BaZr 0.75 Gd 0.25 O 3-α A A C BaZr 0.7 Gd 0.3 O 3-α A A B BaZr 0.65 Gd 0.35 O 3-α B C not measured BaZr 0.84 Sc 0.16 O 3-α A A C BaZr 0.7 Sc 0.3 O 3-α A A B BaZr 0.84 Bi 0.16 O 3-α B A C BaZr 0.8 Bi 0.2 O 3-α A A C BaZr 0.75 Bi 0.25 O 3-α A A C BaZr 0.7 Bi 0.3 O 3-α A A C BaZr 0.95 Yb 0.06 O 3-α A A C BaZr 0.84 Yb 0.16 O 3-α A A C BaZr 0.8 Yb 0.2 O 3-α A A C BaZr 0.75 Yb 0.25 O 3-α A A C BaZr 0.7 Yb 0.3 O 3-α B A C BaZr 0.84 Dy 0.16 O 3-α B A B BaZr 0.75 Dy 0.25 O 3-α A A C BaZr 0.99 La 0.01 O 3-α A A C BaZr 0.95 La 0.05 O 3-α A A C BaZr 0.84 La 0.16 O 3-α A A C BaZr 0.95 Pr 0.05 O 3-α A A C BaZr 0.84 Pr 0.16 O 3-α A A C BaZr 0.75 Pr 0.25 O 3-α A A B BaZr 0.9 Nd 0.1 O 3-α A A C BaZr 0.84 Nd 0.16 O 3-α A A C BaZr 0.9 Pm 0.1 O 3-α A A C BaZr 0.84 Pm 0.16 O 3-α A A C BaZr 0.84 Sm 0.16 O 3-α A A C BaZr 0.8 Sm 0.2 O 3-α A A C BaZr 0.9 Eu 0.1 O 3-α A A C BaZr 0.82 Eu 0.18 O 3-α A A C BaZr 0.8 Eu 0.2 O 3-α A A B BaZr 0.82 Tb 0.18 O 3-α A A C BaZr 0.8 Ho 0.2 O 3-α A A C BaZr 0.74 Er 0.26 O 3-α A A C BaZr 0.72 Tm 0.28 O 3-α A A C BaZr 0.8 Ga 0.2 O 3-α A A C BaZr 0.7 Ga 0.3 O 3-α A A C BaZr 0.8 Sn 0.2 O 3-α A A C BaZr 0.75 Sn 0.25 O 3-α A A C BaZr 0.72 Bi 0.28 O 3-α A A C TABLE 6 Barium Zirconium Cerium System Material Boiling Test Crystallinity Conductivity BaCe 0.1 Zr 0.74 Y 0.16 O 3-α B A B BaCe 0.2 Zr 0.64 Y 0.16 O 3-α A A C BaCe 0.4 Zr 0.4 Y 0.2 O 3-α B A A BaCe 0.05 Zr 0.9 Gd 0.05 O 3-α A A C BaCe 0.15 Zr 0.65 Gd 0.2 O 3-α A A C BaCe 0.4 Zr 0.4 Gd 0.2 O 3-α B A A BaCe 0.5 Zr 0.3 Gd 0.2 O 3-α B A A BaCe 0.2 Zr 0.6 Gd 0.2 O 3-α A A B Ba 0.99 Ce 0.2 Zr 0.6 Gd 0.2 O 3-α A A B BaCe 0.35 Zr 0.5 Gd 0.15 O 3-α A A A Ba 0.99 Ce 0.35 Zr 0.5 Gd 0.15 O 3-α A A A BaCe 0.4 Zr 0.45 Gd 0.15 O 3-α A A B BaCe 0.4 Zr 0.5 Gd 0.1 O 3-α A A B BaCe 0.1 Zr 0.7 Gd 0.29 O 3-α A A C BaCe 0.05 Zr 0.85 Gd 0.1 O 3-α A A C BaCe 0.2 Zr 0.65 Sc 0.05 O 3-α A A C BaCe 0.05 Zr 0.8 Sc 0.15 O 3-α A A C BaCe 0.05 Zr 0.85 Bi 0.1 O 3-α A A C BaCe 0.2 Zr 0.6 Bi 0.2 O 3-α A A C BaCe 0.4 Zr 0.55 Bi 0.05 O 3-α A A C BaCe 0.05 Zr 0.7 Bi 0.25 O 3-α A A C BaCe 0.05 Zr 0.9 Yb 0.05 O 3-α A A C BaCe 0.2 Zr 0.75 Yb 0.05 O 3-α A A C BaCe 0.4 Zr 0.4 Yb 0.2 O 3-α B A A BaCe 0.05 Zr 0.7 Yb 0.25 O 3-α A A C BaCe 0.1 Zr 0.6 Yb 0.3 O 3-α A A C BaCe 0.05 Zr 0.8 Dy 0.15 O 3-α A A C BaCe 0.2 Zr 0.7 Dy 0.1 O 3-α A A C BaCe 0.2 Zr 0.75 La 0.05 O 3-α A A C BaCe 0.05 Zr 0.85 La 0.05 O 3-α A A BaCe 0.4 Zr 0.4 La 0.2 O 3-α A A C BaCe 0.2 Zr 0.75 Pr 0.05 O 3-α A A C BaCe 0.4 Zr 0.5 Pr 0.1 O 3-α B A C BaCe 0.2 Zr 0.7 Nd 0.1 O 3-α A A C BaCe 0.4 Zr 0.45 Nd 0.05 O 3-α B A B BaCe 0.4 Zr 0.4 Nd 0.2 O 3-α B A B BaCe 0.4 Zr 0.4 Pm 0.2 O 3-α B A C BaCe 0.4 Zr 0.5 Pm 0.1 O 3-α B A C BaCe 0.4 Zr 0.5 Sm 0.1 O 3-α B A B BaCe 0.1 Zr 0.7 Sm 0.2 O 3-α A A C BaCe 0.4 Zr 0.4 Eu 0.2 O 3-α B A B BaCe 0.4 Zr 0.5 Eu 0.1 O 3-α B A C BaCe 0.4 Zr 0.4 Eu 0.2 O 3-α B A C BaCe 0.4 Zr 0.55 Tb 0.05 O 3-α B A C BaCe 0.05 Zr 0.8 Ho 0.15 O 3-α A A C BaCe 0.5 Zr 0.4 Er 0.1 O 3-α B A C BaCe 0.5 Zr 0.35 Tm 0.15 O 3-α B A C BaCe 0.4 Zr 0.4 Ga 0.2 O 3-α B A C BaCe 0.05 Zr 0.7 Ga 0.25 O 3-α A A C BaCe 0.1 Zr 0.8 Sn 0.1 O 3-α A A C BaCe 0.05 Zr 0.75 Sn 0.2 O 3-α A A C BaCe 0.4 Zr 0.4 Sb 0.2 O 3-α B A C BaCe 0.4 Zr 0.4 In 0.2 O 3-α B A A Ba 0.99 Ce 0.4 Zr 0.4 In 0.2 O 3-α B A A BaCe 0.2 Zr 0.6 In 0.2 O 3-α A A B BaCe 0.3 Zr 0.5 In 0.2 O 3-α A A A BaCe 0.4 Zr 0.4 In 0.1 O 3-α A A A BaCe 0.5 Zr 0.4 In 0.1 O 3-α A A A BaCe 0.5 Zr 0.3 In 0.2 O 3-α A A A BaCe 0.5 Zr 0.3 In 0.1 O 3-α B A A As becomes clear from this evaluation, mixed ionic conductors in accordance with the present invention have considerably better moisture resistance, while the ion conductivity can be held at a practical level. The above examples have been synthesized by solid state sintering, but there is no limitation to this method, and the oxide also can be synthesized by coprecipitation, nitration, spray granulation or any other suitable method. It is also possible to use film forming methods such as CVD or sputtering methods. It is also possible to use thermal spraying. There is no limitation to the shape of the oxide, and it can be of any shape, including bulk shapes and films. The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The embodiments disclosed in this application are to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, all changes that come within the meaning and range of equivalency of the claims are intended to be embraced therein.

A mixed ionic conductor with an ion conductive oxide has a perovskite structure of the formula Ba d Zr 1−x−y Ce x M y 3 O 3−γ wherein M 3 is at least one element selected from the group consisting of Sm, Eu, Gd, Tb, Yb, Y, Sc, and In; with 0.98≦d≦1; 0.01≦x<0.5; 0.01≦y≦0.3; (2+y−2d)/2≦γ<1.5. Such a mixed ionic conductor has not only the necessary conductivity for electrochemical devices such as fuel cells, but also superior moisture resistance.

BACKGROUND OF THE INVENTION In a principal aspect, the present invention comprises a lock useful for latching a cover to a platform and, more particularly, to a lock having a bolt comprised of opposed and pivoting latch members which positively lock with opposite sides of a strike opening. Storage containers, hard top carriers, and various types of enclosures desirably require the use of a lock which enables lifting of an enclosure cover from a platform when the locking member of the lock is in the unlocked position and positive locking or latching of the cover to the platform when the cover is lowered against the platform to a closed position. Prior art systems which have been used for latching, for example, a car top carrier box against a platform, incorporate latching levers which are biased to a locked position by a spring member. To unlock such a mechanism it is necessary to have a means for mechanically engaging the levers and move them against the biasing force of the spring thereby releasing the latch. Should the spring break or otherwise become disabled through corrosion or due to other circumstances, the lock may become disabled. As a consequence development of a lock mechanism which does not require a spring means in order to maintain the lock in the locked position is deemed desirable. Prior art patents which exemplify locks designed for such environments include U.S. Pat. No. 4,976,123 and U.S. Pat. No. 5,119,654. While such lock mechanisms are useful, there has remained a need for an improved lock mechanism particularly for use in combination with car top carriers and other types of enclosures wherein a box-like enclosure is fitted against a platform and it is desired to lock the enclosure to the platform. SUMMARY OF THE INVENTION Briefly the present invention comprises a lock which includes a housing that is generally planar in construction with pivotally attached first and second, planar bolt lever arms. A cylinder with a key actuated plug is also mounted in the housing in a manner which permits a rotatable stud extending from the plug to project between the two bolt lever arms. The stud is configured so that when the plug is rotated by actuation of a key, the end of the stud will engage the lever arms causing them to pivot thereby separating and positively engaging the opposite sides of a strike. The plug is constructed so that the key can be removed from the plug only when the plug is in the locked position. When in the locked position, the bolt lever arms are positively, mechanically engaged by the actuating stud and locked to the strike. Consequently, even though springs are provided to bias the bolt lever arms toward the unlocked position, failure of the springs when the lock is in the locked position will not result in failure of the lock. The lock will remain in the locked position since it is mechanically forced and maintained in that position by the projecting stud which engages the bolt lever arms. The lock further includes features which facilitate its utility to hold a carrier box in combination and joined to a platform. Thus there is a protective tongue or plate associated with the housing which fits over and parallel to the bolt lever arms to protect the lever arms and prevent them from being inadvertently engaged. The geometry of the housing and the bolt lever arms is chosen so as to physically protect the lever arms and provide the most beneficial mechanical advantage when operating the lever arms. The housing is fashioned and fabricated in a manner which protects the user from the moving parts of the lock and which also enhances the ability to easily mount the lock in a manner which promotes sealing or water tight installation. Thus it is an object of the invention to provide an improved lock construction for use in many environments and especially for use in combination with hard top carriers and similar types of storage assemblies. It is a further objection of the invention to provide a lock which includes a mechanism for positively engaging bolt members with a strike when the lock is in the locked position. Yet another object of the invention is to provide a lock which includes a minimum number of mechanical parts, which may be efficiently and easily manufactured, which is economical, and which is easy to install. These and other objects, advantages, and features of the invention will be set forth in the detailed description which follows. BRIEF DESCRIPTION OF THE DRAWING In the detailed description which follows reference will be made to the drawing comprised of the following figures: FIG. 1 is an exploded isometric view of the lock construction of the invention; FIG. 2 is a plane view of the lock construction in the unlocked position; FIG. 3 is a plane view of the lock in the locked position wherein the cover for the housing has been removed to illustrate the internal construction of the bolt lever arms; FIG. 4 is a plane view of the front side of the lock in the unlocked position; FIG. 5 is a side elevation of the lock of FIGS. 2 and 4; FIG. 6 is a top plane view of the lock of FIG. 4; FIG. 7 is a isometric view of the strike utilizing combination with the lock of FIGS. 1-6; FIG. 8 is a lower or bottom side elevation of the strike of FIG. 7; FIG. 9 is a side elevation of the strike of FIG. 7; FIG. 10 is a partial sectional view of the strike of FIG. 9 taken along the line 10 — 10 . DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the figures, the embodiment of the invention includes a bracket 20 with first and second lever arms or latch bars 22 and 24 pivotally mounted thereon and biased respectively by springs 26 and 28 for pivotal movement toward one another about pivot connections, pivot points, or pivot support studs 30 and 32 , respectively. A protective cover 34 fits over and facilitates retention of the bolt members or latch bars 22 and 24 on studs 30 , 32 . The lock further includes a cylinder 36 integrally cast or formed with and projecting axially from the bracket 20 transverse to the plane of rotation of latch bars 22 , 24 . Cylinder 36 includes a rotatable plug 38 mounted for axial rotation in the cylinder 36 . The plug 38 includes a projecting, generally elliptically shaped, inner end stud 40 which is designed to cooperate and actuate the latch bars or bolts 22 and 24 as described hereinafter. A retainer clip 42 fits over the inside end of the stud 40 to retain the plug 38 rotatably mounted within cylinder 36 of bracket 20 and thereby hold the cover 34 over the bracket 20 and latch bars 22 , 24 . The bracket 20 further includes a planar, projecting tongue or plate 44 which is parallel to and fits against the latch bars 22 and 24 to provide protection during movement of those latch bars 22 and 24 . The bracket 20 further includes laterally projecting wings or arms 50 and 52 with fastener openings 54 and 56 , respectively for attachment of the bracket 20 to the inside face of a car top carrier cover or platform, as the case may be. The cylinder 36 includes an annular surface or land 58 that acts as a sealing surface for the cylinder 36 and for attachment of the bracket to a cover or platform as the case may be. Thus, as depicted in FIG. 6, the bracket 20 may be attached to a housing 60 to position the cylinder 36 including a forward section 62 , an annular seal 58 and a rear enlarged diameter section 64 with respect thereto. The wings or arms 50 and 52 include fasteners (not shown) for attachment of the lock to the housing, platform or cover 60 as the case may be. When attached as described, the latch bars 22 and 24 project or extend or pivot laterally from the sides of bracket 20 and are designed to engage with a strike 70 as illustrated in FIG. 1 wherein the strike 70 includes a strike opening 72 having opposite sides 74 and 76 . The latch bars 22 , 24 are normally biased by springs 26 , 28 to the position illustrated in FIG. 2 when the plug stud 40 is rotated so that the stud 40 will not engage against inside cam surfaces 23 and 25 of the latch bars 22 and 24 , respectively. Thus, the springs 26 , and 28 will bias the latch bars 22 and 24 to the position shown in FIG. 2 . The latch bars 22 , 24 may then pass into the opening 72 of the strike 70 . The plug 38 may then be rotated to the locked position illustrated by FIG. 3 so that the latch bars 22 and 24 will spread or pivot apart, and more particularly, projecting teeth 19 and 21 of the latch bars 22 and 24 will engage through the opening 72 and engage with the opposite sides 74 and 76 of the strike 70 . The stud 40 thus provides a means for locking the latch bars 22 and 24 . The plug 38 is keyed so that the key 39 can be removed only when the lock or latch bars 22 and 24 are in the latched or locked position. Otherwise, the key 39 cannot be removed from the plug 38 . The cover or tongue 44 protects a user from inadvertently catching their fingers or hand in the latch bars 22 , 24 . Additionally, the cover 44 also protects the latch bars 22 , 24 from manipulation from the outside of the platform and serves to protect the integrity of the latch bars 22 , 24 in the latched position. Further, in the event the springs 26 and 28 break or fail, their breakage or failure is inconsequential with respect to the maintenance of the platform or latch bars 22 , 24 in the locked position. The stud 40 acts to engage the lock and maintain it in the locked position and the fact that it is in the locked position, does not depend upon whether the springs 26 and 28 fail. In the preferred embodiment, the pivot axes of the pivots 30 and 32 are parallel and extend axially in the same direction as the axis of the plug 38 . Thus, the stud 40 and the pivot axes of the latch bars 22 and 24 are all parallel. The plug 38 may be easily removed when the assembly is exposed in that the cover 34 provides a retention space 35 for access to the retention clip 42 . By removing the retention clip 42 , one can remove the plug 38 and cover 34 and thus replace the plug 38 with a rekeyed plug 38 . Removal of the entire latch assembly is thus not necessary in order to rekey the lock. The recess 35 also serves to protect the retaining clip 42 so that it will not be inadvertently removed or engaged. The shape of retaining wall 37 about the recess 35 thus facilitates its accessibility as well as its protectability. While there has been set forth a preferred embodiment of the invention, it is to be understood that the invention is to be limited only by the following claims and equivalents thereof.

A lock for attaching a cover to a platform includes first and second pivotally mounted latch bars which spread to engage side walls of a strike opening in response to actuation of a key actuated rotatable plug mounted in the housing of the lock. The latch bars are mechanically spread to engage the strike in a positive manner and do not rely upon biasing means to maintain the lock in the locked position.

This invention relates to a liquid heater assembly or unit and more particularly to a water heater unit for heating water passing therethrough. More specifically, the present invention relates to an "out-of-water" heater as contrasted with conventional immersed heaters for heating the water in flow systems such as those for hot tubs and spas. BACKGROUND OF THE INVENTION Many types of heater units have been designed for heating water in which the water is passed through a passageway located within a heat conducting member in which is located a heating element. The heat generated by the heating element is transferred from the heating element to the passageway for heating the water as it flows through the passageway. Various configurations of such heaters have been devised but have lacked efficiency in utilizing the heat generated by the heating element. This lack of efficiency is because of the location of the heating element with relation to the passageways flowing through the heat conductive member and also because of the inefficiency in transferring the heat from the heat conductive member to the water passageway or passageways extending through the heat conductive member. BRIEF SUMMARY OF THE INVENTION In accordance with my invention, I provide an elongated heat conductive member having a plurality of elongated water passageways equally spaced about the central axis of the heat conductive member. An elongated electrical heating element, electrically isolated from the heat conductive member, is located substantially on the central axis of the heat conductor member which is constructed of a solid heat conductive material substantially encompassing the entire outer walls of the tubular member for conducting heat radiated from the heating element to the water passageways. The passageways in the heat conductive member are spaced one from another less than the cross-sectional dimension of the electrical heating element thereby minimizing the transmission of heat from the heating element to the outer surface of heat conducting member and maximizing the radiation of the heat to the passageway through which the water flows. In my preferred form the number of passageways through the heat conductive member should be sufficient (preferably four or more) to substantially surround the heating elements so as to substantially trap the heat radiated by the heating element in the central portion of the heat conductive member to heat the water from the inside while keeping the outer surface of the heat conductor member relative cool. In the preferred form of this invention, the passageways through the elongated heat conductive member is provided by openings extending through the heat conductive member and receiving tubular members or tubes, preferably stainless steel, through which the water flows. The heating element is located in a central opening extending through the elongated heat conductive member. In one embodiment fluid passageway caps are attached to the ends of the tubes for causing the water to flow in one of the tubes at one of the ends of the heater unit, through all the tubes and out another tube at the same end of the unit. In another embodiment the tubes extend beyond the ends of the heat conductive member and on the ends thereof are located manifold fittings which combine the flow of water through the tubular members so that the flow is straight through each tube, the fittings are in turn connected to pipes extending to the hot tub, spa, or other devices. In order to further maximize the transfer of the heat from the heating element into the tubes or tubular members, I have conceived expanding the tubes against the walls of openings to insure a tight fit. This facilitates maximum heat transfer from the heat conductive member through the tubes into the water. In accordance with this method, each tubular member is inserted into the elongated opening of the conductive member and then hydraulic fluid under high pressure is forced into the inside of the tubular member or tube thereby causing the wall of the tube to be forced against the wall of the opening in the conductive member. This is preferably accomplished by inserting a probe inside the tubular member and providing sealer members at selected positions to select the section of the tubular member to be expanded. The fluid is preferable forced into the inside of the tubular member by a high pressure hydraulic pump. BRIEF DESCRIPTION OF THE DRAWINGS My invention will now be described in detail with reference to the accompanying drawings wherein: FIG. 1 is a side elevational perspective view of one of the embodiments of my heater unit invention; FIG. 2 is a top plan view of the same; FIG. 3 is a cross sectional view of the heat conductor member taken along the plane III--III of FIG. 2; FIG. 4 is a side elevational, exploded view of several components of the heater of this invention; FIG. 5 is a cross-sectional view taken along the plane V--V of FIG. 2; FIG. 6 is a side elevational view of the end cap assembly located on the left end of the heater unit of FIG. 2; FIG. 7 is a top plan view of the end cap assembly of FIG. 6; FIG. 8 is an end view of the end cap assembly of FIG. 6; FIG. 9 is a side elevational view of the end cap assembly on the right end of the heater unit of FIG. 2; FIG. 10 is a plan view of the end cap assembly of FIG. 9; FIG. 11 is an end view of the end cap assembly of FIG. 9; FIG. 12 is a cross-sectional view of one of the caps taken along the plane XII--XII of FIG. 8; FIG. 13 is schematic diagram of the flow path of the water through the heater unit of FIGS. 1 and 2; FIG. 14 is a side elevational, perspective view of another one of the embodiment of my heater unit invention; FIG. 15 is a top plan view of the heater unit of FIG. 14; FIG. 16 is a end view of one of the ends of the heater unit of FIGS. 14 and 15; FIG. 17 is a modified version of the heat conductor member of FIG. 3; FIG. 18 discloses apparatus for expanding a tube within one of the openings of the heat conductive member. DETAILED DESCRIPTION Referring to the drawings, particularly FIGS. 1, 2 and 3, reference numeral 1 designates one embodiment of my heating unit invention which includes the tubular members or tubes 10a, 10b, 10c, and 10d (FIG. 7), heat conductive member 20, and end cap assemblies 40 and 41. Heat conductive member 20 is constructed of a highly heat conductive materials such as aluminum and includes four openings 21a, 21b, 21c, and 21d (FIG. 3) through which the tubes 10a, 10b, 10c, and 10d extend therethrough, respectively. Tubes 10a, 10b, 10c, and 10d are constructed of stainless steel and are tightly fit within the openings 21a, 21b, 21c, and 21d by expanding them within the openings by a unique method as will be explained hereinafter. Heat conductive member 20 preferably has the configuration as disclosed in FIG. 3 which in addition to the openings 21a, 21b, 21c, and 21d includes the recesses 22, 23, 24, and 25. Recess 22 is provided to receive a capillary bulb thermostat (not shown) to sense the temperature of the conductive member which is representative of the heat of the water flowing through the tubes. Recess 23 is provided to accommodate the head of a machine bolt (now shown) for mounting the heating unit 1 on a bracket or other type of support means. The slot or recess 24 is shown attaching a thermostat or over temperature protective device 26 by the sheet metal screws 27 as disclosed in both FIGS. 2 and 3. Recess or slot 25 is provided for the receiving a screw (not shown) for mounting purposes. An opening 28 is located centrally on the axis X of the elongated heat conductive member and extends along its entire length. This opening 28 receives a heater element 30 which will be described in greater detail hereinafter. As disclosed in FIGS. 1 and 2, the tubular members 10a, 10b, 10c, and 10d extend beyond both ends of the heat conductive member and on the ends of the tubular members are received the end cap assemblies 40 and 41 which in the embodiment of FIGS. 1 and 2 are different. End cap assembly 40 is best disclosed in FIGS. 1, 2, 5, and 9-11. It includes a body 42a having at one end openings 40a, 40b, 40c, and 40d respectively receiving one end of the tubes 10a, 10b, 10c, and 10d. Opening 40d communicates with the outlet opening 43a of outlet tube 43 at the opposite end of the end cap assembly 40 while opening 40a communicates with the inlet opening 44a of the inlet tube 44 (FIG. 10). Openings 40c and 40b communicate with the cavity 45a of the caps 45 which provides for flow of water from tube 10c to tube 10b as will be explained hereinafter. End cap assembly 40 also includes an opening 70 for the electrical line leading to the heater element 30. The end cap assembly 41 is very similar to the end cap assembly 40. It includes the body 42 having openings 41a, 41b, 41c, and 41d, as disclosed in dotted lines in FIG. 8. These openings extend through the entire body of the end cap assembly 41 and communicate with tubes 10a, 10b, 10c, and 10d, respectively. Mounted over the opposite ends of openings 41c and 41d is cap 46 like that disclosed in FIG. 12. Cap 46 is shaped to extend into a recess 48 in body 42b. It includes cavity 46a which extends over openings 41d and 41c. Cap 47 is like cap 46, its cavity 46a extends over openings 41a and 41b. Therefore cap 47 provides communication between openings 41a and 41b whereas cap 46 provides communication between the openings 41c and 41d. FIG. 4 discloses in greater detail the heater element 30 located in opening 28 which extends the entire length of heat conductive member 20. It includes the resistant wire 31 located within the sheath 32 and connected at each end to a terminal 33 sometimes referred to as a cold pin. The end of the sheath is sealed with a epoxy. The terminal or cold pin 33 is electrically connected to an electric wire 35 at one end and at the other end to the wire 36 as disclosed in FIG. 1. Wire 36 is electrically connected to the thermostat 26 which is also connected to the wire 37. Wires 35 and 37 are in turn connected to the source of electricity. OPERATION Having described all of the elements of the embodiment of FIGS. 1-8, the basic operation should he evident. One of the tubes 43 or 44 of end cap assembly 40 is connected to the outlet of a pump which circulates water through the hot tub or spa. In the embodiment of FIGS. 1-12 it makes no difference which of the tubes 43 or 44 is connected to the pump or the inlet of the hot tub or spa. However as illustrated in FIG. 13, assuming the pump is connected to tube 44, the water flows through tube 10a, downwardly through end cap 47, through tube 10b, across end cap 45, through tube 10c, upwardly through end cap 46, through tube 10d and out of outlet 43. With the heating element connected to a source of electricity, the heat generated by the heating element 30 is radiated outwardly from the central axis of the heat conductor member through the heat conducting member and is transmitted through the tubes 10a, 10b, 10c, and 10d into the water, heating the water to a desired temperature as determined by thermostat 26 which controls the electrical power supplied to the heating element 30. As the heat generated by the heater element is transmitted through the aluminum of the heat conductive member a maximum amount of such heat radiated by the heater element is transferred to the water rather than to the outer surface of the heat conductive member 20. The reason for this is the relatively narrow path for the flow of heat between the openings 21a, 21b, 21c, and 21d. The distance of the openings spaced one from another is less than the cross sectional dimension of the overall electrical heating element whereby transmission of heat between the openings to the exterior surface of the heat conductive element 20 is restricted. This results not only in great efficiency in the heating of the water but also eliminates high degree of heat on the surface of the heat conductive member 20 which keeps the outer surface that might be contacted by the users cool. It should be evident from the above description that this concept of the use of several tubes surrounding a heating element thereby traps the heat in the center of the heat conducting member 20 until it can be transferred to the water. It should also be evident from the above description that in the use for hot tubs and spa in which chlorine chemicals are used to sanitize the water, the present invention substantially eliminates any serious corrosion such as experienced by current state-of-the-art heating units. The encased conduits through which the liquid passes is completely isolated from the heater and therefore the heater is isolated from the corrosive water. This also gives more freedom for the proper design of the heating element sheath. Exotic alloys generally required to prevent corrosion of the heating element sheaths are not required because the heating element is encased within the heat conductive member and completely isolated from any water. Therefore the life expectancy of the heater can be extended several fold. The present invention also provides a major benefit of safety. As opposed to prior art heating devices in the spa industry in which the heater is immersed in the water along with the user, the present invention completely isolates the heater from the water that the user is immersed in. Further, the aluminum extrusion can be grounded ensuring that even when the heater shorts to ground the water will not be electrified. This is particularly important since spa water which is treated with chemicals to sanitize it, can become a conductor of electrical current and the user can become a conductive path if the voltage radiant develops across the water. The present invention also allows one to heat liquids without having the liquid in contact with welds, cut material which will easily corrode, crevices in the metal, or metals which are easily damaged by heat. Therefore, as previously stated the present invention is a heater assembly which can be easily fabricated to avoid the normal corrosive pit falls that might be encountered in heaters for spas and hot tubs. As previously stated, the present invention also provides for an extremely tight fit between the water conduit stainless steel tubes and the walls of the openings in the heat conductive member 20. It is extremely important that a tight fit is insured to obtain the maximum efficiency of the heater unit. Another aspect of this invention is the method by which such a tight fit is accomplished. Such method will now be described. METHOD OF INSTALLING TUBES IN HEAT CONDUCTING MEMBER FIG. 18 discloses one of the tubular members or tubes 10a located within the opening 21a of the heat conductive member 20. In accordance with the method of this invention, a probe 50 is inserted inside of the tube 10a. This probe 50 is an elongated member having a central passageway 51 and a plurality of openings 52 extending radially from the central passageway 51 so that water forced through the passageway 51 is forced outwardly against the inner walls of the tube 10a. O-rings 53 and 54 are located between tube 10a and probe 50 so that pressurized hydraulic fluid is contained between the "O"rings only. The inner passageway 51 communicates with a high pressure pump system 60 through a pipe 61. Thus, high pressure hydraulic fluid is forced through pipe 61, passageway 62, inner passageway 51 and the openings 52 so as to exert extremely high pressure against the inner wall of the tube 10a causing it to be expanded between the O-rings which prohibit and seal off the flow of the hydraulic fluid through both of the ends of the tube 10a. I have discovered that expanding the stainless steel tubes by this high pressure hydraulic method insures a tight fit and facilitates maximum heat transfer to the water as the water flows through the tubes of the heater unit 1 while heat is being radiated from the centrally located heating element 30. MODIFICATION FIGS. 14, 15, and 16 disclose a modified heating unit 100 with a thermostat 126 like that at 26. In this embodiment the water is caused to flow in one direction through all of the tubes 110a, 110b, 110c, and 110d which correspond to the tubes previously described in relation to FIGS. 1, 2, 3, and 4. The tubes 110a, 110b, 110c, and 110d pass through the heat conducting member 120 which is constructed of the same material as member 20. In fact, the construction of the heating unit 100 is substantially identical to unit 10 except for dimensions and the ends thereof. Instead of the end cap assemblies of heater unit 1, manifold assemblies 140 and 141 are provided. The manifold assemblies 140 and 141 are identical and therefore only one of the manifold assemblies will described in detail. Manifold fitting 140 includes one end 140a having openings 111,112, 113, and 114 which receive the tubes 110c, 110d, 110a, and 110b, respectively. The openings such as openings 111, 112, 113, and 114 communicate with a manifold portion 123 which is configured to provide a flange 145 over which a two-piece collar 146 comprising the pieces 146a and 146b are connected together by screws. The interior circumference of the collar 146 is threaded to receive a pipe leading to a hot tub or spa or to the pump for the hot tub or spa. It should become evident from the drawings and the above description that the operation of the heater unit 100 is substantially the same as that of the heating unit 1. The only difference is that the heating unit 100 passes the water through all of the tubes in one direction. Another possible modification is disclosed in FIG. 17 which discloses a heat conductive member 80 have substantially the same configuration as the heat conductive member of FIG. 3. The only difference is the elimination of certain sections of the conductive member around the tubes leaving spaces 81, 82, 83, and 84. This construction provides a savings in material. Having described my invention, it should be understood that although I have disclosed preferred embodiments, to illustrate and describe the concepts and principles of my invention, it should be apparent to those skilled in the an that the illustrated embodiments may be modified without departing from such concepts and principles. I claim as my invention, not only the illustrated embodiment, but all such modifications, variations and equivalents thereof has come within this true spirit and scope of the following claims.

An elongated heat conductive assembly for heating water including a plurality of water passages equally spaced about the central axis of a heat conductive member in which an elongated electrical heating element is located on the central axis of the heat conductive member. Preferably the water passages are tubes located in a highly heat conductive member whereby the heat is trapped in the center of the conductive member from where it is transferred to the water. In one embodiment, caps are provided at the ends of the tubes so that the water enters a first end and flows to a second end and then back to the first end where it exits to the hot tub. In another embodiment, the water flows through one end to the other end from whence it flows to the hot tub. In another preferred embodiment the transfer of heat from the conductive member to the water flowing in the pipes is maximized by expanding the tubes against the walls of openings in the conductive member by applying hydraulic pressure inside the tubes.

This application is a divisional application of U.S. patent application Ser. No. 10/816,228, now U.S. Pat. No. 7,329,029, filed Mar. 31, 2004, to Chaves et al., entitled OPTICAL DEVICE FOR LED BASED LAMP, which is a continuation-in-part of: U.S. patent application Ser. No. 10/814,598 now abandoned, filed Mar. 30, 2004, to Chaves et al., entitled OPTICAL DEVICE FOR LED-BASED LAMP, which claims the benefit under 35 U.S.C. §119(e) of both provisional Application No. 60/470,691, filed May 13, 2003, to Miñano, entitled OPTICAL DEVICE FOR LED-BASED LIGHT-BULB SUBSTITUTE, and provisional Application No. 60/520,951, filed Nov. 17, 2003, to Falicoff et al., entitled COLOR-MIXING COLLIMATOR, each of provisional Application Nos. 60/470,691 and 60/520,951 are incorporated herein by reference in their entirety; and U.S. patent application Ser. No. 10/461,557, now U.S. Pat. No. 7,021,797, filed Jun. 12, 2003, to Miñano, et al., entitled OPTICAL DEVICE FOR LED-BASED LIGHT-BULB SUBSTITUTE, which claims the benefit under 35 U.S.C. §119(e) of provisional Application No. 60/470,691, filed May 13, 2003, to Miñano, entitled OPTICAL DEVICE FOR LED-BASED LIGHT-BULB SUBSTITUTE, each of U.S. patent application Ser. Nos. 10/816,228, now U.S. Pat. No. 7,329,029 and 10/461,557, and provisional Application No. 60/470,691 are incorporated herein by reference in their entirety. The present embodiments may be further understood and/or can also be utilized with the embodiments described in U.S. patent application Ser. No. 10/461,557, now U.S. Pat. No. 7,021,797, filed Jun. 12, 2003, to Miñano et al., entitled OPTICAL DEVICE FOR LED-BASED LIGHT-BULB SUBSTITUTE, which is incorporated herein by reference in its entirety. BACKGROUND OF THE INVENTION The present invention relates to light-emitting diodes (LEDs), particularly optical means for producing various far-field light intensity distributions for LEDs. Conventional incandescent lamps of less than 100 lumens output can be matched by the latest white LEDs, albeit at a higher price. At this low end of the lumen range, the majority of incandescent applications are battery-powered. It is desirable to have an LED suitable for direct installation in the place of a burnt-out flashlight bulb. LED's can offer superior luminous efficacy over the conventional incandescent lamps used in battery-operated flashlights. Moreover, LEDs are far more tolerant of shock, vibration, and crush-stress. Although they currently cost more to produce than the incandescents, their lifetimes are ten thousand times longer. For the sake of efficacy flashlight bulbs are run hot so they typically last only a few hours until filament failure. Also, the prices of LEDs continue to fall, along with those of the control-electronics to handle variations in battery voltage. Indeed, LED flashlights are commercially available already, but their optics have to be adapted to the geometry of light-emitting diodes, which only emit into a hemisphere. Conventional LED lamps are unsuitable for direct installation into conventional flashlights, both electrically and optically. LED lamps are electrically unsuitable because they are current-driven devices, whereas batteries are voltage sources. Typical variations in the voltage of fresh batteries are enough to exceed an LED's tolerable operating-voltage range. This causes such high currents that the Ohmic heating within the die exceeds the ability of thermal conduction to remove it, causing a runaway temperature-rise that destroys the die. Therefore, a current-control device must accompany the lamp. Conventional LED lamps are optically unsuitable for direct installation into the parabolic reflectors of flashlights. This is because their bullet-lens configuration forms a narrow beam that would completely miss a nearby parabola. Using instead a hemispherically emitting non-directional dome, centered on the luminous die, gives the maximum spread commercially available, a Lambertian pattern, with a sin 2 θ dependence of encircled flux on angle θ from the lamp axis. Since θ for a typical parabolic flashlight reflector extends from 45° to 135°, an LED with a hemispheric pattern is mismatched because it's emission falls to zero at only θ=90°. This would result in a beam that was brightest on the outside and completely dark halfway in. Worse yet, even this inferior beam pattern from a hemispheric LED would require that it be held up at the parabola's focal point, several millimeters above the socket wherein a conventional incandescent bulb is installed. Another type of battery-powered lamp utilizes cylindrical fluorescent lamps. Although LEDs do not yet offer better luminous efficacy, fluorescent lamps nonetheless are relatively fragile and require unsafely high voltages. A low-voltage, cylindrical LED-based lamp could advantageously provide the same luminous output as a fluorescent lamp. Addressing the needs above, U.S. patent application Ser. No. 10/461,557, OPTICAL DEVICE FOR LED-BASED LIGHT-BULB SUBSTITUTE, filed Jun. 12, 2003, which is hereby incorporated by reference in its entirety, discloses such LED-based lamps with which current fluorescent and incandescent bulb flashlights can be retrofitted. It often desirable, however, for LED lamps such as those described in U.S. patent application Ser. No. 10/461,557 to have other far-field intensity distributions of interest. Also, U.S. patent application Ser. No. 10/461,557 touched on the function of color mixing, to make the different wavelengths of chips 23, 24, and 25 of FIG. 2 of U.S. patent application Ser. No. 10/461,557 have the same relative strengths throughout the light coming out of ejector section 12. This assures that viewers will see only the intended metameric hue and not any colors of the individual chips. Previously, rectangular mixing rods have been used to transform the round focal spot of an ellipsoidal lamp into a uniformly illuminated rectangle, typically in cinema projectors. Generally, polygonal mixing rods worked best with an even number of sides, particularly four and six. With color mixing for LEDs, however, such rods are inefficient because half of an LED's Lambertian emission will escape from the base of the rod. There is thus a need in the art for effective and optically suitable LED lamps with various far-field intensity distributions and have proper shaping of their transfer sections enabling polygonal cross-sections to be used. SUMMARY OF THE INVENTION The present invention advantageously addresses the needs above as well as other needs by providing an optical device for LED-based lamps with configurations for various far-field intensity distributions. In some embodiments, an optical device for use in distributing radiant emission of a light emitter is provided. The optical device can comprise a lower transfer section, and an upper ejector section situated upon the lower transfer section. The lower transfer section is operable for placement upon the light emitter and further operable to transfer the radiant emission to said upper ejector section. The upper ejector section can be shaped such that the emission is redistributed externally into a substantial solid angle. In some preferred embodiments, the transfer section is a solid of revolution having a profile in the shape of an equiangular spiral displaced laterally from an axis of said solid of revolution so as to place a center of the equiangular spiral on an opposite side of the axis therefrom. In some embodiments, an optical device for distributing the radiant emission of a light emitter is provided. The optical device can comprise a lower transfer section, and an upper ejector section situated upon the lower transfer section. The lower transfer section can be operable for placement upon the light emitter and operable to transfer the radiant emission to the upper ejector section. The upper ejector section can be shaped such that the emission is redistributed externally into a substantial solid angle. The ejector section can further comprise lower and connecting upper portions. Some preferred embodiments provide an optical device for distributing radiant emissions of a light emitter. The optical device can comprise a transfer section, and an ejector section situated upon the transfer section. The transfer section is operable for placement adjacent with a light emitter and operable to transfer radiant emission from the light emitter to the ejector section. The ejector section is shaped such that the emission is redistributed externally into a substantial solid angle. In some embodiments, the ejector section has an upper surface with a profile of an equiangular spiral with a center at an upper edge of said transfer section. Some embodiments further provide for the ejector section to include a surface comprised of a radial array of V-grooves. Still further embodiments provide that a surface of said transfer section is comprised of an array of V-grooves. Further, the transfer section can be a polygonal, can be faceted and/or have other configurations. In one embodiment, the invention can be characterized as an optical device for distributing radiant emission of a light emitter comprising a lower transfer section and an upper ejector section situated upon the lower transfer section. The lower transfer section is operable for placement upon the light emitter and operable to transfer the radiant emission to the upper ejector section. The upper ejector section is shaped such that the light within it is redistributed out an external surface of the upper ejector section into a solid angle substantially greater than a hemisphere, and approximating that of an incandescent flashlight bulb. The ejector section is positioned at the same height as the glowing filament of the light bulb it replaces. It is easier to optically move this emission point, using the transfer section, than to put the LED itself at such a height, which would make heat transfer difficult, among other problems that the present invention advantageously addresses. In another embodiment, this invention comprises a multiplicity of such transfer sections joined end-to-end, with two LED sources at opposite ends of this line-up. These transfer sections have slightly roughened surfaces to promote diffuse emission, so that the entire device acts as a cylindrical emitter, and approximating the luminous characteristics of a fluorescent flashlight bulb. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description of the invention and accompanying drawings, which set forth an illustrative embodiment in which the principles of the invention are utilized. BRIEF DESCRIPTION OF THE DRAWINGS The above and other aspects, features and advantages of the present invention will be more apparent from the following more particular description thereof, presented in conjunction with the following drawings wherein: FIGS. 1 a through 38 b are cross sectional views of LED lamps having various configurations of transfer and ejector lens sections (hereafter called virtual filaments) according to the present invention, with each cross sectional view accompanied, respectively, by the individual configuration's far field pattern. FIG. 39 is a perspective view of a linear array of V-grooves. FIG. 40 is a diagram of the angles reflected by a linear V-groove array. FIG. 41 is a perspective view of a radial array of V-grooves. FIG. 42 a is a perspective view of the configuration of FIG. 37 a according to the present invention. FIG. 42 b is a perspective view showing the vector triad on the configuration of FIG. 42 a according to the present invention. FIG. 43 is a perspective view of the construction of a V-groove on a curved surface according to the present invention. FIG. 44 is a perspective view of a virtual filament with a curved radial V-groove array on top according to the present invention. FIG. 45 is a perspective view of a virtual filament with a linear V-groove array on its transfer section according to the present invention. FIG. 46 is a perspective view of a six-sided barrel-shaped virtual filament according to the present invention. FIGS. 47 a and 47 b is a side and perspective view, respectively, of a sixteen-sided virtual filament according to the present invention. FIG. 47 c - e show blue (465 nanometers), green (520 nanometers) and red (620 nanometers) emission patterns, respectively, of the embodiments of FIGS. 47 a - b , at the various cylindrical azimuths. FIGS. 48 a and 48 b is a side and perspective view, respectively, of another sixteen-sided virtual filament, with a slotted ejector section according to the present invention. FIG. 48 c depicts a 300° emission pattern produced by the collar of FIG. 48 a. FIGS. 49 a and 49 b is a side and perspective view, respectively, of a faceted virtual filament that mixes the disparate wavelengths of a tricolor LED according to the present invention. FIG. 50 depicts a side view of the faceted virtual filament of FIGS. 49 a and 49 b and a rectangularly cut collimating totally internally reflecting (TIR) lens focused on its output section. FIGS. 51-53 depicts perspective views of the faceted virtual filament and the rectangularly cut collimating TIR lens of FIG. 50 as seen from three different angles. FIG. 54 shows a perspective view of a plurality of the faceted virtual filament and collimating TIR lenses of FIG. 50 cooperated in a row. FIG. 55 shows a luminaire for a row shown in FIG. 54 . FIG. 56 shows an alternative virtual filament cooperated with a TIR lens. Corresponding reference characters indicate corresponding components throughout the several views of the drawings, especially the explicit label in FIG. 1 a of LED package 20 being implied throughout FIG. 2 a to FIG. 38 a. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following description of the presently contemplated best mode of practicing the invention is not to be taken in a limiting sense, but is made merely for the purpose of describing the general principles of the invention. The scope of the invention should be determined with reference to the claims. The present embodiments provide light sources with predefined far-field intensities. The present embodiments can be utilized in numerous applications. For example, in some applications, the embodiments can be utilized to replace and/or substitute for other types of light sources, such as compact light sources, incandescent light sources, florescent light sources and other light sources. As a further example, the present embodiments can be utilized in replacing incandescent light sources in flight lights and other devices using incandescent light sources. The present embodiments can also be utilized with the embodiments described in co-pending U.S. Provisional Patent application No. 60/520,951, filed Nov. 17, 2003, incorporated herein by reference in its entirety. The surface faceting configuration presented herein in FIG. 49A and FIG. 49B , and in co-pending U.S. Provisional Patent Application No. 60/520,951, filed Nov. 17, 2003, can be employed in variations of all of the non-faceted embodiments shown herein in order to achieve the color mixing and other benefits thereof. The present embodiments can further be utilized with the embodiments of and in the applications described in U.S. Provisional Patent Application No. 60/470,691, filed May 13, 2003, and U.S. patent application Ser. No. 10/461,557, filed Jun. 12, 2003, incorporated herein by reference in their entirety. For example, the present embodiments can be utilized in the light sources described in U.S. Provisional Patent Application No. 60/470,691, filed May 13, 2003, and U.S. patent application Ser. No. 10/461,557, filed Jun. 12, 2003. FIGS. 1 a through 38 b are cross sectional views of LED lamps having various configurations of transfer and ejector lens sections (hereafter called virtual filaments) according to some present embodiments, with each cross sectional view accompanied, respectively, by the individual configuration's far field pattern. Only FIG. 1 b has the labels that are implicit in all the output patterns of the preferred embodiments in the figures that follow: semicircular polar plot 2700 shows normalized far-field distribution 2701 on semi-circular angular scale 2702 , with off-axis angle, with zero denoting the on-axis direction, and 180° the opposite direction, totally backward. This is possible for those preferred embodiments having some sideways extension so that 180° is unimpeded by the source. In FIG. 1 a only, the light source is designated as LED package 20 with LED chips 22 , 23 , and 24 , but the same package-outline is depicted without labels in all subsequent figures of virtual filaments. This LED package represents but one possible way for the present invention to utilize multiple light emitters. Such multiple chips can have identical or different wavelengths. For example, the different wavelengths can be red, green, and blue wavelengths that span a chromaticity gamut for human color vision, or amber, red, and infrared wavelengths for night-vision devices, or other combinations of different wavelengths. Similarly in FIG. 1 a only, the position of the focus of ellipse segment 271 is shown by star 271 f . In all subsequent figures, the focus of the profile of the transfer section is also near the bottom point of the same curve on an opposite side of a central axis. FIG. 1 a shows virtual filament 270 comprising compound elliptical concentrator (hereinafter CEC) transfer section 271 , and an ejector section comprising outward slanting lower cone 272 and inward slanting upper cone 273 . FIG. 1 b shows that the far-field distribution of this preferred embodiment peaks in the forward direction with a ±20° extent. FIG. 2 a shows virtual filament 280 comprising CEC transfer section 281 , multiple stacked toroids 282 , and ejector section 283 , shaped as an equiangular spiral with origin at point 283 f . FIG. 2 b shows that the maximum far-field intensity of this preferred embodiment lies on angles from about 50° to 60° off-axis, a so-called bat-wing distribution. FIG. 3 a shows virtual filament 290 , comprising CEC transfer section 291 , cones 292 and 293 , and equiangular spirals 294 and 295 . Predominantly horizontal equiangular spiral 294 has its center at central point 294 f . Equiangular spiral profile 295 has oppositely situated center 295 f . FIG. 3 b shows the far-field distribution of this preferred embodiment, peaking at 40° off-axis and mostly confined to the range of 10-70°, also with a secondary lobe from 150-170°. FIG. 4 a shows virtual filament 300 comprising CEC section 301 , flat 302 , sideways equiangular spiral 303 with center at point 303 f , and top equiangular spiral 304 with center at point 304 f . FIG. 4 b shows a subtle tuning of the far-field resulting from the noticeable profile-modification, as shown in FIG. 4 a , of the preferred embodiment shown in FIG. 3 a . FIG. 4 b shows that the far-field distribution of this preferred embodiment has a primary maximum on a main lobe between 40° and 60° off-axis, and a secondary maximum on a secondary rear lobe extending between 160° and 170°, nearly backwards. The next preferred embodiment is a modification of this one. FIG. 5 a shows virtual filament 310 with CEC transfer section 311 , planar annulus 312 , equiangular spiral 313 with center at axial point 313 f , and upper equiangular spiral 314 with center at opposite point 314 f . In addition to elements in correspondence with those of FIG. 4 a are inward slanting steep cone 315 , upward slanting shallow cone 316 , and upper flat circle 317 . The normalized far-field pattern of this preferred embodiment differs significantly from the previous, as shown in FIG. 5 b , with a fluctuating forward lobe and a half-strength rear lobe. Delving further on the theme of minor modifications, FIG. 6 a shows virtual filament 320 comprising CEC transfer section 321 , planar annulus 322 , equiangular spiral 323 with axial position of its center as shown by star 323 f , upper equiangular spiral 324 with center at opposite point 324 f , and a new element—central upper equiangular spiral 327 , also with center at 324 f . In similarity to FIG. 5 a , virtual filament 320 also comprises inwardly slanting steep cone 325 and upward shallow cone 326 . The normalized far-field pattern of the preferred embodiment of FIG. 6 a is shown by FIG. 6 b to be mainly between 30° and 50° off axis, with a rear lobe from 120° to 170°, with reduced forward emission as compared to FIG. 5 b. FIG. 7 a depicts a preferred embodiment that is the result of small modifications of virtual filament 320 of FIG. 6 a . FIG. 7 a is a cross-section of virtual filament 330 , comprising CEC transfer section 331 , slanting conical section 332 , horizontal equiangular spiral 333 with center at axial point 333 f , steep conic edge 335 , vertical equiangular spiral 334 with oppositely situated center 334 f , and central cone 336 . FIG. 7 b shows its far-field intensity concentrated in a forward lobe within ±20° of the axis, with a strong rearward lobe peaking at 150°. Continuing the theme of component modifications, FIG. 8 a depicts virtual filament 340 comprising CEC transfer section 341 , planar annulus 342 , inwardly slanting steep cone 335 , downward slanting shallow cone 346 , outer edge 348 , horizontal equiangular spiral 343 with center at off-axis point 343 f , vertical equiangular spiral 344 with center at opposite point 344 f , and upper equiangular spiral 347 , also with center at opposite point 344 f . FIG. 8 b shows that its far field pattern has a collimated anti-axial beam and a broader ±30° forward beam. FIG. 9 a depicts virtual filament 350 comprising CEC transfer section 351 , dual conical flanges 352 , and upper conic indentation 353 . FIG. 9 b shows that its far-field pattern has strong forward and rear lobs, but some side emission. FIG. 10 a depicts virtual filament 360 comprising CEC transfer section 361 , conical flange 362 , upper equiangular spiral indentation 363 with center at proximal point 363 f , and cylindrical flange 364 . FIG. 10 b shows how the rearward emission of FIG. 9 b has been eliminated. FIG. 11 a depicts another variation of FIG. 10 a . Virtual filament 370 comprises CEC transfer section 371 , dual conic flanges 372 , central conic indentation 373 , set into central cylinder 374 . The far field pattern of FIG. 11 b shows a forward ±30° main lobe and a small secondary lobe at 125°. FIG. 12 a depicts a variation of component proportions in the preferred embodiment of FIG. 11 a . Virtual filament 380 comprises CEC transfer section 381 , dual conic flanges 382 , and central conic indentation 383 . The far field intensity pattern of FIG. 12 b shows the same overall forward and backward emphasis of FIG. 9 b , with differing details. FIG. 13 a depicts virtual filament 390 comprising CEC transfer section 391 , spheric section 392 , and central conic indentation 393 . In similarity to spheric ejector section 72 of FIG. 7 of U.S. patent application Ser. No. 10/461,557, both surfaces 392 and 393 are diffusing, in that rays from within and going through them are scattered diffusely into air. FIG. 13 b shows a strong forward lobe of ±40° superimposed on a weaker emission that is nearly omnidirectional. FIG. 14 a depicts virtual filament 400 comprising CEC transfer section 401 , steeply slanting cone 402 , outer equiangular spiral 403 with axially located center 403 f , and inner equiangular spiral 404 with center at proximal point 404 f . As shown in FIG. 14 b , its far field intensity pattern has no rearward energy, and somewhat approximates a Lambertian pattern. In a variant of the previous figure, FIG. 15 a depicts virtual filament 410 comprising CEC transfer section 411 , cylindrical stack 412 of multiple toroidal sections 412 t , inner equiangular spiral 414 with center at proximal point 414 f , and upper curve 413 tailored to refract rays coming from 414 f and being reflected at 414 and direct them tangent to 413 . FIG. 15 b shows the resultant far-field pattern to be mostly forward, within ±30°. FIG. 16 a depicts virtual filament 420 , comprising CEC transfer section 421 , cylinder 422 , conical indentation 423 in shallower top cone 424 . FIG. 16 b shows its far-field pattern is mostly between 10° and 20° off axis. FIG. 17 a depicts virtual filament 430 , comprising CEC transfer section 431 , outer cone 432 , and inner conical indentation 433 . In spite of the small differences from FIG. 16 a , the far-field pattern of FIG. 17 b is considerably different from that of FIG. 16 b. FIG. 18 a depicts virtual filament 440 , comprising CEC transfer section 441 , outer cone 442 , and inner conical indentation 443 . In spite of the small differences of this preferred embodiment from that of from FIG. 17 a , the far-field pattern of FIG. 18 b is narrower than that of FIG. 17 b. FIG. 19 a depicts virtual filament 450 comprising CEC transfer section 451 , spline curve 452 , central equiangular spiral 453 with center at proximal point 453 f , and surrounding top conic indentation 454 . FIG. 19 b shows its far-field pattern is predominantly forward, with ±20° at the half-power point. FIG. 20 a depicts virtual filament 460 comprising CEC transfer section 461 , spheric section 462 with radius 462 r that equals 0.38 times the height of section 461 , and central equiangular spiral 463 with center at proximal point 463 f . FIG. 20 b shows its far-field pattern to lie between 10° and 60° off axis. FIG. 21 a depicts another similar configuration, virtual filament 470 comprising CEC transfer section 471 , spheric section 472 with radius 472 r that is 0.7 times the height of section 471 , and central equiangular spiral 473 with center at proximal point 473 f . FIG. 21 b shows that the far-field pattern has significantly narrowed from the previous one. FIG. 22 a depicts another similar configuration, virtual filament 480 comprising CEC transfer section 481 , spheric section 482 with radius 482 r that is 0.8 times the height of section 481 , and central equiangular spiral 483 with center at proximal point 483 f . Spheric section 482 is partially covered with multiple convex toroidal lenslets 482 t . FIG. 22 b shows that the far-field pattern undergoes only minor change from the previous one, with narrowing of the central beam compared to that seen in FIG. 21 b. FIG. 23 a depicts virtual filament 490 comprising CEC transfer section 491 , spheric section 492 with radius 492 r that is 0.62 times the height of section 491 , section 492 being fully surfaced by multiple toroidal lenslets 492 t , and central equiangular spiral 493 with center at proximal point 493 f . FIG. 23 b shows how these lenslets greatly broaden the far-field pattern over that of FIG. 22 b. FIG. 24 a depicts virtual filament 500 comprising CEC transfer section 501 , spheric section 502 with radius 502 r that is 0.76 times the height of section 501 , section 502 being surfaced by multiple convex toroidal lenslets 502 t , and central equiangular spiral 503 with center at proximal point 503 f . FIG. 24 b shows that the far field pattern is not greatly changed from that of FIG. 23 b , by section 502 having a somewhat larger radius than that of section 492 of FIG. 23 a. FIG. 25 a depicts virtual filament 510 comprising CEC transfer section 511 , spheric section 512 with radius 512 r that is equal to the height of section 511 , section 512 surfaced by multiple convex toroidal lenslets 512 t , and central equiangular spiral 513 with center at proximal point 513 f . FIG. 25 b shows that the far field pattern is now considerably changed from that of FIG. 24 b , due to the larger radius of section 512 than that of section 502 of FIG. 24 a. FIG. 26 a depicts virtual filament 520 comprising CEC transfer section 521 , lower spline section 522 , central equiangular spiral 523 with center at proximal point 523 f , and outer cylindrical section 524 covered with multiple convex toroidal lenslets 524 t . FIG. 26 b shows a very broad pattern that does not vary much until 130° and is only reduced by half at 180°. FIG. 27 a depicts virtual filament 530 comprising CEC transfer section 531 , conical section 532 , central equiangular spiral 533 with center at proximal point 533 f , and cylindrical stack 534 surfaced by multiple convex toroidal lenslets 534 t . FIG. 27 b shows that this substitution of a cone for a tailored spline causes the far-field pattern to drop in the near-axis angles, as compared to FIG. 26 b . In the following FIGURE there are no such lenslets. FIG. 28 a depicts virtual filament 540 comprising CEC transfer section 541 , conic section 542 , central equiangular spiral 543 with center at proximal point 543 f , and outer cylinder 544 . FIG. 28 b shows that the far-field pattern of this preferred embodiment is much narrower without the lenslets 534 t of FIG. 27 a. FIG. 29 a depicts virtual filament 550 comprising CEC transfer section 551 , shallow upward cone 552 , central equiangular spiral 553 with center at proximal point 553 f , and outer concave spline 554 . FIG. 29 b shows its far-field pattern, with substantial axial emission. FIG. 30 a depicts virtual filament 560 comprising CEC transfer section 561 , planar annulus 562 , central equiangular spiral 563 with center at proximal point 563 f , and outer cylinder 564 . FIG. 30 b shows its far-field pattern FIG. 31 a depicts virtual filament 570 comprising CEC transfer section 571 , planar annulus 572 , central equiangular spiral 573 with center at proximal point 573 f , and outer conical edge 574 . FIG. 31 b shows that far-field emission is predominantly forward. FIG. 32 a depicts virtual filament 580 comprising CEC transfer section 581 , planar annulus 582 , upper equiangular spiral 583 with center at proximal point 583 f , outer cylinder 584 surfaced with concave toroidal lenslets 584 t , and central upper cone 585 . FIG. 32 b shows that its far-field pattern is predominantly forward, with full intensity within ±30°. FIG. 33 a depicts virtual filament 590 comprising equiangular-spiral transfer section 591 with center at opposite point 591 f , outward cone 592 , central indentation 593 shaped as a higher-order polynomial, and steep outer cone 594 , and surfaces 595 , 596 , and 597 forming a slot. Its far-field pattern is shown in FIG. 33 b , with a sharp cutoff at 150° off-axis and only 2:1 variation from uniform intensity at lesser angles. FIG. 34 a depicts virtual filament 600 comprising equiangular-spiral transfer section 601 with center on opposite point 601 f , protruding cubic spline 602 , and central equiangular spiral 603 with center at proximal point 603 f . Its far field pattern is shown in FIG. 34 b , and is to be compared with those of the following two preferred embodiments, in which the cubic spline protrudes more. FIG. 35 a depicts virtual filament 610 comprising equiangular-spiral transfer section 611 with center at opposite point 611 f , protruding cubic spline 612 , and central equiangular spiral 613 with center at proximal point 613 f . FIG. 35 b shows that its far field pattern has reduced on-axis intensity compared with FIG. 34 b. FIG. 36 a depicts virtual filament 620 comprising equiangular-spiral transfer section 621 with center at opposite point 621 f , protruding cubic spline 622 , and central equiangular spiral 623 with center at proximal point 623 f . FIG. 36 b shows that its far field pattern has reduced on-axis intensity compared with FIG. 35 b. FIG. 37 a depicts virtual filament 630 comprising equiangular-spiral transfer section 631 with center at opposite point 631 f , planar annulus 632 , central equiangular spiral 633 with center at proximal point 633 f , and outer cylinder 634 . FIG. 37 b shows that its far field pattern has no on-axis intensity. FIG. 37 b can be compared with FIG. 30 b , given the similarity of FIG. 37 a to FIG. 30 a. FIG. 38 a depicts virtual filament 640 comprising equiangular-spiral transfer section 641 with center at opposite point 641 f , lower conical section 642 , upper conical section 643 , and outer spline curve 644 . FIG. 38 b shows the far-field pattern. Cone 642 is a white diffuse reflector with Lambertian scattering, so that unlike the diffuse transmissive surface 392 of FIG. 13 a , it only reflects light falling on it. Previous embodiments have complete circular symmetry, since they are formed by a 360° cylindrical profile-sweep. Thus they have no azimuthal shape variation, only the radial variation of the profile. This is because real-world 360° output patterns do not call for azimuthal variation. There is one type of azimuthal shape variation, however, having no azimuthal intensity variations in its light output. This is the V-groove. The geometry of a linear array of V-grooves is shown in FIG. 39 . Reflective 90° V-groove array 650 is bordered by x-z plane 651 and y-z plane 652 . Incoming ray 653 is reflected at first groove wall 650 a become bounce ray 654 , then reflected at second groove wall 650 b to become outgoing ray 655 . Incoming ray 653 has projection 653 yz on border plane 652 and projection 653 xz on border plane 651 . Bounce ray 654 has projection 654 yz on border plane 652 and projection 654 xz on border plane 651 . Outgoing ray 655 has projection 655 yz on border plane 652 and projection 655 xz on border plane 651 . FIG. 39 also shows macrosurface normal N lying perpendicular to the plane of V-groove array 650 , which in the case of FIG. 39 is the xy plane. The directions of projected rays 653 xz and 655 xz obey the law of reflection from a planar mirror with the same surface normal. But on yz plane 652 , outgoing projection 655 yz has the opposite direction of incoming projection 653 yz , which has in-plane incidence angle Ψ. Thus linear V-groove array 650 acts as a combination of retroreflector and conventional reflector. That is, when incoming ray 653 has direction vector (p, q, r), then outgoing ray 655 has direction vector (p, −q, −r). This condition, however, only holds for those rays undergoing two reflections. Of all possible input-ray directions, the fraction that is reflected twice is 1−tan(Ψ). The configuration pertinent to the present invention is when surface 650 is the interface between a transparent dielectric, such as acrylic or polycarbonate, lying above the surface (i.e. positive z) and air below it. The particular case shown in FIG. 39 is also valid for total internal reflection, which occurs whenever the incidence angle θ of a ray on the dielectric-air interface exceeds the local critical angle θ c =arcsin(1/n) for refractive index n. Since the unitary normal vectors on the 2 sides of the grooves are (0, √0.5, √0.5) and (0, −√0.5, √0.5), the condition for total internal reflection can be vectorially expressed as ( p,q,r )·(0,±√0.5,√0.5)<cos θ c which can be rearranged to yield | q |+√(1− p 2 −q 2 )<√[2(1−1/ n 2 )]. FIG. 40 shows contour graph 660 with abscissa p and ordinate q. Legend 661 shows the fraction of rays that are retroreflected by total internal reflection. For p=0, the maximum q value for which there is total internal reflection for the 2 reflections is |cos −1 q|< 45°−θ c which amounts to a vertical width of ±2.8° for acrylic (n=1.492) and ±6° for polycarbonate (n=1.585). These small angles are how much such incoming rays are not in plane 651 . More pertinent to the present invention is radial V-groove array 670 shown in FIG. 41 . Crest-lines 671 and trough-lines 672 are the boundaries of planar triangles 673 , which meet at the crest-lines and trough-lines with 90° included angles 674 . In FIG. 37 a , the genatrix curve of upper surface 633 has the form of an equiangular spiral. It is possible to impose a radial V-groove array on such a surface, so that crest-lines 671 of FIG. 41 would become curved downward, depressing the center point. FIG. 42 a is a perspective view of the preferred embodiment of FIG. 37 a . Virtual filament 680 comprises equiangular-spiral transfer section 681 , equiangular-spiral top surface 683 , and cylindrical side surface 684 , the apparently polygonal shape of which is a pictorial artifact. Crest curves 683 c are shown as twelve in number, to correspond with crest-lines 671 of FIG. 41 . FIG. 42 b is another perspective view of the same preferred embodiment, but with surfaces 683 and 684 of FIG. 42 a removed. Twelve crest-curves 683 c are shown, one shown with tangent vector t, normal vector n, and their vector product the binormal vector b=t×n. If a crest-curve were the path followed at uniform speed by a particle, then its velocity vector lies along tangent vector t and its acceleration vector is the negative the normal vector n. The latter is so that it will coincide with the surface normal of the surface. Because each crest-curve lies in a plane, binormal vector b is constant, meaning the crest-curves have zero torsion. FIG. 43 is a perspective view of the construction of a V-groove on a curved surface according to the present invention. In modifying surface 683 of FIG. 42 a to become like radial-groove array 670 of FIG. 41 , the curvature of the crest-lines would make the groove surfaces become non-planar. In fact, such surfaces would be the envelopes of elemental planes coming off each point on the curve at a 45° angle, as shown in FIG. 43 . Incompletely swept equiangular spiral surface 690 is identical to surface 683 of FIG. 42 a . Part of the sweep is unfinished so that crest-curve 691 can be clearly seen. Tangent to it are three elemental planar ridges 692 with 90° interior angles. Let a crest curve be specified by the parametric function P(t), where t is the path-length along said crest-curve, with normal vector n(t) and binormal vector b(t). Any point X on a 45° plane touching the crest-curve at P(t) is specified by ( X−P ( t ))·( n ( t )± b ( t ))=0  (1) with the ‘±’ referring to there being two such 45° planes corresponding to the walls of a 90 V-groove. Varying t gives a family of such planes. In order to calculate the envelope surface to this family of planes, differentiate Equation (1) with respect to parameter t, giving - ⅆ P ⁡ ( t ) ⅆ t · ( n ⁡ ( t ) ± b ⁡ ( t ) ) + ( X - P ⁡ ( t ) ) · ( ⅆ n ⁡ ( t ) ⅆ t ± ⅆ b ⁡ ( t ) ⅆ t ) = 0 ( 2 ) The orthogonal vector triad formed by the parametrically specified unit vectors t(t), n(t), and b(t) is called the Frenet frame of the curve it follows as t varies. Each of these three vectors has a definition based on various derivatives of the equation for P(t). Differentiating these definitions with respect to t gives the Frenet equations, well-known in differential geometry. A laborious combination of the Frenet equations with Equation (2), and eliminating t, finally yields ( X−P ( t ))· t ( t )=0  (3) Equation (3) and Equation (1) must be fulfilled simultaneously for each point X of the envelope surface. Equation (3) establishes that the same vector X−P is normal to tangent vector t, while Equation (1) implies that the vector X−P is normal to n±b. Thus X−P, for a point satisfying equations (1) and (3), must be in the direction n-b, because n and b are orthogonal unit vectors so that (n−b)·(n+b)=0, i.e., X−P ( t )= s (− n ( t )± b ( t ))  (4) This is the parametric equation of the two envelope surfaces of the ridge. The radial parameter is t and transverse parameter is s, with one ridge for +b(t) and the other for −b(t). Curves 683 c of FIG. 42 b will be crest curves if we take s>0 for both ridges (with s=0 for the crest curves) and they will be trough curves if s<0 (with s=0 for the trough curves in this case). More pertinently, X ( t,s )= P ( t )+ s (− n ( t )± b ( t ))  (5) is the equation of the envelope surface as a function of the crest equation P(t), and its normal and binormal vectors. The parameter s extends to the value of s that at the bottom of the groove, where it meets the corresponding point on the next ridge. The upshot of this differential-geometry proof is that each of the planes of FIG. 43 contributes thick lines 693 to the envelope surface of the curved V-groove. Thick lines 693 of FIG. 43 in fact represent the second term in Equation (5). If successive lines 693 cross as they issue from closely neighbouring points, then the resultant envelope surface may have ripples or even caustics (which are physically unrealisable). In the present invention, any such mathematical anomalies would be too far from the crest curve to be of relevance. FIG. 44 is a perspective view of virtual filament 700 , comprising equiangular-spiral transfer section 701 , radial V-grooves 702 , and cylindrical sidewall 703 . Only twelve V-grooves are shown, for the sake of clarity, but an actual device may have many more. The utility of such grooves is that they enable the designer to avoid the use of a coated reflector. FIG. 45 shows virtual filament 710 , comprising transfer section 711 with longitudinal V-grooves, and ejector section 703 . As shown in FIG. 45 , V-grooves can also be used on the transfer section of the present invention, enabling a cylindrical shape to be used. The discussion of FIG. 2 of U.S. patent application Ser. No. 10/461,557 touched on the function of color mixing, to make different wavelengths from chips 23 , 24 , and 25 have the same relative strengths throughout the light coming out of ejector section 12 . This assures that viewers will see only the intended metameric hue and not any colors of the individual chips. Previously, rectangular mixing rods have been used to transform the round focal spot of an ellipsoidal lamp into a uniformly illuminated rectangle, typically in cinema projectors. Generally, polygonal mixing rods worked best with an even number of sides, particularly four and six. With color mixing for LEDs, however, such rods are inefficient because half of an LED's Lambertian emission will escape from the base of the rod. The following preferred embodiments of the present invention remedy this deficit by proper shaping of its transfer section. This shaping enables polygonal cross-sections to be used in the present invention. FIG. 46 depicts virtual filament 720 , comprising hexagonal transfer section 721 and hemispheric ejector section 722 . Within package 723 are red LED chip 723 r , green chip 723 g , and blue chip 723 b . Transfer section 721 comprises expanding bottom section 721 b , mid-section 721 m with constant cross-section, and contracting upper section 721 u . The shape of sections 721 b and 721 u acts to prevent the escape of rays that a constant cross section would allow if it extended the entire length of transfer section 721 . Similar to the grooves of FIG. 44 and FIG. 45 , a polygonal transfer section would constitute a departure from complete rotational symmetry. FIG. 47 a is a side view of virtual filament 730 comprising sixteen-sided off-axis ellipsoid 731 , conical ejector section 732 , and mounting feet 734 . FIG. 47 b is a perspective view of the same preferred embodiment, also showing spline top surface 733 . FIG. 47 c shows the blue (465 nanometers) emission pattern of this preferred embodiment, at the various cylindrical azimuths, 0° azimuth indicated by reference numeral 735 , 45° azimuth indicated by reference numeral 736 , 90° azimuth indicated by reference numeral 737 , and 135° azimuth indicated by reference numeral 738 , and as indicated in the legend at upper right. FIG. 47 d shows the green (520 nanometers) emission pattern of this preferred embodiment, at the various cylindrical azimuths 735 - 738 and as indicated in the legend at upper right. FIG. 47E shows the red (620 nanometers) emission pattern of this preferred embodiment, at the various cylindrical azimuths 735 - 738 and as indicated in the legend at upper right. FIG. 48 a is a side view of virtual filament 740 comprising sixteen-sided off-axis ellipsoid 741 , conical ejector section 742 , conical collar 744 , and cylindrical connector 745 . FIG. 48 b is a perspective view of the same preferred embodiment 743 . The purpose of the narrowing by collar 744 is to produce the 300° emission pattern 747 shown in FIG. 48 c. FIG. 49 a is an exploded side view of faceted virtual filament 750 and tricolor LED package 755 being inserted into and optically coupled to the filament 750 . Beyond polygonally-shaped transfer sections are more complex departures from circular symmetry. Virtual filament 750 comprises an output section spanned by arrow 751 , transfer section 752 , and mounting feet 753 . Faceted virtual filament 750 is a single piece of plastic, such as acrylic, the surface of which is covered by planar facets 754 . The two mounting feet 753 are designed to be proximate to the outer surfaces of LED package 755 , to aid in alignment and bonding of virtual filament 750 to package 755 . In one embodiment of the invention, adhesive is applied to the inner sidewalls of feet 753 for bonding to LED package 755 . In this instance the inner sidewall of each leg 753 has a surface that is substantially parallel to the proximate edge surface of LED package 755 . Optical coupling of the bottom of virtual filament 750 to the top surface of LED package 755 can be achieved by several means, such as use of optical adhesives, non-curing and curing optical gels (such as available from Nye Optical Products of Fairhaven, Mass.) or index matching liquids (such as available from Cargille Laboratories of Cedar Grove, N.J.). FIG. 49 b is an exploded-part perspective view showing rectangular LED package 755 as removed from virtual filament 750 . Within reflector cup 757 are red chip 758 r , green chip 758 g , and blue chip 758 b . Cup 757 is filled with transparent epoxy (not shown) up to top 756 of package 755 . Top 756 is optically bonded to the bottom of faceted virtual filament 750 . This three-chip configuration is an example of the present invention incorporating multiple light sources. The three chips shown could also be amber, red, and infrared, suitable for illuminators compatible with night-vision devices, and other combinations. Typically the base of a mixing virtual filament is larger than the emitting surface of the RGB LED illuminating it. In one preferred embodiment the inner diameter of the sixteen-sided polygonal shaped base of the mixing optic 750 is 20% larger than the diameter of the circular exit aperture of the RGB LED 755 . In the case where the RGB LED 755 has a non-circular exit aperture, the base of the virtual filament is made sufficiently large to completely cover the exit aperture of the LED. FIG. 50 is a side view showing TIR lens 5030 with its focus at output section 751 of faceted virtual filament 750 . FIG. 51 is a view from below also showing faceted virtual filament 750 , LED package 755 , and TIR lens 5030 , the latter comprising facets 5031 and flat cut-out planes 5032 . FIG. 52 shows the rectangular shape of TIR lens 5030 , positioned above faceted virtual filament 750 . Also shown is LED package 755 coupled to the bottom of virtual filament 750 . There are four mounting feet 5013 , somewhat smaller than the two shown in FIG. 49A , so as not to leak a greater amount of light from LED 755 . FIG. 53 is a perspective view from above showing virtual filament 750 and LED package 755 . Rectangularly cut TIR lens 5030 has planar side walls 5032 and slightly indented upper surface 5033 . FIG. 54 shows lens 5040 comprising a row of rectangular TIR lenses 5030 , and endmost virtual filament 750 . FIG. 55 shows endmost virtual filament 750 and circuit board 5050 upon which it is mounted. Sidewalls 5055 hold row lens 5040 , flat holographic diffuser 5060 just above it, and outer cover 5070 , which is optionally a holographic diffuser. Transverse arrow 5061 shows the long axis of the elliptical pattern of holographic diffuser 5060 . Longitudinal arrow 5071 shows the long axis of the elliptical pattern of a holographic diffuser deployed on cover 5070 . These diffusers cause a distant viewer to see a narrow line of light on cover 5070 . It will have the color of the metameteric resultant of the component colors mixed by faceted virtual filament 750 . FIG. 56 shows an alternative virtual filament configuration. Reflector cup 5061 is analogous to reflector cup 21 of FIG. 49B , in that it contains the system's light-emitting chips. Six-fold compound parabolic concentrator (CPC) section 5062 widens to hexagonal rod 5063 . This CPC section can alternatively be a combination of an equiangular and a parabolic curve, hereinafter referred to as an equiangular-spiral concentrator, to avoid leakage. At the top of rod 5063 , another parabolic (or equiangular spiral) section 5064 narrows the rod again. This widens the angular swath of light from the range of guided angles, about ±48°, to about the full ±90° of LED package 755 . Other even-polygon cross sections for the rod can also be used. Connected to rod 5063 is hemispheric lens 5065 , positioned just under rectangular TIR lens 5066 and delivering light thereinto. Sections 5062 , 5063 , 5064 and 5065 can, in some embodiments, be formed all of one piece of transparent plastic, such as acrylic or polycarbonate. Light received into section 5062 is mixed by section 5063 and emitted out section 5065 into collimating lens 5066 . While the invention herein disclosed has been described by means of specific embodiments and applications thereof, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope of the invention as set forth in the claims.

An optical device for coupling the luminous output of a light-emitting diode (LED) to a predominantly spherical pattern comprises a transfer section that receives the LED's light within it and an ejector positioned adjacent the transfer section to receive light from the transfer section and spread the light generally spherically. A base of the transfer section is optically aligned and/or coupled to the LED so that the LED's light enters the transfer section. The transfer section can comprises a compound elliptic concentrator operating via total internal reflection. The ejector section can have a variety of shapes, and can have diffusive features on its surface as well. The transfer section can in some implementations be polygonal, V-grooved, faceted and other configurations.

CROSS-REFERENCE TO RELATED APPLICATION(S) [0001] This application is a continuation application of U.S. application Ser. No. 14/309,786, filed Jun. 19, 2014, which is a continuation of U.S. patent application Ser. No. 14/059,271 (now abandoned), filed Oct. 21, 2013, which is a continuation of U.S. patent application Ser. No. 13/290,944, filed Nov. 7, 2011 (now U.S. Pat. No. 8,601,291), which is a continuation of U.S. patent application Ser. No. 11/459,011 (now abandoned), filed Jul. 20, 2006, which is a continuation of U.S. patent application Ser. No. 10/313,314, filed Dec. 6, 2002 (now U.S. Pat. No. 7,171,461), which is a continuation-in-part of U.S. patent application Ser. No. 09/930,780, filed Aug. 15, 2001, (now U.S. Pat. No. 7,043,543), which is a continuation-in-part of U.S. patent application Ser. No. 09/732,557, filed Dec. 8, 2000 (now U.S. Pat. No. 7,099,934), which is a continuation-in-part of U.S. patent application Ser. No. 09/375,471 filed Aug. 16, 1999 (now U.S. Pat. No. 6,711,613) which is a continuation-in-part of U.S. application Ser. No. 08/685,436, filed Jul. 23, 1996 (now U.S. Pat. No. 5,949,974) the entireties of all of which are incorporated herein by reference. TECHNICAL FIELD [0002] The technical field relates generally to power management systems, and more particularly to electrical power distribution devices and methods. BACKGROUND [0003] Network server “farms” and other network router equipment have settled on the use of the equipment bays in 19″ standard RETMA racks. Many of these server and router farms are located at telephone company (TelCo) central equipment offices because they need to tie into very high bandwidth telephone line trunks and backbones. So each TelCo typically rents space on their premises to the network providers, and such space is tight and very expensive. [0004] The typical network router, server, or other appliance comes in a rack-mount chassis with a standard width and depth. Such chassis are vertically sized in whole multiples of vertical units (U). Each rented space in the TelCo premises has only so much vertical space, and so the best solution is to make best use of the vertical space by filling it with the network appliances and other mission-critical equipment. [0005] Two kinds of operating power are supplied to such network appliances, alternating current (AC) from an uninterruptable power supply (UPS) or direct from a utility, the second kind is direct current (DC) from TelCo central office battery sets. Prior art devices have been marketed that control such AC or DC power to these network appliances. For example, Server Technology, Inc. (Reno, Nev.) provides operating-power control equipment that is specialized for use in such TelCo premises RETMA racks. Some of these power-control devices can cycle the operating power on and off to individual network appliances. [0006] Such cycling of operating power will force a power-on reset of the network appliance, and is sometimes needed when an appliance hangs or bombs. Since the network appliance is usually located remote from the network administration center, Server Technology has been quite successful in marketing power managers that can remotely report and control network-appliance operating power over the Internet and other computer data networks. [0007] Conventional power management equipment or bottoms of the server farm RETMA racks, and thus has consumed vertical mounting space needed by the network appliances themselves. So what is needed now is an alternative way of supplying AC or DC operating power to such network appliances without having to consume much or any RETMA rack space. SUMMARY [0008] Briefly, a vertical-mount network remove power management outlet strip embodiment of the present disclosure comprises a long, thin outlet strip body with several independently controllable power outlet sockets distributed along its length. A power input cord is provided at one end, and this supplies AC-operating power to relays associated with each of the power outlet sockets. The relays can each be addressably controlled by a microprocessor connected to an internal I2C-bus serial communications channel. The power-on status of each relay output to the power outlet sockets can be sensed and communicated back to the internal I2C-bus. A device-networking communications processor with an embedded operating system may translate messages, status, and controls between external networks, the internal I2C-bus, and other ports. [0009] In alternative embodiments of the present disclosure, a power management architecture provides for building-block construction of vertical and horizontal arrangements of outlet sockets in equipment racks. The electronics used in all such variants is essentially the same in each instance. Each of a plurality of power input feeds can have a monitor that can provide current measurements and reports on the internal I2C-bus. Each of the power input feeds could be independently loaded with a plurality of addressable-controllable outlets. Each outlet can also capable of measure the respective outlet socket load current and reporting those values on the internal I2C-bus. Separate digital displays can be provided for reach monitored and measured loan and infeed current. The internal I2C-bus, logic power supply, network interfaces, power control modules and relays, etc., could be distributed amongst several enclosures that have simple plug connections between each, the infeed power source, and the equipment loads in the rack. [0010] An advantage of certain embodiments of the present disclosure is that a network remote power management outlet strip is provided that frees up vertical rackmount space for other equipment. [0011] Another advantage of certain embodiments of the present disclosure is that a network remote power management outlet strip is provided for controlling the operating power supplied to network appliances over computer networks, such as TCP/IP and SNMP. [0012] A further advantage of certain embodiments of the present disclosure is that a network remote power management outlet strip is provided that allows a network console operator to control the electrical power status of a router or other network device. [0013] A still further advantage of certain embodiments of the present disclosure is that a network remote power management outlet strip is provided for reducing the need for enterprise network operators to dispatch third party maintenance vendors to remote equipment rooms and POP locations simply to power-cycle failed network appliances. [0014] There are other objects and advantages of the various embodiments of the present disclosure. They will no doubt become obvious those of ordinary skill in the art after having read the following detailed description of the preferred embodiments which are illustrated in the various drawing figures. BRIEF DESCRIPTION OF THE DRAWINGS [0015] FIG. 1 is a functional block diagram of a network remote power management outlet strip embodiment of the present disclosure. [0016] FIG. 2A is a front diagram of an implementation of the network remote power management outlet strip of FIG. 1 . [0017] FIG. 2B is an assembly diagram of the network remote power management outlet strip of FIG. 2A without the sheet metal enclosure, and shows the interwiring amongst the AC-receptacles, the power input plug, and the various printed circuit board modules. [0018] FIG. 3 is a non-component side diagram of a printed circuit board (PCB) implementation of an intelligent power module IPT-IPM, similar to those of FIGS. 1 , 2 A and 2 B, and further illustrates an insulating sheet that is fitted to the back. [0019] FIG. 4 is a component-side diagram of a printed circuit board (PCB) implementation of an intelligent power module IPT-IPM, similar to those of FIGS. 1 , 2 A, 2 B, and 3 , and further illustrates the bus connections of the power outlet receptacles it sockets into. [0020] FIG. 5 is functional block diagram of an IPT-NetworkPM module embodiment of the present disclosure. [0021] FIG. 6 is a schematic diagram of a circuit that could be used in an implementation of the IPT-PS of FIGS. 1 , 2 A, and 2 B. [0022] FIG. 7 is a functional block diagram of a network remote power management system embodiment of the present disclosure. [0023] FIG. 8 is a functional block diagram of an expandable power management system embodiment of the present disclosure. [0024] FIG. 9 is a functional block diagram of a power distribution unit embodiment of the present disclosure. [0025] FIG. 10 is a schematic diagram of one way to implement the IPT-IPM's in any of FIGS. 1-9 . DETAILED DESCRIPTION [0026] FIG. 1 represents a network remote power management outlet strip embodiment of the present disclosure, and is referred to herein by the general reference numeral 100 . The outlet strip 100 provides independently managed power to each of sixteen AC-output receptacles 101 - 116 . A power supply (IPT-PS) module 118 senses and totalizes the combined current delivered to all the AC-output receptacles 101 - 116 from its AC-power input. [0027] Peripheral integrated circuits (IC's) that have to communicate with each other and the outside world can use a simple bi-directional 2-wire, serial data (SDA) and serial clock (SCL) bus for inter-IC (I2C) control developed by Philips Semiconductor. The I2C-bus has become a worldwide industry-standard proprietary control bus. [0028] The IPT-PS module 118 digitally encodes the total AC-current information onto an internal I2C-bus 119 . The IPT-PS module 118 supplies DC-operating power for the internal I2C-bus 119 which is derived from the AC-power input. Each of four intelligent power modules (IPT-IPM) 120 - 123 have four relays (K1-K4) that switch AC-power from the IPT-PS module 118 to respective ones of the sixteen AC-output receptacles 101 - 116 . Such relays K1-K4 are controlled by a single I2C transceiver daisy-chain connected to others along the internal I2C-bus 119 . Each such I2C transceiver is independently addressable on the I2C-bus 119 , and provides a digitally encoded power-on status indication for all four relays K1-K4. [0029] An I2C-module (IPT-I2C) 124 receives digital messages on the internal I2C-bus 119 and decodes and displays the totalized combined current, e.g., in AC-amperes, on an LED-readout 126 . A user is thus able to see the effect on the total current caused by plugging or unplugging a load from any or all of the AC-output receptacles 101 - 116 . [0030] The Philips 87LPC762 microcontroller is used as an 120 interface to a dual seven-segment display. Port-0 pins select the illuminated segments of a seven-segment display. Pin P1.7 selects which of the two seven-segment displays is being driven, and alternates between the two seven-segment displays fast enough to avoid flicker. The I2C slave address is configurable. Five commands are supported: STAT (status) RBTN (Read button), RPRB (Read probe), CRST (Clear reset), and WDSP (Write display). A checksum is used on received/sent bytes for data integrity across the I2C-bus. [0031] The IPT-I2C microcontroller starts up with the I2C interface in idle slave mode. Main () waits in a loop until the I2C interface is flagged as non-idle. After an I2C start occurs, and the rising edge of SCL sets DRDY (and thus ATN), an I2C interrupt occurs. The I2C ISR disables the I2C interrupt and sets a global I2C non-idle flag. The main loop then proceeds to read in the first byte from the I2C-bus. When seven bits are received, the target I2C is known and is compared to the IPT-I2C microcontroller's own module address. If different, the I2C interface processing stops and waits for another start to begin again. If the same, the last bit of the first byte is read, which is the RJW bit. If a Read, then the IPT-I2C microcontroller acknowledges the byte and repeatedly sends a fixed number of response bytes: an address byte, a type byte, one or more data bytes, and a checksum. If a Write, then the IPT-I2C microcontroller acknowledges the byte, and then will read up to four more bytes: a command byte one or more data bytes, and a checksum. As received, the bytes are acknowledged and compared to expected valid commands and data. As soon as a valid command, any data parameters and a valid checksum are received and acknowledged, the command is acted upon. Without a valid checksum, the command is not acted upon. If an unexpected command or data is received, or more bytes are received than expected, then a negative acknowledge occurs after the next byte is received, and the I2C interface is stopped, and another start is needed to begin again. Throughout the I2C processing loop, a bus timeout (by Timer 1 interrupt) resets the I2C interface to idle and the I2C processing loop to the appropriate states Timer U also guards the I2C interface with a 5-millisecond inter-clock timeout and a 15 second total I2C timeout. The total I2C timeout is reset when the IPT-I2C microcontroller is addressed on the I2C with its primary address (not the secondary address). [0032] The I1C IPT-I2C microcontroller commands include the STAT command which sets the IPT-I2C microcontroller to a read type to STAT. This means that an I2C Read will send four bytes (address, type data checksum) in which the data byte represents the status of the IPT-I2C microcontroller. [0033] The RBTN command sets the IPT-I2C microcontroller read type to RBTN. This means that an I2C Read will send four bytes (address, type, data, checksum) in which the data byte represents the status of the button. [0034] The RPRB command sets the IPT-I2C microcontroller read type to RPRB. This means that an I2C Read will send five bytes (address, type data, data, checksum) in which the data bytes represent the type of 1-wire bus probe and the probe data. [0035] The CRST command clears the Reset Flag (RSTF), Power On Reset Flag (PORF), Brownout Reset Flag (BORF), and WatchDog Reset Flag (WDRF) bits of the IPT-I2C microcontroller status byte. [0036] The WDSP command sets the values for the dual seven-segment display. [0037] At power up, the dash-dash blinks until a valid WDSP command is received. After that, if ten seconds pass without receiving a valid WDSP command, the display reverts back to the blinking dash-dash. [0038] A read command is started by the master addressing the slave with the RIW bit set. [0039] A read command to the slave IPT-I2C microcontroller results in a fixed number of bytes repeatedly being transmitted by the slave (address, type, datal . . . dataN checksum). The first byte is the address of the slave. The second byte indicates the type of data in the following data byte(s). The last byte is a checksum of all the previous bytes. [0040] A write command is started by the master addressing the slave with the RIW bit cleared. This is followed by the master transmitting multiple bytes to the slave, followed by a stop, or restart. [0041] The internal I2C-bus 119 is terminated at a network personality module (IPT-NetworkPM) 128 . Such provides an operating system, HTTP-server, and network interface between the internal I2C-bus 119 , an external I2C-bus 130 , an Ethernet 10/100 BaseT 132 , a modem 134 , and a local operator's console 136 . The IPT-NetworkPM 128 preferably uses Internet protocols like TCP/IP and supports simple network management protocol (SNMP). In one application, the outlet strip 100 could be used in the remote power management environment described in U.S. Pat. No. 5,949,974, issued Sep. 7, 1999. Such Patent is incorporated herein by reference. [0042] Network messages, e.g., using TCPIIP and SNMP, are communicated over the Ethernet 10/100 BaseT interface 132 . Such messages are able (a) to independently control the power on-off to each of AC-output receptacles 101 - 116 , (b) to read the power-on status of each, and (c) to report load current supplied by each outlet, or simply the total combined current measured passing through IPT-PS 118 . [0043] In one embodiment, the power applied to AC-output receptacles 101 - 116 is not allowed by the individual IPT-IPM modules 120 - 123 to be simultaneously applied. Instead, each is allowed to turn on in succession so any instantaneous load in-rush currents cannot combine to exceed the peak capabilities of the AC-power input source. [0044] The total input current display 126 could be used to advantage by a technician when installing or troubleshooting a RETMA equipment rack by watching how much current change is observed when each network appliance is plugged in and turned on. Unusually high or low currents can indicate particular kinds of faults to experienced technicians. [0045] FIGS. 2A and 2B represent a network remote power management outlet strip embodiment of the present disclosure, which is referred to herein by the general reference numeral 200 . These illustrate one way the network remote power management outlet strip 100 of FIG. 1 could be physically implemented and arranged. The outlet strip 200 provides independently managed power to each of sixteen AC-output receptacles 201 - 216 . These have AC-neutral and AC-ground bussed through two sets of eight, e.g., with 12-gauge wire. A power supply (IPT-PS) module 218 is daisy-chained in an internal I2C-bus 219 to a series of four intelligent power modules (IPT-IPM) 220 - 223 . The IPT-PS module 218 has, for example, a Philips microcontroller type 87LPC762 that senses and totalizes the combined current delivered on the AC-Line leads to all of four intelligent power modules (IPT-IPM) 220 - 223 . [0046] The Philips 87LPC762/7 microcontroller is programmed as an I2C 8-bit I/O Expander, with an 8-bit 4-channel A/D converter. Eight pins are individually selectable as either an Input (quasi-bidirectional) or Output (open drain). Four address lines determine the I2C slave address. Eight commands are supported: STAT (Status), RCFG (Read Config) RPRT (Read Port), RADC (Read ADC), CRST (Clear Reset), WCFG (Write Config), WPT (Write Port), and ADCE (ADC Enable). A checksum is used on received/sent bytes for data integrity across the I2C-bus. Without a valid checksum, a command will not be acted upon. [0047] The microcontroller starts up with the I2C interface in idle slave mode. Main() waits in a loop until the I2C interface is flagged as non-idle. After an I2C start occurs, and the rising edge of SCL sets DRDY and thus ATN, an I2C interrupt occurs. The I2C ISR disables the I2C interrupt and sets a global I2C non-idle flag. The main loop then proceeds to read in the first byte from the I2C-bus. When seven bits are received, the target I2C is known and is compared to the I/O Expander's own module address. If different, the I2C interface processing stops and waits for another start to begin again. If the same-the last bit of the first byte is read, which is the R/W bit. If a Read, then the microcontroller acknowledges the byte, and repeatedly sends a fixed number of response bytes (an address byte, a type byte one or more data bytes, and a checksum). If a Write, then the microcontroller acknowledges the byte and then will read up to three more bytes (a command byte, a data byte, and a checksum). As received, the bytes are acknowledged and compared to expected valid commands and data. As soon as a valid command, any data parameters and a valid checksum are received and acknowledged, the command is acted upon. If an unexpected command or data is received, or more bytes are received than expected, then a negative acknowledge occurs after the next byte is received, and the I2C interface is stopped and another start is needed to begin again. [0048] Throughout the I2C processing loop, a bus timeout by Timer 1 interrupt resets the I2C interface to idle and the I2C processing loop to the appropriate state. Timer 0 also guards the I2C interface with a 5-millisecond inter-clock timeout and a 15-second total I2C timeout. The total I2C timeout is reset when the I/O Expander is addressed on the I2C with its primary address, not the secondary address. [0049] The I2C microcontroller commands include the STAT command, which sets the I/O Expander read type to STAT. An I2C Read will send four bytes: address, type, data, checksum. The data byte represents the status of the I/O Expander. [0050] The RCFG command sets the I/O Expander read type to RCFG. This means that an I2C Read will send four bytes: address, type, data, checksum. The data byte represents the I/O configuration of the eight I/O pins. [0051] The RADC command sets the microcontroller read type to RADC. This means that an I2C Read will send eight bytes (address, type, ADCE status, ADCO data, ADCI data, ADC2 data, ADC3 data, checksum) in which the data bytes represent the value of the four ADC channels. For ADC channels that are disabled, a value 0×FF is returned. For enabled ADC channels, the value represents the average of the last eight averages of 64 A/D conversions during the last four AC cycles. All four channels are converted once during each 1.042 ms, about 260 us apart. After four AC (60 Hz) cycles, each channel has been converted 64 times. For each channel these 64 conversions are averaged and stored. The most recent eight stored averages are then again averaged, making the reported value the truncated average over 64×8=512 AC cycles, which spans just over a half second. [0052] The CRST command clears the ReSeT Flag (RSTF) Power On Reset Flag (PORF), BrownOut Reset Flag (BORF), and WatchDog Reset Flag (WDRF) bits of the I/O Expander status byte. [0053] The WCFG command sets the microcontroller I/O configuration of the eight I/O pins. The WCFG command also sets the read type to RCFG. [0054] The WPRT command sets the state of the eight I/O pins that are configured as outputs. The WPRT command also sets the read type to RPRT. [0055] The ADCE command enables or disables any or all four ADC channels. The ADCE command also sets the read type to RADC. [0056] A read command is started by the master addressing the slave with the R/W bit set. A read command to the slave IPT-I2C microcontroller results in a fixed number of bytes repeatedly being transmitted by the slave (address, type, datal .. . dataN checksum). The first byte is the address of the slave. The second byte indicates the type of data in the data bytes that follow. The last byte is a checksum of all the previous data bytes. [0057] A write command is started by the master addressing the slave with the R/W bit cleared. This is followed by the master transmitting multiple bytes to the slave, followed by a stop or restart. [0058] The IPT-PS module 218 digitally encodes the total AC-input current information onto the internal I2C-bus 219 . The IPT-PS module 218 derives DC-operating power from the AC-power input for modules on the internal I2C-bus 219 . Each of the IPT-IPM modules 220 - 223 have four relays (K1-K4) that switch the AC-Line from the IPT-PS module 218 to respective ones of the AC-Line connections on each of the sixteen AC-output receptacles 201 - 216 . Such relays K1-K4 are controlled by a single I2C transceiver located on each IPT-IPM 220 - 223 . For example, such I2C transceiver could be implemented with a Philips microcontroller type 87LPC762. [0059] Each such I2C transceiver is independently addressable on the I2C-bus 219 , and provides a digitally encoded power-on status indication for all four relays K1-K4. An I2C-module (IPT-I2C) 224 receives digital messages on the internal I2C-bus 219 and decodes and displays the totalized combined current, e.g., in AC-amperes, on an LED-readout 226 . The internal I2C-bus 219 terminates at a IPT-NetworkPM 228 . [0060] Preferably, IPT-NetworkPM 228 includes an operating system, an HTML webpage, and a network interface. Such can connect a remote user or command console with the internal I2C-bus 219 , an external I2C-bus that interconnects with other outlet strips through a RJ-11 socket 230 , an Ethernet 10/100 BaseT RJ-45 type socket 232 , etc. The IPT-NetworkPM 228 preferably uses Internet protocols like TCP/IP and supports simple network management protocol (SNMP). [0061] The modular construction of outlet strip 200 allows a family of personality modules to be substituted for IPT-NetworkPM 228 . Each such would be able to communicate with and control the IPT-IPM's 220 - 223 via the inter al I2C-bus 219 . [0062] The manufacturability and marketability of IPT-IPM 220 - 223 could be greatly enhanced by making the hardware and software implementation of each the same as the others. When a system that includes these is operating, it preferably sorts out for itself how many IPM's are connected in a group and how to organize their mutual handling of control and status data in and out. [0063] FIG. 3 illustrates a printed circuit board (PCB)·implementation of an intelligent power module IPT-IPM 300 , similar to those of FIGS. 1 , 2 A, and 2 B. On the component side of the PCB, the IPT-IPM 300 has a two-position connector 302 for AC-Neutral, and on the non-component side screw connector for the AC-Line. A PCB trace 306 distributes AC-Line power input to a series of four power control relays, as shown in FIG. 4 . An insulator sheet 310 screws down over the IPT-IPM 300 and protects it from short circuits with loose wires and the sheet metal outlet strip housing. [0064] For example, insulator sheet 310 can be made of MYLAR plastic film and may not necessarily have a set of notches 312 and 314 that provide for connector tabs 302 and 304 . Connector tabs 302 and 304 can alternatively be replaced with a two-position connector with screw fasteners. [0065] FIG. 4 illustrates the component side of a PCB implementation of an IPT-IPM module 400 , e.g., the opposite side view of the IPT-IPM module 300 in FIG. 3 . The IPT-IPM module 400 comprises a pair of I2C daisy chain bus connectors 402 and 404 , a PCB trace 406 distributes AC-Line power input from AC-Line screw connector 304 connect at a via 408 to a series of four power control relays 410 - 413 . A microcontroller 414 processes the I2C communications on the internal I2C-bus, e.g., I2C-bus 119 in FIGS. 1 and 219 in FIGS. 2A and 2B . [0066] FIG. 5 shows the basic construction of an IPT-NetworkPM module 500 , and is similar to the IPT-NetworkPM module 128 of FIG. 1 and 228 of FIGS. 2A and 2B . A NetSilicon (Waltham, MA type NET+50 32-bt Ethernet system-on-chip for device networking is preferably used to implement a communications processor 502 . A flash memory 504 provides program storage and a RAM memory 506 provides buffer and scratchpad storage for the communications processor operations. A local I2C-bus is implemented in part with a pair of 2N7002 transistors, for example. It connects into the I2C daisy chain with a J1-connector (CON4) 510 . An extern I2C-bus is implemented in part with a pair of 2N7002 transistors, for example. It connects into an external I2C system with an RJ12-type J7-connector 510 . Such external I2C system can expand to one additional outlet strip that shares a single IPT-NetworkPM module 500 and a single network connection. [0067] An Ethernet 10/100 BaseT-interface with the media access controller (MAC) internal to the communications processor 502 is provided by a physical layer (PHY) device 516 . An Intel type LXT971A fast Ethernet PHY transceiver, for example, could be used together with an RJ45 connector 518 . A pair of RS-232 serial interfaces are implemented in part with an SP3243E transceiver 520 , an RJ45H connector 52 , another SP3243E transceiver 524 , and an IDC10 connector 526 . [0068] The flash memory 504 is preferably programmed with an operating system and HTML-browser function that allow web-page type access and control over the Ethernet channel. A complete OS kernel, NET+Management simple network management protocol (SNMP) MIBII and proxy agent, NET+Protocols including TCP/IP, NET+Web HTTP server, and XML microparser, are commercially available from NetSilicon for the NET+50 32-bit Ethernet system-on-chip. [0069] FIG. 6 represents a circuit 600 that could be used in an implementation of the IPT-PS 118 of FIG. 1 and IPT-PS 218 of FIGS. 2A and 2B . An AC-Line input 602 from the AC-power source is passed through the primary winding of an isolation transformer 604 . A set of four AC-Line outputs 606 are then connected to the four IPT-IPM's, e.g., 120 - 123 in FIG. 1 and 20 - 223 in FIGS. 2A and- 2 B. The voltage drop across the primary winding of isolation transformer 604 is relatively small and insignificant, even at full load. So the line voltage seen at the AC-Line outputs 606 is essentially the full input line voltage. [0070] A voltage is induced into a lightly loaded secondary winding that is proportional to the total current being drawn by all the AC-loads, e.g., AC-receptacles 101 - 116 in FIG. 1 and 201 - 216 in FIGS. 2A and 2B . An op-amp 608 is configured as a precision rectifier with an output diode 610 and provides a DC-voltage proportional to the total current being drawn by all the AC-loads and passing through the primary of transformer 604 . An op-amp 612 amplifies this DC-voltage for the correct scale range for an analog-to-digital converter input (A0) of a microcontroller (uC) 616 . A Philips Semiconductor type P87LPC767 microcontroller could be used for uC 616 . Such includes a built-in four-channel 8-bit multiplexed A/D converter and an I2C communication port. When a READ ADC command is received on the I2C communication port, the AO input is read in and digitally converted into an 8-bit report value which is sent, for example, to LED display 126 in FIG. 1 . [0071] A prototype of the devices described in connection with FIGS. 1-6 was constructed. The prototype was a combination of new hardware and software providing for a 4-outlet, 8-outlet, or 16-outlet vertical-strip power manager that could be accessed out-of-band on a single RJ45 serial port, or in-band over a 10/100Base-T Ethernet connection by Telnet or an HTML browser. An RJ12 port was connected to a second, nearly identical vertical-strip power manager that was almost entirely a slave to the first, e.g., could only be controlled by/via the first/master vertical power manager. [0072] Vertical power manager hardware and software was used for the IPT-PS power supply board, the IPT-IPM quad-outlet boards, and IPT-I2C peripheral/display board. For the master vertical power manager, new personality module hardware and software was developed. This personality module, trademarked SENTRY3, was based upon the NetSilicon NetARM+20M microprocessor, and provided all of the control and user interface (UI). On the slave vertical power manager, a preexisting IPT-Slave personality module was modified slightly to bridge the external and internal I2C-buses. This allowed the master to control the slave vertical power manager exactly the same as the master vertical power manager, with no software or microprocessor needed on the slave. New software could be included to run in a microprocessor on the slave vertical power manager personality module to act as a backup master for load-display and power-up sequencing only. [0073] A new SENTRY3 personality module was developed to support an HTML interface for Ethernet, and a command-line interface for Telnet and serial multiple users were supported, up to 128. One administrative user (ADMN) existed by default, and will default to having access to all ports. Outlet grouping was supported, with up to 64 groups of outlets. [0074] There were two I2C-buses that can support up to sixteen quad-IPM (IPT-IPM) boards, across four power inputs, with at most four quad-IPM's per input, and with each input having its own load measurement and display. Each power input was required to have the same number of quad-IPM's that it powered. There was one I2C peripheral/display (IPT-I2C) board for each power input. Each bus had only one smart power supply (IPT-PS) board at I2C address 0×5 E. Each bus had at least one I2C peripheral/display (IPT-I2C) board at I2C address 0×50, and at least one quad-IPM (IPT-IPM) board at I2C address 0×60 (or 0×40). [0075] Determining what was present on an I2C-bus, and at what address, was done by reading the 8-bit I/O port of the power supply. The eight bits were configured as, Bit 0=→Undefined [0076] Bit 1=→Display orientation (1=Upside-Up, 0+Upside-Down) Bit 2=→Number of quad-IPM's per power input Bit 3=→Number of quad-IPM's per power input Bit four=→Overload point (1=30.5 A [244 ADC], 0=16.5 A [132 ADC]) Bit 5=→Undefined [0077] Bit 6=→Number of power inputs Bit 7=→Number of power inputs [0078] Bits 2 and 3 together determine how many quad-IPM's there were per power input. Bits 6 and 7 together determine how many power input feeds there were. [0079] The I2C address of the quad-IMP's were determined by the version of the LPC code on the IPT-PS board, as determined by a read of the STATus byte of the IPT-PS. [0000] Version 3+→quad-IPM's start @-×60 and were 0×60, 0×62, 0×64, 0×66, 0×68, 0×6 A, 0×6 C, 0×6 E, 0×70, 0×72, 0×74, 0×76, 0×78, 0×7 A, 0×7 C, 0×7 E. Version 2−→quad-IPM's start @0×40 and were 0×40, 0×42, 0×44, 0×46, 0×48, 0×4 A, 0×4 C, 0×4 E, 0×50, 0×52, 0×54, 0×56, 0×58, 0×5 A, 0×5 C 0×5 E. [0080] Up to four IPT-I2C peripheral/display boards were supported at I2C addresses: 0×50, 0×52, 0×54 and 0×56. [0081] There was a direct mapping relationship between power inputs, IPT-I2C peripheral/display boards I2C addresses, and the IPT-IPM boards I2C addresses: [0000] IPT-I2C IPT-IPM v3+ Addresses Power Input Address (subtract 0x20 for v2−) A 0x50 0x60, 0x62, 0x64, 0x66 B 0x52 0x68, 0x6A, 0x6C, 0x6E C 0x54 0x70, 0x72, 0x74, 0x76 D 0x56 0x78, 0x7A, 0x7C, 0x7E [0082] Considering that each input power feed can support up to four quad-IPM's (sixteen ports), and that each bus can have four input feeds, and that there were two I2c-busses, an addressing scheme for a port must include three fields (a) Bus ID, (b) Input Feed ID, and (c) Relay ID. [0083] The Bus ID could be regarded as vertical-strip power manager/enclosure ID, since one I2C-bus were for the internal/local I2C vertical power manager components and the other I2C-bus were for the external/remote vertical power manager. Other implementations could use a CAN bus in place of the external I2C-bus. Each enclosure had an address on the bus, e.g., an Enclosure ID. Thus the three address fields needed were (a) Enclosure ID, (b) Input Feed ID, and (c) Relay ID. [0084] The Enclosure ID was represented by a letter, starting with “A”, with a currently undefined maximum ultimately limited to “Z”. Only “A” and “B” existed for the prototype. The Input Feed ID was represented by a letter, with a range of “A” to “D”. The Relay ID was represented by a decimal number, with a range of “1” to “16”. [0085] An absolute identifier as needed for the user to enter commands. A combination of Enclosure ID, Input Feed ID, and Relay ID must be expressed in the absolute ID. This were done with a period followed by two alphabet characters and then one or two numeric characters, e.g., “{enclosure_id}[input_feed_id]{#}[#]”. [0086] The first alphabet character represented the Enclosure ID (“A” to “Z”). The second alphabet character represented the Input Feed ID (“A” to “D”). The third and fourth number characters represented the Relay ID (“1” to “16”), e.g., “.{A-Z}[A-D]{1-16}”. The input feed ID was optional. If not specified, “A” was assumed. With an absolute ID scheme, a period, letter, and number must always be entered, making it very similar to our current scheme, but allowing for future multiple input feeds. For displaying IDs, the optional input feed ID should only be shown when the port was in an enclosure with 2 or more input feeds. A vertical power manager ID could be specified with just a period and letter. An input feed ID could be specified with a period and two letters. [0087] Existing outlets were determined by reading the power supply I/O port of the master and slave vertical power manager. One administrative user exists by default, and has access to all outlets and groups. This administrator (ADMN) could be removed, but only if one or more other users with administrative privileges exist. Additional users could be created or removed. Administrative privileges could be given to or removed from added users. [0088] The administrative privilege allows access to all currently-detected outlets and groups without those outlets or groups actually being in the user's outlet or group tables. Lists of outlets or groups for administrative users should include all currently-detected outlets and groups. This allowed administrative privileges to be given or taken away without affecting the users outlet and group tables. [0089] Groups of outlets could be created or removed. Outlets could be added or removed from groups. Outlets or groups of outlets, could be added or removed from users. An outlet may belong to multiple groups. All user-defined outlet and groups names were unique. This were enforced at the time names were defined by the user. All user-defined names also cannot be the same any KEYWORDS. For example, they cannot be “GROUP”, “OUTLET”, or “ALL”. This were enforced at the time names were defined by the user. Usernames were uppercased when stored and displayed, and were compared case-insensitive. Passwords were stored and compared case-sensitive. Separate tables existed for each user's outlet access and group access. [0090] When an ADMN user specifies “ALL” it means all currently detected outlets. For non-ADMN users, the “ALL” parameter refers to all of the outlets in the current user's outlet access table. There was no “all” to refer to all groups. [0091] All commands that specify. outlet IDs need to be bounds-checked against the currently detected number of enclosures, number of input feeds on the target enclosure, and the number of relays on the target enclosure. Power actions could be applied to only one target at a time. The target could be an outlet or a group of outlet. [0092] A wakeup state determined the default power-up state of each outlet. Power-on sequencing occurred independently on each vertical power manager and power feed, with each outlet being initialized to its wakeup state two seconds after the previous outlet, e.g., starting with outlet-1. Outlet names could be up to 24-characters. These were stored and displayed case-sensitive, but were compared case-insensitive as command parameters. Group names could be up to 24-characters. These were stored and displayed case-sensitive, but were compared case-insensitive as command parameters. A 24-character vertical power manager/enclosure name could be user-defined. This were stored and displayed case-sensitive, but was compared case-insensitive as a command parameter. A 32-character location name could be user-defined. This were stored and displayed case-sensitive. Username could be 1-16 characters, and were case-insensitive. Passwords also could be 1-16 characters, and were case-sensitive. Variable length command parameters were length-checked for validity. An error was displayed if too short or too long, as opposed to and automatic behavior, such as truncating a string that was too long. [0000] Prototype I2C Address Map I2C Address I2C .Address Device (binary) (hex) I2C-01 0101-000x 0x50 I2C-02 0101-001x 0x52 I2C-03 0101-010x 0x54 I2C-04 0101-011x 0x56 IPT-PS 0101-111X 0X5E IPM-01 0101-000x 0x60 IPM-02 0101-001x 0x62 IPM-03 0101-010x 0x64 IPM-04 0101-011x 0x66 IPM-05 0101-100x 0x68 IPM-06 0101-101x 0x6A IPM-07 0101-110x 0x6C IPM-08 0101-111x 0x6E IPM-09 0101-000x 0x70 IPM-10 0101-001x 0x72 IPM-12 0101-010x 0x74 IPM-13 0101-011x 0x76 IPM-14 0101-100x 0x78 IPM-15 0101-101x 0x7A IPM-16 0101-110x 0x7C IPM-17 0101-111x 0x7E [0093] The prototype required several major software components to be constructed for use with the NetSilicon NET+50 device. The configuration and operational control blocks used in the prototype were described in the following tables. All of the control blocks were readable by all components in the system. The configuration control blocks were written by the user interface tasks. When the configuration control blocks were modified, the modifications were mirrored in EEPROM where copies of these control blocks were stored. The operational control blocks were also accessible to all components for read access, but each operational control block has an “owner” that performs all writes to the operational control blocks. If a non “owner” wishes to change an operational control block, a signal or message was used to let the “owner” know the control block should be updated. [0094] The major design tasks for the prototype included designing and documenting the external I2C protocol that was used to communicate to “chained” SENTRY boxes, and the new command line interface commands to support features that were previously available only via the SENTRY SHOW Screen interface. The HTML code was developed for the prototype, as well as the “slave” SENTRY code to run in a personality module of a “chained” SENTRY. Further discrete design efforts were required to code the system initialization, the local I2C task, the external I2C task, the serial port. control task, the telnet control task, the user interface task, the power coordination task, the extern user interface (button/LED) control task, and the WEB control task. [0095] The major software components developed for the prototype are listed in the following Tables. [0000] SeniNIT—SENTRY initialization procedure. This software was the first SENTRY software that executes. It performs hardware, software (builds the Configuration and Operational global control blocks), and OS initialization. This code spawns the SENTRY operational tasks that provide the system services. TskSER—One instance of this task was spawned for each active serial port. In the initial product there was one instance of this task. This task spawns TskUSR when a logon was detected. This task owns the serial port operational array control block in global memory. This control block was updated to reflect the status of the serial port. Once a TskUSR was spawned, this task performs serial port monitoring functions and if modem status signal indicate a lost connection, this task will signal TskUSR (via an OS interface) of this event. TskTELNET—One instance of this task was spawned to listen for telnet connections. When a connection was detected, the task spawns TskUSR for the connection. TskFTP—One instance of this task was spawned to listen for FTP connections. The function of this task was to provide field software updates for the system. The mechanism used was determined based on the developer kit capabilities. TskWEB—This task was to provide WEB access via the system provided WEB server. The mechanism and number of instances of this task was determined based on the developer kit capabilities. TskI2C—There were two versions of this task; the local version that controls internal I2C connections and the global version that controls external I2C connections. For the first implementation there were two instances of this task, one to control the single I2C internal connection and one to control the single I2C external connection. These tasks implement the protocol for communicating control requests from the system to the I2C connected devices. Control requests were received via system signals or messages (depending on the OS capabilities) from the power control coordinating task (TskPCntl) for power control requests and from the external user interface task (TskEUI) for LED control requests. This task communicates power control status updates received from the IPM's to TskPCntl and external button status updates to TskEUI using system signals or messages as necessary. TskPCntl—This was the power control coordinating task. There was one instance of this task. This task receives power control request from the user interface tasks (TskUSR and TskWEB) via system provided signals messages and passes them to the correct I2C task (internal or external) using signals or messages. This task receives status updates from the I2C tasks via signals or messages. TskPCntl “owns” the IPMO and PCRO arrays and it updates the status fields in entries in these arrays as necessary. TskEUI—This was the external user interface task that handles the push button functions and the LED display functions for the system. This task communicates with the local TskI2C via signals or messages to update the LED. TskI2C sends signals or messages to this task when the state of the external push button changes. TskUSR—This command line user interface task was spawned by TskSER and TskTELNET when a user connection was detected. This task verifies the user login and then implements the command line interface. This routine communicates power-control commands via signals or messages to TskPCntl. This routine “owns” the active command line user array. Because there were multiple instances of this task, locks were used to serialize access to the active user array. TskSYS—This was the general system task. Specific functions for this task were defined as development progressed. [0096] The control blocks were globally addressable by all software in the system. Such data structures exist in RAM and were mirrored in EEPROM memory. They were constructed during system initialization using the nonvolatile versions in EEPROM memory. If the EEPROM memory was empty, the control blocks were built using defaults and the EEPROM memory was initialized using defaults as well. All software has read access to all of the data structures. The data in these control blocks was configuration data and was only changed as a result of configuration updates. The data was mostly static and was written during initialization and when configuration changes occur during an authorized user session. All write access to this data consists of a two-step process where the Global RAM copy of the data was updated followed by an update of the EEPROM copy of the data. There were seven global configuration control blocks as illustrated below. The following Tables describe each control block structure used in the prototype. [0000] SENTRY Configuration Table (SCT)—This control block contains global configuration information. There was a single instance of this control block. Username/Password Array (UNP)—This was an array of control blocks with each entry representing a user defined to the system. System locks were used to serialize access to this array when adding/deleting users. There was room for sixty-four entries in this array. Intelligent Power Module (IPM) Array—This was an array of control blocks with each entry representing an IPM defined to the system. There was room for 32 entries in this array. Power Control Relay (PCR) Array—This was an array of control blocks with each entry representing an PCR defined to the system. There was room for 128 entries in this array. Group Power Control Relay (GRP) Array—This was an array of control blocs with each entry representing an Group of PCRs. There was room for 64 entries in this array. Serial Port (SER) Array—This was an array of control blocks with each entry representing a serial port that can be used to access the system There was room for two entries in this array. I2C Array—This was an array of control blocks with each entry representing an I2C connection. There was room for two entries in this array. [0097] The Global RAM Operational Control Block Structures were globally addressable by all software in the system. These data structures exist only in RAM and are lost during a system restart. They were constructed during system initialization using current operational values. All software has read access to all of the data structures. The data in these control blocks was operational data and was changed to reflect the current operational status of devices in the system. Each of these control blocks has an “owner” task that performs updates by writing to the control block. There were six global operational control blocks as illustrated below. Complete descriptions of each control block structure follows. [0000] Intelligent Power Module (IPMO) Array—This was an array of control blocks with each entry representing an IPM defined to the system. There was room for 32 entries in this array. The entries in this array correspond directly to the IPM configuration control block. These control blocks contain dynamic information that changes regularly. The relay coordination task (TskPCntl) “owns” this array. Power Control Relay (PCRO) Array—This was an array of control blocks with each entry representing an PCR defined to the system. There was room for 128 entries in this array. The entries in this array correspond directly to the PCR configuration control block. These control blocks contain dynamic information that changes regularly. The relay coordination task (TskPCntl) “owns” this array. I2C (I2CO) Array—This was an array of control blocks with each entry representing an I2C connection. There was room for 2 entries in this array. The entric/8 in this array correspond directly to the I2C configuration control block. These control blocks contain dynamic information that changes regularly. The I2C task (Tski2C) “owns” this array. Serial Port (SERO) Array—This was an array of control blocks with each entry representing a serial port that can be used by the system. There was room for two entries in this array. The entries in this array correspond direct to the serial port configuration control block. These control blocks contain dynamic information that changes regularly. The serial port task (TskSER) “owns” this array. Active Command Line User (UCLI) Array—This was an array of control blocks with each entry representing a current active command line user of the system. The SCT was room for 5 entries in this array. These control blocks contain dynamic information that changes regularly. The user interface task (TskUSR) “owns” this array. There were multiple instances of TskUSR so locks were used for this array. Active HTTP Interface User (UHTP) Array—This was an array of control blocks with each entry representing. a WEB user. There was room for 5 entries in this array. These control blocks contain dynamic information that changes regularly. The WEB task (TskWEB) “owns” this array. [0098] In FIG. 7 , a network remote power management system 700 includes a host system 702 connected over a network 704 to a remote system 706 . A power manager 708 , e.g., like outlet strips 100 and 200 of FIGS. 1 , 2 A, and 2 B, is used to monitor and control the operating power supplied to a plurality of computer-based appliances 714 associated with a network interface controller (NIC) 716 . [0099] Such computer-based appliances 714 are subject to software freezing or crashing, and as such can become unresponsive and effectively dead. It is also some mission-critical assignment that suffers during such down time. It is therefore the role and purpose of the network remote power management system 700 to monitor the power and environmental operating conditions in which the computer-based appliance 714 operates, and to afford management personnel the ability to turn the computer-based appliance 714 on and off from the host system 702 . Such power cycling allows a power-on rebooting of software in the computer-based appliance 714 to be forced without it actually having to visit the site. The operating conditions and environment are preferably reported to the host 702 on request and when alarms occur. [0100] The power manager 708 further includes a network interface controller (NIC) 718 , and this may be connected to a security device 720 . If the network 704 is the Internet, or otherwise insecure, it is important to provide protection of a protocol stack 72 from accidental and/or malicious attacks that could disrupt the operation or control of the computer-based appliance 714 . At a minimum, the security device 720 can be a user password mechanism. Better than that, it could include a discrete network-firewall and data encryption. [0101] The protocol stack 722 interfaces to a remote power manager 724 , and it converts software commands communicated in the form of TCP/IP datapackets 726 into signals the remote power manager can use. For example, messages can be sent from the host 702 that will cause the remote power manager 724 to operate the relay-switch 712 . In reverse, voltage, current, and temperature readings collected by the sensor 710 are collected by the remote power manager 724 and encoded by the protocol stack 722 into appropriate datapackets 726 . Locally, a keyboard 728 can be used to select a variety of readouts on a display 730 , and also to control the relay-switch 712 . [0102] The display 730 and keyboard 728 can be connected as a terminal through a serial connection to the power manager 724 . Such serial connection can have a set of intervening modems that allow the terminal to be remotely located. The display 730 and keyboard 728 can also be virtual, in the sense that they are both emulated by a Telnet connection over the network 704 . [0103] The host 702 typically comprises a network interface controller (NIC) 732 connected to a computer platform and its operating system 734 . Such operating system can include Microsoft WINDOWS-NT, or any other similar commercial product. Such preferably supports or includes a Telnet application 736 , a network browser 738 , and/or an SNMP application 740 with an appropriate MIB 742 . A terminal emulation program or user terminal 744 is provided so a user can manage the system 700 from a single console. [0104] If the computer-based appliance 714 is a conventional piece of network equipment, e.g., as supplied by Cisco Systems (San Jose, Calif.), there will usually be a great; deal of pre-existing SNMP management software already installed, e.g., in host 702 and especially in the form of SNMP 740 . In such case it is usually preferable to communicate with the protocol stack 722 using SNMP protocols and procedures. Alternatively, the Telnet application 736 can be used to control the remote site 706 . [0105] An ordinary browser application 738 can be implemented with MSN Explorer, Microsoft Internet Explorer, or Netscape NAVIGATOR or COMMUNICATOR. The protocol stack 722 preferably includes the ability to send hypertext transfer protocol (HTTP) messages to the host 702 in datapackets 726 . In essence, the protocol stack 722 would include an embedded website that exists at the IP-address of the remote site 706 . An exemplary embodiment of similar technology is represented by the MASTERSWITCH-PLUS marketed by American Power Conversion (West Kingston, R.I.). [0106] Many commercial network devices provide a contact or logic-level input port that can be usurped for the “tickle” signal. Cisco Systems routers, for example, provide an input that can be supported in software to issue the necessary message and identifier to the system administrator. A device interrupt has been described here because it demands immediate system attention, but a polled input port could also be used. [0107] Network information is generally exchanged with protocol data unit (PDU) messages, which are objects that contain variables and have both titles and values. SNMP uses five types of PDU's to monitor a network. Two deal with reading terminal data, two deal with setting terminal data, and one, the trap, is used for monitoring network events such as terminal start-ups or shut-downs. When a user wants to see if a terminal is attached to the network, for example, SNMP is used to send out a read PDU to that terminal. If the terminal is attached, a user receives back a PDU with a value “yes, the terminal is attached”. If the terminal was shut off, a user would receive a packet informing them of the shutdown with a trap PDU. [0108] In alternative embodiments of the present disclosure, it may be advantageous to include the power manager and intelligent power module functions internally as intrinsic components of an uninterruptable power supply (UPS). In applications where it is too late to incorporate such functionally, external plug-in assemblies are preferred such that off-the-self UPS systems can be used. [0109] Once a user has installed and configured the power manager 7u08, a serial communications connection is established. For example, with a terminal or terminal emulation program. Commercial embodiments of the present disclosure that have been constructed use a variety of communications access methods. [0110] For modem access, the communication software is launched that supports ANSI or VT100 terminal emulation to dial the phone number of the external modem attached to the power manager. When the modems connect, a user should see a “CONNECT” message. A user then presses the enter key to send a carriage return. [0111] For direct RS-232C access, a user preferably starts any serial communication software that supports ANSI or VT100 terminal emulation. The program configures a serial port to one of the supported data rates (38400, 79200, 9600, 4800, 7400, 7200, and 300 BPS), along with no parity, eight data bits, and one stop bit, and must assert its Device Ready signal (DTR or DSR). A user then presses the enter key to send a carriage return. [0112] For Ethernet network connections, the user typically connects to a power manager 708 through a modem or console serial port, a TELNET program, or TCP/IP interface. The power manager 708 preferably automatically detects the data rate of the carriage return and sends a username login prompt back to a user, starting a session. After the carriage return, a user will receive a banner that consists of the word “power manager” followed by the current power manager version string and a blank line and then a “Username:” prompt. [0113] A user logged in with an administrative username can control power and make configuration changes. A user logged in with a general username can control power on/off cycling. Users logged in administrative username can control power to all intelligent power modules, a user logged in with a general username may be restricted to controlling power to a specific intelligent power module or set of intelligent power modules, as configured by the administrator. [0114] A parent case, U.S. Pat. No. 7,099,934, issued Aug. 29, 2006, titled NETWORK-CONNECTING POWER MANAGER FOR REMOTE APPLIANCES, includes many details on the connection and command structure used for configuration management of power manager embodiments of the present disclosure. Such patent application is incorporated herein by reference and the reader will find many useful implementation details there. Such then need not be repeated here. [0115] Referring again to FIG. 7 , a user at the user terminal 744 is able to send a command to the power manager 724 to have the power manager configuration file uploaded. The power manager 724 concentrates the configuration data it is currently operating with into a file. The user at user terminal 744 is also able to send a command to the power manager 724 to have it accept a power manager configuration file download. The download file then follows. Once downloaded, the power manager 724 begins operating with that configuration if there were no transfer or format errors detected. These commands to upload and download configuration files are preferably implemented as an extension to an already existing repertoire of commands, and behind some preexisting password protection mechanism. HyperTerminal, and other terminal emulation programs al low users to send and receive files. [0116] In a minimal implementation, the power manager configuration files are not directly editable because they are in a concentrated format. It would, however be possible to implement specialized disassemblers, editors, and assemblers to manipulate these files off-line. [0117] FIG. 8 is a diagram of an expandable power management system 800 that could be implemented in the style of the outlet strip 100 ( FIG. 1 ). In one commercial embodiment of the present disclosure, a first power controller board 802 is daisy-chain connected through a serial cable 803 to a second power controller board 804 . In turn, the second power controller board 804 is connected through a serial cable 805 to a third power controller board 806 . All the power controller boards can communicate with a user terminal 808 connected by a cable 809 , but such communication must pass through the top power controller board 802 first. [0118] Alternatively, the user terminal could be replaced by an IP-address interface that provided a web presence and interactive webpages. If then connected to the Internet, ordinary browsers could be used to upload and download user configurations. [0119] Each power controller board is preferably identical in its hardware and software construction, and yet the one placed at the top of the serial daisy-chain is able to detect that situation and take on a unique role as gateway. Each power controller board is similar to power controller 208 ( FIG. 2 ). Each power controller board communicates with the others to coordinate actions. Each power controller board independently stores user configuration data for each of its power control ports. A typical implementation had four relay-operated power control ports. Part of the user configuration can include a user-assigned name for each control port. [0120] A resynchronization program is executed in each microprocessor of each power controller board 802 , 804 , and 806 , that detects where in the order of the daisy-chain that the particular power controller board is located. The appropriate main program control loop is selected from a collection of firmware programs that are copied to every power controller board. In such way, power controller boards may be freely added, replaced, or removed, and the resulting group will resynchronize itself with whatever is present. [0121] The top power controller board 802 uniquely handles interactive user login, user-name tables, its private port names, and transfer acknowledgements from the other power controller boards. All the other power controller boards concern themselves only with their private resources, e.g., port names. [0122] During a user configuration file upload, power controller board 802 begins a complete message for all the power controller boards in the string with the user-table. Such is followed by the first outlets configuration block from power controller board 802 k , and the other outlet configuration blocks from power controller boards 804 and 806 . The power controller board 802 tells each when to chime in. Each block carries a checksum so transmission errors could be detected. Each block begins with a header that identifies the source or destination, then the data, then the checksum. [0123] During a user configuration file download, power controller board 802 receives a command from a user that says a configuration file is next. The user-name table and the serial-name table is received by power controller board 802 along with its private outlets configuration block and checksum. The next section is steered to power controller board 804 and it receives its outlets configuration block and checksum. If good, an acknowledgement is sent to the top power controller board 802 . The power controller boards further down the string do the same until the whole download has been received. If all power controller boards returned an acknowledgement, the power controller board 802 acknowledges the whole download. Operation then commences with the configuration. Otherwise a fault is generated and the old configuration is retained. [0124] In general, embodiments of the present disclosure provide power-on sequencing of its complement of power-outlet sockets so that power loading is brought on gradually and not all at once. For example, power comes up on the power outlet sockets 2-4 seconds apart. An exaggerated power-up in rush could otherwise trip alarms and circuit breakers. Embodiments display otherwise report the total current being delivered to all loads, and some embodiments monitor individual power outlet sockets. Further embodiments of the present disclosure provide individual remote power control of independent power outlet sockets, e.g., for network operations center reboot of a crashed network server in the field. [0125] The power-on sequencing of the power-outlet sockets preferably allows users to design the embodiments to be loaded at 80% of full capacity, versus 60% of full capacity for prior art units with no sequencing. In some situations, the number of power drops required in a Data Center can thus be reduced with substantial savings in monthly costs. [0126] FIG. 9 represents a power distribution unit (PDU) embodiment of the present disclosure, and is referred to herein by the general reference numeral 900 . The PDU 900 allows a personality module 902 to be installed for various kinds of control input/output communication. For an Ethernet interface, a NetSilicon type NET+50 system-on-a-chip is preferred, otherwise a Philips Semiconductor type P89C644 microcontroller could be used in personality module 902 . [0127] The PDU 900 further comprises an I2C peripheral board 904 , and a set of four IPM's 906 , 908 , 910 , and 912 . Such provide sixteen power outlets altogether. A power supply 914 provides +5-volt logic operating power, and a microcontroller with a serial connection to an inter-IC control (I2C) bus 917 . Such I2C bus 917 preferably conforms to industry standards published by Philips Semiconductor (The Netherlands). See, www.semiconductor.philips.com. Philips Semiconductor type microcontrollers are preferably used throughout PDU 900 because I2C-bus interfaces are included. [0128] A SENTRY-slave personality module 916 could be substituted for personality module 902 and typically includes a Server Technology, Inc. (Reno, NV) SENTRY-type interface and functionality through a standard RJ12 jack. See, e.g., website at www.servertech.com. A slave personality module 918 could be substituted for personality module 902 and provides a daisy-chain I2C interface and functionality through a standard RJ12 jack. A terminal-server personality module 920 could be substituted for personality module 902 and provides a display terminal interface, e.g., via IC through a standard RJ12 jack, or RS-232 serial on a DIN connector. A network personality module 922 preferably provides a hypertext transfer protocol (http) browser interface, e.g. via 100Base-T network interface and a CAT-5 connector. The on-board microcontroller provides all these basic personalities through changes in its programming, e.g., stored in EEPROM or Flash memory devices. All of PDU 900 is preferably fully integrated, e.g., within power distribution outlet strip 100 , in FIG. 1 . [0129] FIG. 10 illustrates an intelligent power module (IPT-IPM) 1000 and represents one way to implement IPT-IPM's 120 - 123 of FIG. 1 ; IPT-IPM's 220 - 223 of FIGS. 2A and 2B ; IPT-IPM 300 of FIG. 3 ; IPT-IPM 400 of FIG. 4 ; power controller boards 802 , 804 , and 806 of FIG. 8 ; and, 4-port IPM's 906 , 908 , 910 , and 912 of FIG. 9 . The IPT-IPM 1QOO comprises an I2C microcontroller 1002 connected to communicate on a daisy-chain I2C serial bus with in and out connectors 1004 and 1006 . An AC-Line input 1008 , e.g., from IPT-PS 118 in FIG. 1 , is independently switched under microcontroller command to AC-Line output-1 1010 , AC-Line output-2 1011 , AC-Line output-3 1012 , and AC-Line output-4 1013 . A set of four relays (K1-K4) 1014 - 1017 provide normally open (NO) contacts 1018 - 1021 . DC-power to operate the relays is respectively provided by relay power supplies 1024 - 1025 . Optical-isolators 1026 - 1029 allow logic level outputs from the microcontroller 1002 to operate the relays in response to I2C commands received from the I2C-bus. [0130] Similarly, optical-isolators 1030 - 1033 allow the presence of AC-Line voltages at AC-Line output-1 1010 , AC-Line output-2 1011 , AC-Line output-3 1012 , and AC-Line output-4 1013 , to be sensed by logic level digital inputs to microcontroller 1002 . These are read as status and encoded onto the I2C-bus in response to read commands. A local user is also provided with a LED indication 1034 - 1037 of the AC-Line outputs. A set of load sensors 1038 - 1041 sense any current flowing through the primaries of respective isolation transformers 1042 - 1045 . A logic level LS1-LS4 is respectively provided to microcontroller 1002 to indicate if current is flowing to the load. [0131] In general, remote power management embodiments of the present disclosure are configurable and scalable. Such provides for maximum fabricator flexibility in quickly configuring modular components to meet specific customer requests without overly burdening the manufacturing process. The following list of various customer requirements can all be met with minimal hardware, and no software changes: Vertical or Horizontal enclosure mounting; Variable controllable outlet configurations (4, 8, 12 ,16 outlets/enclosure); Variable number of power input feed configurations to support redundant power to critical network equipment (up to 4 input feeds); Option of displaying one or more input load currents on a dual 7-segment LED display(s); Ability to reorient the enclosure without having to invert the 7-segment LED display(s); Measuring per outlet load current for individual appliance load reporting; and a Variety of user interfaces that can be substituted at final product configuration time. [0132] A modular component concept allows for communications and automated detection of any included modular components over a common communications channel so a multi-drop, addressable, and extensible bus architecture is used. The Inter-IC (I2C) bus developed by Philips semiconductor is preferred. Each modular component contains a microprocessor capable of interpreting and responding to commands over I2C-bus. An application layer enhancement on top of the standard I2C protocol allows for data integrity checking. A-checksum is appended to all commands and responses. Such checksum is validated before commands are acted upon, and data responses are acknowledged. Each module on the I2C power control bus has either a hard-coded or configurable address to enable multiple components to communicate over the same two wires that comprise the bus. Configuration jumpers on the power supply module are used to select operational items, e.g., #Power input feeds, #four port Intelligent Power Modules (IPM) attached to each input feed, Input feed overload current threshold, and Display inversion. [0133] The main components used in most instances are the power supply boar (IPT-PS) that supplies DC voltage on the interconnection bus, and monitors and reports input feed load and enclosure configuration information; the intelligent power module IPM (IPT-IPM) which controls the source of power to each outlet based on I2C commands from the master controller personality module (PM), and that reports whether the outlet is in the requested state and the outlet load current back to the master controller; the display board (IPT-I2C) used to display load current as supplied by the master controller and to monitor user-requested resets, and that can communicate with sensors attached to its Dallas Semiconductor-type “1-wire” bus to the master controller; and, the personality modules that act as an I2C-bus master, e.g., IPT-Serial PM, IPT-Slave PM, and IPT-Network PM. [0134] Such personality module can initialize, issue commands to, and receive responses from the various components on the bus. It also is responsible for executing user power control and configuration requests, by issuing commands on the bus to the various modules that perform these functions. These personality modules support several user interfaces and can be swapped to provide this functionality. The IPT-Serial PM is used for serial only communications. The IPT-Slave PM is used to connect to an earlier model controllers, and allows for a variety of user interfaces, e.g., Telnet, Http, SNMP, serial, modem. The IPT-Network PM has much of the same functionality as a previous model controller, but has all that functionality contained on the personality module itself and requires no external enclosure. [0135] By combining and configuring these components, a variety of power control products can be constructed in many different enclosure forms, each with a variety of power input feed and outlet arrangements. [0136] Lower-cost power control products can be linked to a more expensive master controller using an IPT-Network PM to configure a large-scale power control network that needs only a single IP-address and user interface. Such would require a high level, high bandwidth, multi-drop communications protocol such as industry-standard Controller Area Network (CAN). The CAN bus supports 1-Mbit/sec data transfers over a distance of 40 meters. This would enable serial sessions from a user to serial ports on the device being controlled to be virtualized and thus avoid needing costly analog switching circuitry and control logic. [0137] Although the present disclosure has been described in terms of the present embodiment, it is to be understood that the disclosure is not to be interpreted as limiting. Various alterations and modifications will no doubt become apparent to those skilled in the art after having read the above disclosure. Accordingly, it is intended that the appended claims be interpreted as covering all alterations and modifications as fall within the true spirit and scope of the disclosure.

A power management device can include a housing, a power input associated with the housing, and a plurality of power outputs associated with the housing. At least certain power outputs can be connectable to one or more electrical loads external to the housing and to the power input. In some embodiments, a communications bus and one or more power control sections can be associated with the housing. In some embodiments, one or more power control sections can communicate with the communications bus and with one or more corresponding power outputs among the plurality of power outputs. In some embodiments, a power information display can communicate with the communications bus. If desired, a power information determining section can be associated with the housing and in communication with the communications bus. The power information determining section may communicate power-related information to the power information display.

TECHNOLOGICAL FIELD [0001] The present disclosure relates to methods, systems and apparatuses for energy storage. More particularly the present disclosure relates to improvements in lithium ion battery technology comprising the introduction of thermally responsive polymer electrolytes. BACKGROUND [0002] Increasing energy demands, along with the need to use energy from intermittent, renewable resources has led to a continued interest in the field of energy storage and delivery, including the field of batteries. Such energy devices must safely deliver required energy output for many uses, including transportation and portable power systems. Lithium-ion and lithium metal batteries have emerged as one candidate to meet such demands. [0003] The term “lithium-ion battery” or “lithium-ion cell” encompasses batteries where the anode and cathode materials act as a host for the lithium ion (Li + ) and the terms are used equivalently and interchangeably throughout this disclosure. Lithium ions migrate from the anode to the cathode during discharge and are inserted into the voids in the crystallographic structure of the cathode. The ions reverse direction during charging. Alternating layers of anode and cathode are separated by a porous film, known as a separator. An electrolyte, typically comprising an organic solvent along with dissolved lithium salt provides the media for the lithium ion transport. Lithium-ion cells can be made by stacking alternating layers of electrodes, or by winding long strips of electrodes into a roll configuration (typical for cylindrical cells). Electrode stacks or welds are typically inserted into hard cases that are sealed with gaskets, laser-welded hard cases, or enclosed in foil pouches and heat-sealed. Lithium batteries are similar in principle to lithium-ion batteries, but are often single-use primary batteries with lithium metal anodes that offer high energy density. For purposes of this application, lithium metal batteries are included in the general category of “lithium ion” batteries, and the advantages of the present disclosure are understood to apply also to lithium metal batteries. It is further understood, for the purposes of this application, that the terms “lithium ion cell” and “lithium ion battery” are used interchangeably, with equivalent meaning. [0004] Lithium-ion cells in today's market therefore have similar designs featuring a negative electrode (anode) made from carbon/graphite coated onto a copper current collector, a metal oxide positive electrode (cathode) coated onto an aluminum current collector, a polymeric separator, and an electrolyte comprising a lithium salt in an organic solvent. [0005] Lithium-ion cells have a safe operating voltage range over which it can be cycled that is determined by specific cell chemistry. The safe operating range is a range where the cell electrodes will not rapidly degrade due to lithium plating onto the electrodes, will not undergo copper dissolution, or sustain other undesirable reactions, including thermal runaway, for example. [0006] Typical electrolytes feature a mixture of organic carbonates such as ethylene carbonate or diethyl carbonate. The mixture ratios vary depending on the desired cell properties. The electrolytes comprise lithium-ions provided to the electrolyte in the form of lithium salts, such as, for example, lithium hexafluorophosphate (LiPF 6 ). [0007] Typical lithium-ion cells may also contain various additives to increase the performance, stability and safety, such as, for example, additives that act as flame retardants, overcharge protectors, cathode protection agents, lithium salt stabilizers or corrosion inhibitors. [0008] During normal device operation, the temperature of lithium ion cells increases as a result of the exothermic lithium reactions, and cells are designed to efficiently transport the heat to the outside of the cell. Problems within the cell can cause the internal temperature to increase beyond an acceptable limit, which causes the lithium reaction rates to increase, further increasing the temperature of the cell. Most lithium-ion cells are not designed to withstand temperatures above approximately 60° C. during operation or storage. Most commercial lithium-ion cell contain chemistries resulting in breakdown occurring in the temperature range of from about 75° C. to about 90° C., during the time discharge rates are high. [0009] Thermal runaway refers to cell conditions where rapid self-heating of the cell occurs due to the inherent exothermic chemical reaction of the highly oxidized cathode and the highly reducing anode. In a thermal runaway reaction, a cell rapidly releases stored energy. Since lithium-ion cells have high energy densities and flammable electrolytes, lithium-ion cell thermal runaway can be dangerous, and will at least lead to the destruction of the cell, and could contribute to conditions that could lead to the destruction of the device being powered. Certainly, when cells are arranged in series to discharge power, thermal runaway in one cell can damage adjacently-positioned cells. [0010] Attempts to achieve lithium-ion cell shutdown (as a safety measure) in the event of thermal runaway have focused on separator technology or the use of solid-state electrolytes. Lithium-ion cell separators are typically made from porous polymers including polyethylene, polypropylene, or combinations thereof. The separators act to prevent the direct contact between the anode and cathode. The pores in the separators allow the cyclical transport of lithium ions during alternating charge and discharge cycles via diffusion through the separator. When temperatures elevate above a predetermined “safe” operating temperature, many separators are designed to soften, thus closing the pores, and stopping lithium ion transport through the separator. While such a shutdown of the cell can inhibit the threat of thermal runaway from occurring, the shutdown permanently disables the cell in the case of an internal temperature rise. In addition, at certain internal temperatures, the separators may melt entirely, which cannot only lead to permanent cell failure, but also risks fire or explosion. Similarly, the use of solid state electrolytes has been proposed, where low ionic conductivity limits cell performance (particularly the power density of the cell). However, like the proposed separators, thermal decay occurs at elevated temperatures. While this potentially improves safety by reducing the chance of fire or explosion, the mechanisms triggering such safety measures render the cells useless. [0011] Managing heat generation in small format lithium-ion cells has become relatively routine due to the cells' limited size. This has resulted in limited risk of thermal failure. Therefore, some commercially available cells adopt arrays of small format cells. However, large format lithium-ion cells have shown an increased risk of catastrophic thermal failure due to, for example, high surface contact between electrode and electrolyte, high amount of heat generated in a confined space, and large distances to dissipate heat from the cell. Further, limitations in thermal management have limited the size and scale of secondary lithium-ion batteries. [0012] Methods and apparatuses for lithium-ion cells that could ameliorate or impede internal temperature rises, and reduce the hazards of thermal runaway would be highly advantageous. Further, methods for impeding thermal runaway while also preserving the function of the lithium-ion cell itself would be also highly advantageous. SUMMARY [0013] According to one aspect, the present disclosure is directed to methods for controlling lithium-ion cell performance comprising a lithium-ion cell, with the cell comprising a thermally responsive electrolyte that exhibits a predetermined phase transition at a temperature of from about 50° C. to about 160° C. The terms lithium-ion cell and lithium-ion battery are understood to be equivalent terms for purposes of the present application. Further, lithium metal batteries and cells are understood to be included in the term lithium-ion cells for purposes of the present application. [0014] The contemplated phase transition can be reversible or irreversible. Therefore, according to one aspect, the phase transition is reversible. [0015] In a still further aspect, the thermally responsive electrolyte comprises a thermally responsive polymer, a solvent and a lithium salt, with the thermally responsive electrolyte exhibiting a predetermined phase transition at a temperature of from about 50° C. to about 160° C. [0016] In another aspect, the thermally responsive polymer is selected from the group consisting of: polyethylene oxide and other polyether derivatives; poly(aryl methacrylates), where aryl denotes an aromatic group, such as poly(benzy methacrylates); poly(-alkyl methacrylates), where alkyl denotes any hydrocarbon side group such as, without limitation, poly(n-butyl methacrylates); poly(-alkyl acrylamides); poly(n-isopropylacrylamides), and other poly(methacrylate) derivatives, poly(ionic) liquids, copolymers or cross-linked polymers of these aforementioned materials, and combinations thereof. [0017] In another aspect, the thermally responsive electrolyte comprises a thermally responsive polymer selected from the group consisting of poly(ethylene oxide) and other polyether derivatives; poly(aryl methacrylates), poly(alkyl methacrylates) and other poly(methacrylate) derivatives, poly(ionic liquids), copolymers or cross-linked polymers therein, and combinations thereof. [0018] In yet another aspect, the solvent is an ionic liquid selected from the group comprising of imidazolium-, pyrrolidinium-, phosphonium-, ammonium- and sulfonium-based ionic liquids, and combinations. [0019] In a further aspect, the thermally responsive electrolyte further comprises a lithium salt, with the lithium salt selected from the group consisting of lithium tetrafluoroborate, lithium hexafluorophosphate, lithium bis(trifluoromethanesulfonyl)imide (also referred to herein as “LiTFSI”), lithium perchlorate, or any lithium salt, and combinations thereof. [0020] In a still further aspect, the phase transition occurs at a temperature less than a temperature required to damage a lithium-ion cell separator. Such temperature typically occurs between from about 100° C. to about 160° C. [0021] In another aspect, the thermally responsive electrolyte inhibits conductivity within the lithium-ion cell when the temperature of the electrolyte is in the temperature range of from about 50° C. to about 160° C. [0022] In yet another aspect, the phase transition of the thermally responsive electrolyte inhibits lithium-ion transport in the electrolyte. [0023] In another aspect, the thermally responsive electrolyte inhibits the charge transfer or ion intercalation when the temperature of the electrolyte is in the range of from about 50° C. to about 160° C. [0024] In yet another aspect, the phase transition of the electrolyte inhibits ion transport in the electrolyte. [0025] In a still further aspect, the present disclosure is directed to a lithium-ion cell or a lithium-metal cell comprising a thermally responsive electrolyte. The electrolyte exhibits a phase transition at a temperature of from about 50° C. to about 160° C. [0026] In another aspect, the present disclosure is directed to a lithium-ion cell or a lithium-metal cell comprising a thermally responsive electrolyte, with the electrolyte comprising a thermally responsive polymer, a thermally stable solvent, and a lithium salt, wherein the thermally responsive polymer in the solvent exhibits a predetermined phase transition at a temperature of from about 50° C. to about 160° C. [0027] In another aspect, the thermally responsive electrolyte comprises a thermally responsive polymer, a thermally stable solvent, and a lithium salt, and wherein the thermally responsive electrolyte exhibits a predetermined phase transition at a temperature of from about 50° C. to about 160° C. [0028] In yet another aspect, the thermally responsive polymer is selected from the group consisting of poly(ethylene oxide) and other polyether derivatives; poly(aryl methacrylates), where aryl denotes any aromatic group, such as poly(benzyl methacrylate); poly(alkyl methacrylates), where alkyl denotes any hydrocarbon side group, such as poly(n-butyl methacrylate), poly(-alkyl acrylimides), where alkyl denotes any hydrocarbon side group, such as poly(n-isopropylacrylamide), and other poly(methacrylate) derivatives, poly(ionic liquids), copolymers or cross-linked polymers of these materials, and combinations thereof. [0029] In another aspect, the thermally responsive polymer has an average molecular weight of from about 1,000 to about 1,000,000. [0030] In yet another aspect, the preferred solvent is an ionic liquid selected from the group consisting of imidazolium-, pyrrolidinium-, pyridinium-, phosphonium-, ammonium-, and sulfonium-based ionic liquids and combinations thereof. However, it is understood that, acting as the cation, the ionic liquid may comprise many other compounds. [0031] In a further aspect, the lithium salt is selected from the group consisting of: lithium tetrafluoroborate, lithium hexafluorophosphate, lithium bis(trifluoromethanesulfonyl)imide, lithium perchlorate, or any lithium salt, and combinations thereof. [0032] According to a further aspect, the present disclosure is directed to a thermally responsive electrolyte comprising a thermally responsive polymer, a thermally stable solvent, and a lithium salt. [0033] In a further aspect, the thermally responsive electrolyte of claim 15 , wherein the thermally responsive polymer is selected from the group consisting of: poly(ethylene oxide) and other polyether derivatives; poly(aryl methacrylates), poly(alkyl methacrylates), and other poly(methacrylate) derivatives, poly(ionic liquids), copolymers or cross-linked polymers therein, and combinations thereof. [0034] In yet another aspect, the thermally responsive electrolyte has an average molecular weight of from about 1000 to about 1,000,000. [0035] In a still further aspect, the phase transition occurs at a temperature less than a temperature required to damage a lithium-ion cell separator, which occurs at a temperature of between from about 100° C. and 160° C. [0036] In another aspect, the thermally responsive electrolyte exhibits a predetermined phase transition at a temperature of from about 50° C. to about 160° C. [0037] In yet another aspect, a polyethylene oxide-containing compound in the thermally responsive electrolyte exhibits a predetermined phase transition at a temperature ranging from about 50° C. to about 160° C. [0038] In another aspect, the thermally responsive electrolyte inhibits conductivity within the lithium-ion cell when the temperature of the electrolyte is in the temperature range of from about 50° C. to about 160° C. [0039] In yet another aspect, the phase transition of the thermally responsive electrolyte inhibits lithium-ion transport in the cell. [0040] In another aspect, the present disclosure is directed to a thermally responsive electrolyte, with the electrolyte exhibiting a phase transition with increasing temperature of from about 50° C. to about 160° C. The phase transition may be a solid-liquid or a liquid-liquid phase separation. In one aspect, the thermally responsive electrolyte comprises a thermally responsive polymer, a thermally stable solvent, and a lithium salt. [0041] In another aspect, the thermally responsive polymer comprises a polyether-containing compound or poly(methacrylate)-containing compound, a solvent, and a lithium salt. [0042] In another aspect, the thermally responsive polymer is selected from the group consisting of: poly(ethylene oxide) and other polyether derivatives; poly(aryl methacrylates), where aryl denotes any aromatic group, such as poly(benzyl methacrylate); poly(alkyl methacrylates), where alkyl denotes any hydrocarbon side group, such as poly(n-butyl methacrylate), poly(-alkyl acrylimides), where alkyl denotes any hydrocarbon side group, such as poly(n-isopropylacrylamide), and other poly(methacrylate) derivatives, poly(ionic liquids), copolymers or crosslinked polymers of these materials, and combinations thereof. [0043] In yet another aspect, the solvent is an ionic liquid selected from the group consisting of imidazolium, pyrrolidinium, pyridinium, phosphonium, ammonium, and sulfonium based ionic liquids and combinations thereof. [0044] In a further aspect, the lithium salt is selected from the group consisting of lithium tetrafluoroborate, lithium hexafluorophosphate, lithium bis(trifluoromethanesulfonyl)imide, lithium perchlorate or any lithium salt and combinations thereof. [0045] In another aspect, the thermally responsive electrolyte exhibits a predetermined phase transition at a temperature of from about 50° C. to about 160° C. [0046] In yet another aspect, the present disclosure is directed to a component comprising a lithium-ion cell or a lithium-metal cell comprising a thermally responsive electrolyte. [0047] In another aspect, the electrolyte comprises a polyether-containing compound or a poly(methacrylate)-containing compound, a thermally stable ionic liquid, and a lithium salt. The polyether-containing compound, or the poly(methacrylate-containing compound exhibits a phase transition at a temperature of from about 50° C. to about 160° C. [0048] In yet another aspect, the present disclosure is directed to a vehicle comprising a lithium-ion cell comprising a thermally responsive electrolyte. [0049] In a further aspect, the electrolyte comprises a polyether-containing compound or a poly(methacrylate)-containing compound such as, for example a polyethylene oxide-containing compound, a thermally stable ionic liquid, and a lithium salt. The polyethylene-oxide-containing compound exhibits a phase transition at a temperature of from about 50° C. to about 160° C. It is further contemplated that the phase transition may occur at temperatures above about 160° C., if desired. BRIEF DESCRIPTION OF THE DRAWINGS [0050] Having thus described variations of the disclosure in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein: [0051] FIGS. 1 a . 1 to 1 a . 3 are a series of three drawings showing RPE phase separation; [0052] FIG. 1 b shows two drawings of electrodes, one of which is carbon coated; [0053] FIG. 1 c is a schematic representation of an electrochemical test cell; [0054] FIGS. 2 a -2 b are graphs showing temperature dependence of optical transmittance for RPEs; [0055] FIGS. 3 a -3 c are graphs showing temperature dependence of ionic conductivity for RPEs; [0056] FIGS. 4 a -4 d are graphs showing temperature dependence of cyclic voltammetry profiles for selected RPEs; [0057] FIGS. 5 a - f are graphs showing temperature dependence of electrochemical impedance spectroscopy measurements for RPEs; [0058] FIGS. 6 a - d are graphs showing temperature dependence of the Ohmic and double layer resistances of AC and MC electrodes with RPEs; and [0059] FIGS. 7 a - b are graphs showing the performance of a lithium-ion battery comprising a lithium titanate anode, lithium iron phosphate cathode, and a non-woven mat separator soaked in [EMIM][BF 4 ] with 0.2 M LiTFSI and 5 wt % poly(benzyl methacrylate. DETAILED DESCRIPTION [0060] Presently known thermal management systems, including shutoff mechanisms for lithium-ion cells fail to adequately address safety hazards, and otherwise fail to address the permanent destruction of cell performance in the event a cell shutdown. [0061] New and presently disclosed approaches overcome thermal runaway reactions that can result in fires and explosions, as well as lithium-ion cell failures. The present disclosure is directed to thermally responsive and reversible electrolyte solutions for use in lithium-ion cells comprising a thermally responsive electrolyte that exhibits a phase separation when the internal temperature of the cell increases. According to one aspect of the present disclosure, the thermally responsive electrolyte comprises a polymer, an ionic liquid and a lithium salt. The electrolyte solutions of the present disclosure provide a reversible mechanism for inhibiting lithium-ion cell operation when a temperature increases beyond a preselected temperature. When the preselected temperature occurs within a lithium-ion cell, the thermally responsive polymer undergoes a polymer-ionic liquid phase separation that is also reversible. Such a thermally induced phase separation causes a decrease in ion conductivity, thereby affecting the local concentration of ions at the electrode. In addition, an increase in charge transfer resistance occurs that is associated with phase-separated polymer impacting the electrode surface. The use of thermally responsive polymers dissolved in ionic liquids (ILs) provides thermally responsive electrolytes that offer thermal stability and chemical stability at normal operating temperatures to lithium-ion cells. The thermally responsive polymer electrolytes disclosed herein predictably and reproducibly inhibit conductivity and charge transfer at preselected elevated temperatures that ordinarily cause thermal instabilities in lithium-ion cells, yet maintain their formation when temperatures return to ambient conditions. The thermally responsive polymer electrolytes (RPEs) disclosed herein exhibit an inherent temperature-based control mechanism. [0062] For purposes of this present application, lithium metal batteries are included in the general category of “lithium ion” batteries, and the advantages of the present disclosure are understood to apply also to lithium metal batteries. It is further understood, for the purposes of this application, that the terms “lithium ion cell” and “lithium ion battery” are used interchangeably, with equivalent meaning. [0063] Polymers are particularly attractive for responsive systems as their molecular properties can be tailored to add functionality or change the extent to which a desired property can be altered. In polymeric materials, the molecular weight, structure, composition and function can be designed to tailor how the material will respond to external stimulus (e.g. pH, light, temperature, chemical composition, electric current, force, etc.) and influence a reversible change in the mechanical, electrical, chemical or optical properties. As disclosed herein, certain “smart” materials, such as mixtures of poly(ethylene oxide), or PEO in an ionic liquid such as, for example, 1-ethyly-3-methylimidazolium tetrafluoroborate ([EMIM][BF 4 ]), in the presence of lithium salts, offer a potential solution to overcome the thermal hazards associated with lithium-ion cells, while simultaneously avoiding the use of low performance systems or other destructive safety measures. [0064] While bound to no particular theory, it is believed that the inherent temperature-based control mechanism arises from a change in electrolyte conductivity, and the composition at the electrode/electrolyte interface. The RPEs disclosed herein are further believed to permit the incorporation of high conductivity electrolyte systems in lithium-ion cells needed for, among other systems, large-format energy storage systems. [0065] Thermally responsive polymer electrolytes were investigated by preparing PEO polymers with two distinct molecular weights (1,500 MW and 20,000 MW) in two PEO/IL weight compositions (80/20 and 50/50). These polymers are referred to hereinafter as PEO/IL(80/20), L-PEO/IL(80/20), PEO/IL(50/50) and L-PEO/IL(50/50), where composition is designated and the “low” MW (1,500 MW) PEO mixtures are labelled L-PEO/IL. When the PEO/IL mixtures are heated above their lower critical solution temperature (LCST), they separated into a low conductivity PEO-rich phase and a high conductivity IL-rich phase ( FIG. 1 a . 1 to 1 a . 3 ). Below this temperature, the mixture displayed a high conductivity due to the low ionic resistivity of the IL and a favorable PEO/IL conductive pathway. Above the LCST of the solution, a liquid-liquid phase separation occurred in the PEO/IL mixture due to increasing entropic contributions to the free energy, consistent with traditional thermally responsive polymers. This separation resulted in a cloudy, opaque solution similar to the solid-liquid phase transition observed in aqueous poly(N-isopropylacrylamide) systems. Driven by density differences between the two materials (˜1.3 for [EMIM][BF 4 ] and ˜1.0 for PEO), the two liquids gradually separated into a biphasic mixture with time, and a further increase in temperature. Due to the high resistivity of PEO in the IL deficient top phase, a drastic decrease in conductivity across the system occurred due to the biphasic mixture. The change in solution properties and the extent to which the electrochemical behavior of electrochemical systems change with temperature were measured using the RPEs with carbon on stainless steel mesh electrodes ( FIGS. 1 b -1 c ). [0066] As shown in FIG. 1 a . 1 , a beaker 10 contains an amount of PEO/IL solution 12 . After heating above the solution's lower critical solution temperature (LCST), the solution 12 began to optically cloud, indicating the beginning of a phase separation. See FIG. 1 a . 2 . After continued heating above the solution's lower critical solution temperature (LCST), the phase separation is clearly observed in solution 12 , with the solution 12 separating into a low conductivity PEO-rich phase and a high conductivity IL-rich phase. See FIG. 1 a . 3 . [0067] According to aspects of the present disclosure, electrodes prepared by dispersing either mesoporous (MC) or activated carbon (AC), conductive graphite, and poly(vinylidene fluoride) in an 80/10/10 weight percent ratio in N-methyl-2-pyrrolidone. The resulting carbon pastes were then spread on 316 stainless steel sheets (60×60 mesh) and dried under vacuum. FIG. 1 b shows an aspect of the present disclosure. A first drawing shows a stainless steel electrode 14 awaiting coating. In a second drawing, stainless steel electrode 14 has been coated with a carbon-containing coating 16 . [0068] FIG. 1 c shows a further aspect of the present disclosure wherein an electrode-electrolyte setup for electrochemical impedance spectroscopy measurements consisting of electrodes described in FIG. 1 b and electrolyte confined within a 1 mm thick poly(ether ether ketone) (PEEK) spacer with an internal diameter of 12 mm. An electrochemical cell 20 is shown comprising outer casing 22 encasing electrodes 16 that sandwich a spacer 24 that comprises an electrolyte. [0069] Cloud point (CP) measurements were performed in a N 2 purged cell equipped with a temperature control element in a UV-Vis spectrophotometer to determine the effect of the PEO, IL, and salt concentration on the phase behavior of the RPE systems. A transmittance of 100% indicated a well-mixed, single phase solution with a decrease in the transmittance (below 80%) indicated a thermal phase separation between the PEO and IL. FIGS. 2 a -2 b show the optical transmission behavior through the PEO/IL (80/20) and PEO/IL (50/50) RPEs. All RPE mixtures were well mixed, single phase solutions below 100° C. While both solutions containing the 20K MW PEO exhibited phase transitions (118° C. and 123° C. for the PEO/IL (80/20) and PEO/IL (50/50), respectively), a change in optical transmission was not observed in the 1.5K MW PEO mixtures within our setup, even for temperatures up to 190° C. These mixtures, however, showed a visual cloud point (188° C. and 174° C. for L-PEO/IL (80/20) L-PEO/IL (50/50), respectively), which is likely slightly higher than the onset of phase separation. CP measurements for the PEO/IL (80/20) and PEO/IL (50/50) were comparable to previously reported differential scanning calorimetry (DSC) measurements. The visual transitions observed for the low molecular weight solutions were slightly higher than their results for 2K MW polymers; however, this is expected for lower MW PEO. [0070] The addition of lithium tetrafluoroborate (LiBF 4 ) to 20K MW PEO/IL (80/20) and PEO/IL (50/50) mixtures caused an increase in the LCST, which is referred to as the “salting in” effect. FIG. 2 a shows that the addition of LiBF4 in Li:O (# of Li+ relative to O in PEO) ratios of 1:256, 1:128, and 1:64 to PEO/IL (80/20) mixtures results in an increase in CP from 11° C. (no salt) to 125° C., 141° C., and 173° C., respectively. At high concentrations (Li:O ratios of 1:16 and above), the LCST of PEO/IL (80/20) disappeared. The temperature range was maintained below 200° C., where PEO degradation is known to occur. FIG. 2 b shows that the addition of the salt has a less pronounced effect on the LCST in the PEO/IL (50/50). The addition of LiBF 4 increases the CP from 123° C. (no salt) to 127° C., 129° C., and 140° C. for the 1:256, 1:128, and 1:64 Li:O ratios. The smaller effect of salt concentration observed in PEO/IL (50/50) is attributed to the overall lower molarity of Li+ within these solutions, due to a lower composition of PEO (and therefore O groups) relative to the 80/20 mixture. Similar to PEO/IL (80/20), high salt concentration mixtures (ratios of 1:16 and above), did not display LCST behavior. [0071] Cloud point measurements for the 1.5K MW PEO with the lithium salt were not measured due to the high LCST temperatures observed for the L-PEO/IL (80/20) and L-PEO/IL (50/50) and the degradation point of PEO (approximately 190° C.-200° C.). These results indicate a strong correlation between phase separation temperature and the composition of each component, but more importantly, that the LCST can be tailored to achieve a target transition temperature. It should be noted that the liquid-liquid phase separation described herein, between PEO and IL with increased temperature, is a reversible process. In other words, as the temperature decreases, the mixture returns to its initial single phase system. Electrochemical impedance spectroscopy (EIS) measurements were performed in a test cell with stainless steel electrodes and a poly(ether ether ketone)(PEEK) spacer to determine how temperature and phase separation affect the RPE conductivity. [0072] Ionic conductivity was determined from the corresponding resistive component of the impedance spectrum using a cell constant calibrated from a 1M NaCl solution at 25° C. FIG. 3 a shows the measured conductivity of the salt free RPE systems as a function of temperature, composition, and PEO MW. For both the PEO/IL (80/20) and PEO/IL (50/50) systems, the conductivity rises slowly with temperature, similar to traditional aqueous and nonaqueous electrolytes. Above the LCST, a liquid-liquid phase separation occurs, resulting in PEO aggregation and a decrease in conductivity. As the temperature is further increased, nearly an order of magnitude reduction in conductivity is observed as the electrolyte segregates into the biphasic mixture (PEO-rich top, IL-rich bottom). Unlike the high MW mixtures, the L-PEO/IL (80/20) and L-PEO/IL (50/50) systems exhibited an increase in conductivity over the entire range of temperatures, similar to conventional electrolytes. These observations suggest that the very low molecular weight polymer mixtures do not efficiently phase separate (80-PEO(1.5):IL), even though visual changes are observed with the mixtures. Low MW polymers do not aggregate to the same extent as their high MW counterparts, therefore, the phase separated polymer domains fail to coalesce into the biphasic mixture, which is necessary to inhibit conductivity through the mixture. The effect of adding LiBF 4 to the PEO/IL (80/20) solutions is shown in FIG. 3 b for Li:O ratios of 1:256, 1:128, 1:64, and 1:16. As the salt concentration is increased, the temperature at which the conductivity begins to decrease also increases, consistent with the CP measurements described above. At high concentrations (Li:O ratios of 1:16 and above), no change in conductivity was observed, as these compositions did not exhibit an LCST phase transition. FIG. 3 c shows that increasing the LiBF4 concentration in PEO/IL (50/50) solutions resulted in an increase in the temperature at which conductivity changed. The shift in temperature is much less in PEO/IL (50/50) compared to PEO/IL (80/20), which is consistent with the CP measurements above and attributed to lower Li+ concentrations. Unlike traditional PEO-LiBF4 and IL-LIBF4 electrolytes, the RPE systems of the present disclosure show an abrupt decrease in conductivity near their LCST, except for high Li+ concentrations. As seen with CP experiments, the addition of the lithium salt can be used to control the point at which the LCST occurs and (along with composition and MW), which affects the temperature at which conductivity deactivates. [0073] The application of RPE solutions in an energy storage cell was investigated using carbon coated stainless steel mesh electrodes. A symmetric 2-electrode cell was fabricated using carbon electrodes soaked in the RPEs overnight separated by a PEEK washer/spacer. Two types of carbons were investigated: mesoporous carbon (MC) with a low surface area and large pore diameter (50-100 m2/g, 13.7 nm) and activated carbon (AC) with a large surface area and small pore diameter (2000 m2/g, 2.1 nm). The mechanism for energy storage within these electrodes is electrical double layer capacitance, where ions physically accumulate at the electrode/electrolyte interface in a non-Faradaic process (no charge transfer). Very high surface area carbons (AC) are capable of higher capacitance, but possess lower current rates and power density due to the highly disordered ionic pathway compared to low surface area materials with open porous structures (MC). [0074] Cyclic voltammetry (CV) measurements were used to determine how the electrical double layer capacitance of carbon electrodes with PEO/IL electrolytes, which depends on accessible surface area and ion concentration, are affected by solution temperature. FIGS. 4 a -4 d show CV profiles of symmetric supercapacitors containing AC and MC carbon electrodes in pure IL and two of the RPEs of interest. For devices comprised of AC electrodes in pure IL, the measured CV current increases linearly with temperature from 100° C. up to 160° C., as expected ( FIG. 4 a ). The integrated area under the profiles, which is a representation of the amount of charge stored, correspondingly increases with temperature, as shown in inset of FIG. 4 a (charge values are normalized to the initial value at 100° C.). CV profiles of cells comprising AC electrodes in L-PEO/IL (50/50) electrolyte are shown in FIG. 4 b while heating the system from 100° C. up to 160° C. Similar to the pure IL, the relative amount of charge stored in these electrodes initially increases between 100° C. and 120° C., consistent with an increase in ion conductivity. Although the L-PEO/IL (50/50) did not display a change in conductivity or a visual CP until above 174° C., the current observed during the CV cycling showed a significant decrease as the cell was heated about 120° C. As shown in FIG. 4 b , the CV shows a decrease in current above 140° C., however, the shape of the CV suggests that ion diffusion is not a limiting factor (profile maintains a rectangular shape) and that either a loss of electrode area has occurred or an increase in resistance for charges entering the double layer has increased. [0075] These observations support the hypothesis that the L-PEO/IL (50/50) electrolytes exhibit a thermally induced phase separation that cannot be detected cloud point measurements, where PEO aggregates in solution and within the electrode pores and then binds to the surface of the carbon. Although the conductivity of the electrolyte continues to increase with temperature ( FIG. 3 c ), the formation of a PEO-rich phase or coating inside the nanopores of AC creates a barrier to charge insertion and accumulation at the electrode/electrolyte interface, resulting in a decrease in electrochemical activity. The inset in FIG. 4 b shows that the charge capacity (or electrode capacitance) at 160° C. decreases to approximately 70% of its value at 100° C. To put this value in perspective, devices utilizing IL electrolytes exhibited a 1.7× increase in charge capacity, which suggests that the use of the L-PEO/IL electrolyte causes a 50% decrease the electrochemical activity relative to how the conductivity would increase in the absence of the phase separation. [0076] Comparable to devices comprised of AC electrodes in pure IL, cells containing MC electrodes exhibit a linear increase in charge capacitance with temperature, as shown in FIG. 4 c . The electrochemical performance of cells using PEO/IL (50/50) electrolytes are shown in FIG. 4 d over a temperature range of 100° C. to 160° C. The double layer capacitance of these devices initially increases until the cell reaches the LCST of 123° C., as observed in the devices with pure IL. Above this temperature, however, the electrical double layer capacitance decreases as a result of a decrease in conductivity change and the formation of a barrier to the charging of the electrode/electrolyte interface. Contrary to L-PEO/IL (50/50) devices that only exhibit a decrease in double layer capacitance, these devices exhibit a noticeable change in the CV profile shape (rectangular to egg-shaped) which is indicative of ion diffusion limitation characteristics. [0077] The inset in FIG. 4 d shows that the charge stored above 160° C. again decreases to approximately 70% of if its value at 100° C. These results demonstrate that the electrochemical processes occurring within an energy storage device can be limited with RPEs. Electrochemical impedance spectroscopy (EIS) measurements were performed to determine the mechanism for the decrease in electrochemical activity on AC and MC electrodes when the cell temperature is increased above the LCST of the respective electrolytes. Understanding the mechanism of ion adsorption and charge transfer inhibition is useful for further developing electrolyte materials and compositions that can be used to inhibit electrochemical devices that tend to overheat and exhibit thermal runaway, such as lithium-ion batteries. Measurements were carried out using symmetric cells of each electrode type in pure IL electrolytes ( FIGS. 5 a and 5 d ) and all four RPEs ( FIGS. 5 b , 5 c and 5 e , 5 f ). While CV measurements reveal changes in ELDC properties for one specific scan rate, EIS provides insight into device characteristics over a range of time-scales, which can be fit to extract resistive and capacitive components of the electrochemical processes. Carbon EDLCs are often modeled using de Levie's Transmission Line Model (TLM) equivalent circuit due to their highly porous and tortuous structure and intricate internal resistance. Here, we use a more simplified EIS model to reveal two important electrode/electrolyte characteristics: the ohmic resistance (RS), which is the intersection point with the x-axis in the high frequency region, and the internal resistance to charging the EDLC electrode/electrolyte interface or the “double layer” resistance. This internal resistance was determined with the use of the EIS data fitting program ZVIEW and applying a modified Randles circuit model (charge transfer and Warburg impedance in parallel to a capacitor) of the high- to mid-range frequency region. The in-series combination of the pseudo charge transfer resistance and Warburg impedance is referred to here as the “double layer” resistance (RDL). The pseudo charge transfer resistance results from the combination of various changes in solution conductivity and mobility of ions in the nanostructured carbon pores and the change in the electrode/electrolyte interface due to PEO physisorption. [0078] For the IL, L-PEO/IL (50/50) and PEO/IL (50/50) electrolytes on AC electrodes ( FIGS. 5 a -5 c ), EIS measurements reveal a relatively high internal “double layer” resistance (RDL) that results from the ion transport within the nanoscale pores of the AC. The Nyquist plots indicate that each electrolyte is highly dependent on this internal resistance over the frequencies down to 1 Hz, where characteristics of diffusion limited behavior are observed (45° slope in −Z″ vs Z′). In FIG. 5 a , devices containing pure IL exhibit a RDL that decreases with increasing temperature due to the increase in ion conductivity, similar to conventional electrolyte solutions. Devices with AC electrodes in L-PEO/IL (50/50) initially show a decrease in RDL with increasing temperature (below the LCST) as evidenced by the slight decrease in high- to mid-range frequency semicircle radius ( FIG. 5 b ). [0079] Even though we observed that the solution conductivity continues to increase above the LCST ( FIG. 3 a ), from the EIS measurements, we found that semicircle radius of the Nyquist plot associated with RDL increases drastically, indicating an increase in double layer resistance. The increased resistance is attributed to an increased PEO concentration within the pores of the electrodes combined with polymer physisorption on the carbon surface, which supports our observations of decreased electrode capacitance. FIG. 5 c shows that devices containing PEO/IL (50/50) display a similar but less significant trend. [0080] Although the higher MW PEO system is capable of modulating the conductivity, the mixture contains PEO polymers that are larger than the AC pores thereby preventing the polymer from diffusing into and coating the pore walls. Without complete coverage or physisoprtion on the carbon surface (as observed with 1.5K MW PEO), the electrolyte containing 20K MW PEO has a limited effect on the double layer resistance in the nanoporous electrodes. Interestingly, these results confirm that electrochemical activity is strongly affected by polymer adsorption on the electrode interface as well as a decrease in ion conductivity above the phase transition temperature. [0081] In devices comprising MC electrodes with IL, L-PEO/IL (50/50) and PEO/IL (50/50) electrolytes ( FIGS. 5 d -5 f ), EIS analysis reveals a much lower RDL (smaller hemisphere radius) as a result of the larger pore size and ion accessibility in the mesoporous carbon. Unlike in devices prepared with the AC electrodes, the limiting charging/discharging mechanism changes from RDL to ion diffusion at much higher frequencies, 10-20 Hz, indicating that these cells containing MC electrodes will be limited by ion mobility (conductivity) under most operating conditions. In these systems, we expect electrolyte conductivity to have a significant impact on the electrochemical activity. [0082] As disclosed herein, RDL decreases with increasing temperature in devices with pure IL electrolytes ( FIG. 5 d ), which is similar to the behavior on AC electrodes. Since the mechanism on MC electrodes is governed by ion-transport rather than polymer adsorption, there is no significant change in RDL above the LCST of L-PEO/IL (50/50), as shown in FIG. 5 e . In fact, the characteristics of the Nyquist plot are quite similar to results from devices with pure IL, as both electrolytes exhibit a continuous increase in conductivity with increasing temperature. The radius of the high- to mid-range frequency semicircle continues to decrease at temperatures up to 160° C., indicating a decrease in the RDL. Contrary to the behavior in devices with AC electrodes, electrolytes using low MW PEO do not seem to significantly affect the resistance of cells comprising carbon electrodes with large pores (greater than about 13 nm). Electrolytes comprising high MW PEO display a change in conductivity about their LCST. As the ion-adsorption mechanism of MC electrodes is governed by ion-diffusion, it is expected that the electrochemical behavior of MC devices with the PEO/IL (50/50) electrolyte correlate with the conductivity measurements of these systems ( FIG. 3 c ). Indeed, these cells initially show an initial decrease in RDL as the temperature increases, followed by a significant increase in capacitance, as evidenced by the increasing radius of the Nyquist semicircle ( FIG. 51 ) above 120° C. In carbon electrodes with large pores, electrochemical activity can be modulating using high MW PEO by inhibiting the ion conductivity between the electrodes. [0083] A summary of the changes for both the Ohmic resistance and double layer resistance over the temperature range of 100° C. to 160° C. is shown in FIGS. 6 a -6 d . Values for resistances at each temperature were modeled with a modified Randles circuit and normalized to the resistance at 100° C. to display each profile on the same plot. FIG. 6 a shows how the Ohmic resistance (series) in the AC electrodes changed when using the pure IL, L-PEO/IL (50/50), and PEO/IL (50/50) electrolytes. As previously described, the solution resistance (which is a large component of the Ohmic resistance in the electrochemical cell) only increases the 20K MW PEO electrolyte, which exhibits a decrease in conductivity above the LCST. With the MC electrodes ( FIG. 6 b ), a similar but more pronounced change in the Ohmic resistance is observed since the governing mechanism in these materials is ion-diffusion (under the test conditions). The double layer resistance in the AC electrodes is strongly affected by the phase transition of L-PEO/IL (50/50) and PEO/IL (50/50) electrolytes above their LCST ( FIG. 6 c ). As expected, devices with pure IL electrolyte show a decrease in RDL as the temperature increases. Both the L-PEO/IL (50/50) and PEO/IL (50/50) electrolytes show a drastic increase in RDL when heated above their LCST. A more pronounced increase is seen in the AC electrodes with the L-PEO/IL (50/50), since the smaller PEO chains can infiltrate the nanoscale (about 2 nm) pores and absorb on the electrode surface. On the MC electrodes, the double layer resistance increases for devices with pure IL and L-PEO/IL (50/50), as both systems exhibit and increase in conductivity with increasing temperature ( FIG. 6 d ). Cells with PEO/IL (50/50) electrolytes, however, show a 3-fold increase in RDL above the LCST, as expected due to the decrease in ion conductivity between the carbon electrodes, which reduces ion concentrations near the electrode surface. In summary, we have shown how a LCST phase transition can be used to modulate the electrochemical activity of electrode interfaces, which can be used to control the function of energy storage devices. Using electrolytes comprised of an ionic liquid, [EMIM][BF 4 ] and PEO, and Li+ salts, we showed that the solution conductivity can be designed to decrease when the temperature of the system increasing beyond the LCST of the mixture. Upon phase separation of PEO from the IL, the double layer resistance of carbon electrodes increases as a result of either polymer adsorption on the electrode interface (low MW PEO in 2 nm pores), or a decrease in conductivity which limits the ion concentration near the electrode surface (high MW PEO in greater than about 13 nm pores). Furthermore, the composition of PEO and IL, in addition to the concentration of Li+ salt, affect the temperature at which the transition occurs and the extent to which the conductivity can be decreased. The polymer systems disclosed herein are capable of altering both the Ohmic (solution) resistance and the double layer capacitance of carbon based devices. The electrolyte designs disclosed herein mitigate thermal hazards associated with cells and electrochemical devices overheating. [0084] Lithium-ion battery cells were constructed using a lithium titanate (Sigma Aldrich) coated copper foil as the anode and a lithium iron phosphate coated aluminum foil (MTI Corp.) as the cathode. The electrodes were separated using a high-temperature stable non-woven mat separator (Dreamweaver, Intl.) soaked in an ionic liquid ([EMIM][BF 4 ]) (Ionic Liquid Technologies, 98+%) with 0.2-1 M LiTFSI (Sigma Aldrich) and 1-5 wt % poly(benzyl methacrylate). The thermally activated phase transition in these electrolytes varied with ionic content and polymer weight % in the ionic liquid electrolyte, which ranged between 90° C. and 150° C. [0085] The temperature-dependent battery behavior of the lithium-ion cell comprising the high-temperature stable non-woven mat separator soaked in [EMIM][BF 4 ] with 0.2 M LiTFSI and 5 wt % poly(benzyl methacrylate) is shown in FIGS. 7 a - b . In these cells, a significant increase in cell resistance is observed at temperatures above the thermal transition of the electrolyte (120° C.). As a result of the increase in internal resistance, the discharge voltage and power of the battery becomes limited, as shown in FIG. 7 b . At 150° C., the battery exhibits a decrease in capacity, which eventually shuts off as the internal resistance in the cell becomes too high to deliver the specified current density. [0086] FIGS. 7 a - b show the performance of a lithium-ion battery comprising a lithium titanate anode, lithium iron phosphate cathode, and a non-woven mat separator soaked in [EMIM][BF 4 ] with 0.2 M LiTFSI and 5 wt % poly(benzyl methacrylate). FIG. 7 a shows a Nyquist plot of the battery with increasing cell temperature from 60° C. to 160° C. FIG. 7 b shows the constant current discharge characteristics of the cell at 60° C. and 150° C. Examples [0087] Polymer electrolyte solutions were prepared by mixing PEO (1,500 MW (Fluka), 20,000 MW (Polysciences)), ([EMIM][BF 4 ]) (Ionic Liquid Technologies, 98+%), and LiBF4 (Sigma Aldrich) while stirring at 90° C. under N 2 for 30 minutes. Once mixed, solutions were dried under vacuum (mTorr) at 90° C. while stirring for at least 12 hours, then immediately transferred and sealed in the electrochemical or spectroscopic test cells. [0088] The cloud point of the PEO/[EMIM][BF 4 ]/LiBF 4 solutions was determined using optical transmittance. Electrolyte solutions were mixed and dried under vacuum (mTorr) at 90° C. while stirring for 12 hours then purged with nitrogen prior to transmission measurements. Temperature-controlled cells with sapphire windows were placed in a UV-Vis spectrophotometer (Varian Cary 50 Bio) and heated at a rate of 2° C./min while continually recording UV-Vis scans. An average transmittance was calculated over a range of wavelengths (600-800 nm). The cloud point or LCST was defined as the temperature at which the transmittance dropped below 80% of its initial value. [0089] Carbon electrodes were prepared using a mesoporous carbon (Sigma Aldrich, surface area ˜50-100 m2/g, average pore diameter 13.7 nm) and an activated carbon (MTI, surface area 2000 m2/g, average pore size 2.1 nm). Electrodes were prepared by dispersing the mesoporous (MC) or activated carbon (AC), conductive graphite (MTI), and poly(vinylidene fluoride) (Sigma Aldrich) in an 80/10/10 weight percent ratio in N-methyl-2-pyrrolidone (Acros). The resulting carbon pastes were then spread on 316 stainless steel sheets (60×60 mesh, roughly 20 mm×20 mm squares each). Electrodes were dried for at least 12 hours at 100° C. under vacuum and then soaked in their respective electrolyte (PEO-IL mixture) for at least 6 hours at 100° C. under vacuum (˜30 in Hg) prior to electrochemical testing. [0090] Electrochemical measurements were performed with a Gamry galvonstat/potentiostat in a 2-electrode setup using a split test coin cell (MTI, EQ-STC) mounted in a modified convection oven. Solutions were heated at approximately 2° C./min and allowed to equilibrate at set temperatures for 30 minutes prior to electrochemical measurements. Bulk conductivity measurements were conducted on electrolytes between stainless steel electrodes separated by a poly(ether ether ketone) (PEEK) spacer over a temperature range of 70° C. to 180° C. [0091] Electrochemical impedance spectroscopy (EIS) was performed over a frequency range of 1 Hz to 1 MHz (0V, 20 mV RMS). Ionic conductivity was determined from the corresponding resistive component of the impedance spectrum and calculated using a cell constant calibrated from a 1M NaCl solution at 25° C. Two electrode cells were constructed with either MC or AC electrodes, which were separated by a PEEK spacer and the PEO-IL electrolyte. Cells were characterized using cyclic voltammetry (CV) and EIS for the pure IL and PEO-IL electrolytes. CV scans were performed at 300 mV/s (MC) and 5 mV/s (AC) over a potential range of −1.0 to 1.0 V to demonstrate the symmetry of the cell. EIS analysis was performed over a frequency range of 100 mHz to 1 MHz (1V, 20 mV RMS) over a temperature range of 100° C. to 180° C. [0092] According to additional aspects, the present disclosure further contemplates that thermally responsive electrolytes can comprise thermally responsive polymers that can be directed to preferentially adhere to electrodes in a predetermined fashion. In such a case, as the electrode temperature reaches a predetermined level, the thermally responsive polymers will undergo a phase transition, and reversibly form a coating, on the electrode interface, to achieve a predetermined level of thermal control, safety, and reversible shutdown, of a lithium-ion cell or lithium-metal cell system. [0093] According to still further aspects, the present disclosure further contemplates that thermally responsive electrolytes disclosed herein can be incorporated into batteries for portable electronics, back-up power units, load-leveling systems, large-format stationary energy storage (e.g. renewable energy generation such as wind and solar), and high-power energy storage. Further contemplated applications that can benefit from the thermally responsive electrolytes disclosed herein include, sensors, anti-fouling interfaces and responsive interfaces, as well as self-healing materials. Virtually any system that relies upon a change in conductivity or electrochemical process or switching between a bare and covered surface (e.g. sensors) is contemplated as benefiting from the thermally responsive electrolytes disclosed herein. [0094] While the preferred variations and alternatives of the present disclosure have been illustrated and described, it will be appreciated that various changes and substitutions can be made therein without departing from the spirit and scope of the disclosure. Accordingly, the scope of the disclosure should only be limited by the accompanying claims and equivalents thereof.

Methods compositions for controlling lithium-ion cell performance, using thermally responsive electrolytes incorporating compounds that exhibit a phase transition at elevated temperatures and are suited for incorporation into lithium-ion and lithium-metal cells are disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS This application of U.S. application No. 13/062,454, filed Mar. 4, 2011, now abandoned, which is a national phase application under 35 U.S.C. §371 of International application No. PCT/US09/56020, filed Sep. 4, 2009, which claims priority to U.S. Provisional Application No. 61/094,474, filed Sep. 5, 2008, the entirety of each of which is hereby incorporated by reference. FIELD OF THE INVENTION This application pertains to processes useful in the preparation of 8-[{1-(3,5-Bis-(trifluoromethyl)phenyl)-ethoxy}-methyl]-8-phenyl-1,7-diaza-spiro[4.5]decan-2-one compounds and intermediates useful in the synthesis thereof, and the intermediate compounds prepared thereby. BACKGROUND OF THE INVENTION Identification of any publication, patent, or patent application in this section or any section of this application is not an admission that such publication is prior art to the present invention. The preparation of diazaspirodecan-2-ones for example, 8-[{1-(3,5-Bis-(trifluoromethyl)phenyl)-ethoxy}-methyl]-8-phenyl-1,7-diaza-spiro[4.5]decan-2-one, for example, (5S,8S)-8-[{(1R)-1-(3,5-Bis-(trifluoromethyl)phenyl)-ethoxy}-methyl]-8-phenyl-1,7-diazaspiro[4.5]decan-2-one (the compound of Formula I) has been described in U.S. Pat. No. 7,049,320 (the '320 patent), issued May 23, 2006, the disclosure of which is incorporated herein in its entirety by reference. The compounds described in the '320 patent are classified as tachykinin compounds, and are antagonists of neuropeptide neurokinin-1 receptors (herein, “NK-1” receptor antagonists). Other NK 1 receptor antagonists and their synthesis have been described, for example, those described in Wu et al, Tetrahedron 56, 3043-3051 (2000); Rombouts et al, Tetrahedron Letters 42, 7397-7399 (2001); and Rogiers et al, Tetrahedron 57, 8971-8981 (2001) and in published International Application No. WO05/100358, each of which is incorporated herein in their entirety by reference. A process for preparing the compound of Formula I is also disclosed in U.S. Application No. 2008/003640, filed Mar. 20, 2008 (the '640 application). “NK-1” receptor antagonists have been shown to be useful therapeutic agents, for example, in the treatment of pain, inflammation, migraine, emesis (vomiting), and nociception. Among many compounds disclosed in the above-mentioned '320 patent are several novel diazaspirodecan-2-ones, including the compound of Formula I, which are useful in the treatment of nausea and emesis associated with any source of emesis, for example, emesis associated with recovery from anesthesia or chemotherapy treatments (Chemotherapy-induced nausea and emesis, herein, CINE). The synthesis method for preparing the compound of Formula I described in the '320 patent generally follows Scheme A in the provision of 8-[{1-(3,5-Bis-(trifluoromethyl)phenyl)-ethoxy}-methyl]-8-phenyl-1,7-diaza-spiro[4.5]decan-2-one compounds. The process for the preparation of the compound of Formula I described in the '320 patent is carried out in 18 individual steps from commercially available starting materials, and in many steps of the process described in the '320 patent, intermediate compounds must be isolated or isolated and purified before use in a subsequent step, often utilizing column chromatography for that purpose. In general, the synthetic scheme described in the '320 patent consumes a larger than desirable percentage of starting and intermediate compounds in the production of unwanted isomers. The process for the preparation of the compound of Formula I described in the '640 application generally follows Scheme B: The process described in Scheme B comprises about half the number of steps compared to Scheme A and produces the compound in greater yield than Scheme A, however, both schemes suffer from poor diastereoselectivity. Accordingly, what is needed is a more convergent and efficient process which has improved diastereoselectivity. SUMMARY OF THE INVENTION What is needed is a synthetic scheme for the preparation of 8-[{1-(3,5-Bis-(trifluoromethyl)phenyl)-ethoxy}-methyl]-8-phenyl-1,7-diaza-spiro[4.5]decan-2-one compounds which has a reduced number of steps, increases diastereoselectivity, and provides a reaction scheme affording practical scale up to a batch size suitable for commercial scale preparation. These and other objectives are advantageously provided by the present invention, which in one aspect, as illustrated in Scheme I, is a process of making (5S,8S)-8-[{1-(R)-(3,5-Bis-(trifluoromethyl)phenyl)-ethoxy}-methyl]-8-phenyl-1,7-diaza-spiro[4.5]decan-2-one hydrochloride monohydrate, the compound of Formula VIII. wherein the process comprises: a) providing the salt compound of Formula VIa, [5(R)-[[[1(S)-[[1(R)-[3,5-bis(trifluoromethyl)-phenyl]ethoxy]-methyl]-1-phenyl-2-propenyl]amino]methyl]-5-ethenyl-2-pyrrolidinone] [Salt 2], wherein “Salt 2” represents at least one proton bonded to a base functional group in the compound of Formula VIa, for example, a nitrogen electron pair, thus forming an ammonium cation, and associated therewith a coordinated anion moiety, for example, the conjugate base of an acid, and cyclizing the diene-amine salt compound of Formula VIa using a ring closing metathesis catalyst; b) converting the cyclized product from Step (a) to a salt to obtain the compound of Formula VII [(5R,8S)-8-[1-(R)-(3,5-bis-trifluoromethyl-phenyl)-ethoxymethyl]-8-phenyl-1,7-diazaspiro[4.5]dec-9-en-2-one] Salt 3, wherein “Salt 3” represents at least one proton bonded to a base functional group in the compound of Formula VII and associated therewith a coordinated anion moiety; c) treating from the salt compound of Formula VII provided in Step (b) with a hydroxide base of Formula M-OH, for example, wherein “M” is a alkaline metal or alkali earth metal, to provide the corresponding freebase compound of Formula VIIb, reducing the freebase compound of Formula VIIb and treating the reduction product with HCl to obtain the 1,7-diazaspiro[4.5]dec-2-one hydrochloride hydrate of Formula VIII; and d) optionally recrystallizing the HCl salt of Formula VIII thereby obtaining the compound of Formula Ia. In some embodiments of Scheme I, it is preferred to carry out the reduction in Step “c” on the salt compound of Formula VII without liberating the freebase form thereform and recovering the reduced salt product produced thereby instead of precipitating the salt of the freebase reduction product. In some embodiments of the present invention, preferably Step (a) of Scheme I is carried out in the presence of a sufficient amount of added acid to decrease the loading (amount of catalyst present) of the ring-closing metathesis catalyst employed. In some embodiments of Scheme I using added acid in Step (a), it is preferred to use an acid having a pKa which is about equal to or less than that of the diene compound of Formula VI being cyclized in the reaction, for example, an acid having a pKa equal to or less than 6.5. In some embodiments of Scheme I employing added acid in Step (a), it is preferred for the acid to be: (i) a mineral acid, for example, HCl, HBr, or sulfuric acid; (ii) a mono- or di-organic acid, for example, acetic, proponoic, maleic, fumaric, trifluoroacetic, or tartatic acids; or (iii) a sulfonic acid, for example, an alkyl-sulfonic acid or substituted alkylsulfonic acid, for example, methanesulfonic acid, 4-methylbenzenesulfonic acid monohydrate, or trifluoromethanesulfonic acid, or an aromatic arylsulfonic acid, for example p-toluenesulfonic acid or a substituted arylsulfonic acid. In some embodiments utilizing an excess acid in Step 2, the acid is preferably an arylsulfonic acid, more preferably p-tolysulfonic acid. In some embodiments employing excess acid in Step 2, it is preferred to add the acid in an amount of from about 0.1 to about 2.0 equivalents relative to the amount of substrate initially present in the reaction mixture. In some embodiments of Scheme I it is preferred to carry out the cyclization reaction in Step (a) by the process illustrated in Scheme Ia. wherein the dotted line of the compound of Structure XX represents an optional double bond and “Salt 2” is as defined above; Ar is an aryl moiety, for example, phenyl or mesityl (2,4,6-trimethylphenyl); L is P(R 2a ) 3 , wherein R 2a is selected independently and is phenyl, aryl, alkoxylphenyl or alkyl; M is a metal which is ruthenium, palladium, or iridium; X is halogen; R is H, aryl, or heteroaryl; and HX is an acidic species, preferably where “X” is: halogen, for example, chloride, bromide, or iodide; sulfate; sulfite; or a sulfonate moiety, for example, mesylate, trifluoromethylsulfonate, or an aryl sulfonate, for example tosylate, the process comprising: (i) contacting a secondary amine salt of Formula VI with an acid of the Formula HX; (ii) adding a ring closing metathesis catalyst to the mixture from step (i), preferably in an amount which is sub-stoichiometric with respect to the amount of the compound of Formula VI used; and (iii) heating the mixture to cyclize the compound of Formula VI. In some embodiments of Scheme 1a, the ring-closing metathesis catalyst used in the reaction is preferably selected from the compounds of Formulae XXa, XXb, or XXd: where the metal (M) is preferably a transition metal with a formal oxidation state providing 8 “d” orbital electrons (a group 8 transition metal, for example, ruthenium, palladium or iridium, or a group 6 transition metal, for example, molybdenum), “L 1 ” is a sigma-bonded carbon ligand with substantial Pi-backbonding capability, for example, the imidazole ligand shown in the compounds of Formulae XXa and XXd, and L 2 is a monodentate ligand, for example, a phosphine ligand, for example (Cy 3 P), or, as indicated, L 2 is optionally bonded to the R 3 substituent of the carbene (ligand, and when optionally bonded to the carbene ligand via R 3 , illustrated by the semicircular dotted line between L 2 and R 3 , L 2 forms a bidentate ligand, and L 2 is a chelating moiety, for example, an oxygen, phosphorous, or nitrogen moiety, for example, the oxygen moiety in the alkoxybenzylidene bidentate ligand shown in the catalyst of Formula XXd, for example, an isoproxy-benzylidene ligand, R 1 is independently selected from aryl, heteroaryl, alkyl, or hydrogen, R 3 is an alkyl heteroaryl or aryl, for example, a phenyl moiety, or when R 3 is not bonded to L 2 , R 3 may be hydrogen, and (X) is a conjugate base of a strong acid, preferably X is a sulfonate moiety, for example, tosylate, or halogen moiety, for example, chloride. It will be appreciated that in reaction Scheme I shown above, although the compound of Formula Ia is the (S,S,R) enantiomer, the process of the invention can be employed using starting materials of the appropriate stereoisomer configuration to prepare all of the isomers of the compound of Formula I, i.e., In some embodiments of the invention it is preferred to provide the compound of Formula VIa used in Scheme I by the process of Scheme Iaa wherein the process comprises: a) providing the pyrazolo-5-one of Formula III; b) providing the freebase compound of Formula IV, [(1S)-1-({(1R)-1-[3,5-bis(trifluoromethyl)phenyl]ethoxy}methyl)-1-phenylprop-2-enyl)amine, and reacting it with the compound of Formula III provided in Step (a) to yield the diene-imine of Formula V, [((5R)-5-((Z)-{[(1S)-1-({(1R)-1-[3,5bis(trifluoromethyl)-phenyl]-ethoxy}methyl)-1-phenylprop-2-en-1-yl]imino}methyl)-5-vinylpyrrolidin-2-one)]; c) reducing the diene-imine compound of Formula V prepared in Step (b) to obtain the corresponding diene-amine compound, converting it to the corresponding salt compound of Formula VI, [5(R)-[[[1(S)-[[1(R)-[3,5-bis(trifluoromethyl)-phenyl]ethoxy]-methyl]-1-phenyl-2-propenyl]amino]methyl]-5-ethenyl-2-pyrrolidinone] [Salt 2], wherein “Salt 2” represents at least one proton bonded to a base functional group in the compound of Formula VI, for example, the electron pair in a nitrogen atom in the compound, and associated therewith a coordinated anion moiety. In some embodiments of the present invention it is preferred to provide the pyrazolo-5-one compound of Formula III in Step (a) of Scheme 1aa by treating the compound of Formula II, (3R)-(1,1-dimethylethyl)-7aR-ethenyltetrahydro-1 (R/S)-hydroxy-3H,5H-pyrrolo[1,2-c]oxazol-5-one, with an appropriate base, for example, triethylamine. In some embodiments of the present invention it is preferred to provide the free-base compound of Formula IV in Step (b) of Scheme 1aa by treating the corresponding salt compound of Formula IVa with a water soluble base, for example, sodium hydroxide, wherein Salt 1 represents at least one proton bonded to a base functional group, for example, the amine substituent, in the compound of Formula IVa and associated therewith a coordinated anion moiety. Suitable acids for preparing the salt compounds of Formula IVa are, for example: organic acids, for example, maleic acid, succinic acid, or malic acid; and inorganic acids, for example, HCl, HBr, and HI. In some embodiments of the present invention, in Step 2, preferably, the ring-closing metathesis catalyst is a ring-closing metathesis catalyst of Formula XX, described in Scheme 4 (below). In some embodiments of the present invention it is preferred to prepare the intermediate of Formula IV using the process illustrated in Scheme 2, steps 2-3 and beyond. In some embodiments it is preferred to provide the intermediate of Structure X for use in preparing the compound of Formula IV as shown in Scheme II, steps 2-1 and 2-2. wherein the process comprises: Step 2-1: cyclyzing the 2-phenylglycine derivative shown with PhCH(OCH 3 ) 2 to obtain the oxazolidinone of Formula IX, wherein Cbz is a carboxybenzyl-amine protecting group; Step 2-2: combining the compound of Formula IX with [3,5-bis(trifluoromethyl)phenyl]-ethoxy-bromomethyl ether to obtain the lactone of Formula X; Step 2-3: reducing the lactone of Formula X to the lactol of Formula XI; Step 2-4: opening the ring of the lactol of Formula XI to obtain the aldehyde of Formula XII; Step 2-5: Converting the aldehyde of Formula XII to the alkenyl amine of Formula XIII; and Step 2-6: deprotecting the alkenyl amine of formula XIII and converting the corresponding free base thus obtained to the salt of Formula IV. In some embodiments of the process of the invention it is preferred to prepare the intermediate of Formula II in accordance with the process illustrated in Scheme 3. wherein the process comprises: Step 3-1: treating pyroglutamic acid with trimethylacetaldehyde and methanesulfionic acid to obtain (3R,6S)-3-tert-butyldihydro-1H-pyrrolo[1,2-c][1,3]oxazole-1,5(6H)-dione of Formula XIV; Step 3-2: reacting the pyrrolo[1,2-c][1,3]oxazole-1,5(6H)-dione of Formula XIV with methyl formate to obtain the pyrrolo[1,2-c]oxazole-7a-carbaldehyde of Formula XV; Step 3-3: converting the carbaldehyde of Formula XV to the 7a-vinyl-dihydro-pyrrolo[1,2-c][1,3]oxazole-1,5-dione of Formula XVI; and Step 3-4: reducing the dione of Formula XVI to obtain the (3R)-1,1-dimethyl-7a(R)-ethenyl-tetrahydro-1(R/S)-hydroxy-3H,5H=pyrrolo[1,2-c]oxazol-5-one of Formula II. Another aspect of the present invention relates to the following novel intermediates used or prepared in the processes represented in Schemes 1-3: Scheme 4 illustrates a chemical process for removing metathesis catalyst from the reaction mixture after ring closure is complete. In some embodiments of the present invention it is preferred to employ the chemical process illustrated in Scheme 4 at the end of reaction Step 2 shown in Scheme 1 to removal of the metal associated with the metathesis catalyst employed in the cyclization reaction. Accordingly, Scheme 4 illustrates removal of a metathesis catalyst of Formula XXa′, preferably the complex of Formula XXa′ is an N-heterocyclic carbine metal complex, but it will be appreciated that the process can be employed to chemically remove any metal metathesis catalyst from the reaction mixture. wherein the dotted lines represent optional bonds; Ar is phenyl, 2,4,6-trimethylphenyl, or 2,6-dimethylphenyl; M is preferably a transition metal with a formal oxidation state providing 8 “d” orbital electrons (a group 8 transition metal, for example, ruthenium, palladium or iridium) or a group 6 transition metal, for example, molybedinum; L 2 is a phosphine ligand, for example, P(R) 3 , where “R” is phenyl aryl, or alkyl, for example, (Cy) 3 P, or optionally, L 2 is bonded to the carbene substituent via R 3 , indicated by the semicircular dotted line between L 2 and R 3 , forming a bidentate ligand, wherein L 2 is a chelating moiety, for example, an oxygen, phosphorous, or nitrogen moiety, for example, the oxygen moiety in the isoproxy-benzylidene bidentate ligand shown in the catalyst of Formula XXd (herein), R 1 is independently selected from aryl, alkyl, or hydrogen; R 2 is H, OH, or ═O; R 3 is an aryl, alkyl or phenyl moiety, or H if L 2 is not bonded to R 3 , and (X) is a conjugate base of a strong acid, for example, a halogen, a sulfate, sulfite or sulfonate anion, preferably “X” is a sulfonate anion, for example tosylate or a halogen moiety which is chloride or bromide, the process comprising: (i) heating a mixture of an aqueous solution of a reducing reagent, preferably a reducing reagent which is sodium metabisulfite (Na 2 S 2 O 5 ), sodium sulfite (Na 2 SO 3 ), sodium bisulfite (NaSO 3 H), hypophosphorous acid (phosphinic acid, H 3 PO 2 ), sodium formate (NaOCHO) or phosphorous acid sodium salt (NaH 2 PO 3 ), or mixtures of two or more, in the presence of a solution comprising a water-immiscible organic solvent and at least one N-heterocyclic carbine metal complex of Formula [XX], [XXa], [XXb] or [XXd]; and (ii) separating the metal complex of Formula ML 2 from the organic layer after heating Step (i) by: (a) filtration where the metal complex is insoluble; or (b) where the metal complex is soluble, uptake of the metal complex into the aqueous layer and separating the organic and aqueous layers. In some embodiments it is preferred to carry out the process of Scheme 4 in the presence of a phase transfer catalyst, for example a quaternary ammonium salt, for example, a quaternary ammonium salt of the Formula [(R a3 ) 4 N] + X − , wherein R a3 is alkyl, for example, n-butyl-, and X is a halide, sulfonate, or nitrate. In some embodiments it is preferred to employ as the reducing reagent: (i) one or more inorganic salt compounds, for example, Na 2 S 2 O 5 , Na 2 SO 3 , or NaH 2 PO 3 ; (ii) a phosphorous acid, for example, H 3 PO 2 ; (iii) one or more metal hydride compounds, for example, sodium hydride, sodium borohydride, or lithium aluminum hydride; (iv) a reduction carried out with hydrogen and a catalyst, for example, palladium on carbon; (v) an organic reducing reagent, for example, ascorbic and oxalic acids; (vi) hydrogen peroxide; or (vii) one or more metal reducing reagents, for example, copper, zinc, iron or magnesium. It will be appreciated that while Scheme 4 is illustrated with the metathesis catalyst of Formula XXa, the process will yield similar results and advantages if used in the presence of any metathesis catalyst. Other aspects and advantages of the invention will become apparent from following Detailed Description. DETAILED DESCRIPTION OF THE INVENTION Earlier processes for the preparation of the compound of Formula I include preparation of the piperidinyl moiety, followed by reactions to add the spiro pyrrolidinyl ring, while the presently claimed process cyclizes a 3,5-bis(trifluoromethyl)phenyl]ethoxy]methyl]-1-phenyl-2-propenyl]amino]methyl]-5-ethenyl-2-pyrrolidinone. Compared to previous procedures, the present invention for preparing the compound of Formula I is convergent and shorter, provides for improved enantiomeric and diastereomeric selectivity, provides the compound in higher yield, and is easier and more cost-effective to use. Terms used in the general schemes herein, in the examples, and throughout the specification, include the following abbreviations, together with their meaning, unless defined otherwise at the point of their use hereinafter: Me (methyl); Bu (butyl); t-Bu (tertiary butyl); Cbz- (Carboxybenzyl); Et (ethyl); Ac (acetyl); t-Boc or t-BOC (t-butoxycarbonyl); DMF (dimethylformamide); THF (tetrahydrofuran); DIPEA (diisopropylethylamine); RT (room temperature, generally 25° C.); TFA (trifluoroacetic acid); TEA (triethyl amine); NMP (1-methyl-2-pyrrolidinone); MTBE or TBME (tert-butyl methyl ether); Me (methyl); Mes, when used as a structural substituent (mesityl, which is 2,4,6-trimethylphenyl-moiety); Ph (phenyl); NaHMDS (sodium hexa-methyldisilizane); DMI (1,3-dimethyl-2-imidazolidinone); AcOH (acetic acid); LHMDS (lithium bis(trimethylsilyl)amide); TMSCl (chlorotrimethylsilane or trimethylsilyl chloride); TFAA (trifluoroacetic anhydride); and IPA (isopropanol). As used herein, the following terms, unless otherwise indicated, are understood to have the following meanings: Alkyl means a straight or branched chain aliphatic hydrocarbon having 1 to 6 carbon atoms. Halogen means a halogen moiety, for example, fluoro, chloro, bromo or iodo. PTC, a phase-transfer catalyst, an agent which facilitates transfer of a reactive moiety or reaction product from one phase to another phase in a reaction mixture. A wavy line appearing on a structure and joining a functional group to the structure in the position of a bond generally indicates a mixture of, or either of, the possible isomers, e.g., containing (R)- and (S)-stereochemistry. For example, means containing either, or both of As well known in the art, a bond drawn from a particular atom wherein no moiety is depicted at the terminal end of the bond indicates a methyl group bound through that bond to the atom, unless stated otherwise. For example: However, sometimes in the examples herein, the CH 3 moiety is explicitly included in a structure. As used herein, the use of either convention for depicting methyl groups is meant to be equivalent and the conventions are used herein interchangeably for convenience without intending to alter the meaning conventionally understood for either depiction thereby. The term “isolated” or “in isolated form” for a compound refers to the physical state of said compound after being isolated from a process. The term “purified” or “in purified form” for a compound refers to the physical state of said compound after being obtained from a purification process or processes described herein or well known to the skilled artisan, in sufficient purity to be characterizable by standard analytical techniques described herein or well known to the skilled artisan. In the reaction schemes depicting the present inventions, brackets around a structure indicate that the compound is not necessarily purified or isolated at that stage, but is preferably used directly in the next step. Also, various steps in the general reaction schemes do not specify separation or purification procedures for isolating the desired products, but those skilled in the art will recognize that well known procedures are used. Typical parameters for the process described in Scheme 1 are discussed below. With reference to Scheme I, above, in some embodiments step 1 is typical carried out in accordance with the following reaction scheme: In some embodiments, it is preferred to provide the compound of Formula III by carrying out Step 1a, wherein the compound of Formula II is converted to the compound of Formula III by treatment with a base, for example, a lower alkyl amine, for example, a tertiary amine, for example, triethylamine, diisopropylethylamine, or tributylamine, in a solvent that is miscible with water, for example, a lower alcohol (that is, having from about 1 to about 6 carbon atoms), for example ethanol, methanol, isopropanol, butanol or mixtures thereof, at a temperature of from about 0° C. to about 80° C., preferably from about 10° C. to about 60° C., more preferably from about 20° C. to about 30° C., and for a period of from about 3 hours to about 10 hours. In Step 1b, the compound of Formula III, for example, as the mixture from Step 1a, is added to a solution of the free base of Formula IV and heated to react the two. After addition the mixture is heated to reflux and water generated in the reaction is removed via azeotropic distillation to drive the reaction. In some embodiments, the freebase of Formula IV is prepared from a salt of Formula IVa by treating the salt of Formula IVa with a water soluble base, for example, NaOH dissolved in a low polarity solvent, for example, toluene or a non-polar solvent, for example, xylenes, or mixtures of the two. In some embodiments, in Step 1c, it is preferred to reduce the product of Step 1b is with a source of hydride, for example, metal hydride reducing reagents, for example, sodium borohydride, sodium cyanoborohydride, or sodium triacetoxyborohydride, in the presence of an acid, for example, acetic acid, trifluoroacetic acid, phosphoric acid, methanesulfonic acid or trifluoromethanesulfonic acid and mixtures thereof to obtain the free base of Formula VI. In some embodiments it is preferred to carry out the reaction in toluene, acetonitrile, 1,2-dichloroethane, tetrahydrofuran, ethyl acetate, isopropyl acetate, or mixtures of two or more thereof. In some embodiments it is preferred to carry out the reaction at a temperature of from about 0° C. to about 80° C., preferably from about 10° C. to about 60° C., more preferably from about 15° C. to about 25° C. In some embodiments it is preferred to carry out the reaction for a period of from about 2 hours to about 10 hours. After obtaining a free base of Formula VI, it is converted (step 1c′) to a salt compound of Formula VIa by treatment with an acid reagent, for example, p-toluene sulfonic acid, methanesulfonic acid, trifluoromethanesulfonic acid, trifluoroacetic acid, HCl, HBr, or sulfuric acid. In some embodiments it is preferred to carry out the conversion to a salt compound of Formula VIa in a water-miscible solvent, for example, alkyl alcohol having from about 1 to about 6 carbon atoms, for example, methanol, ethanol, propanol, isopropanol, or butanol and its isomers, or a mixture of two or more thereof, and thereafter isolate the salt product. In Step 2, the salt compound of Formula VIa is converted to a free base, which is then cyclized with a ring closing metathesis catalyst, and the resultant product is converted again to a salt and isolated. The ring closing metathesis catalysts are preferably those containing a metal with a carbene ligand, for example, the catalyst of Formula XX: where the metal (M) is preferably a transition metal with a formal oxidation state providing 8 “d” orbital electrons (a group 8 transition metal, for example, ruthenium, palladium or iridium) or a group 6 transition metal, for example, molybdenum; (X) is a conjugate base of a strong acid, preferably X is: a sulfonate moiety, for example, tosylate; or halogen moiety, for example, chloride; (L 1 ) is a sigma-bonded carbon ligand with substantial Pi-backbonding capability, for example, as shown in the catalyst of Formula XXa, an imidazolidine ligand (wherein Ar is an aryl moiety, for example benzyl, phenyl or mesityl (2,4,6-trimethyl phenyl)moiety), L 2 is a phosphine ligand, for example (Cy 3 P), or, as indicated, L 2 is optionally bonded to R 3 , illustrated by the semicircular dotted line between L 2 and R 3 , when L 2 is bonded to the carbene moiety via R 3 , it forms a bidentate ligand, and L 2 is a chelating moiety, for example, an oxygen, phosphorous, or nitrogen moiety, for example, the oxygen moiety in the isoproxy-benzylidene bidentate ligand shown in the catalyst of Formula XXd, R 1 is independently selected from aryl, alkyl, or hydrogen, and R 3 is an alkyl or phenyl moiety, or when R 3 is not bonded to L 2 , R 3 may be hydrogen. Suitable ring-closing metathesis catalysts are commercially available, for example: (i) the catalysts described as “Grubbs' First generation catalyst” in U.S. Pat. No. 6,215,019 and that described as “Grubbs' Second Generation catalysts” in published PCT Application Nos. WO 99/51344 and WO 00/71554 and the catalysts described as “Hoveyda-Grubbs' First and Second Generation catalysts” in published PCT Application No. PCT/US01/24955, both available from Materia; (ii) Zhan's catalyst described in published international application publication no. WO 2007/003135), available from Zannan Pharma; and (iii) Grela's catalyst described in published international application publication no. W)2004/035596, available from Boehringer-Ingelheim. In some embodiments of the present invention it is preferred to use a catalyst having: (i) a chelating isoproxybenzylidene ligand; and (ii) a bismestiylene-substituted N-heterocyclic carbene ligand, for example, the Hoveyda-Grubbs' Second Generation Catalyst. In some embodiments it is preferred to employ a catalyst of the formula: In some embodiments it is preferred to employ a catalyst of the formula: where R 4 is “H—”, a nitro moiety (—NO 2 ), or a sulfonamide moiety (—SO 2 N(R 5 ) 2 , wherein R 5 is an alkyl moiety of 10 carbon atoms or less). With reference to Scheme 1, Step 2, in some embodiments it is preferred to use a reaction mixture loading of the ring-closing metathesis catalyst (catalyst loading) in an amount of from about 100 mol % to about 0.1 mol %, more preferably the catalyst is used in an amount of from about 20 mol % to 0.1 mol %, and more preferably about 10 mol % to about 0.5 mol %, relative to the amount of the compound of Formula V initially present in the reaction mixture. As mentioned above, the addition of acid to the reaction mixture in Step 2, for example, 4-methylbenzenesulfonic acid monohydrate or toluenesulfonic acid, can reduce the reaction mixture catalyst loading required to achieve complete, or nearly complete, conversion of the substrate under given reaction conditions. Table I, below, illustrates the results obtained by adding various amounts of p-toluenesulfonic acid to the reaction mixture and observing the amount of substrate conversion as a function of catalyst loading with and without added acid. In some embodiments where acid is added to reduce catalyst loading it is preferred to add acid in an amount of from about 0.01 equivalents (eq.) to about 2 equivalents (eq.) relative to the amount of substrate initially present in the reaction mixture, more preferably, acid is added in an amount of from about 0.1 eq. to about 1.8 eq., and more preferably acid is added in an amount of from about 0.2 eq. to about 1.5 eq. relative to the amount of substrate initially present in the reaction mixture. Without wanting to be bound by theory, the inventors believe that best results respecting the use of added acid in Step 2 for the reduction of catalyst loading will be achieved by adding to the reaction mixture an acid possessing a pKa≦6.5, which is the calculated pKa of intermediate IV. Various types of acid are believed to be useful for reducing the required catalyst loading to achieve high conversion of the substrate, for example, but not limited to: (i) mineral acid, for example HCl, HBr, HI, phosphoric acid, or sulfuric acid or mixtures thereof; and (ii) organic acid, for example, acetic acid, trifluoroacetic acid, methanesulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, p-nitrobenzenesulfonic acid, halogen-substituted benzenesulfonic acid, or heteroaromatic sulfonic acid, or mixtures thereof. TABLE I Conversion vs. Catalyst Loading vs. TsOH Charged Catalyst Additional TsOH Reaction Conversion Loading (mol %) Added (mol %) (% of VII/VI) 5 0 85-90  5.5-7 0 90-100 >7 0 100 1 20 57 5 20 100 3 60 100 5 60 100 5 100 100 2 100 93-100 1 100 88 1.5 150 98-100 1 150 98 0.5 150 76 1 200 44 With reference to Table I, cyclization reactions in accordance with Step 2 of Scheme I (above) were run employing from 0 to about 2 mole equivalents (eq.) of added acid relative to the amount of substrate to be cyclized. These data show that adding acid to the reaction mixture in Step 2 can reduce by a factor of more than 4.5 the catalyst loading required in the reaction mixture to achieve a high percentage conversion of the substrate. Accordingly, where loadings of 7 mol. % or more were needed to achieve nearly 100% substrate conversion without added acid, conversions approaching 100% of substrate could be achieved using a catalyst loading of 1.0 mol. % in conjunction with 150 mol. % additional acid in the reaction mixture. In some embodiments it is preferred to carry out the ring-closing reaction of Step 2 in an anhydrous, degassed (for example, using N 2 ) reaction medium comprising a non-coordinating medium polarity solvent, for example, toluene, trifluorotoluene, chlorobenzene, benzene, xylene(s), chloroform, dichloromethane, or dichloroethane. In general, the reaction is carried out at atmospheric pressure or a pressure slightly elevated above atmospheric pressure. In some embodiments it is preferred to carry out the ring-closing metathesis reaction by dissolving the catalyst in a solvent which is the same as, or similar to, the reaction solvent and adding the catalyst solution slowly over a period of about 30 minutes while maintaining the temperature of the reaction mixture within a temperature range of from about 20° C. to about 100° C., preferably from about 30° C. to 90° C. and more preferably from about 60° C. to about 80° C. In some embodiments, at the end of the cyclization reaction it is preferred to remove the metal from the catalyst using the process described in Scheme 4, i.e., the product of the ring-closing procedure is treated with an aqueous solution of a reducing reagent and the resultant metal species is extracted into the aqueous layer. Suitable reducing reagents include, but are not limited to, inorganic reagents, for example, sodium bisulfite, sodium metabisulfite, sodium thiosulfite, sodium formate, sodium borohydride and its derivatives. In some embodiments employing the process of Scheme 4 to remove metal from the metathesis catalyst, it is preferred to employ also in the reaction mixture a phase transfer catalyst (PTC) in an amount of from about 0.05 mol % of PTC relative to the amount of reducing reagent employed to about 200 mol % of PTC relative to the amount of reducing reagent employed, preferably PTC is employed in an amount which is from about 0.1 mol % to about 100 mol % relative to the amount of reducing reagent employed. Suitable phase transfer catalysts for use in the process include, but are not limited to, quaternary ammonium salts of the Formula (R* 4 N + X − ) wherein “R*” is an alkyl group, as defined herein, and “X” is an anion, preferably “X” is Cl − , Br − , I − , F − , or NO 3 − . The inventors have surprisingly found that when the process is carried out in the presence of a suitable phase transfer catalyst, the PTC permits the reduction to proceed to completion at either a lower temperature, for example, as low as 25° C., within a shorter period of time, for example, in less than 1 hour, or depending upon the temperature regime selected, both the reaction period and the reaction temperature can be reduced over that required to achieve a complete reduction in the absence of a phase transfer catalyst. In some embodiments it is preferred to convert the cyclized product from which the catalyst has been removed to a salt by treatment of the reaction mixture containing the cyclized product with a reagent comprising: (i) a mineral acid, for example, HCl, HBr, HI, H 3 PO 4 , or H 2 SO 4 ; (ii) an organic acid or substituted organic acid, for example, Maleic Acid, Fumaric Acid, Tartaric Acid or trifluoroacetic acid; (iii) a sulfonic acid or substituted sulfonic acid, for example, methanesulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, p-Toluenesulfonic acid, or p-nitrobenzenesulfonic acid. In some embodiments it is preferred to prepare the HCl salt of the compound of Formula VI. With reference to Scheme I, in Step 3, the salt of Formula VII is converted to the free base form. In some embodiments it is preferred to accomplish the conversion by treating the compound of Formula VII with a base, for example, NaOH, KOH, NaOR (where “R” is an alkyl group containing from about 1 to about 12 carbon atoms). In some embodiments the conversion of the compound of Formula VII in Step 3 is carried out in a reaction solvent comprising a low polarity organic solvent, for example, toluene, Xylene, ethers (for example, diethyl ether and methyl t-butyl ether), to obtain the free base of VII, and subsequently reduce the free base to the compound of Formula VIII by hydrogenation, for example by treatment with hydrogen in the presence of a hydrogenation catalyst, for example, palladium on carbon, platinum on carbon, palladium oxide, ruthenium, or Wilkinson's catalyst, or mixtures thereof. In some embodiments it is preferred to carry out Step 3 in a low polarity, organic solvent, for example, toluene or Xylene, or in a polar organic solvent, for example alcohols (C1 to C12 linear or branched alkyl), or ethers, or in water, or a mixtures of two or more thereof. In some embodiments, after the hydrogenation reduction is complete, the catalyst employed in Step 3 is removed from the reaction mixture, for example, by filtration, and the product compound in the reaction mixture is then treated with an acid to make the corresponding salt, for example, in embodiments where the product compound is treated with HCl at this step, the compound of Formula VIII (Scheme I) is obtained as the hydrochloride hydrate. The inventor's have surprisingly found that alternatively, with reference to Scheme I, above, the tetrahydropyridine salt compound of Formula VII can be directly reduced to yield the corresponding amine-salt compound. When the compound of Formula VII is a hydrochloride salt, reduction of the salt compound of Formula VII yields the hydrochloride hydrate compound of Formula VIII directly without having to generate the intermediate free-base form of the tetrahydropyridine, the compound of Formula VIIb. In some embodiments employing direct reduction of the tetrahydropyridine salt compound of Formula VII, preferably after the reduction reaction is complete, the catalyst employed in the reduction is removed from the reaction mixture by mechanical means, for example, by filtration, and the resultant amine salt is recovered from the filtrate. For carrying out the reduction of a salt compound of Formula VII directly without first providing the free-base form of the tetrahydropyridine, the inventors have surprisingly found that the reaction is preferably carried out in a solvent which is: (i) a low polarity organic solvent, for example, toluene or xylene or a mixture thereof; (ii) a polar organic solvent, for example, alcohols comprising from about 1 carbon atom to about 12 carbon atoms or a mixture of two or more thereof; (iii) organic ethers comprising from about 2 to about 12 carbon atoms or a mixture of two or more thereof; and (iv) water, or mixtures of any two or more thereof. Suitable methods for reducing the salt-form of the tetrahydropyridine compound to the corresponding cyclohexylamine include treatment of the compound of Formula VII with hydrogen in the presence of a hydrogenation catalyst Suitable hydrogenation catalysts include, for example, palladium on carbon, palladium oxide, platinum on carbon, ruthenium and Wilkinson's catalyst or mixtures of two or more thereof. In some embodiments, following Step 3 of Scheme I, it is preferred to carry out Step 4, recrystallizing the product of Step 3 from an alcohol/water solution, thereby providing a desirable crystalline form of the compound of Formula Ia. Suitable alcohol solvents useful in carrying out Step 4 include, but are not limited to, alcohols having from about 1 to about 12 carbon atoms, or a mixture of two or more thereof. Alternatively to recrystallization, the compound of Formula VIII can be suspended in toluene, the suspension extracted with aqueous NaOH, and then treated with HCl to precipitate compound of Formula Ia. As mentioned above, in some embodiments of the present invention it is preferred to prepare the intermediate of Formula IV using the process illustrated in Scheme 2. In some embodiments employing the process of Scheme 2 to provide the compound of Formula IV, it is preferred to use the conditions and parameters illustrated below in Scheme 2ab in carrying out Scheme 2. In the process of Scheme 2ab, Steps 2-1 to 2-3 are described in the above-mentioned U.S. Pat. No. 7,049,320 (the '320 patent) the Examples, columns 43 to 44, compounds 1 to 3, and removal of the triphenylphosphine oxide resulting from carrying out step 2-5.1 shown in Scheme 2ab is described on pages 4 to 5 of European published application No. EP 0850902. In some embodiments it is preferred to carry out Step 2-4 of Scheme 2ab using a base, for example, KHCO 3 or NaHCO 3 in a solvent, for example, NMP water, a mixture of acetonitrile and water, or a mixture of acetone and water. In some embodiments it is preferred to stir the reaction mixture while maintaining the reaction mixture at a temp of from about 0° C. to about 60° C., preferably from about 5° C. to about 50° C., more preferably from 15° C. to about 25° C., and after a period of agitation, heat the reaction mixture up to a temperature of less than about 90° C., preferably to a temperature of less than about 70° C., more preferably, of from about 45° C. to about 55° C., followed by cooling the reaction mixture to ambient temperature (typically about 25° C.) and extracted the ambient temperature reaction mixture with an organic solvent, for example, methyl t-butyl ether (MTBE), ethyl acetate, isopropyl acetate, toluene, Xylene or a mixture of two or more thereof. With further reference to Scheme 2ab, Step 2-5 is carried out by adding the product of Step 2-4 to a mixture of Ph 3 PCH 3 X (X═Cl. Br, or I) and sodium or lithium hexamethyldisilizane or lithium diisopropylamide, sodium or potassium alkoxide in an organic solvent for example, toluene, THF, MTBE at a temperature range from −20 to 60° C., preferably from 5 to 40° C., more preferably from 10 to 25° C. The reaction mixture is warmed to room temperature and stirred, then cooled to range from −30 to 40° C., preferably from −20 to 30° C., more preferably from −10 to 20° C., and quenched with dilute acetic acid and washed with sodium bicarbonate solution. The product is treated with MgCl 2 and stirred at room temperature, then treated with silica gel. Filtration of solid gives the compound of Formula XIII. In step 2-6, the crude product Formula XIII is treated with TMSI (iodotrimethylsilane) and quenched with an alcohol having from about 1 to about 12 carbon atoms, thereby providing (with reference to Scheme I, step 1b) the free base of Formula IV. As illustrated in Step 2-6 of scheme 2ab, the free base of Formula IV provided is treated with an acid, for example, maleic acid, hydrochloric acid, and hydrobromic acid, to form the corresponding salt, preferably maleic acid is used, thereby providing the corresponding maleate salt compound of Formula IVa. In some embodiments, it is preferred to cyrstallize the salt thereby provided from toluene and an anti solvent, for example, hexane, heptane or octane, to provide a crystalline form of the salt. As mentioned above, in some embodiments of the present invention it is preferred to prepare the intermediate of Formula II using the process illustrated in Scheme 3. In some embodiments employing the process of Scheme 3 to provide the compound of Formula II, it is preferred to use the conditions and parameters illustrated below in Scheme 3ab in carrying out Scheme 3. With reference to Scheme 3ab, in some embodiments it is preferred to carry out Step 3-1 using one of several methods: a) refluxing pyroglutamic acid with diethylene glycol dimethyl ether, trimethylacetaldehyde and a strong acid, for example methanesulfonic acid; or b) heating pyroglutamic acid with trimethylacetaldehyde and a strong acid, for example, methanesulfonic acid; or c) refluxing pyroglutamic acid with hexamethyl disilizane, then reacting the product with trimethylacetaldehyde and methanesulfonic acid; or d) heating pyroglutamic acid and triethylamine with chlorotrimethylsilane, and then reacting the product with trimethylacetaldehyde and a strong acid, for example, methanesulfonic acid; or e) adding trifluoroacetic anhydride to a mixture of pyroglutamic acid, trimethylacetaldehyde and a strong acid and maintaining the temperature from about 50° C. to about 100° C. until the reaction is complete. In method (a), the compound of Formula XIV is prepared by refluxing pyroglutamic acid in diethylene glycol dimethyl ether solvent, in the presence of trimethylacetaldehyde and a strong acid. In some embodiments it is preferred for the strong acid to be trifluoroacetic acid, phosphoric acid, sulfuric acid, methanesulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid or p-nitrobenzenesulfonic acid. In some embodiments of method (a) refluxing with pyroglutamic acid is carried out in the presence of a co-solvent, for example, toluene, Xylene, cyclohexane, THF, or a mixture of two or more thereof, at refluxing temperature employing a Dean Stark water-removal apparatus on the refluxing apparatus until the reaction is complete. In method (b), a mixture of pyroglutamic acid with trimethylacetaldehyde and a strong acid, without the diethylene glycol dimethyl ether solvent used in method (a) is heated in an apparatus permitting, water removal, for example, a Dean Stark water-removal apparatus. In method (b), as in method (a), in some embodiments it is preferred to select as a strong acid trifluoroacetic acid, phosphoric acid, sulfuric acid, methanesulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid or p-nitrobenzenesulfonic acid. In some embodiments the mixture is heated to reflux, typically from about 100° C. to about 120° C., while water is azeotropically distilled off through the trap, and reflux is continued until water removal is complete. On a bench-scale equipment this is typically accomplished in about 14.5 hours. In method (c), pyroglutamic acid and hexamethyl disilizane in a solvent which is preferably dioxane, diglyme, toluene or N-methylpyrrolidinone (NMP) are heated to reflux for a period of from about 6 hours to about 12 hours. Trimethylacetaldehyde and a strong acid, for example, trifluoroacetic acid, phosphoric acid, sulfuric acid, methanesulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid or p-nitrobenzenesulfonic acid are added to the product, and the resultant mixture is heated to 90° C. for a period of from about 4 hours to about 12 hours. In method (d), chlorotrimethylsilane is added to a mixture of pyroglutamic acid and triethylamine in toluene while keeping the temperature under 30° C., and then the mixture is heated to reflux until the silylation is completed. The resultant trimethylsilyl-protected compound is added to a solvent, for example, N-methyl-2-pyrrolidone, or acetonitrile and treated with trimethylacetaldehyde and a strong acid, for example, trifluoroacetic acid, phosphoric acid, sulfuric acid, methanesulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid or p-nitrobenzenesulfonic acid, maintaining the temperature of the reaction mixture in a temperature range of from about 50° C. to about 100° C., preferably from about 60° C. to about 90° C., more preferably, from about 70° C. to about 85° C. until the reaction is complete, typically a period of from about 18 hours to about 24 hours. In method (e), a mixture of pyroglutamic acid, trimethylacetaldehyde, and a strong acid is prepared and trifluoroacetic anhydride is added to it. In some embodiments the strong acid is selected from: organic acid, for example, trifluoroacetic acid; mineral acid, for example, phosphoric acid or sulfuric acid; sulfonic acid, for example, methanesulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid or p-nitrobenzenesulfonic acid. In some embodiments it is preferred to carry out the reaction in an organic solvent, for example, toluene or N-methyl-pyrrolidone. In some embodiments it is preferred to maintain the reaction mixture at a temperature of from about 70° C. to about 95° C., more preferably the temperature is maintained at from about 80° C. to about 95° C. In general the reaction mixture is maintained in the desired temperature range until the reaction is complete, typically about 5 to about 10 hours. In Step 3-2, the compound of Formula XIV is mixed with: (i) a solvent which is preferably 1,3-dimethyl-2-imidazolidinone (DMI) or tetrahydrofuran, (ii) methyl formate or ethyl formate; and (iii) optionally a Lewis acid, for example, CuCl or ZnCl 2 . When a Lewis acid is employed, typically the Lewis acid is added in amounts of up to about 1 eq. relative to the amount of the compound of Formula XIV employed. In some embodiments a Lewis acid is employed in this step to increase yield and simplify workup of the reaction mixture. Following the addition of the constituents, the reaction mixture is cooled to a temperature of from about [−100]° C. to about [−55]° C., then, maintaining the temperature of the reaction mixture, to the reaction mixture is added lithium bis(trimethylsilyl)amide (LiHMDS) followed by chlorotrimethylsilane (TMSCl). After addition is complete, the reaction mixture is warmed to a temperature of from about 0° C. to about [+10]° C. and combined with an aliquot of a citric acid or acetic acid solution. The resultant intermediate is treated with trifluoroacetic acid to obtain the pyrrolo[1,2-c]oxazole-7a-carbaldehyde of Formula XV. In Step 3-3, the carbaldehyde of Formula XV is converted to the 7a-vinyl-dihydro-pyrrolo[1,2-c][1,3]oxazole-1,5-dione of Formula XVI by a Wittig reaction, for example by treating it with methyltriphenylphosphonium halide (Halide=Cl. B, or I) and sodium or lithium hexamethyldisilizane or lithium diisopropylamide, sodium or potassium alkoxide in an organic solvent, preferably toluene, THF, or MTBE, at a temperature range from about [−20]° C. to about [+60]° C., preferably from about [−10]° C. to about [+30]° C., more preferably from about [+5]° C. to about [+15]° C., then the reaction mixture is quenched by adding NaCl and acetic acid. The product is treated with MgCl 2 and the MgCl 2 -triphenylphosphine oxide complex thus formed is separated from the reaction mixture by filtration. The product remaining in the reaction mixture is crystallized from toluene and heptane to give the compound of Formula XVI. In Step 3-4, the compound of Formula XVI is dissolved in an ether solvent which is preferably tetrahydrofuran or MTBE, or in a low polarity organic solvent, for example, toluene. The reaction mixture is maintained at a temperature of from about [−40]° C. to about 0° C., preferably at a temperature of from about [−30]° C. to about [−5]° C., more preferably at a temperature of from about [−25]° C. to about [−15]° C., and then the reaction mixture is treated with lithium tri(t-butoxy)aluminum hydride, lithium aluminum hydride, or Lithium diisobutylaluminium hydride and the temperature is raised to a temperature of from about [−10° C. to about [+10]° C. over a period of from between about 10 hours to about 16 hours and maintained until the reaction is complete. When the reaction is completed, the reaction mixture is quenched with an acetate solvent, which is preferably ethyl acetate, methyl acetate, or isopropyl acetate, and then contacted consecutively with aliquots of an acid, preferably glacial acetic acid or trifluoroacetic acid, and then an aliquot sodium sulfate decahydrate to obtain the compound of Formula II. For the intermediate compounds claimed per se, i.e. In some embodiments it is preferred to isolate compound IV as either a maleate salt, including hydrates thereof, or as a hydrochloride salt, including hydrates thereof. In some embodiments the compounds of Formulae VI and VII are preferably isolated as a hydrochloride salt or a 4-methyl-benzenesulfonic acid salt, more preferably the hydrate of a 4-methyl-benzenesulfonic acid salt. As mentioned above, at the conclusion of Step 2 of Scheme 1, the process illustrated in Scheme 4, above, can be employed to remove metal from the reaction mixture of a ring closing metathesis reaction, allowing the metal to be recycled and providing the product intermediate compound substantially free of contamination from the metathesis catalyst. With reference to Scheme 4, illustrated above herein, the inventors have surprisingly found that the metathesis catalyst can be removed from the reaction mixture when the ring-closing reaction is complete by treating the reaction mixture containing the metathesis catalyst with a reducing reagent that reacts with the metathesis catalyst. The process described in Scheme 4 comprises reducing the catalyst in the reaction mixture which comprises a water-immiscible solvent by contacting the reaction mixture with an aqueous solution containing a reducing reagent, wherein, the reduction product of the metathesis catalyst is either soluble in the aqueous layer, and thus is physically separated from the organic layer using the immiscibility of the two layers, for example, by separation or decantation, or is insoluble in either the organic or aqueous layer, and thus physically separated from the reaction mixture by filtration. For carrying out the metathesis reduction reaction described in Scheme 4, above, suitable reducing reagents include: (i) one or more inorganic salt compounds, which are Na 2 S 2 O 5 , Na 2 SO 3 , NaSO 3 H, NaOC(O)H, or NaH 2 PO 3 ; (ii) a phosphorous acid, for example, H 3 PO 2 ; (iii) one or more metal hydride compounds, for example, sodium hydride, sodium borohydride, or lithium aluminum hydride; (iv) hydrogen in the presence of a reduction catalyst, for example, palladium on carbon; (v) an organic reducing reagent, for example, ascorbic and oxalic acids; (vi) hydrogen peroxide; or (vii) one or more metals capable of carrying out a reduction reaction, for example, copper, zinc, iron or magnesium. In some embodiments it is preferred to include in the reaction an inorganic salt compound which can function in the reaction as a phase transfer catalyst (PTC), for example, a quaternary ammonium salt, for example (CH 3 (CH 2 ) 3 ) 4 N + X − , wherein X is preferably a chloride, bromide, iodide, fluoride, bisulfate (HSO 4 − ), sulfate (SO 4 −2 ), or nitrate anion. The inventors have found surprisingly that including a PTC can permit the reaction to be carried out at a temperature of as low as about 20° C., whereas, without a PTC the reaction required a temperature of about 40° C. to proceed. Moreover, the presence of a PTC in the reaction can significantly reduce the time required to complete the reaction at a particular temperature, for example, reducing to a period of about 6 minutes a reaction requiring a reaction time for a particular temperature of about 1 hour. Accordingly, in some embodiments utilizing the reaction process of Scheme 4 to remove the metathesis catalyst used for ring-closure in the synthesis, it is preferred to employ, as a water-immiscible solvent comprising the reaction mixture toluene, trifluorotoluene, chlorobenzene, benzene, xylene(s), dichloromethane, or dichloroethane or mixtures of two or more thereof. In some embodiments utilizing the reaction process of Scheme 4 to remove the metathesis catalyst used for ring-closure in the synthesis, it is preferred to carry out the reduction reaction at a temperature of from about 20° C. to about 100° C. In some embodiments utilizing the reaction process of Scheme 4 to remove the metathesis catalyst used for ring-closure in the synthesis, it is preferred to run the reaction for a period of from about 0.1 hour to about 24 hours. Generally, when this method is employed to remove the metathesis catalyst, the reaction is continued until all of the metathesis catalyst has been reduced. At the end of the reduction reaction the reduced metal, typically in the form of an ML 2 complex, is either soluble, and so in the course of the reaction is extracted into the aqueous solution comprising the reducing reagent, or is insoluble in either the organic or aqueous layers, and therefore precipitates from the organic and aqueous mixture. In some embodiments utilizing the reaction process of Scheme 4 to remove the metathesis catalyst used for ring-closure in the synthesis, where “M” of the metathesis catalyst, for example, the metathesis catalyst of Formula XXa, is ruthenium, it is preferred to employ Na 2 S 2 O 5 , Na 2 SO 3 or Pd on carbon in the presence of hydrogen as the reducing reagent. In some embodiments utilizing the reaction process of Scheme 4 to remove the metathesis catalyst used for ring-closure in the synthesis, where “M” of the metathesis catalyst, for example, the metathesis catalyst of Formula XXa, is ruthenium, it is preferred to include also a PTC as described above, more preferably, in processes wherein “M” of the metathesis catalyst is ruthenium, it is preferred to employ [(CH 3 (CH 2 ) 3 ) 4 N + (HSO 4 − )] or [(CH 3 (CH 2 ) 3 ) 4 N + ] 2 (SO 4 −2 )] as the phase transfer catalyst. It will be appreciated that the novel method presented above for separating a metathesis catalyst from the reaction mixture at the end of the reaction can be used to cleanly remove a metal metathesis catalyst from other reactions employing such catalysts so long as the reduction product containing the metal is either insoluble in the mixed-phase reaction product obtained after reduction or is soluble in the aqueous phase of the mixed-phase reaction product. There follows examples illustrating the processes of the invention. Unless otherwise specified, all reagents are articles of commerce, laboratory grade, and used as received. EXAMPLE 1 Preparation of [(1S)-1-({(1R)-1-[3,5-Bis(trifluoromethyl)phenyl]ethoxy}methyl)-1-phenylprop-2-enyl]amine, monomaleate Step 1: To a solution of the compound of Formula XI (prepared as described in WO 2003/054840) (100.0 g, 154.9 mmol) in NMP (200 mL) at RT were sequentially added KHCO 3 (4.6 g, 45.9 mmol) and water (3 mL, 166.7 mmol). The resulting mixture was stirred vigorously for 16 h at 20° C. The temperature was then raised to 50° C. and the reaction was stirred for another 2 h. After the reaction was cooled back to RT, 200 mL of water was added. The resulting solution was extracted with TBME (2×200 mL). The combined organic layers were sequentially washed with a solution of 14% NaHSO 3 and 7% AcOH in water (2×100 ml), a saturated aq. NaHCO 3 solution, and brine. The organic layer was dried (Na 2 SO 4 ), filtered and concentrated in vacuum. The crude compound of Formula XII was carried through to the next stage without further purification. 1 H NMR (DMSO-d 6 , 600 MHz) δ 9.53 (s, 1 H), 8.36 (s, 1H), 8.00 (s, 1H), 7.89 (s, 1H), 7.34 (m, 10H), 5.09 (dd, 2H), 4.72 (dd, 1H), 4.03 (d, 1H), 3.90 (d, 1H), 1.34 (d, 3H). Step 2: To a slurry of Ph 3 PCH 3 Br (78.0 g, 217.0 mmol) in toluene (200 mL) was added NaHMDS (13% in toluene, 306 g, 217 mmol) slowly at −15° C. After slurrying the resulting mixture for 1 h, the crude product from step 1 was added slowly. The reaction was then warmed up to RT and stirred for an additional hour. After cooling to 0° C., the reaction was quenched with 6% AcOH water solution (400 mL) and washed with a saturated aqueous NaHCO 3 solution. The organic layer was then treated with MgCl 2 (25 g, 263 mmol) and stirred for 3 h at RT. After filtration, the organic layer was treated with silica gel (100 g) and stirred for 30 min. After filtration, the solid was washed with toluene (2×100 mL). The filtrates were collected and concentrated in vacuum to give the crude product of Formula XIII in toluene, which was carried through the next step without further purification. 1 H NMR (CDCl3, 400 MHz) δ 7.59, (1H, s), 7.38 (2H, s), 7.10-7.22 (10H, m), 6.15-6.22 (1H, dd), 5.50 (1H, s), 5.17 (1H, d), 5.02 (1H, d), 4.91 (2H, dd), 4.33 (1H, q), 3.65 (1H, broad), 3.48 (1H, broad), 1.26 (3H, d). Step 3: To the solution of the product of step 2 in toluene (300 mL), was added trimethylsilyl iodide (21 mL, 152.4 mmol) slowly. The resulting reaction mixture was stirred for 3 h. The reaction was then quenched with MeOH (12.4 mL, 305 mmol) and washed sequentially with 15% aq. NaHSO 3 (200 mL) followed by saturated aq. NaHCO 3 (200 mL). The organic layer containing the crude product of the free base of Formula XIII was carried through to the next stage without further purification. Step 4: To the above crude product of step 3 in toluene was added maleic acid (18 g, 155 mmol) dissolved in MeOH (50 mL). The resulting mixture was stirred for 1 h. The volume of the resulting solution was then reduced to 100 mL at 40° C. under vacuum distillation. At 40° C., n-heptane (100 mL) was added to the resulting solution. Upon cooling to RT, crystallization of the maleate salt occurred and additional n-heptane (500 mL) was added. After stirring 2 h, the solid was filtered and washed with toluene (400 mL), n-heptane (200 mL) and water (250 mL). The wet cake was dried at 45° C. under vacuum for 12 h to give the compound of Formula IVa (61 g; 77% yield from 619734-D). MP. 135° C.-140° C. 1 H NMR (DMSO-d 5 , 600 MHz) δ 8.87 (s, 2 H), 7.94 (s, 1H), 7.90 (s, 2H), 7.45 (t, 1H), 7.41 (t, 2H), 7.37 (d, 2H), 6.16 (dd, 1H), 6.06 (s, 2H), 5.47 (d, 1H), 5.36 (d, 1H), 4.83 (q, 1H), 3.97 (d, 1H), 3.83 (d, 1H), 1.43 (d, 3H). 13 C NMR (DMSO-d s , 500 MHz) 167.5, 146.6, 137.4, 136.4, 136.0, 130.8, 130.5, 130.3, 130.0, 128.5, 128.3, 126.9, 126.6, 126.1, 124.4, 122.3, 121.2, 120.1, 117.9, 76.6, 71.8, 62.1, 22.9. LC-MS exact mass calculated for [C 20 H 20 F 6 NO + ] calculated: 404.14436. found: 404.14456. EXAMPLE 2 [(1S)-1-({(1R)-1-[3,5-Bis(trifluoromethyl)phenyl]ethoxy}methyl)-1-phenylprop-2-enyl]amine, hydrochloride monohydrate To the solution of the crude product Step 3 from Example 1 (free base) in toluene was added conc. HCl (13 mL, 156 mmol, 37% in water). After stirring for 1 h, the volume of the resulting mixture was reduced to 200 mL at 40° C. under vacuum distillation and then water (6.6 mL, 465 mmol) was added. After cooling to RT, n-heptane (700 mL) was added slowly. The resulting slurry was stirred at RT for 6 h, then cooled to 0° C., and stirred for an additional 6 h. The product was filtered, washed with n-heptane (200 mL) and dried at RT under vacuum for 12 h to afford IVb as a white solid (51.8 g; 73% mol yield from XI). Mp. (with decomposition) 37° C. 1 H NMR (CDCl 3 , 400 MHz) δ 9.4 (bs, 3h), 7.8-7.4 (m, 8H), 6.2 (dd, 1H), 5.2 (m. 2h), 4.6 (q, 1H), 4.1 (d, 1h), 3.8 (s, 1H), 1.5 (d, 3h). EXAMPLE 3 Step 1: Preparation of (3R,6S)-3-tert-Butyldihydro-1H-pyrrolo[1,2-c][1,3]oxazole-1,5(6H)-dione Method (a): To a 250 mL three neck flask equipped with an agitator, thermometer, Dean Stark, reflux condenser, and a nitrogen inlet, were added L-pyroglutamic acid (20.0 g, 154.8 mmol), toluene (60 mL), diethylene glycol dimethyl ether (60 mL), trimethylacetaldehyde (40.0 g, 464.4 mmol), and CH 3 SO 3 H (1.5 g, 15.6 mmol). The reaction mixture was heated to reflux at 102-120° C. (reflux) for 14.5 h or until reaction completion with water removal via a Dean-Stark apparatus. The reaction mixture was cooled to 35° C. and distilled under vacuum to a final volume of 50 mL. The mixture was cooled to 20° C. over 1 h, and n-heptane (140 mL) was added over 1h. The reaction mixture was cooled to −5° C. over 1 h and agitated for 1 h. The slurry was filtered and washed with heptane (60 mL) and water (60 mL), dried under vacuum at 50° C. to afford XIV (23.9 g, 79% yield) as an off-white crystalline solid. Mp (with decomposition) 116-168° C., 1 H-NMR (DMSO-d 6 ) δ 5.32 (s, 1H), 4.53 (t, J=8.1 Hz, 1H), 2.69 (m, 1H), 2.43 (m, 1H), 2.30 (m, 1H), 2.29 (m, 1H), 0.91 (s, 9H). LC/MS calculated for C 10 H 16 NO 3 (M+H) + (m/z): 197.231. found: 197.227. Method (b): To a 250 mL three neck flask equipped with an agitator, thermometer, reflux condenser, and a nitrogen inlet, was added L-pyroglutamic acid (200 g, 1.6 mol), NMP (400 mL), trimethylacetaldehyde (500 mL, 397 g, 4.6 mol), and CH 3 SO 3 H (30 mL 44.5 g, 0.46 mol). The reaction mixture was heated to 82.5° C. (reflux) for 15 min and TFAA (240 mL, 1.1 eq.) was added slowly over a period of 4.5 h. The temperature was maintained at 82.5° C. for an additional 4.5 h. The flask was cooled to 20° C. over 1 h and the mixture was transfer to a slurry of NaHCO 3 (325 g, 3.9 mmol) in water (2 L) at 5° C. over 1 h. The slurry was filtered and washed with ice-cold water (400 mL). The wet cake was then dried under vacuum at 50° C. to afford XIV (244 g, 72% yield) as an off-white crystalline solid. Method (c): To a 250 mL three neck flask equipped with an agitator, thermometer, reflux condenser, and a nitrogen inlet, was added L-pyroglutamic acid (250 g, 1.94 mol), toluene (1000 mL), and (CH 3 ) 3 SiNHSi(CH 3 ) 3 (890 mL, 4.26 mol). The mixture was heated to reflux for 6 h, during which time the reflux temperature slowly increased from 80 to 100° C. After 6 h, the mixture was distilled to a volume of 400 mL at 80 mm Hg and 50° C. Additional toluene (1000 mL) was charged and the mixture was distilled to a volume of 400 mL in vacuum. Then trimethylacetaldehyde (500 mL, 397 g, 4.6 mol), and CH 3 SO 3 H (30 mL 44.5 g, 0.46 mol) were charged and the reaction mixture was heated to 90° C. for 4 h. The reaction mixture was cooled to 35° C., toluene (1200 mL) was added and the mixture was distilled under vacuum to a final volume of 1000 mL. The flask was cooled to 20° C. and the mixture was transferred to a solution of NaHCO 3 (65 g) in water (1250 L) at −5° C. over 1 h. The slurry was filtered and washed with ice-cold water (400 mL) and then ice-cold isopropyl alcohol (100 mL). The wet cake was then dried under vacuum at 50° C. to afford the compound of Formula XIV (267 g, 68% yield) as an off-white crystalline solid. Method (d): To a 1 L three neck flask equipped with an agitator, thermometer, reflux condenser and a nitrogen inlet, was charged L-pyroglutamic acid (50 g, 0.39 mol), toluene (450 mL) and Et 3 N (113 mL 0.81 mol). (CH 3 ) 3 SiCl (103 mL, 0.81 mol) was added while keeping the temperature below 30° C. The reaction mixture was heated to 110° C. and agitated for a period of 3 h. The suspension was cooled to 5° C. and diluted with heptane (100 mL). The triethylammonium hydrochloride salt was removed by filtration and washed with a toluene/heptane solution (200 mL). The filtrate was concentrated to a final volume of 150 mL and NMP (50 mL), trimethylacetaldehyde (100 mL, 0.78 mol) and CH 3 SO 3 H (2.5 mL, 0.04 mol) was added. The reaction mixture was heated to 80° C. for 24 h then cooled to 40° C. The reaction mixture was concentrated to about 100 mL and diluted with acetone (100 mL). The reaction mixture was transferred to a solution of NaHCO 3 (13 g) in water (250 mL) at 20° C. The suspension was cooled to 5° C. and stirred for 1 h. The slurry was filtered and washed with ice-cold water (50 mL) and then ice-cold isopropyl alcohol (50 mL). The product was then dried under vacuum at 45° C. to afford XIV (48.3 g, 63%) as an off-white crystalline solid. Method (e): To a 1 L three neck flask equipped with an agitator, thermometer, reflux condenser and a nitrogen inlet, was charged L-pyroglutamic acid (20 g, 0.16 mol), trimethylacetaldehyde (50 mL, 0.39 mol), methane sulfonic acid (1.4 ml, 0.02 mol) toluene (140 mL) and N-methylpyrrolidone (20 mL). The mixture was heated to 90° C. and maintained at 90° C. whilst slowly adding trifluoroacetic anhydride (27 mL). The reaction was maintained at 90° C. for 8 hours, achieving 100% conversion of the acid. Step 2: To a 2 L three neck flask equipped with an agitator, thermometer, reflux condenser, and a nitrogen inlet were charged XIV (100 g, 0.5 mol), CuCl (10 g), DMI (100 mL), THF (1.2 L), and methyl formate (100 mL). After cooling to below [−60]° C., LHMDS (700 mL, 1.0 M in THF) was charged at a rate such that the temperature did not exceed −60° C. After addition of LHMDS, TMSCl was charged at a rate such that the temperature did not exceed [−60]° C. The mixture was warmed to between 0 and 10° C. over 30 min and the batch was concentrated in vacuum to 250 mL and EtOAc (300 mL) was added. To a mixture of citric acid (120 g), water (1 L), and EtOAc (1 L) at 5° C. was then transferred the crude reaction mixture over 30 min while maintaining a temperature between 0 and 15° C. The flask containing the crude mixture was then rinsed with EtOAc (200 mL). After agitating for 10 min, the layers were separated and the organic layer was sequentially washed with 12.5% aq. citric acid (800 mL), 10% aq. citric acid (700 mL) and 8% aq. citric acid solution (600 mL). To a mixture of the organic layer and water (300 mL) at 5° C., was charged trifluoroacetic acid (30 mL) over 10 min while maintaining a temperature between 5 and 15° C. After completing the addition, the mixture was warmed to 25° C. and agitated for 3.5 h. An aqueous solution of KHCO 3 (200 mL, 20%) was charged over 30 min while maintaining a temperature below 20° C., followed by saturated NaCl solution (500 mL) and the layers were separated and split. The aqueous layer was back extracted with EtOAc (250 mL). The EtOAc fraction was washed with saturated NaCl solution (500 mL). Water (35 mL) was charged to the combined organic layers and the solution was concentrated in vacuum to a final volume of 100 mL. MTBE (400 mL) was charged and the mixture was concentrated in vacuum to a final volume of 100 mL. Additional MTBE (400 mL) was charged and the suspension was agitated for 2 h at RT. The resulting slurry was filtered, rinsed with MTBE (200 mL) and XV was obtained in 61% yield (70 g) after drying in vacuum at 45° C. for 12 h. MP 196° C.-198° C. 1 H NMR (400 MHz in CDCl 3 ): δ 9.7 (s, 1 H), 5.5 (s, 1H), 2.7 (m, 1H), 2.6 (m, 1H), 2.4 (m, 2H), 0.9 (s, 9H). 13 CNMR (400 MHz, CDCl 3 ): 192.0, 181.1, 169.7, 97.6, 73.4, 36.5, 31.7, 30.6, 24.6. ES-MS: [M+H + ]calcd for C 11 H 15 NO 4 : 226.10. found: 226.27. Step 3: To a 3-neck 1-L flask equipped with a thermometer and mechanical stirrer were charged Ph 3 PCH 3 Br (122.9 g; 344.1 mmol) and toluene (100 mL). At 10° C., a solution of NaHMDS in toluene (540 mL, 13%) was added slowly to maintain the temperature at 10° C. This slurry was agitated at 10° C. for 1 h and then added slowly to a slurry of XV (50 g, 222 mmol) in toluene (100 mL) at 10° C., over a period of 2-4 h via peristaltic pump. After stirring for an additional hour, the batch was quenched into a solution of NaCl (10% aqueous), AcOH (38.5 mL, 666 mmol), and toluene (50 mL) over 30 min at 25° C. The resulting mixture was stirred for 30 min and the layers were settled, split and the lower aqueous layer was removed. The organic layer was then treated with MgCl 2 powder (70 g, 776 mmol) for 2 h at RT. The solids were then filtered off and the solid MgCl 2 -triphenylphosphin oxide complex was washed with MTBE (100 mL). The organic filtrates were combined, washed with aq. NaCl (100 mL, 10%) and concentrated to 100 mL in vacuum. To the resulting slurry was charged heptane (400 mL) and the volume was reduced to 100 mL in vacuum. Additional heptane (400 mL) was added and the volume was reduced to 250 mL in vacuum. A third portion of heptane (400 mL) was added; the batch was then cooled to 0° C. over 2 h and stirred for another 2 h at this temperature. The solids were then removed by filtration and washed with ice-cold N-heptane (200 mL). The wet cake was dried under vacuum at 30° C. for 18 h to produce 62 g of XVI (63% yield) as an off-white solid. Mp 85° C.-87° C. 1 H-NMR (CDCl 3 ) δ 5.98 (m, 1H), 5.31 (m, 3H), 2.56 (m, 1H), 2.17 (m, 3H), 0.81 (s, 9H). ES-MS: [M+H + ]calcd for C 12 H 18 NO 3 : 224.12. found: 224.38. Step 4: To a 500 mL three-necked flask (1) equipped with an agitator, thermometer, and a nitrogen inlet were added XVI (30.0 g, 132 mmol) and THF (300 mL). After cooling mixture to −20° C., lithium tri(t-butoxy)aluminum hydride (1 M THF; 162 mL) was added over 2 h while maintaining the temperature around −20° C. Temperature was then raised to 0° C. over 12 h. The reaction is quenched with the addition of EtOAc (12.0 mL) over 30 min, followed by agitation for 30 min at 0° C., and then slow addition of glacial AcOH (12.0 mL) over 30 min. To another 1-L three-necked flask (2) equipped with an agitator, thermometer, and a nitrogen inlet were added finely ground sodium sulfate decahydrate (30 g, 93 mol) and THF (150 mL) at 0° C. The reaction mixture in flask (1) was slowly transferred to flask (2) containing the sodium sulfate decahydrate solution while maintaining the temperature at 0° C. The temperature of flask (2) was raised over a 1 h period and agitated for 1 h at 20° C. The contents of flask (2) were filtered, the wet cake was washed three times with THF (180 mL, 120 mL, and then 120 mL), and the filtrates were combined and concentrated in vacuum to 60 mL. To a 1000 mL three-necked flask (3) equipped with an agitator, thermometer, and a nitrogen inlet was added water (300 mL). The mixture from flask (2) was cooled to 5° C. and then added to the water with high agitation over a 2 h period, whereupon the product precipitated. The slurry was concentrated in vacuum to 450 mL and the solid was isolated via filtration. The wet cake was dried at 50° C. for 12 h to afford 25.1 g of the compound of formula H as a white/off white solid in 83% yield. Mp 88° C. 1 H-NMR 500 MHz (DMSO-d 6 ) δ 6.92 (d, J=3.9 Hz, 1H), 6.03 (dd, J=15.8, 11.1 Hz, 1H), 5.36 (d, J=3.9 Hz, 1H), 5.24 (d, J=17.6 Hz, 1H), 5.11 (d, J=11.1 Hz, 1H), 4.75 (s, 1H), 2.72 (ddd, J=16.8, 10.2, 8.7 Hz, 1H), 2.28 (ddd, J=16.7, 10.5, 3.7 Hz, 1H), 2.45 (ddd, J=12.8, 10.4, 8.9 Hz, 1H), 1.82 (ddd, J=12.9, 10.5, 3.7 Hz, 1H), 0.85 (s, 9H). 13 C-NMR (125 MHz DMSO-d 6 ) δ 180.7, 142.1, 113.3, 96.2, 93.9, 73.6, 34.5, 33.2, 26.8, 25.9 ppm. LC/MS calculated mass for C 12 H 20 NO 3 [M+H]+(m/z) 226.14377. found 226.14398. EXAMPLE 4 5(R)-[[[I(S)-[[I(R)-[3,5-bis(trifluoromethyl)phenyl]ethoxy]methyl]-I-phenyl-2-propenyl]amino]methyl]-5-ethenyl-2-pyrrolidinone 4-methylbenzenesulfonate hydrate a) To a mixture of II (49.6 g, 0.22 mol) in EtOH (50 mL) and Et 3 N (50 mL) was added water (50 mL) at RT. The resulting mixture was agitated at 25° C. After 4 h, more EtOH (350 mL) was added and the mixture was concentrated in vacuum to 180 mL. b) To a mixture of IVa (100 g, 0.193 mol) in toluene (440 mL) was added at RT aq. NaOH (440 mL, 1 N). The reaction mixture was agitated at RT for 30 min. The aqueous layer was separated and the organic layer was washed twice with 10% NaCl aqueous solution (440 mL). The crude product IV freebase was used without further purification. The crude solution of III in EtOH was then added to the above solution of IV free base in toluene and the resulting mixture was heated to reflux. Water was removed from reaction through azeotropic distillation and more toluene/EtOH (3/2 v/v) were added if necessary based on conversion. After reaction completion, EtOH was removed through solvent-exchange with toluene and the crude solution of V in toluene (530 mL) was slowly added to a mixture of NaBH(OAc) 3 (57.3 g, 0.27 mol) and AcOH (15.5 mL, 0.27 mol) in toluene (270 mL) at RT. The reaction mixture was agitated at RT for about 6 h, and then water (440 mL) was slowly added and the resulting mixture was agitated at RT for 1 h. The aqueous layer was separated and the organic layer was washed once with 5% NaHCO 3 aqueous solution (440 mL) and twice with 10% NaCl aqueous solution (440 mL) to obtain a solution of VI. Solvent was exchanged to isopropanol through vacuum distillation. c) To the crude free base solution of VI in isopropanol (200 mL) was added at RT a solution of p-toluenesulfonic acid (40.4 g, 0.212 mol) in isopropanol (270 mL) followed by water (440 mL). The mixture was seeded with approximately 0.5 g of crystalline VIa and agitated at RT for 1 h before addition of more water (880 mL). After agitation for 8 h at RT, the crystals were collected by filtration, washed with isopropanol/water, water and heptanes, and dried to give VIa as a white crystalline powder (122 g, yield 88% based on V). Mp 80.2-93.4° C. 1 H NMR (CDCl 3 , 400 MHz) δ 9.52 (bs, 1H), 8.80 (bs, 1H), 8.33 (s, 1H), 7.74 (d, J=8.1 Hz, 2H), 7.73 (s, 1H), 7.55 (s, 2H), 7.52-7.50 (m, 2H), 7.37-7.29 (m, 3H), 7.16 (d, J=8.0 Hz, 2H), 6.22 (dd, J=17.5, 11.1 Hz, 1H), 5.90 (dd, J=17.2, 10.6 Hz, 1H), 5.56 (d, J=11.0 Hz, 1H), 5.34 (d, J=17.1 Hz, 1H), 5.25 (d, J=17.5 Hz, 1H), 5.23 (d, J=10.6 Hz, 1H), 4.79 (q, J=6.3 Hz, 1H), 4.35 (d, J=10.5 Hz, 1H), 3.83 (d, J=10.4 Hz, 1H), 3.35-3.18 (m, 2H), 2.35 (s, 3H), 2.35-2.15 (m, 3H), 2.00-1.91 (m, 1H), 1.39 (d, J=6.4 Hz, 3H). EXAMPLE 5 (5R,8S)-8-[1-(R)-(3,5-Bis-trifluoromethyl-phenyl)-ethoxymethyl]-8-phenyl-1,7-diaza-spiro[4.5]dec-9-en-2-one, hydrochloride A solution of 130.0 g (181.4 mmol) of VIa (VI p-toluenesulfonic acid (TsOH) monohydrate) and 51.7 g (272.1 mmol) of toluenesulfonic acid in toluene (3.25 L) was distilled under reduced pressure (60-80 mm Hg) at 50° C. to a final volume of 1.95 L. Upon completion of the distillation, the toluene solution containing VIa and toluenesulfonic acid was evacuated to ˜80 mm Hg and then purged with N 2 via a submersed needle. This sparging process was repeated two times. In a second reactor, 1.14 g (1.8 mmol) of Hoveyda-Grubbs' Second Generation Catalyst (HG-II), having the structure was dissolved in anhydrous, degassed toluene (650 mL, prepared in a manner identical to the above toluene solution). This catalyst solution was slowly charged to the first reactor over 30 min at between 60 to 80° C. The reaction mixture was stirred at the same temperature range for 4 h and the conversion is monitored by HPLC. Upon completion of the reaction, a 16% solution of aq. Na 2 S 2 O 5 (650 mL) was added to the reactor over 30 min and stirred at 60 to 80° C. for 3 h, after which the mixture was cooled to 25° C. and an aq. 0.5 N NaHCO 3 solution was added (650 mL). The biphasic mixture was then stirred at 25° C. for 1 h, allowed to settle and the lower aqueous layers and interface were removed. The organic phase was washed with 0.5 N aq. NaHCO 3 (1.3 L), then 10% aq. NaCl (1.3 L) and finally water (1.3 L). The organic phase was filtered through a pad of celite and to the filtrate was charged 12 N aq. HCl (14.4 mL). The toluene/H 2 O was concentrated to below 390 mL under vacuum (50-60 mm Hg) at a temperature above 50° C. The resulting solution was cooled to 45° C. and seeded with Vila in heptanes (65 mL). After 30 min of stirring at 45° C., the reaction mixture was cooled from 45° C. to 20° C. over 6 h. Then heptanes (1.82 L) were charged to the reaction mixture at 20° C. over 3 h. The solid precipitate was filtered and washed with heptanes (520 mL). The wet cake was dried at 25° C. for 4 h then 65° C. in a vacuum oven overnight to afford 83 g of Vila (85% yield) as a grayish-to of-white colored solid. In addition, the aqueous layers can be combined and filtered to recover the Ru-salts. Mp 190-195° C. 1 H NMR (400 MHz, CDCl 3 ) δ 10.58 (bs, 1H), 10.21 (bs, 1H), 8.25 (s, 1H), 7.70 (s, 1H), 7.58-7.43 (m, 7H), 6.16 (d, J=11, 1H), 6.05 (d, J=11, 1H), 4.65 (q, J=6 Hz, 1H), 4.23 (d, J=9.4 Hz, 1H), 3.81 (d, J=13.6 Hz, 1H), 3.73 (d, J=9.5 Hz, 1H), 2.99 (app. t, J=11 Hz, 1H), 2.48-2.40 (m, 2H), 2.06-1.94 (m, 2H), 1.43 (d, J=6.4 Hz, 1H); 13 C NMR (100.6 MHz, CDCl 3 ) δ 176.7, 145.8, 135.1, 132.5, 132.4, 132.0, 130.0, 129.7, 127.5, 127.0, 126.5, 124.8, 122.1, 122.0, 122.0, 78.4, 73.1, 63.5, 55.9, 50.0, 32.2, 29.6, 24.3 ppm. ES-MS: [M+H + ] calcd for C 25 H 25 F 6 N 2 O 2 : 499.18. found: 499.05. EXAMPLE 5a Reduction of Metathesis Catalyst in the Presence of a PTC Example 5 was repeated as described above until HPLC indicated complete conversion of the compound of Formula VIa to the compound of Formula VIIIa. Upon completion of the reaction, a 16% solution of aq. Na 2 S 2 O 5 (650 mL) was added to the reactor over 30 min along with 2.5 g of tetra-n-butyl-ammonium chloride. The mixture was stirred for 0.7 hours maintaining the reaction mixture at a temperature between 60° C. and 80° C., after which the mixture was cooled to 25° C. and an aq. 0.5 N NaHCO 3 solution was added (650 mL). The biphasic mixture was then stirred at 25° C. for 1 h, allowed to settle and the lower aqueous layers and interface were removed, and the reaction mixture worked up as described in Example 5. The results were the same, demonstrating the advantage provided by the use of a PTC in reducing the metathesis catalyst via the process of Scheme 4 described herein above. EXAMPLE 6 (5S,8S)-8-[1-(R)-(3,5-Bis-trifluoromethyl-phenyl)-ethoxymethyl]-8-phenyl-1,7-diaza-spiro[4.5]decan-2-one hydrochloride hydrate To a mixture of Vila (100 g, 0.187 mol) in toluene (600 mL) was charged aqueous NaOH (5%, 300 mL). After agitating the mixture for 15 min, the organic layer was separated and washed with brine (10%, 2×500 mL). The organic layer was then subjected to hydrogenation with Pd/C (10 g, 10% in carbon 50% wet) and Nuchar-Aquaquard (50 g) under 60 to 80 psi pressure for 4 to 8 h or until reaction completion. The reaction was filtered through a pad of celite. The celite was washed with toluene (100 mL). The combined toluene solution was concentrated to 500 mL. A solution of aqueous HCl (˜35%, 20 ml, ˜1.3 eq) was slowly added into the reaction solution and the mixture was slowly cooled down to 0° C. The product was collected by filtration and washed with a solution of toluene and MTBE (1:1). The wet cake was dried at 40 to 45° C. to give 95 g of VIII (95% yield) as a white to off-white solid. Mp152-154° C. 1 H NMR (400 MHz in DMSO-d 6 ): δ 10.62 (dd, J=10, 12 Hz, 1H, N—H), 9.62 (d, J=12 Hz, 1H, N—H), 7.92 (br, NH), 7.92 (s, 2H), 7.66 (s, 1H), 7.58 (d, J=7.5 Hz, 2H), 7.44 (m, 2H), 7.40 (m, 1H), 4.65 (q, J=6.4 Hz, 1H), 4.30 (d, J=10 Hz, 1H), 3.36 (d, J=10 Hz, 1H), 3.22 (d, J=13 Hz, 1H), 2.88 (dd, J=13, 10 Hz, 1H), 2.49 (md, J=14.5 Hz, 1H), 2.19 (md, J=14.5 Hz, 1H), 2.15 (m, 1H), 2.24 (m, 1H), 1.88 (m, 1H), 1.67 (m, 1H), 1.41 (d, J=6.4 Hz, 3H), 1.79 (md, J=13.5 Hz, 1H), 1.39 (md, J=13.5 Hz, 1H); 13 C NMR (100 MHz, DMSO): δ 175.3, 146.6, 134.7, 130.1 (2) ( 2 J CF =33 Hz), 128.5 (2), 128.0, 126.4 (2), 126.3 (2) ( 3 J CF =2.6 Hz), 120.9 ( 3 J CF =3.7 Hz), 119.9 (2) (J CF =273 Hz), 75.8, 73.2, 63.1, 55.6, 48.9, 31.2, 30.8, 28.8, 24.8, 23.1. EXAMPLE 7 (5S,8S)-8-(1-(R)-[3,5-Bis(trifluoromethyl)phenyl]ethoxy)methyl)-8-phenyl-1,7-diazaspiro[4.5]decan-2-one hydrochloride monohydrate Method 1: VIII (20 g) was suspended in 155.0 g of an EtOH-isopropanol-water-HCl stock solution (stock solution preparation: 168.6 g absolute EtOH, 368.7 g water, 11.6 g of isopropanol, 1.6 g of 37% HCl) and heated to reflux (78-79° C.) until a clear solution was obtained. The mixture was then cooled slowly to a temperature between 72 and 73° C. and optionally, seeded with 0.4 g of micronized Ia suspended in 20 ml of the stock solution. The amount of seed used can be varied between 0.0 and 2.0 g to effect changes in the particle size distribution (PSD) of the product. The batch was further cooled to 0° C. at a rate of 0.5° C./min, filtered under vacuum and washed with 40 mL of stock solution. Finally, the batch was dried under vacuum at a temperature of 40° C. for at least 18 h to give 18.7 g (91.2%) of Ia as white solid. Method 2: Thirty grams of VIII was suspended in 231-232 g of a 40:60% by volume EtOH-water stock solution (stock solution preparation: 400 mL EtOH (95% EtOH, 5% MeOH), 600 mL water) and heated to reflux (78-79° C.) until a clear solution was obtained. The mixture was then cooled slowly to a temperature between 67.5 and 68.5° C. and seeded with 1.5 g of micronized Ia suspended in 30 mL of the stock solution. The amount of seed used can be varied between 0.0 and 3.0 g to effect changes in the PSD of the product. The batch was further cooled to 0° C. at a rate of 0.5° C./min and an additional 35 g of water was added to improve yield. The batch was filtered under vacuum and washed with 60 mL of a 35:65 by volume EtOH:water solution. Finally, the batch was dried under vacuum at a temperature of 40° C. for at least 18 h to produce 28.2-28.9 g (89.6-91.8%) of 1a. Method 3: VIII (11.6 g) was dissolved at RT in EtOH (47 mL). To the solution, water (186 mL) was added over about 35 min and the temperature of the suspension was maintained at 25° C. The resulting suspension was cooled to 0° C. to improve yield and agitated for 30 min. The batch was then filtered under vacuum and washed with 25 mL of a 20:80 by volume EtOH:water solution. Finally, the batch was dried under vacuum at a temperature of 40° C. for at least 18 h. Yield: 9.7 g (83.6%). Method 4: VIII (22.9 g) was dissolved at RT in EtOH (76 mL). The solution was then filtered and added over about 25 min to water (366.8 g). The resulting suspension was cooled to 0° C. to improve yield and agitated for 30 min. The batch was then filtered under vacuum and washed with 70 mL of a 20:80 by volume EtOH:water solution. Finally, the batch was dried under vacuum at a temperature of 40° C. for at least 18 h. Yield: 20.4 g (89.1%). Method 5: VIII (16.4 g) was suspended at 25° C. in toluene (115 mL). 50 mL of a 1N NaOH solution was added to the suspension and the batch was agitated for 30-60 min. The batch was then allowed to split for about 30 min and the aqueous bottom layer was removed. To the organic layer, 2.82 g of 37% HCl was added to form and precipitate Ia, the monohydrate hydrochloride salt. The batch was stirred for 30 min and then filtered under vacuum and washed with toluene (32 mL). Finally, the batch was dried under vacuum at a temperature of 40° C. for at least 18 h to afford 12.4 g (75.6%) of Ia. Using similar procedures, isomers Ib to Ih were prepared. The physical data for the compounds is as follows: Formula Ib (S,R,R): Isolated as a pale brown oil after column chromatography. 1 H NMR (400 MHz in DMSO-d 6 ): δ 10.23 (dd, J=10, 12 Hz, 1 H, N—H), 9.68 (d, J=12 Hz, 1H, N—H), 7.93 (s, 1H), 7.75 (s, 2H), 7.61 (d, J=7.5 Hz, 2H), 7.42 (m, 2H), 7.35 (m, 1H), 4.53 (q, J=6.4 Hz, 1H), 3.82 (d, J=10 Hz, 1H), 3.67 (d, J=10 Hz, 1H), 3.00 (d, J=13 Hz, 1H), 2.65 (dd, J=13, 10 Hz, 1H), 2.46 (md, 2H), 2.15 (m, 1H), 2.24 (m, 1H), 1.81 (m, 1H), 1.14 (d, J=6.4 Hz, 3H), 1.53 (md, J=13.5 Hz, 1H), 1.62 (md, J=13.5 Hz, 1H); 13 C NMR (100 Mhz, DMSO): δ 175.9, 147.1, 134.9, 130.4 (2) ( 2 J CF =33 Hz), 130.0 (2), 128.5, 127.0 (2), 125.0 (2) ( 3 J CF =2.6 Hz), 122.3 ( 3 J CF =3.7 Hz), 121.3 (2) (J CF =273 Hz), 76.5, 73.7, 62.9, 56.0, 47.5, 31.1, 30.9, 29.4, 25.6, 22.8. MS. Calculated for C 25 H 26 F 6 N 2 O 2 .HCl.H 2 O, (M+H) + 500.47 (m/z): 500.19. Formula Ic (R,S,R): Isolated as an off-white solid from diethyl ether. 1 H NMR (400 MHz in DMSO-d 6 ): δ 7.95 (d, J=12 Hz, 1H, N—H), 7.79 (d, J=7.5 Hz, 2H), 7.52 (md, 2H), 7.43 (d, J=7.5 Hz, 1H), 7.32 (m, 2H), 7.21 (m, 1H), 4.55 (q, J=6.4 Hz, 1H), 3.28 (d, J=10 Hz, 1H), 3.11 (d, J=10 Hz, 1H), 2.50 (d, J=13 Hz, 1H), 2.40 (d, J=13, 1H), 2.22 (md, 2H), 2.18 (m, 2H), 1.76 (m, 2H), 1.30 (d, J=6.4 Hz, 3H), 1.45 (md, J=13.5 Hz, 2H); 13 C NMR (100 Mhz, DMSO): δ 175.9, 147.9, 142.2, 130.6 (2) ( 2 J CF =33 Hz), 129.8 (2), 128.4, 127.5 (2), 126.6 (2) ( 3 J CF =2.6 Hz), 125.0, 122.3, 121.2 (2), 78.4, 76.4, 58.4, 57.4, 50.4, 33.3, 29.8, 27.9, 23.6. MS. Calculated for C 25 H 26 F 6 N 2 O 2 .HCl.H 2 O, (M+H) + 500.47 (m/z): 500.18. Formula Id (R,R,R): Isolated after purification by column chromatography, via trituration in 1:2 diethyl ether/heptane as an off white solid. 1 H NMR (400 MHz in DMSO-d 6 ): δ 9.71 (dd, J=10, 12 Hz, 1H, N—H), 8.92 (d, J=12 Hz, 1H, N—H), 8.51 (br, NH), 7.99 (s, 1H), 7.88 (s, 2H), 7.66 (d, J=7.5 Hz, 2H), 7.52 (m, 2H), 7.48 (m, 1H), 4.61 (q, J=6.4 Hz, 1H), 4.03 (d, J=10 Hz, 1H), 3.78 (d, J=10 Hz, 1H), 3.22 (d, J=13 Hz, 1H), 2.88 (m, J=13, 10 Hz, 1H), 2.49 (md, J=14.5 Hz, 1H), 2.19 (md, J=14.5 Hz, 1H), 2.25 (m, 3H), 1.90 (m, 2H), 1.87 (md, 1H), 1.72 (md, J=13.5 Hz, 1H), 1.28 (d, J=6.5 Hz, 3H); 13 C NMR (100 Mhz, DMSO-d 6 ): δ 173.6, 147.0, 135.4, 130.2 (2) ( 2 J CF =33 Hz), 129.0, 128.6, 127.8 (2), 127.0, 126.3 (2) ( 3 J CF =2.6 Hz), 120.9, 122.3, 121.4, 119.6, 76.6, 73.3, 63.4, 52.9, 49.1, 31.5, 29.2, 24.9, 22.6. MS. Calculated for C 25 H 26 F 6 N 2 O 2 .HCl.H 2 O, (M+H) + 500.47 (m/z): 500.34 Formula Ie (S,S,S) Isolated as a fine white HCl salt by triturating in diethyl ether at 10° C. for 3 hours after column chromatography. 1 H NMR (400 MHz in DMSO-d 6 ): δ 10.58 (dd, J=10, 12 Hz, 1H, N—H), 76 (d, J=12 Hz, 1H, N—H), 8.57 (s, 1H), 8.11 (s, 1H), 7.89 (d, J=12 Hz, 2H), 7.61 (d, J=10 Hz, 2H), 7.55 (m, 3H), 4.66 (q, J=6.4 Hz, 1H), 4.09 (d, J=10 Hz, 1H), 3.83 (d, J=10 Hz, 1H), 3.27 (d, J=13 Hz, 1H), 2.65 (dd, J=13, 10 Hz, 1H), 2.35 (md, 2H), 2.29 (m, 1H), 1.97 (m, 1H), 1.32 (d, J=6.4 Hz, 3H), 1.58 (dd, J=13.5 Hz, 9 Hz, 1H), 1.78 (md, J=13.5 Hz, 1H); 13 C NMR (100 MHz, DMSO-d 6 ): δ 175.7, 147.0, 134.9, 130.4 (2) ( 2 J CF =33 Hz), 130.0 (2), 128.5, 127.0 (2), 126.9 (2) ( 3 J CF =2.6 Hz), 122.3 ( 3 J CF =3.7 Hz), 121.4 (2) (J CF =273 Hz), 76.6, 73.7, 63.1, 56.0, 47.8, 31.6, 31.1, 29.2, 25.9, 22.9. MS. Calculated for C 26 H 26 F 6 N 2 O 2 .HCl.H 2 O, (M+H) + 500.47 (m/z): 500.4 Formula If (S,R,S): After purification by column chromatography, isolated as an off-white HCl salt from diethyl ether. 1 H NMR (400 MHz in DMSO-d 6 ): δ 10.30 (dd, J=10, 12 Hz, 1H, N—H), 9.81 (d, J=12 Hz, 1H, N—H), 8.11 (s, 1H), 7.86 (s, 1H), 7.58 (m, 4H), 7.46 (m, 4H), 4.84 (q, J=6.4 Hz, 1H), 4.28 (d, J=13 Hz, 1H), 3.59 (s, 1H), 3.52 (d, J=10 Hz, 1H), 3.36 (d, J=10 Hz, 1H), 3.01 (d, J=13 Hz, 1H), 2.72 (dd, J=13, 10 Hz, 1H), 2.43 (md, 2H), 2.08 (m, 2H), 1.57 (d, J=6.4 Hz, 3H), 1.85 (md, J=13.5 Hz, 1H), 1.72 (md, J=13.5 Hz, 1H); 13 C NMR (100 Mhz, DMSO-d 6 ): δ 175.7, 147.1, 134.6, 130.7 (2) ( 2 J CF =33 Hz), 130.3 (2), 128.9, 128.4 (2), 126.8 (2) ( 3 J CF =2.6 Hz), 122.3 ( 3 J CF =3.7 Hz), 121.3 (2) (J CF =273 Hz), 76.2, 73.7, 66.9, 49.3, 43.8, 31.1, 31.6, 29.2, 25.2, 23.5. MS. Calculated for C 25 H 26 F 6 N 2 O 2 .HCl.H 2 O, (M+H) + 500.47 (m/z): 500.3 Formula Ig (R,S,S) Isolated as an off-white HCl salt triturated in diethyl ether at 5° C. for 12 hours after purification by column chromatography. 1 H NMR (400 MHz in DMSO-d 6 ): δ 10.00 (dd, J=10, 12 Hz, 1H, N—H), 9.64 (d, J=12 Hz, 1H, N—H), 7.94 (s, 1H), 7.78 (s, 2H), 7.63 (d, J=7.5 Hz, 2H), 7.41 (m, 2H), 7.37 (m, 1H), 4.55 (q, J=6.4 Hz, 1H), 3.82 (d, J=10 Hz, 1H), 3.69 (d, J=10 Hz, 1H), 3.10 (d, J=13 Hz, 1H), 2.76 (dd, J=13, 10 Hz, 1H), 2.20 (md, 2H), 2.15 (m, 1H), 1.94 (m, 1H), 1.83 (m, 1H), 1.14 (d, J=6.4 Hz, 3H), 2.44 (md, J=13.5 Hz, 2H); 13 C NMR (100 Mhz, DMSO-d 6 ): δ 175.8, 147.1, 134.9, 130.2 (2) ( 2 J CF =33 Hz), 129.0 (2), 127.8, 127.0 (2), 125.0 (2) ( 3 J CF =2.6 Hz), 122.3 ( 3 J CF =3.7 Hz), 121.3 (2) (J CF =273 Hz), 76.5, 73.7, 62.9, 56.0, 47.5, 31.1, 30.9, 29.4, 25.7, 22.8. MS. Calculated for C 25 H 26 F 6 N 2 O 2 .HCl.H 2 O, (M+H) + 500.47 (m/z): 500.33 Formula Ih (R,R,S): Isolated as the HCl salt by trituration in diethyl ether at 5° C. for 3 hours after purification by column chromatography. 1 H NMR (400 MHz in DMSO-d 6 ): δ 9.56 (dd, J=10, 12 Hz, 1H, N—H), 9.42 (d, J=12 Hz, 1H, N—H), 7.97 (s, 1H), 7.97 (s, 1H), 7.52 (s, 2H), 7.46 (d, J=7.5 Hz, 2H), 7.41 (m, 2H), 7.35 (m, 1H), 4.60 (q, J=6.4 Hz, 1H), 4.20 (d, J=10 Hz, 1H), 3.59 (s, J=10 Hz, 1H), 3.16 (d, J=13 Hz, 1H), 2.87 (dd, J=13, 10 Hz, 1H), 2.19 (md, 2H), 2.12 (m, 1H), 1.94 (m, 1H), 1.72 (m, 1H), 1.36 (d, J=6.4 Hz, 3H), 1.63 (md, J=13.5 Hz, 1H), 13 C NMR (100 Mhz, DMSO-d 6 ): δ 175.8, 147.1, 131.2, 130.4 ( 2 ) ( 2 J CF =33 Hz), 130.1 (2), 128.5, 126.7 (2), 124.9 (2) ( 3 J CF =2.6 Hz), 122.2 ( 3 J CF =3.7 Hz), 121.3 (2) (J CF =273 Hz), 119.5, 76.3, 73.7, 66.1, 56.1, 47.6, 31.1, 30.9, 26.1, 23.8. MS. Calculated for C 25 H 26 F 6 N 2 O 2 .HCl.H 2 O, (M+H) + 500.47 (m/z): 500.3 The above description of the invention is intended to be illustrative and not limiting. Various changes or modifications in the embodiments described herein may occur to those skilled in the art. These changes can be made without departing from the scope or spirit of the invention

This application discloses a novel process to synthesize 8-[{1-(3,5-Bis-(trifluoromethyl)phenyl)-ethoxy}-methyl]-8-phenyl-1,7-diaza-spiro[4.5]decan-2-one compounds, which may be used, for example, as NK-1 inhibitor compounds in pharmaceutical preparations, intermediates useful in said process, and processes for preparing said intermediates; also disclosed is a process for removal of metals from N-heterocyclic carbine metal complexes.

BACKGROUND OF THE INVENTION There is currently a large amount of attention being paid to the use of additive materials in cement in order to maintain or increase the strength of the cement while reducing the overall energy required to produce the material. In practice, a number of natural and manufactured materials are added to clinker in order to reduce the need for clinker minerals in the cement. These materials include limestone, waste slag from the manufacture of steel and iron, and naturally occurring pozzolan. Disadvantages exist to the use of these materials in practice. Quality concerns limit the introduction of limestone, as limestone naturally provides little to the strength of the finished product. Certain types of slag can be utilized positively for the introduction of strength to cement, but as a waste product of the manufacture of other compounds, the slag often does not have a consistent chemistry. Slags can also contain large amounts of free iron, which can cause premature wear of grinding elements used in the manufacture of cement. Pozzolan provides positive strength development in finished cement, but as a naturally occurring material, is not generally available in locations where the primary raw materials used in the manufacture of cement are mined. In recent years, a number of processes have gained prominence in the production of artificial pozzolan from the calcining of clay. The manufacture of artificial pozzolan requires lower temperatures and less energy than the production of cement clinker, and is therefore gaining importance among cement manufacturers for its lower cost of production, as well as the positive effects of producing lower emissions (particularly CO 2 ). In practice, however, while the chemistry may be consistent with a positive effect on strength development, the production of these artificial pozzolans may create materials which are colored differently than the clinker used in the manufacture of cement. This is problematic where the color of the finished product is an important concern, such as when multiple sources of cement may be used for a single project. These issues with the coloration of the final product serve to limit the introduction of these synthetic pozzolans in the production of cement. Therefore, it is an object of the present invention to provide a method for producing synthetic pozzolan having desired color characteristics, and in particular having a light grey color that many cement producers find desirable. BRIEF DESCRIPTION OF THE INVENTION The above and other objects are achieved by the process of the present invention according to which the coloration of the artificial pozzolan produced may be controlled as desired. Having a synthetic pozzolan product with desirable color characteristics will enable the end user to introduce higher amounts of pozzolan into the finished cement, thus resulting in a higher quality product produced utilizing lower fuel consumption than other cement producing systems. The invention broadly comprises breaking apart a raw clay material, preferably a kaolinic clay, to a small feed size, calcining the clay to a product pozzolan, and then by affecting the oxidation state of the color-producing components of the artificial pozzolan product, particularly iron and aluminum, through the creation of localized reducing conditions as the pozzolan product cools to a temperature below its color-stabilizing temperature, which color-stabilizing temperature is determined by the amount and identity of color-producing components in the raw materials and therefore in the resulting synthetic pozzolan. More specifically, wet kaolinic raw feed materials including clay are fed to a device for sufficient material drying and disagglomeration/crushing of larger material (a “drier crusher”). The product from the drier crusher is collected in a cyclone, and directed to a calciner. Fuel is fed to the calciner to maintain an exit temperature from the calciner that will provide sufficient dehydration and calcinations of the product. The feed material is calcined at least to a temperature (the “activation temperature”) at which the pozzolanic properties, such as the strength of the end material, are optimized and at which, in effect, the raw kaolinic material is converted to a synthetic pozzolan. This activation temperature will generally range between about 700° C.-900° C., depending upon the properties of the specific kaolinic raw material being utilized. The product from the calciner is collected, such as in a collection cyclone, and the material is fed to a cooler where it is cooled from its activation temperature. The gases from the collector may optionally be used for drying and conveying material through the drier crusher. Reducing conditions are maintained in the cooler for at least a portion, and most preferably the initial portion, of the cooling process. When only a portion of the process of cooling the synthetic pozzolan from its activation temperature to its color-stabilizing temperature is performed under reducing conditions, it is preferred that the balance of the cooling process be performed in an oxygen depleted environment. Pozzolan material fed to the cooler may be treated with a small amount of fuel (preferably oil) to maintain a reducing atmosphere near the material inlet. Further into the cooler, water may be optionally sprayed to assist in cooling of the pozzolan to below its color-stabilizing temperature while maintaining a low oxygen environment. Alternatively, an oxygen depleted gas can be passed through the cooler along with or in place of the water vapor to cool the pozzolan to below its color-stabilizing temperature while maintaining a low oxygen environment. The product from the cooler may then be introduced into one or more optional additional coolers, such as a cyclone cooling system, for further cooling. If the material entering the any additional downstream coolers is at a temperature below its color-stabilizing temperature, a reducing or oxygen-depleted atmosphere will not have to be maintained in such additional cooler. The finally cooled product is thereafter collected. The preheated gases from any additional cooler may be optionally directed to the calciner as hot tertiary air. DESCRIPTION OF THE DRAWINGS The invention is described with reference to the drawings, in which like numerals represent similar elements, and in which: FIG. 1 is a diagram of one embodiment of a calcining system for manufacture of synthetic pozzolan of a suitable coloration, in which a flash calciner is utilized. FIG. 2 is a second embodiment of a system for manufacture of synthetic pozzolan. FIG. 3 is a third embodiment of a system for manufacture of synthetic pozzolan. FIG. 4 is another embodiment of heat exchanger region 100 with three cyclones 25 , 52 , 55 being used as a counter current heat exchanger to capture more heat from the synthetic pozzolan 21 to increase the temperature of the combustion air 23 in duct 26 which subsequently enters flash calciner 13 . FIG. 5 is another embodiment of heat exchanger region 200 with three cyclones 4 , 62 , 65 being used as a counter current heat exchanger to capture more heat from the calciner exhaust gas to increase the temperature of the dried, crushed material in chutes 10 a or 10 b. FIG. 6 is an embodiment of a kiln system for manufacture of synthetic pozzolan of a suitable coloration in which a rotary kiln is used for processing raw clay. DETAILED DESCRIPTION OF THE INVENTION In all the figures, dashed arrows represent the flow of gas, while solid arrows represent the flow of solid material. With reference to FIG. 1 , raw clay material 1 is directed to the drier crusher 2 where the material is crushed to less than 5 mm and preheated and dried from a initial moisture content ranging from about 5% (wt) to about 35% to a moisture content of from about 0.025% to about 2.5% by the hot gas in duct 16 from the calciner cyclone 15 . The dried, crushed material is of a size suitable to be suspended and conveyed in a gas stream through duct 3 to the drier crusher cyclone 4 where it is separated from the gas stream. The gas stream 5 is pulled by an optional ID fan 6 . After the ID fan 6 , any remaining fine dust is removed by dust collector 7 . After the dust collector the gas is pulled by ID fan 8 and exits the system via stack 9 . The fine dust from dust collector 7 is directed either (a) to the calciner 13 via chute 12 a ; (b) to duct 16 via 12 b and thereafter into drier crusher 2 ; or (c) to duct 3 via chute 12 c and thereafter into drier crusher cyclone 4 . Most of the dried, crushed material collected in the drier crusher cyclone 4 is directed to the calciner 13 via chutes 10 a or 10 b . Optionally, a small amount of the dried, crushed material collected in the drier crusher cyclone 4 may be directed to duct 16 for temperature control of the gas in duct 16 . The calciner 13 shown in FIG. 1 is an updraft calciner where the combustion air enters through duct 26 into the lower portion of the calciner. Water vapor and/or oxygen depleted gas and some vaporized fuel from inlet 18 enter the calciner through the riser 28 . Fuel can be directed into the calciner 13 or the duct 26 leading to the calciner through a single location or multiple locations 19 a , 19 b , 19 c and 19 d . The number of fuel locations and the proportion of the fuel depend upon the properties of the fuel and the need to control the combustion in the calciner 13 . Optionally, a stoichiometric excess of fuel may be utilizing in calciner 13 to promote calcination under reducing conditions. The crushed, dried materials can be directed into the calciner 13 through a single location or multiple locations 10 a and 10 b . The split of material in chutes 10 a and 10 b is determined by the de-hydration and activation properties of the raw materials and the split also can be used to help control the combustion of the fuel in the calciner 13 . In the calciner the hydrated moisture will be dried off and the material will be calcined to its activation temperature. The desired activation temperature in the calciner 13 will depend on the chemistry of the feedstock and the associated minerals in the clay feed and will be between 500° C. and 900° C. and most prevalently between about 700° C. and 850° C. Most of the synthetic pozzolan will thereafter become entrained in the gas stream in the calciner 13 and exit via duct 14 . The entrained pozzolan in duct 14 is captured by the calciner cyclone 15 and directed to cooler 20 , which as depicted is a rotary cooler, via chute 17 . A small amount of fuel, between 10 to 40 kcal fuel per kg of synthetic pozzolan, is added to the synthetic pozzolan via inlet 18 and preferably immediately prior to the pozzolan entering cooler 20 . The preferred fuel is fuel oil. The fuel creates local reducing conditions, i.e., an oxygen deleted or low (from about 0% to about 5% by volume) oxygen environment and either CO and/or volatized hydrocarbons, near the synthetic pozzolan during at least the initial part of the cooling process. Downstream from the cooler area in which the small amount of fuel was added, water sprayer 22 is utilized to spray water onto the calcined pozzolan to contribute to cooling the pozzolan below the color-stabilizing temperature of the color producing metals, particularly iron, which generally between about 150° C. and about 600° C., and more typically between about 180° C. and about 400° C., with the actual color-stabilizing temperature depending on the composition of the pozzolan, and specifically the amount of iron content. Since the calcined pozzolan is kept well above 100° C. the calcined pozzolan remains dry. The water vaporizes upon contact with the hot pozzolan. The generated water vapor occupies most of the space inside the cooler 20 , this helps to maintain an oxygen depleted atmosphere (i.e. no more than about 10% oxygen) in that portion of the cooler which retards the oxidation of metals. The water vapor exits the cooler 20 via the riser 28 . A portion of the fuel oil will volatilize and exit the cooler 20 via the riser 28 . In addition some CO produced by burning the fuel and excess water vapor will exit cooler 20 via riser 28 . By preventing the oxidation of iron, in particular, and other metals including aluminum, magnesium, manganese and chromium during the cooling process, the pozzolan is prevented from changing to a reddish or other color and may be fixed as white or light grey. As a supplement or alternative to using water as described above an oxygen depleted gas can be passed through the cooler to cool the pozzolan below the color-stabilizing temperature of the color producing metals. Two possible sources of the oxygen depleted can be the exhaust stream 9 or the gas exiting fan 6 ; however, any oxygen depleted gas can be used. In an optional embodiment, the objects of the invention can be achieved if the clay is calcined into pozzolan under reducing conditions by utilizing a sufficient amount of excess fuel during the calcining process and thereafter continuing to cool to the “color-stabilizing temperature” under reducing and/or oxygen depleted conditions. The term “color-stabilizing temperature” as used herein means the temperature at which the pozzolan can continue cooling, such as in ambient air, without significant oxidation of the primary color-producing species in the pozzolan taking place. This temperature will vary according to the relative proportion by weight of color-producing species, which is defined as those compounds which go from a white or light grey shade to a red or other color when oxidized, and which constitute primarily iron, but also to a lesser extent aluminum, chromium, manganese, titanium and magnesium, in the cooling pozzolan material. Typically, this temperature will range from about 180° C. to about 400° C. If oxidation of a substantial (i.e. at least 90 wt percent) amount of the primary color-producing species is inhibited while the material is cooled to its color-stabilizing temperature, the final cooled product will typically have a light grey shade. The activation and color stabilization temperatures, as defined herein, for a given sample of material can be determined by one skilled in the art by a number of test procedures. For example, the activation temperature for a given clay sample may be determined by running a furnace test or a thermogravimetric analysis on the sample and the color stabilization temperature may be determined by running thermal studies on the cooling synthetic pozzolan material made from said raw material. As used herein, the term “reducing conditions” or “reducing atmosphere” means that the overall conditions in the cooler (or the calciner) favor reduction of the color-changing species in the pozzolan. As used herein, the term “oxygen depleted” or “oxygen deprived” atmosphere or conditions means that while overall conditions do not promote reduction of the color-changing species in the pozzolan, there is also not sufficient oxygen to promote their oxidation. The synthetic pozzolan exits the cooler 20 via chute 21 and is directed into duct 24 where it is further cooled by air 23 . The entrained synthetic pozzolan is captured by cyclone 25 and leaves the system as the synthetic pozzolan product 27 . The air preheated by the synthetic pozzolan exits cyclone 25 and is directed to the calciner 13 via duct 26 . The temperature of the air in duct 26 will be almost the same as the product 27 . FIG. 2 shows another embodiment of this invention. This embodiment is identical to the embodiment shown in FIG. 1 and described above except that all or most of the water vapor and/or oxygen depleted gas is pulled out of the cooler 20 via duct 40 . This embodiment increases the fuel efficiency of the system since the water vapor and/or oxygen depleted gas is not heated in the calciner 20 . Ambient air 41 is drawn into or injected into duct 40 to lower the dew point temperature and prevent corrosion in the downstream ductwork and dust collector 42 . Any dust captured in the exhaust duct 40 leaves the system as synthetic pozzolan product 45 . The water vapor, oxygen deleted gas, and ambient air is pulled through the dust collector 42 and exits the system via stack 44 . In this embodiment ID fans 43 and 8 are operated in balance with each other so that the gas, primarily water vapor and/or oxygen depleted gas, in a small area in region 29 , (hashed area in FIG. 2 ), is stagnant. The gas in this small area in region 29 will not consistently move either to the calciner 13 or to the cooler 20 . FIG. 3 shows another embodiment of this invention. This embodiment is identical to the embodiment shown in FIG. 2 and described in the previous paragraph, except that that the riser 28 is replaced by hopper 70 and chute 30 . Any material that may build up in the calciner 13 and is cleaned out is conveyed to the cooler via chute 30 . This allows the ID fans 8 and 43 to be operated independently without upsetting conditions in either calciner 13 or cooler 20 thereby allowing all the water vapor, oxygen depleted gas and volatilized fuel to exit cooler 20 via duct 40 . Optional region 100 in FIGS. 1, 2 and 3 shows a single stage (one cyclone), counter current heat exchanger that preheats a portion of the hot gas in duct 26 , which is combustion gas for the calciner, and correspondingly pozzolan product 21 from rotary cooler 20 . This single stage cyclone can be replaced by multiple stages which will increase the heat captured from pozzolan product 21 and raise the temperature of the hot gases in duct 26 to the calciner 13 . As the number of stages increases, the temperature of the gas in duct 26 will increase while the temperature of pozzolan product 21 will decrease. As the number of stages is increased, the heat returned to the calciner is increased and the fuel consumption will decrease. Therefore, the preferable number of cyclones, (if any), will depend upon the temperature of the pozzolan exiting the cooler and the tradeoff between the capital cost of the cyclones versus the operational cost savings. In the embodiment of FIG. 4 , region 100 is modified by the addition of two more cooling cyclones 52 and 54 which serves to cool the synthetic pozzolan 21 and correspondingly heat cooling air 23 . The use of multiple stage cyclones will increase the heat captured from the synthetic pozzolan 21 and raise the temperature of the combustion air 23 in duct 26 which is subsequently used in the calciner 13 . With only a single stage, the synthetic pozzolan product 27 and the air in duct 26 have approximately the same temperature. As the number of stages increases, the temperature of the air in duct 26 will increase—while the temperature of synthetic pozzolan product will decrease. In this embodiment, the synthetic pozzolan exits the cooler 20 (as per FIGS. 1-3 ) via chute 21 and is directed into duct 24 where it is cooled by the air from cyclone 52 . The entrained synthetic pozzolan is captured by cyclone 25 and is directed to duct 51 via chute 50 . The air preheated by the synthetic pozzolan exits cyclone 25 and is directed to the calciner 13 via duct 26 . The synthetic pozzolan in duct 51 is transported to cyclone 52 where it is captured and directed to duct 54 via chute 53 . The synthetic pozzolan in duct 54 is transported to cyclone 55 where it is captured and leaves the system as product 27 . Region 200 in FIGS. 1, 2 and 3 shows a single stage (one cyclone), counter current heat exchanger that preheats a portion of the raw material by inserting it in duct 16 , which is off gas from the calciner, and correspondingly cooling the gas in duct 16 . This single stage cyclone can be replaced by multiple stages which will increase the heat captured from the gas in duct 16 and raise the temperature of the dried, crushed material in chutes 10 a and 10 b . When only a single stage cyclone 4 is utilized, the dried, crushed material in chutes 10 a and 10 b and the gas in duct 5 have approximately the same temperature. As the number of stages increase, the temperature of the gas in duct 5 will decrease, while the temperature of the dried, crushed material in chutes 10 a and 10 b will increase. However, as the number of stages is increased, the drying capacity of the drier crusher will be reduced, while the fuel consumption in the calciner will decrease. Therefore, the preferable number of cyclones will depend upon the moisture content of the raw material and the tradeoff between the capital cost of the cyclones versus the operational cost savings. Per FIG. 5 , raw material 1 is directed to the drier crusher 2 where the material is crushed to its desired sized, preheated and dried by the hot gas in duct 63 coming from cyclone 62 . The dried, crushed material is conveyed in duct 3 to the drier crusher cyclone 4 where it is separated from the gas stream. The gas stream 5 is pulled by an optional ID fan 6 (not shown in FIG. 5 ). The fine dust 12 from dust collector 7 (not shown in FIG. 5 ) is to the duct 61 via chute 12 a or to duct 63 via 12 b and thereafter into drier crusher 2 or to duct 3 via chute 12 c and thereafter into drier crusher cyclone 4 . Most of the dried, crushed material collected in drier crusher cyclone 4 is directed to the duct 61 via chutes 60 a , while some the dried, crushed material collected in drier crusher cyclone 4 may be directed to duct 63 via chute 60 b for temperature control of the gas in duct 63 . The dried, crushed material in duct 61 is transported to cyclone 62 where it is captured and directed to duct 16 via chute 64 . The dried, crushed material in duct 16 is transported to cyclone 64 where it is captured and directed to the calciner 13 via chutes 10 a and 10 b. FIG. 6 depicts an embodiment of the invention in which a rotary kiln is utilized as the calciner rather than the flash calciner depicted in the various embodiments set forth in FIGS. 1-3 herein. When using a rotary kiln as the calciner, the front end of the process, that is, the drying and crushing steps, is essentially similar to what is utilized with a flash calciner. In this regard, the embodiment set forth in FIG. 5 may be utilized with a rotary kiln. According to FIG. 6 , crushed and dried feed material is inserted into rotary kiln 80 via conduit 10 . Fuel is added through inlet 79 and combined with combustion air added via inlet 83 to produce a flame 84 at the end of the kiln opposite where the raw material enters to thereby heat the combustion gases. The material travels through the kiln in countercurrent relation to the heated gases in the kiln and is calcined. Pozzolan exits the kiln via duct 28 and enters rotary cooler 20 . In duct 28 gas from cooler 20 is directed to rotary kiln 80 . As with the flash calciner, the pozzolan is exposed to a low oxygen environment within rotary cooler 20 , due to the introduction of fuel oil, via inlet 18 b , near the material entrance into the cooler 20 . The low oxygen environment within cooler 20 is further promoted by the spraying of water onto the synthetic pozzolan and/or by passing an oxygen depleted gas through the cooler. Optionally, fuel oil may also be inserted behind flame 84 in rotary kiln 80 , via inlet 18 a , to begin exposing the synthetic pozzolan to a low oxygen environment in an area of the kiln in which the temperature experienced by the pozzolan begins to decrease from the maximum temperatures experienced within the kiln. The insertion of fuel oil in the rotary kiln will always be done in concert with maintaining at least a portion of cooler 20 under reducing conditions. In addition, cooler 20 may also provide for the removal of water vapor and oxygen depleted gas through a dust collector in the manner depicted in FIGS. 2 and 3 .

Disclosed is a process for the calcining and manufacturing of synthetic pozzolan with desirable color properties. Feed material is dried, crushed, and preheated in a drier crusher. The dry, crushed material is collected and fed to a calciner where it is heated to become a synthetic pozzolan. The synthetic pozzolan is then fed to a cooler where it is maintained for a least a portion of the cooling step in a reducing atmosphere.

FIELD OF THE INVENTION The present invention relates to digital cellular communication systems, and in particular to digital cellular communication systems facilitating voice communications over the Internet. BACKGROUND OF THE INVENTION In recent years, the popularity of digital cellular communication systems has been phenomenal. Today, digital cellular subscribers number in the millions throughout the world. The growth of the digital cellular market has fuelled research into novel services for use by subscribers, including caller ID, fax messaging, voice mail, call waiting, call forwarding and conference calls. The newest generation of digital cellular communication systems, PCS, introduced a range of features and services surpassing those previously available including include sleep mode, short message service (SMS), increased resistance to eavesdropping, text dispatch service, etc. SMS, which first appeared in the early 1990s in Europe, provides a mechanism for transmitting short messages to and from digital cellular handsets. A Short Message Service Center (SMSC) is used to store and forward short messages to PCS digital cellular handsets. The digital cellular telecommunications network is used to transport the messages between the SMSC and the digital cellular handsets. A digital cellular handset that is active can receive or transmit a short message at any time, regardless of whether a voice or data call is in progress. SMS is characterized by out-of-band packet delivery and low-bandwidth message transfer. At the same time as digital cellular communications have gained in popularity, the Internet itself has grown to be considered as an alternative voice communication tool. In recent years there have been many advancements and developments in the area of Internet telephony, which refers to communication services e.g. voice, facsimile, and/or voice-messaging applications that are transported via the Internet, rather than the Public Switched Telephone Network (PSTN). Telephone subscribers are drawn to Internet telephony as an alternative to traditional forms of communications, especially for long-distance telephone calls, because it offers tremendous cost savings relative to the PSTN. With the use of Internet telephony, subscribers can bypass long-distance carriers and their per-minute usage rates and run their voice traffic over the Internet for a flat monthly Internet access fee. Due to the complexity of both the digital cellular telecommunications systems and the hardware and software requirements of Internet telephony, there are no prior art systems that marry the flexibility of digital cellular communications systems with the cost savings of Internet telephony. Since digital cellular handsets have no fixed location, call set-up, initiation and establishment are particularly difficult to accomplish in the Internet domain. Consequently, a need has developed to provide a system for providing a digital cellular handset that is enabled for Internet telephony. Still further, a need has developed to provide a means for setting up, initiating and establishing a digital cellular telephone call over the Internet. SUMMARY OF THE INVENTION In accordance with one aspect of the present invention, there is provided a digital cellular handset capable of supporting voice communications over the Internet, in addition to the digital cellular handset's usual mode of voice communications over the digital cellular network/public telephony network. In accordance with another aspect of the present invention there is provided the use of the Short Message Service (SMS) with PCS digital cellular communication systems to allow call alerting for call set-up, initiation and establishment. Internet communications facilitated by the present invention are enabled by embedding Internet protocol software within the digital cellular handset device, and by modifying the handset's hardware to accommodate the novel features of the present invention. In operation, a digital cellular handset of the present invention will establish a normal data call through the digital cellular network and into the Internet. The data call will establish a data link between the handset and an Internet-enabled terminating device (such as a computer or Internet phone) on the Internet. Once the Internet enabled terminating device and the digital cellular handset have established a data connection, both units will exchange voice telephony information over the data link. The voice telephony information will be encoded as per one of the emerging Internet voice protocols such as ITU H.323 voice over Internet protocol (International Telecommunication Union Standard H.323: Visual Telephone System and Equipment for Local Area Networks Which Provide a Non-Guaranteed Quality of Service) which will be built into the handset and run on an H.323 Digital Signal Processor (DSP) and H.323 processor device. Other emerging voice over Internet standards may also be employed, such as Session Initiation Protocol (SIP), and Media Gateway Control Protocol (MGCP). Hardware modifications to prior art digital cellular handsets will be required to allow the voice information received over the data link to be used. These include: i. increased DSP resources and memory to run the Internet voice protocol, and, ii. an internal pathway must be set up to allow the Internet information received over the data path to be applied to the audio path after it has been processed by the DSP. In accordance with one embodiment of the present invention, the hardware modifications will make use of existing audio Analog to Digital (A/D) converters, Digital to Analog (D/A) converters, and audio transducers in the handset. The handset must be modified to allow the information received over the data path to be applied to the audio path after it has been processed by the handset's H.323 Digital Signal Processor (DSP) and H.323 processor device. Normally when a data call is made with a digital cellular handset, the data does not interact with the voice path at all but is sent out the data interface on the handset to another device such as a laptop computer. In accordance with the present invention, there is established a normal cellular/PCS data call from a user's digital cellular handset to an Internet Service Provider (ISP) connected to the Internet. From the ISP, the data from the digital cellular handset is then transferred over the Internet in packet form to a far end device, be it an Internet protocol enabled telephone (wireline or digital cellular), or voice enabled computer. The digital cellular handset-to-ISP portion of the data link will typically be local to the user's geographic area and will thus incur no long distance charges. The Internet portion of the data link can connect the user to any geographically distant far end device, limited only by the reach of the Internet. Typically, the Internet portion of the data link will be free of long distance charges and will only incur Internet service provider fees. Once the data link is established end-to-end, the digital cellular handset and the far end device will run well-known Internet voice protocols to translate the data packets so that interactive voice communication can be realized. For example, the data packets transmitted between the user's digital cellular handset and the far end device over the Internet then will be converted into voice signals as per ITU H.323. The data rates of digital cellular and PCS networks in use today (9.6 Kilobits/s to 14.4 Kilobits/s) are sufficient to support the present invention. Of course, persons skilled in the art will recognize that the quality of voice communication will improve as data rates increase, and Internet-inherent delays decrease. Another aspect of this invention is the use of SMS as an alerting mechanism for call set-up and initiation, when the called device has no fixed Internet Protocol (IP) address. A common problem with Internet telephony is that currently there is no mechanism for the calling device to alert the called device of an incoming call, where that device has no fixed IP address. The present invention makes use of the existing SMS to accomplish end-to-end alerting between a digital cellular handset device and an Internet protocol enabled far end device. When a digital cellular handset user wants to establish a voice call over the Internet with an Internet protocol enabled far end device that has no fixed IP address, the present invention provides for the forwarding of an SMS containing an IP address to the far end device to provide call alerting and set-up. The SMS that is sent also contains an embedded Internet protocol call request message for receipt by the far end device. The Internet protocol call request message will instruct the far end device to use the IP address to initiate a voice over Internet protocol session with the calling device (i.e. the digital cellular handset). An Internet call will then be established. In accordance with an aspect of the present invention there is provided a digital cellular handset comprising: an antenna; a radio transceiver connected to said antenna; a radio analog-to-digital converter and a digital-to-analog converter connected to said transceiver; a digital cellular processor/microcontroller connected to said radio analog-to-digital and digital-to-analog converters; an Internet protocol processor/microcontroller connected to said digital cellular processor/microcontroller; an audio analog-to-digital converter and a digital-to-analog converter connected to said Internet protocol processor/microcontroller; and a speaker connected to said audio digital-to-analog converter and a microphone connected to said audio analog-to-digital converter; wherein, in the receive direction the transceiver receives radio signals from said antenna and converts them into analog baseband signals, the radio analog-to-digital converter converts said analog baseband signals into raw data signals, the digital cellular processor/microcontroller processes said raw data signals into a voice over Internet Protocol packetized data stream, the Internet protocol processor/microcontroller unpacketizes said voice over Internet Protocol packetized data stream into a voice data stream, the audio digital-to-analog converter converts said voice data stream into analog waveforms, and the speaker broadcasts said analog waveforms, and, in the transmit direction the microphone receives analog waveforms, the audio analog-to-digital converter converts said analog waveforms into raw data signals, the Internet protocol processor/microcontroller packetizes said raw data signals into a voice over Internet Protocol packetized data stream, the digital cellular processor/microcontroller processes said voice over Internet Protocol packetized data stream into a voice data stream, the radio digital-to-analog converter converts said voice data stream into analog signals, and the transceiver converts the analog signals into a modulated carrier signal which is forwarded to said antenna. In accordance with another aspect of the present invention there is provided a method of digital cellular communications comprising the steps of: receiving radio signals from a digital cellular network; converting said radio signals into raw data signals; processing said raw data signals into a voice over Internet Protocol packetized data stream; unpacketizing said voice over Internet Protocol packetized data stream into a voice data stream; converting said voice data stream into analog waveforms; broadcasting said analog waveforms. Methods and apparatuses for the transmit direction, as well as both transmit and receive directions are also described herein. Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures. BRIEF DESCRIPTION OF THE DRAWINGS Preferred embodiments of the invention will now be described with reference to the attached drawings in which: FIG. 1 is a flow chart of three scenarios for the establishment of digital cellular voice communications over the Internet; FIG. 2 is a schematic diagram of a typical Internet-digital cellular network topology; FIG. 3 is a flowchart of steps showing how SMS is used to establish a digital cellular call over the Internet; FIG. 4A is a schematic diagram of an SMS data packet; FIG. 4B is a schematic diagram of a portion of an SMS packet containing an IP communication request, and an IP address; and, FIG. 5 is a block diagram of an Internet protocol-enabled digital cellular handset. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT All digital cellular systems, including EIA/TIA 553 Analog Mobile Phone System (AMPS), IS-136 Time Division Multiple Access (TDMA) digital system, IS-95A Code Division Multiple Access (CDMA) digital system, J-STD-008 (CDMA) PCS System, J-STD-007 (PCS1900), J-STD-009 (TDMA), Global Standard for Mobiles (GSM) have data transmission capabilities. The present invention uses these data transmission capabilities to facilitate voice communication over the Internet. While the present invention is applicable to any of the PCS and cellular systems set out above, it is unlikely to be implemented in the older AMPS system. This is because the present invention requires digital signal processing resources within a digital cellular handset that an AMPS handset would not normally have. As well, since the AMPS system does not provide for SMS, that aspect of the present invention would not be able to be implemented with AMPS system in any event. AMPS would also require the incorporation of a modem device in order to transmit data. In general, the first step in the establishment of a digital cellular Internet call is the establishment of a digital cellular data call from the calling device to the called device. Once the calling device and the called device have established a data connection, both units will exchange voice telephony information over the data link. The voice telephony information will be encoded as per one of the emerging Internet voice protocol such as ITU H.323 voice over Internet protocol which will be built into both the calling device and the called device. In order for an Internet call to be carried out, the called device and the calling device must exchange IP addresses. Knowledge of the other party's IP address is mandatory for interactive Internet communications. First and foremost, the calling device must have knowledge of the called device's IP address for an Internet call to be initiated. FIG. 1 is a flow chart of three scenarios for the establishment of digital cellular voice communications over the Internet. Scenario 1 is from Internet Wireless Enabled Handset (“IWEH”) to Internet Protocol Enabled Telephone (“IPET”), Scenario 2 is from IPET to IWEH, and Scenario 3 is from a first IWEH (“IWEH 1 ”) to a second IWEH (“IWEH 2 ”). Step 10 is merely indicative of a set-up stage for all three scenarios. Referring to Scenario 1 at step 11 , an Internet-digital cellular call is to be established from an IWEH (the “calling device”) to an IPET (the “called device”). In this situation, IPET is a fixed device having a permanent Internet Protocol (IP) address. At step 12 , IWEH would retrieve the IP address of the called device from its memory. Typically, in an IWEH (such as a PCS1900), a directory of telephone numbers and IP addresses is stored on the Subscriber Identification Module (SIM) of the handset internal memory, or in an external EEPROM. This directory can be searched for the necessary IP address of IPET. Alternatively, an online IP directory address service could be accessed by IWEH to retrieve the IP address of IPET. At step 13 , IWEH will then initiate a data call connection to the Internet through its Internet Service Provider (ISP). At step 14 , using the IP address of IPET, IWEH will be connected to IPET over the Internet. At step 15 , voice communications would commence over the Internet. There is an alternative to Scenario 1 that is not illustrated in FIG. 1 for the situation where the called device has a fixed IP address but where the calling device cannot retrieve that IP address from its memory (either because it is not stored or for some other reason). If the calling device has the called device's e-mail address, the calling device can forward an e-mail to the called device, requesting that the called device initiate communications using Scenario 2, described below. With respect to Scenario 2 at step 21 , an Internet call is to be established from an IPET (the “calling device”) to an IWEH (the “called device”). In this case, IWEH is mobile, and thus has no permanent IP address. Thus at step 22 it is determined that the IP address of IWEH cannot be retrieved. The purpose of the SMS steps of the invention is to facilitate communication where the calling device (such as an IPET) tries to reach a called device (such as an IWEH) that has no permanent IP address. As is explained in further detail with respect to FIG. 3 , at step 23 , IPET will send an SMS containing an IP communication request and its IP address to IWEH, and requesting that IWEH establish a call back to IPET. At step 24 , IWEH receives the SMS and retrieves the IP address of IPET. Once IWEH receives the IP address of IPET, IWEH (the “called device”) connects to the Internet at step 25 . At step 26 , when a connection to the Internet has been established, the IP address of IPET is used to connect IWEH to IPET. At step 15 , voice communications over the Internet are exchanged. With respect to Scenario 3 at step 31 , an Internet call is to be established between two IWEHs, IWEH 1 (the “calling device”) and IWEH 2 (the “called device”). In this case, both devices are mobile, and thus have no permanent IP address (step 32 ). At step 33 , IWEH 1 connects to the Internet through its ISP. At step 34 , IWEH 1 is assigned and receives a temporary IP address from its ISP. Once IWEH 1 receives its temporary IP address, steps 23 et. seq. of Scenario 2 are used to establish a call to IWEH 2 . FIG. 2 is a schematic diagram of a typical Internet-digital cellular network topology. As with FIG. 1 , three scenarios for digital cellular Internet telephony will be discussed: (1) IWEH 1 to IPET, (2) IPET to IWEH 1 , and (3) IWEH 1 to IWEH 2 . A sub-scenario of Scenarios 1 and 2, between IWEH 1 and Internet Protocol Voice Enabled Computer (IPVEC) will also be discussed. As with FIG. 1 , call establishment refers to the establishment of a digital cellular data call from a calling device to a called device. Once the calling device and the called device have established a data connection, both units will exchange voice telephony information over the data link. As a reference, the link path from IWEH 1 50 to standard wireline telephone 52 will first be presented. This is a non-Internet call. When a call is initiated from IWEH 1 50 , a radio link 98 is established with radio tower 56 . A connection is then established between radio tower 56 and digital cellular network 62 over link 101 . A call initiated by IWEH 1 50 and destined for telephone 52 is transmitted across digital cellular network 62 , and to PSTN 64 through link 109 . The call is passed across PSTN 64 and to telephone 52 across local link 111 . In scenario 1, the link path from IWEH 1 50 to IPET 55 is considered. This is an Internet call. In this situation, IPET 55 is an Internet protocol enabled fixed device having a permanent IP address. As such, IWEH 1 50 would know the IP address of IPET 55 , or would have the capability to retrieve it. Using this IP address, IWEH 1 50 establishes a connection to its ISP 60 through links 98 , 101 , 102 and 103 . ISP 60 would then assign a temporary IP address to IWEH 1 50 using the Dynamic Host Configuration Protocol (DHCP) described in RFC-1541 from the IETF. The Internet protocol (such as H.323, SIP or MGCP) used to establish the connection would embed this temporary IP address into the data being transmitted to IPET 55 . IPET 55 will use this temporary IP address to transmit data back to IWEH 1 50 to facilitate interactive communications. Next, using IPET's IP address, ISP 60 will initiate a connection between itself and IPET 55 . The link path for this connection would be across Internet 66 over links 97 and dedicated Internet link 110 . In this case, IPET 55 has a direct connection to the Internet through a router and/or gateway (not shown). Communications emanating from IPET 55 to IWEH 1 50 would follow the reverse path. A sub-scenario of Scenario 1 is a call from IWEH 1 50 to IPVEC 53 . As with IPET 55 , IPVEC 53 is a fixed device with a permanent IP address. In this scenario, IWEH 1 50 would either know the IP address of IPVEC 53 , or would have the capability to retrieve it. With this IP address, IWEH 1 50 establishes a connection to its ISP 60 though links 98 , 101 , 102 and 103 . ISP 60 would then assign a temporary IP address to IWEH 1 50 . Next, using IPVEC's IP address, ISP 60 will initiate a connection between itself and ISP 59 , the ISP providing Internet services to IPVEC 53 . The link path for this connection would be across Internet 66 over links 97 and 106 . Unlike IPET 55 , IPEVC 53 does not have a direct connection to the Internet. As a result, ISP 59 must establish a connection through link 107 , across PSTN 64 , to local link 108 and modem 54 . Modem 54 , which is shown exterior to IPEVC for illustration purposes only, provides the final connection to IPEVC 53 . Of course, persons skilled in the art will appreciate that local link 108 and modem 54 are merely representative of a wide number of interconnections with the Internet, including cable modems and Digital Subscriber Line (DSL) technologies. Communications emanating from IPVEC 53 to IWEH 1 50 would follow the reverse path. In Scenario 2, the link path from IPET 55 to IWEH 1 50 is considered. This is an Internet call. In this situation, while IPET 55 is a fixed device with a permanent IP address, IWEH 1 50 is mobile, and thus has no permanent IP address. The purpose of the SMS steps of the invention is to facilitate communication where the calling device (such as IPET 55 ) tries to reach a called device (such as IWEH 1 50 ) that has no permanent IP address. In the circumstances, it is necessary that an SMS message containing the IP address for IPET 55 be sent to IWEH 1 50 so that a call can be established. For this to be accomplished, IPET 55 connects to the Internet 66 through dedicated Internet link 110 . An appropriate SMS server (not shown) within Internet 66 and working in conjunction with the digital cellular service provider of IWEH 1 50 will be used to send an SMS message to IWEH 1 50 . SMS servers of this type are well known in the art, and are used to enable wireline customers to send SMS message to digital cellular customers. The SMS message, sent across links 123 and 120 to radio tower 56 , will be embedded with the IP address for IPET 55 . Radio tower 56 will transmit the SMS to IWEH 1 50 across radio link 98 using conventional methods. IWEH 1 will store the IP address received in its memory. At this point, IWEH 1 50 is aware of the IP address of IPET 55 , and therefore call establishment between IWEH 50 and IPET 55 will follow the stages set out above in accordance with Scenario 1. With reference to sub-scenario 2, i.e. a call between IPEVC 53 and IWEH 50 , a similar procedure is employed. Once again, while IPEVC 53 is a fixed device with a permanent IP address, IWEH 50 is mobile, and thus has no permanent IP address. Once again, it is necessary that an SMS message containing the IP address for IPET 55 be sent to IWEH 1 50 so that a call can be established. For this to be accomplished, IPEVC 53 connects to the Internet 66 though modem 54 , PSTN 64 and ISP 59 . As above, an appropriate SMS server (not shown) within Internet 66 and working in conjunction with the digital cellular service provider of IWEH 1 50 will be used to send an SMS message to IWEH 1 50 . The SMS message, sent across links 123 and 120 to radio tower 56 , will be embedded with the IP address for IPEVC 53 . Radio tower 56 will transmit the SMS to IWEH 1 50 across radio link 98 using conventional methods, to be described in detail below. IWEH 1 50 will store the IP address received in its memory. At this point, IWEH 1 50 is aware of the IP address of IPEVC 53 , and therefore call establishment between IWEH 1 50 and IPET 55 will follow the stages set out above in accordance with Scenario 1. In scenario 3, the link path for call establishment from IWEH 1 50 to IWEH 2 51 is considered. This is an Internet call. In this situation, neither the calling device nor the called device has a permanent IP address because these are both mobile devices. To establish a call connection, IWEH 1 50 will first contact ISP 60 across links 98 , 101 , 102 , and 103 to obtain a temporary IP address. The temporary IP address will then be returned to IWEH 1 50 over a reverse path. At this point, IWEH 1 50 is aware of its IP address, and therefore call establishment between IWEH 1 50 and IWEH 2 51 will follow similar stages to those set out above in accordance with Scenario 2. In brief, IWEH 1 will forward an SMS message to IWEH 2 containing its IP address. Upon receipt of this SMS message, IWEH 2 will strip off the IP address, and establish a connection across digital cellular network 62 and PSTN 64 to ISP 58 , the ISP that provides it with access to the Internet. ISP 58 would then assign a temporary IP address to IWEH 2 51 . Next, using IWEH 1 's IP address, ISP 58 will initiate a connection between itself and ISP 60 , the ISP providing Internet services to IWEH 1 50 . A final connection will then be established between ISP 60 and IWEH 1 50 . FIG. 3 is a flowchart of steps showing how an SMS message is used to establish a digital cellular call over the Internet under scenario 3. The steps shown in FIG. 3 are similar to those shown in FIG. 1 , but with further detail provided. Step 301 is the initial state, where IP enabled device 1 (be it an IWEH, IPET, or IPEVC), wishes to reach IP enabled device 2 using an Internet digital cellular connection, and where IP enabled device 2 is a mobile device having no fixed IP address. At step 302 , a decision is made as to whether IP enabled device 1 has a fixed IP address. If IP enabled device 1 is an IPET or IPEVC, then the next step is step 305 . If IP enabled device 1 is an IWEH, then at steps 303 and 304 , an Internet connection is made between IP enabled device 1 and its ISP so the device can be assigned a temporary IP address. In this case, IP enabled device 1 (which is an IWEH), will run an application program embedded in its microcontroller to connect to its ISP. When its ISP answers the call from IP enabled device 1 , a data connection will be established with IP enabled device 1 , which will be received through the device's radio input/output device (i.e. antenna), radio transceiver, digital signal processor and microcontroller. The temporary IP address of IP enabled device 1 assigned by the ISP will be transmitted to the device by way of this data connection. At step 305 , the microcontroller (in the case of an IWEH) or microprocessor (in the case of an IPET or IPEVC) of IP enabled device 1 will generate an SMS with an IP communication request, and its IP address embedded therein. The layout of the SMS message to be delivered is shown in FIG. 4 A. The data size of an SMS-DELIVER packet is 140 octets. The definitions of the various parameters contained in an SMS-DELIVER packet are described in Table 1 as follows: TABLE 1 Description of Parameters Contained in SMS-DELIVER Packet Abbreviation Reference Description TP-MTI TP-Message-Type- Parameter describing the Indicator message type TP-MMS TP-More-Messages- Parameter indicating to-Send whether or not there are more messages to send TP-RP TR-Reply-Path Parameter indicating that Reply Path exists TP-UDHI TP-User-Data- Parameter indicating that Header-Indicator the TP-UD field contains a Header TP-SRI TP-Status-Report- Parameter indicating if Indication the (Short Message Entity) SME has requested a status report TP-OA TO-Originating Address of the originating Address SME TP-PID TP-Protocol- Parameter identifying the Identifier above layer protocol, if any TP-DCS TP-Data-Coding- Parameter identifying the Scheme coding scheme within the TP-User-Data TP-SCTS TP-Service- Parameter identifying time Centre-Time-Stamp when the SC received the message TP-UDL TP-User-Data- Parameter indicating the Length length of the TP-User-Data field to follow TP-UD TP-User-Data Parameter containing the user data to be transmitted Any unused bits will be set to zero by the sending entity and will be ignored by the receiving entity. Persons skilled in the art will appreciate that the majority of the above parameters would be set to standard values independent of the IP communication request, and IP address sent by IP enabled device 1 . For the purposes of the present invention, the essential components of the SMS message are as follows: i. TP-UDHI is set to “1” to indicate that the TP-User-Data contains header information that must be acted upon by the SMS recipient's (i.e. IP enabled device 2 ) microcontroller; ii. the first component of the TP-User-Data header contains a type field used to uniquely identify an IP communication request. A suggested type field for this purpose would be “IPCALLRQ”; and, iii. the second component of the TP-User-Data header contains the IP address of IP enabled device 1 . FIG. 4B is a schematic diagram of a portion of an SMS packet containing an IP communication request (IPCALLRQ), and a hypothetical IP address <47.127.80.111> for IP enabled device 1 . The IP communication request and IP address would be embedded in octets 1-140 of TP-UD, as illustrated in FIG. 4 B. Of course, as the Internet evolves, expanded IP addresses, or those of different formats, can be accommodated by the present invention. Referring back to FIG. 3 , at step 306 , the SMS is sent over the digital cellular network to IP enabled device 2 . Persons skilled in the art will be familiar with the network elements and architecture, involved in SMS transfer. These include a Short Message Service Center (SMSC), SMS-Gateway/Interworking Mobile Switching Center (SMS-GMSC), Home Location Register (HLR), Mobile Switching Center (MSC), Visitor Location Register (VLR), and Base Station System (BSS). The details of SMS network elements involvement are not essential to the operation of the invention. At step 307 , IP enabled device 2 receives the SMS containing the IP communication request and IP address of IP enabled device 1 . At steps 308 and 309 , the microcontroller of IP enabled device 2 will recognize the IP communication request in TP-UD, and extract the IP address of IP enabled device 1 from the SMS. At step 310 , the microcontroller of IP enabled device 2 will then initiate a data connection to its ISP for the purpose of enabling Internet communications with IP enabled device 1 with the use of that device's IP Eli address. At step 311 , a connection is made over the Internet to IP enabled device 1 . At step 312 , voice communication is exchanged between IP enabled device 1 and IP enabled device 2 over the Internet. FIG. 5 is a block diagram of an Internet protocol-enabled digital cellular handset. The following description of the present invention will use the PCS1900 (J-STD-0007) digital cellular network as the implementation example, although as noted this invention is applicable to all-digital cellular and PCS networks. As mentioned, this invention is equally applicable to other digital cellular/PCS handsets. As such, the functional block diagrams for the other cellular/PCS handsets would be similar to that of FIG. 5 . FIG. 5 shows a typical PCS1900 handset circuitry block diagram, with the additional components necessary to perform H.323 Internet telephony indicated in doubled line form. It should be noted that the present invention is also applicable to other emerging Internet voice protocols such as SIP and MGCP, and H.323 has been selected for illustration purposes only. In accordance with the present invention, the PCS1900 handset can work in three modes: (1) normal voice mode, (2) normal data mode, and (3) voice over IP mode. In normal voice mode, the user is able to have a voice conversation with another party using the normal voice facilities provided by the digital cellular network. In normal data mode, bi-directional data is provided at an External Data Interface 521 that can be connected to an external device such as a laptop computer. Voice communications are not operational during normal data mode. In voice over IP mode, voice conversation is enabled by providing additional hardware resources to the handset and by performing H.323 protocols on these additional hardware resources. The additional hardware resources consist of an H.323 microcontroller 519 with external random access memory (RAM) 517 and a read only memory (ROM) 518 , an H.323 Digital Signal Processor (DSP) 508 with internal RAM 509 and a ROM 510 , a voice electronic switch 511 , and a data electronic switch 555 . Ports Data Out 533 and Data In 534 connect the PCS1900 microcontroller 520 to the external data interface 521 through data electronic switch 555 . Data electronic switch 555 provides a switched connection 531 between port Data Out 533 and H.323 microcontroller 519 . A switched connection is also provided between port Data In 534 and H.323 microcontroller 519 . In normal data mode, data electronic switch 555 is set so that data from PCS microcontroller 520 is sent to the external data interface 521 . When in normal voice mode, the connection is still made between PCS microcontroller 520 and external data interface 521 , but no data will be supplied to external data interface 521 . When in voice over IP mode, data electronic switch is set so that data out from PCS microcontroller 520 is applied to H.323 microcontroller 519 , and data out from H.323 microcontroller 519 is input to PCs microcontroller 520 . Connections 541 and 542 connect PCS1900 DSP 505 with PCS1900 microcontroller 520 , and likewise connections 535 and 536 connect H.323 DSP 508 with H.323 microcontroller 519 . The H.323 DSP 508 requires internal RAM 509 and ROM 510 since high-speed operation is required. In general, ten nanosecond RAM and ROM is required for H.323 DSP 508 . Less expensive and slower external RAM and ROM (i.e. 90 nanosecond) are sufficient for the H.323 microcontroller 519 . A chart showing the memory requirements of all processing elements of this handset is as shown in Table 2. Table 2 also shows the processing power requirements of each block, given in million instructions per second (MIPS). TABLE 2 RAM/ROM/MIPS Requirements for H.323 Enabled Handset Hardware RAM (Kb) ROM (Kb) MIPS PCS 1900 DSP 505 16 96 60 H.323 DSP 508 36 44 60 PCS 1900 256 512 20 Microcontroller 520 H.323 200 1024 30 Microcontroller 519 In order to implement the present invention, specialized Internet protocol software algorithms must form part of H.323 DSP 508 and H.323 microcontroller 519 . First, the H.323 lower layer protocol stack must be added to the H.323 DSP 508 protocol stack. Second, the higher H.323 layers must be added to the H.323 microcontroller software present in ROM 518 . The software protocols which must be added are: i. ITU-T H.323, Visual telephone systems and equipment for local area networks which provide a non-guaranteed quality of service. This is an umbrella standard which includes the following other standards: ii. ITU-T Recommendation H.225.0 (1996) Media stream packetization and synchronization for visual telephone systems on non-guaranteed quality of service LANs. This is the call control signalling protocol); iii. ITU-T Recommendation H.245 (1996), Control protocol for multimedia communications. This is the communications signalling protocol; iv. CCITT Recommendation G.723.1 (1996), Speech coders: Dual rate speech coder for multimedia communications transmitting at 5.3 and 6.3 kbit/s; and, v. ITU-T Recommendation G.729 (1996) Coding of speech at 8 kbit/s using conjugate structure algebraic code excited linear prediction (CS-ACELP). With reference to FIG. 5 , the operation of the handset in each of the three modes outlined above will now be described. During the Normal Voice Mode, PCS1900 DSP 505 and PCS1900 microcontroller 520 are active, while H.323 DSP 508 and H.323 microcontroller 519 are inactive and placed in a low-power standby state. PCS1900 microcontroller 520 sets signal Switch Control 526 to enable voice electronic switch 511 to select PCS OUT to Audio D/A converter 512 and PCS IN to audio A/D converter 513 . This is the steady-state status of the PCS1900 handset before normal voice communications have been initiated. A stored program in ROM 523 is used to instruct PCS microcontroller 520 when to cause signal Switch Control 526 to switch the states of voice electronic switch 511 and data electronic switch 555 , which will cause the handset to switch between normal voice mode, normal data mode, and voice over IP mode. When voice communications are to be initiated, a PCS1900 radio base station (such as the one illustrated in FIG. 2 ) would transmit radio energy to the handset. The transmitted radio energy would contain digital voice information and control information as per J-STD-007. After call set-up has been negotiated between the handset and the base station via the control channel (as per J-STD-007), the handset would also transmit radio energy towards the base station. Radio energy in each direction is confined to a single 200 kHz channel (one of 300 full duplex channels in the PCS1900 system). The handset transmits on one channel within the band 1850-1910 MHz and the base station transmits simultaneously within the band 1930-1990 MHz. Each channel is further divided into 8 timeslots and the handset would be instructed by the base station to use specific timeslots for both transmitting and receiving. The receive path of radio energy in normal voice mode is as follows. Antenna 501 receives a radio frequency (RF) signal from the base station. The PCS1900 transceiver 502 filters and amplifies the RF signal, and converts it to a baseband signal (typically between 0 to 200 kHz). The baseband signal is converted to digital by the radio A/D converter 503 and thereafter applied to the PCS1900 DSP 505 . PCS1900 DSP 505 performs equalization and demodulation of the baseband signal in order to recover the digital bitstream sent by the base station. Frame alignment, error detection and correction, and demultiplexing of control data, and SMS data (if any) and voice data are also performed. Control messages are assembled into proper layer 3 format and are sent to PCS1900 microcontroller 520 . PCS1900 microcontroller 520 receives the layer 3 messages and performs high-level protocol operations as per J-STD-007. These protocol operations include receiving calls, initiating calls, and controlling the overall operation of the handset. PCS1900 microcontroller 520 , which has its own RAM 522 and ROM 523 , also controls the user interface by receiving input from keypad 524 and sending information to the liquid crystal display (LCD) 525 . The PCS1900 microcontroller 520 also sets the state of the switch control signal 526 , which puts the handset into normal voice mode or voice over IP mode. PCS1900 DSP 505 performs vector sum excited linear predictive coding (VSELP) decoding on the received voice bits. VSELP decoding converts the compressed voice information sent over the radio channel into non-compressed linear voice data. PCS1900 DSP 505 sends linear voice data via signal PCS OUT 537 through voice electronic switch 511 and connection 550 to the audio D/A converter 512 . Audio D/A converter 512 converts the digital information into an analog audio waveform, which is amplified and applied to the handset speaker 514 . The normal voice path is from PCS1900 DSP 505 , through voice electronic switch 511 to the speaker 514 and vice versa. The transmit path of the normal voice mode of the handset is essentially a reverse order process of the receive path. Analog audio waveforms received from handset microphone 515 are amplified, and applied to the Audio A/D converter 513 . The audio A/D converter 513 converts the analog waveforms into linear voice data that are sent through the voice electronic switch 511 to the PCS1900 DSP 505 using signal paths 551 and PCS IN 538 . The PCS1900 DSP 505 performs vector sum excited linear predictive encoding (VSELP) on the information. VSELP encoding converts the non-compressed linear voice data into compressed voice information. The PCS1900 microcontroller 520 sends layer 3 control messages to the PCS1900 DSP 505 as required. PCS1900 DSP 505 converts layer 3 messages into control data bits to be sent over the radio link to the base station. PCS1900 DSP 505 performs multiplexing of control data, SMS data (if any) and voice data into an assembled frame. PCS1900 DSP 505 adds error detection and correction bits to the assembled frame, and performs digital modulation on the information converting it to a digital baseband signal. The baseband signal is converted to an analog baseband signal by radio D/A converter 504 . PCS1900 radio transceiver 502 modulates the analog baseband signal onto a particular radio channel specified by the PCS1900 microcontroller 520 . PCS1900 radio transceiver 502 also amplifies the radio signal to a high power signal (up to 2 watts peak), and applies this signal at the appropriate timeslot onto the antenna 501 . The antenna 501 converts the electrical signal into radio waves which are transmitted to the base station. During the Normal Data Mode, PCS1900 DSP 505 and PCS1900 microcontroller 520 are active, while H.323 DSP 508 and H.323 microcontroller 519 are inactive, and in a low-power standby state. During this state, PCS1900 microcontroller 520 sets signal Switch Control 526 to enable voice electronic switch 511 to select signal path 550 to connect H.323 OUT 539 to audio D/A converter 512 , and signal path 551 to connect H.323 IN 540 to audio A/D converter 513 . H.323 DSP 508 is inactive, and thus no audio is heard through speaker 514 . In operation in this mode, PCS1900 radio base station first transmits radio energy to the handset. The radio energy contains digital data information and control information as per J-STD-007. After the call has been negotiated between the handset and the base station via a control channel (as per J-STD-007), the handset also transmits radio energy towards the base station. Radio energy in each direction is confined to a single 200 kHz channel (one of 300 full duplex channels in the PCS1900 system). The handset transmits on one channel within the band 1850 to 1910 MHz and the base station transmits simultaneously within the band 1930-1990 MHz. Each channel is further divided into eight timeslots and the handset is instructed by the base station to use a certain timeslot for transmitting and receiving. The receive path is as follows. Antenna 501 first receives an RF signal from the base station. PCS1900 transceiver 502 filters and amplifies the RF signal, and then converts the signal to a baseband signal. (For example, radio channel #1 between 1,930.0 MHz and 1,930.2 MHz is converted to a baseband signal from 0 to 200 kHz). The baseband signal is then converted to digital by radio A/D converter 503 and thereafter applied to the PCS1900 DSP 505 . PCS1900 DSP 505 performs equalization and demodulation of the baseband signal in order to recover the digital bitstream sent by the base station. PCS1900 DSP 505 performs frame alignment, error detection and correction, demultiplexing of control data, short message service data (if any) and the data information. PCS1900 DSP 505 assembles control messages into proper layer 3 format and sends these control messages to the PCS1900 microcontroller 520 . PCS1900 microcontroller 520 receives layer 3 messages and performs the PCS1900 high-level protocol operations as per J-STD-007. These protocol operations ID, include receiving calls, initiating calls, and controlling the overall operation of the handset. PCS1900 DSP 505 then sends the raw data information to the PCS1900 microcontroller 520 . The PCS1900 microcontroller 520 performs radio link protocol (RLP) on the received raw data from the PCS1900 DSP 505 . The PCS1900 microcontroller 520 converts the data to asynchronous 9.6 kbit/sec data, and applies this data to the output pin of the external data port Data Out 533 , where it is available to the external data interface 521 . The signal path from PCS1900 DSP 505 through PCS1900 microcontroller and to external data port Data Out 533 and vice versa is the normal data path. The transmit path of the normal data mode is essentially a reverse order process of the receive path. Data is input by an external device to the external data interface 521 which is connected to the PCS1900 microcontroller 520 by way of port Data In 534 . The external device applies data at 9.6 Kbit/sec in an asynchronous format. PCS1900 microcontroller 520 performs radio link protocol (RLP) on the asynchronous data from the external data interface 521 . The RLP essentially converts the data from an asynchronous format to a synchronous format. PCS1900 microcontroller 520 then sends the RLP data information to the PCS1900 DSP 505 . The PCS1900 microcontroller 520 sends layer 3 control messages to the PCS1900 DSP 505 as required. PCS1900 DSP converts layer 3 messages into control data bits to be sent over the radio link to the base station. PCS1900 DSP 505 also performs multiplexing of control data, short message service data (if any) and RLP data into a frame. PCS1900 DSP 505 adds error detection and correction bits to assembled frame, and performs digital modulation on the information converting it to a digital baseband signal. The baseband signal is then converted to an analog baseband signal by the radio D/A converter 504 . PCS1900 radio transceiver 502 modulates the analog baseband signal onto a particular radio channel, which is specified by the PCS1900 microcontroller 520 . PCS1900 radio transceiver 502 amplifies the radio signal to a high power signal (up to 2 watts peak), and applies this signal at the appropriate timeslot onto the antenna 501 . The antenna 501 converts electrical signal into radio waves which are transmitted to the base station. In voice over IP mode, PCS1900 DSP 505 , PCS1900 microcontroller 520 , H.323 DSP 508 and H.323 microcontroller 519 are all active. PCS1900 microcontroller 520 sets signal Switch Control 526 to enable voice electronic switch 511 to select H.323 Out to Audio D/A converter 512 across connection 550 and H.323 In to Audio A/D converter 513 across connection 551 . In operation, the first step is to place all handset circuitry not associated with the H.323 function (i.e. all circuitry other than H.323 DSP 508 , H.323 microcontroller 519 and its RAM 517 and ROM 518 ) into PCS1900 normal data mode as outlined above. Thus 9.6 Kb/sec bi-directional data is available at ports Data Out 533 and Data In 534 . However, the 9.6 Kb/sec asynchronous data will be applied across data electronic switch 555 to the H.323 microcontroller 519 through signal path 531 , rather than the external data interface 521 . Likewise, data from H.323 microcontroller 519 will be applied across data electronic switch 555 to Data In port 534 across signal path 530 . With respect to the Receive Path in voice over IP mode, the operation details given above for the Normal Data Mode, Receive Path will apply. Thus, only the manner of processing the 9.6 Kb/sec asynchronous data will be described. When the H.323 microcontroller 519 receives the 9.6 Kb/sec asynchronous data from the PCS1900 microcontroller 520 , H.323 microcontroller 519 performs processing as per ITU-T H.323. (ITU-T H.323 is the umbrella recommendation which references other standards including H.225.0 and H.245). The 9.6 Kb/sec asynchronous data, which has the format of Internet Protocol packets, is first collected into a RAM buffer in RAM 517 . H.323 microcontroller 519 examines the buffered data to find an Internet Protocol (IP) 20 byte header, followed by the next header after the IP 20 byte header. The header following the IP header is either a UDP (User Datagram Protocol) header which signifies voice information or a TCP (Transmission Control Protocol) header which will signify call control (H.225.0) or system control (H.245) information. H.323 microcontroller 519 then separates received data packets in terms of UDP (voice) header or TCP (call/system control) header into separate buffers in RAM 517 . H.323 microcontroller 519 further separates TCP packets into either H.225.0 packets or H.245 packets, which are placed into separate buffers in RAM 517 . H.323 microcontroller 519 then processes H.225 Call Control packets from the RAM buffer. These packets are used for call control, signalling channels, call set up request, and call alerting. H.323 microcontroller 519 then processes H.245 System Control packets from the RAM buffer. These packets are used to open and close logical channels, exchange capabilities between terminal endpoints, and to describe the contents of the logical channels. H.323 microcontroller 519 then examines the UDP (voice) packets in the RAM buffer and strips off the RTP (Real Time Protocol) header from each packet. The RTP header contains a sequence number and time stamp for each incoming voice packet, and indicates which voice-encoding format is used, either G.723 or G.729. H.323 microcontroller 519 then sends a message to H.323 DSP 508 instructing the DSP which voice-encoding format to use based on the RTP header. The H.323 microcontroller 519 assembles the raw voice packets into a “jitter buffer” in RAM 517 . This process involves examining the RTP header sequence number and placing the voice information into the buffer in the correct order in which it was sent, since packets can be received out of sequence. Also the RTP header time stamp is examined in order to determine if packets are missing. It missing packets are found they are replaced with the previous valid packet. The H.323 microcontroller 519 then reads out the raw voice information from the RAM “jitter buffer” at regular intervals and supplies this to the H.323 DSP 508 . H.323 DSP 508 performs voice decoding on the raw voice information as per G.723 or G.729, converting the voice data to linear format. H.323 DSP 508 also performs echo cancellation on the decoded voice information, and applies the voice data to audio D/A converter 512 via the electronic switch 512 . The resulting analog waveform is amplified and applied to handset speaker 514 . As for the transmit path, analog audio from the microphone 515 is applied to the audio A/D converter 512 , which converts the microphone signal to a digital signal. The digital signal from the audio A/D converter 513 is applied to the H.323 DSP 508 via the voice electronic switch 511 and signal path H.323 IN. H.323 DSP 508 collects voice frame of 30 milliseconds duration, performs voice-encoding as per G.723 or G.729, and sends voice data to H.323 microcontroller 519 . H.323 microcontroller 519 adds an RTP header, UDP header, and IP header to the voice frame received from H.323 DSP 508 . H.323 microcontroller 519 then sends assembled IP packet out over 9.6 Kb/s asynchronous data link to PCS1900 microcontroller 520 at port Data In 534 . H.323 microcontroller 519 then processes any H.225 Call Control packets to be sent. These packets are used for call control, signalling channels, call set up request, and call alerting. H.323 microcontroller 519 also processes any H.245 system control packets to be sent. These packets are used to open and close logical channels, exchange capabilities between terminal endpoints, and to describe the contents of the logical channels. H.323 microcontroller 519 then adds TCP header to any H.225 or H.245 packets, IP header to any TCP packets, and sends the fully assembled IP packets out over 9.6 Kb/s asynchronous data link to PCS1900 microcontroller 520 at port Data In 534 . Once received by PCS1900 microcontroller 520 , the fully assembled IP packets are treated the same as any form of data, and are processed in accordance with the steps described above in accordance with the handset's normal data mode. The above description describes the manner in which voice communication is realized once a voice over IP handset call has been established, be it by way of direct call establishment (i.e. Scenario 1 of FIG. 1 ), or by SMS transfer (Scenarios 2 and 3 of FIG. 1 ). With reference to steps 302 - 310 of FIG. 3 , the following is a description of how the PCS1900 handset illustrated in FIG. 5 uses SMS to establish a call over the Internet. At step 302 , a software program stored in ROM 523 and running on PCS microcontroller 520 will ascertain that it does not have a fixed IP address. Accordingly, the process will proceed to step 303 . At step 303 , an Internet connection is made between the handset and its ISP so the device can be assigned a temporary IP address. First, PCS microcontroller 520 will retrieve the telephone number of its ISP from RAM 522 . This telephone number will have been previously identified as a telephone number for a data call. PCS microcontroller 520 will then store a layer 3 message in RAM 522 requesting data call set-up to the ISP telephone number. PCS microcontroller then sends the layer 3 message to PCS DSP 505 , which will send a data call set-up message to the handset's basestation over a control channel. Upon establishment of the data call, the handset's ISP will return a data call confirmation to the handset. At step 304 , the handset's ISP will assign a temporary IP address to the handset. The handset will switch to normal data mode in order to exchange data with the ISP. Note that any data exchanged with the ISP will not be applied to external data interface 521 , but is consumed by the PCS microcontroller 520 . PCS microcontroller will run Point-to-Point protocol (PPP) over the data channel with the ISP. The ISP will then deliver a temporary IP address to the handset over that data channel. The PCS microcontroller will then store the temporary IP address in RAM 522 . At step 305 , PCS microcontroller 520 will first retrieve the temporary IP address from RAM 522 . PCS microcontroller 520 of IP enabled device 1 (a digital cellular handset, of the same or similar type to IWEH 1 illustrated in FIG. 2 ) will then generate in its RAM buffer an SMS message addressed to IP enabled device 2 (also a digital cellular handset, of the same or similar type as IWEH 2 in FIG. 2 ), also containing its own IP address, and the Internet protocol call request IPCALLRQ embedded therein. At step 306 , PCS microcontroller 520 retrieves the SMS message from its RAM buffer, and then formats it into a layer 3 message (as per J-STD-007) and stores it in RAM 522 . PCS microcontroller sends the layer 3 message to PCS DSP 505 , which is then applied to the radio channel in accordance with the handset's short message service mode (The SMS is sent over the control channel, and this occurs simultaneously with any data or voice channel operation). At step 307 , IP enabled device 2 receives the layer 3 message (representing the incoming SMS message from IP enabled device 1 ). The PCS microcontroller of IP enabled device 2 converts the layer 3 message into an SMS message and stores it in RAM. At step 308 , the PCS microcontroller of IP enabled device 2 reads the Internet protocol call request and the IP address of IP enabled device 1 . The IP address of IP enabled device 1 is stored in the RAM of IP enabled device 2 . At step 309 , IP enabled device 2 repeats steps 303 and 304 for itself (i.e. to establish a data connection with its own ISP so that it can obtain its own temporary IP address from its ISP). At step 310 , IP enabled device 2 has both its own IP address, and the IP address of IP enabled device 1 . Both devices also have live data connections with their ISPs. IP enabled device 2 then switches to voice over IP mode as above. When this occurs, the PCS microcontroller of IP enabled device 2 sends H.225 call control information to IP enabled device 1 causing IP enabled device 1 to switch over to voice over IP mode as above. IP enabled device 1 and IP enabled device 2 then exchange H.225 call control information, which indicates the establishment of a H.323 voice call. As per H.323, IP enabled device 1 and IP enabled device 2 then exchange H.245 control information. At this point, voice communication is established and exchanged. Numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practised otherwise than as specifically described herein. The above description of a preferred embodiment should not be interpreted in any limiting manner since variations and refinements can be made without departing from the spirit of the invention. The scope of the invention is defined by the appended claims and their equivalents.

A digital cellular handset capable of supporting voice communications over the Internet, in addition to the digital cellular handset's usual mode of voice communications over the digital cellular network/public telephony network is disclosed. Internet protocol software such as H.323, Session Initiation Protocol (SIP), and Media Gateway Control Protocol (MGCP) is stored within the digital cellular handset device run on an H.323 Digital Signal Processor (DSP) and H.323 microcontroller to packetize and unpacketize the digital data streams received by or transmitted from the handset. There is also disclosed the use of the Short Message Service (SMS) with PCS digital cellular communication systems to allow call alerting for digital cellular call set-up, initiation and establishment.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a camera and a strobe device, and more particularly, to a camera and a strobe device which can vary a color temperature of an emitted light color of strobe light. [0003] 2. Description of the Related Art [0004] A camera provided with an auto bracketing shooting function has been widely known in which multiple photos are continuously and automatically shot only with one release operation while the exposure value is varied stepwise, with respect to a determined exposure value of the camera, that is, shutter speed and an aperture value. [0005] Japanese Patent Application Laid-Open No. 5-196985 describes a technique capable of quickly and accurately performing the auto bracketing shooting even if the auto bracketing shooting is performed by using a strobe device. [0006] Moreover, among cameras such as digital still cameras, there is also a camera provided with a white balance bracketing shooting function in which a variable parameter for the bracketing shooting is white balance instead of the exposure value. [0007] Japanese Patent Application Laid-Open No. 2001-333432 describes a technique of the white balance bracketing shooting function in which multiple photos can be continuously and automatically shot while the white balance is varied stepwise only with one release operation. [0008] Moreover, a conventional strobe device of a camera uses a xenon tube as a light source. For example, if strobe shooting is performed in order to correct backlight under sunlight in the morning or the evening, since the xenon tube has spectral characteristics close to daylight colors, the photos may be in unnatural colors. [0009] Japanese Patent Application Laid-Open No. 2002-116481 describes a technique in which a color temperature of an emitted light color can be manually or automatically varied by using light emitting elements of R, G and B, and for example, if the backlight under the sunlight in the morning or the evening is corrected, the backlight correction in accordance with a color temperature of the sunlight can be performed to eliminate unnaturalness due to a color temperature of strobe light at the time of the strobe shooting. [0010] However, in the invention according to Japanese Patent Application Laid-Open No. 5-196985, although the images at an appropriate exposure can be obtained by using the strobe device, since a color temperature of a strobe light source is constant, for example, if the backlight under the sunlight in the morning or the evening is corrected, the photos may be in the unnatural colors. [0011] Moreover, in the invention according to Japanese Patent Application Laid-Open No. 2001-333432, for example, if a strobe is used in order to correct the backlight under the sunlight in the morning or the evening, since the color temperature of the strobe light source and the color temperature of the sunlight are different, it is difficult to perform the shooting with good white balance for both a subject illuminated with the strobe light source and a background illuminated with the sunlight in the white balance bracketing shooting. [0012] Moreover, in the invention according to Japanese Patent Application Laid-Open No. 2002-116481, if there is any error in measurement of a color temperature of a subject field, there is a problem that the color temperature of the strobe light which has been set based on a result of the measurement cannot match the color temperature of the subject field. [0013] In the invention according to Japanese Patent Application Laid-Open No. 2002-116481, after the color temperature of the emitted light color has been manually or automatically set, it is necessary to convert the set color temperature into a ratio of light emission amounts of R, G and B. For this purpose, a method of having a correspondence table between the color temperature and the RGB ratio in an EEPROM or the like is conceivable. [0014] However, even with the same color temperature difference, the colors significantly vary in an area of a low color temperature, while the colors insignificantly vary in an area of a high color temperature. Therefore, if RGB ratio data is held at regular intervals of the color temperature, there is a problem in which the color temperature cannot be finely set in the area of the low color temperature if the intervals of the color temperature are wide, and useless data increases in the area of the high color temperature if the intervals of the color temperature are narrow. SUMMARY OF THE INVENTION [0015] The present invention has been made in view of the above described circumstances, and it is an object of the present invention to provide a camera which can ensure strobe shooting with strobe light at a color temperature which is approximately same as a color temperature of a subject field even if there is any error in measurement, setting or the like of the color temperature of the subject field. Furthermore, it is another object of the present invention to provide a strobe device and a camera which can minimize required data of a ratio of light emission amounts of R, G and B, and can efficiently utilize a memory. [0016] In order to achieve the above described object, according to a first aspect of the present invention, a camera which continuously performs shooting at predetermined time intervals in conjunction with one shutter release operation, comprises: a strobe light source which emits strobe light whose color temperature is adjustable; a light emission control device which controls the strobe light source to emit the strobe light in synchronization with each shooting in the continuous shooting; and a color temperature adjustment device which adjusts the color temperature of the strobe light emitted from the strobe light source for each shooting in the continuous shooting to vary color temperature with each shooting within a predetermined color temperature variable range which has been previously set. [0017] In other words, since the shooting is continuously performed with the strobe light emission at each different color temperature, it is possible to perform the shooting with the strobe light emission at a color temperature intended by a shooter. [0018] According to a second aspect of the present invention, the camera according to the first aspect further includes a color temperature detection device which detects a color temperature of a subject field, and the color temperature adjustment device adjusts the color temperature of the strobe light to vary color temperature within the predetermined color temperature variable range with the color temperature detected by the color temperature detection device at the center. [0019] Thereby, the center of the color temperature of the strobe light which is continuously emitted can be set to the color temperature of the subject field. [0020] According to a third aspect of the present invention, the camera according to the first aspect further includes a color temperature setting device which manually sets the color temperature including a light source type, and the color temperature adjustment device adjusts the color temperature of the strobe light to vary color temperature within the predetermined color temperature variable range with the color temperature set by the color temperature setting device at the center. [0021] Thereby, the center of the color temperature of the strobe light which is continuously emitted can be set to the color temperature which has been manually set. [0022] According to a fourth aspect of the present invention, the camera according to the first aspect further includes a scene selection device which selects a shooting scene, and the color temperature adjustment device adjusts the color temperature of the strobe light to vary color temperature within the predetermined color temperature variable range, depending on the shooting scene selected by the scene selection device. [0023] Thereby, the center of the color temperature of the strobe light which is continuously emitted can be set to the color temperature depending on the shooting scene. [0024] According to a fifth aspect of the present invention, in the camera according to the first aspect, the strobe light source comprises light emitting diodes of three colors of R, G and B. [0025] According to a sixth aspect of the present invention, in the camera according to the fifth aspect, the color temperature adjustment device adjusts the color temperature by controlling a ratio of light emission amounts of R, G and B of the light emitting diodes of the three colors. [0026] According to a seventh aspect of the present invention, the camera according to the sixth aspect further includes a storage device which stores the ratio of the light emission amounts of R, G and B of the light emitting diodes of the three colors for emitting the strobe light corresponding to each color temperature, for each color temperature at predetermined intervals. And the color temperature adjustment device reads a corresponding ratio of the light emission amounts of R, G and B from the storage device depending on the color temperature at which the light emission should be performed, and controls each of light emission amounts of the light emitting diodes of the three colors to match the read ratio of the light emission amounts of R, G and B. [0027] According to an eighth aspect of the present invention, in the camera according to the seventh aspect, the storage device stores the ratio of the light emission amounts of R, G and B with the predetermined intervals varied according to the color temperature. [0028] Thereby, the memory can be efficiently used. [0029] In order to achieve the above described object, a strobe device according to a ninth aspect of the present invention comprises: a strobe light source which emits strobe light whose color temperature is adjustable, and is configured with light emitting elements of three colors of R, G and B whose respective light emission amounts can be independently controlled; a light emission control device which controls the strobe light source to emit the strobe light in synchronization with shooting; a storage device which stores ratios of the light emission amounts of the light emitting elements of the three colors of R, G and B for emitting the strobe light corresponding to each color temperature, for each color temperature at predetermined intervals; and a color temperature adjustment device which reads a corresponding ratio of the light emission amounts of R, G and B from the storage device depending on the color temperature at which the light emission should be performed, and adjusts the color temperature of the strobe light by controlling the respective light emission amounts of the light emitting elements of the three colors so that the respective light emission amounts of the light emitting elements of the three colors have the read ratio of the light emission amounts of R, G and B. Moreover, the storage device stores the ratio of the light emission amounts of R, G and B with the predetermined intervals varied according to the color temperature. [0030] Thereby, the memory can be efficiently used. [0031] According to a tenth aspect of the present invention, in the strobe device according to the ninth aspect, the light emitting elements are light emitting diodes. [0032] According to an eleventh aspect of the present invention, in the strobe device according to the ninth aspect, the storage device stores the ratio of the light emission amounts of R, G and B, with the predetermined intervals narrowed in a range of the color temperature in which the ratio of the light emission amounts of R, G and B widely varies with respect to variation in the color temperature, and with the predetermined intervals widened in a range of the color temperature in which the ratio of the light emission amounts of R, G and B insignificantly varies with respect to the variation in the color temperature. [0033] According to a twelfth aspect of the present invention, the strobe device according to the ninth aspect further includes a color temperature detection device which detects a color temperature of a subject field. And the color temperature adjustment device reads, from the storage device, a ratio of the light emission amounts of R, G and B corresponding to a color temperature closest to the color temperature detected by the color temperature detection device, or a color temperature closest to the color temperature detected by the color temperature detection device on a low temperature side, or a color temperature closest to the color temperature detected by the color temperature detection device on a high temperature side, and adjusts the color temperature of the strobe light by controlling the respective light emission amounts of the light emitting elements of the three colors to match the read ratio of the light emission amounts of R, G and B. [0034] According to a thirteenth aspect of the present invention, the strobe device according to the ninth aspect further includes a color temperature detection device which detects a color temperature of a subject field. And the color temperature adjustment device reads ratios of the light emission amounts of R, G and B corresponding to a color temperature closest to the color temperature detected by the color temperature detection device on a low temperature side and a color temperature closest to the color temperature detected by the color temperature detection device on a high temperature side, respectively from the storage device, calculates a ratio of the light emission amounts of R, G and B by interpolating the read ratios of the light emission amounts of R, G and B with the detected color temperature, and adjusts the color temperature of the strobe light by controlling the respective light emission amounts of the light emitting elements of the three colors to match the calculated ratio of the light emission amounts of R, G and B. [0035] In order to achieve the above described object, according to a fourteenth aspect of the present invention, a camera which shoots a subject and records image data of the shot subject, comprises: a strobe light source which emits strobe light whose color temperature is adjustable, and is configured with light emitting elements of three colors of R, G and B whose respective light emission amounts can be independently controlled; a light emission control device which controls the strobe light source to emit the strobe light in synchronization with shooting; a storage device which stores ratios of the light emission amounts of the light emitting elements of the three colors of R, G and B for emitting the strobe light corresponding to each color temperature, for each color temperature at predetermined intervals; and a color temperature adjustment device which reads a corresponding ratio of the light emission amounts of R, G and B from the storage device depending on the color temperature at which the light emission should be performed, and adjusts the color temperature of the strobe light by controlling the respective light emission amounts of the light emitting elements of the three colors so that the respective light emission amounts of the light emitting elements of the three colors have the read ratio of the light emission amounts of R, G and B. Moreover, the storage device stores the ratio of the light emission amounts of R, G and B with the predetermined intervals varied according to the color temperature. [0036] Thereby, the memory can be efficiently used. [0037] According to a fifteenth aspect of the present invention, in the camera according to the fourteenth, the light emitting elements are light emitting diodes. [0038] According to a sixteenth aspect of the present invention, in the camera according to the fourteenth aspect, the storage device stores the ratio of the light emission amounts of R, G and B, with the predetermined intervals narrowed in a range of the color temperature in which the ratio of the light emission amounts of R, G and B widely varies with respect to variation in the color temperature, and with the predetermined intervals widened in a range of the color temperature in which the ratio of the light emission amounts of R, G and B insignificantly varies with respect to the variation in the color temperature. [0039] According to a seventeenth aspect of the present invention, the camera according to the fourteenth aspect further includes a color temperature detection device which detects a color temperature of a subject field. And the color temperature adjustment device reads, from the storage device, a ratio of the light emission amounts of R, G and B corresponding to a color temperature closest to the color temperature detected by the color temperature detection device, or a color temperature closest to the color temperature detected by the color temperature detection device on a low temperature side, or a color temperature closest to the color temperature detected by the color temperature detection device on a high temperature side, and adjusts the color temperature of the strobe light by controlling the respective light emission amounts of the light emitting elements of the three colors to match the read ratio of the light emission amounts of R, G and B. [0040] According to an eighteenth aspect of the present invention, the camera according to the fourteenth aspect further includes a color temperature detection device which detects a color temperature of a subject field. And the color temperature adjustment device reads ratios of the light emission amounts of R, G and B corresponding to a color temperature closest to the color temperature detected by the color temperature detection device on a low temperature side and a color temperature closest to the color temperature detected by the color temperature detection device on a high temperature side, respectively from the storage device, calculates a ratio of the light emission amounts of R, G and B by interpolating the read ratios of the light emission amounts of R, G and B with the detected color temperature, and adjusts the color temperature of the strobe light by controlling the respective light emission amounts of the light emitting elements of the three colors to match the calculated ratio of the light emission amounts of R, G and B. [0041] According to the present invention, even in a situation where the strobe light emission at a right color temperature is difficult, it is possible to perform the shooting with the strobe light emission at the color temperature intended by the shooter because in a color bracketing shooting, shootings are performed in conjunction with continuously emitting the strobe light at the different color temperature. Furthermore, it is possible to provide the strobe device and the camera which can minimize required data of the ratio of the light emission amounts of R, G and B for varying a color temperature of an emitted light color of a strobe in which the light emitting elements of R, G and B are used, and can utilize the memory efficiently. BRIEF DESCRIPTION OF THE DRAWINGS [0042] FIG. 1 is a top view of a camera according to an embodiment of the present invention; [0043] FIG. 2 is a rear perspective view of the camera according to the embodiment of the present invention; [0044] FIG. 3 is a front perspective view of the camera according to the embodiment of the present invention; [0045] FIG. 4 is a block diagram showing an internal configuration of the camera shown in FIG. 1 ; [0046] FIG. 5 is a block diagram showing details of a strobe device built in or externally attached to the camera shown in FIG. 1 ; [0047] FIGS. 6A , 6 B, 6 C and 6 D are timing charts showing operations of the camera shown in FIG. 1 ; [0048] FIG. 7 is a view showing an LCD display screen of the camera shown in FIG. 1 ; [0049] FIG. 8 is a flowchart showing the operations of the camera shown in FIG. 1 ; [0050] FIG. 9 is a view showing a display in a finder of the camera shown in FIG. 1 ; [0051] FIG. 10 is a timing chart showing the operations of the camera shown in FIG. 1 ; [0052] FIG. 11 is a flowchart showing the operations of the camera shown in FIG. 1 ; [0053] FIGS. 12A , 12 B and 12 C are enlarged views of the display in the finder of the camera shown in FIG. 1 ; [0054] FIG. 13 is a graph representing a relationship between a color temperature and a ratio of three primary colors RGB; [0055] FIGS. 14A and 14B are views showing the display in the finder of the camera shown in FIG. 1 ; [0056] FIG. 15 is a flowchart showing the operations of the camera shown in FIG. 1 ; and [0057] FIG. 16 is a view showing the LCD display screen of the camera shown in FIG. 1 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0058] Preferred embodiments of a strobe device and a camera according to embodiments of the present invention will be described below according to the accompanying drawings. First Embodiment [0059] FIG. 1 is a top view of an electronic camera capable of color bracketing shooting according to an embodiment of the present invention. [0060] As shown in FIG. 1 , a mode dial 101 can be rotated to set to any shooting mode among a manual shooting mode, an auto shooting mode, a person mode and the like. Moreover, in front of the mode dial 101 , a shutter release button 102 having a switch S 1 to be turned on for half-pressing the button and a switch S 2 to be turned on for fully pressing the button are provided. [0061] FIG. 2 is a rear perspective view of the electronic camera capable of the color bracketing shooting according to the embodiment of the present invention. [0062] On a rear side of this electronic camera 100 , as shown in FIG. 2 , an LCD finder 103 , a menu button 104 , a cross button 105 and an LCD monitor 152 are provided. [0063] FIG. 3 is a front perspective view of the electronic camera capable of the color bracketing shooting according to the embodiment of the present invention. [0064] On a front side of this electronic camera 100 , as shown in FIG. 3 , a shooting lens 110 and a strobe device 146 are provided. [0065] FIG. 4 is a block diagram showing an internal configuration of the electronic camera 100 shown in FIG. 1 . [0066] In FIG. 4 , a subject image imaged on a light receiving surface of a solid-state image pickup element (CCD) 114 via the shooting lens 110 and an aperture 112 is converted into a signal charge of an amount depending on an incident light amount of light at each sensor. The signal charge stored in this way is read out to a shift register with a read gate pulse applied from a CCD driving circuit 116 , and sequentially read out as a voltage signal depending on the signal charge with a register transfer pulse. It should be noted that this CCD 114 has a so-called electronic shutter function in which the stored signal charge can be flushed with a shutter gate pulse and thereby a charge storage time (shutter speed) is controlled. [0067] The voltage signal sequentially read from the CCD 114 is applied to a correlated double sampling circuit (CDS circuit) 118 , in which R, G and B signals for each pixel are sampling-held and applied to an A/D converter 120 . The A/D converter 120 converts the R, G and B signals which are sequentially applied from the CDS circuit 118 , into digital R, G and B signals and outputs the digital R, G and B signals. In addition, the CCD driving circuit 116 , the CDS circuit 118 and the A/D converter 120 are synchronously driven with a timing signal applied from a timing generation circuit 122 . [0068] The R, G and B signals outputted from the above described A/D converter 120 are temporarily stored in a memory 124 , and subsequently, the R, G and B signals stored in the memory 124 are applied to a digital signal processing circuit 126 . The digital signal processing circuit 126 is configured with a synchronization circuit 128 , a white balance adjustment circuit 130 , a gamma correction circuit 132 , a YC signal generation circuit 134 , a memory 136 and the like. [0069] The synchronization circuit 128 converts dot sequential R, G and B signals read from the memory 124 into simultaneous signals, and outputs the R, G and B signals simultaneously to the white balance adjustment circuit 130 . The white balance adjustment circuit 130 is configured with multipliers 130 R, 130 G and 130 B which increase and decrease digital values of the R, G and B signals respectively, and the R, G and B signals are applied to the multipliers 130 R, 130 G and 130 B respectively. At another input of each of the multipliers 130 R, 130 G and 130 B, a white balance correction value (gain value) for controlling white balance is added from a central processing unit (CPU) 138 . Each of the multipliers 130 R, 130 G and 130 B multiplies two inputs, and outputs R′, G′ and B′ signals subjected to white balance adjustment based on this multiplication to the gamma correction circuit 132 . In addition, the white balance correction value added from the CPU 138 to the white balance adjustment circuit 130 will be described in detail later. [0070] The gamma correction circuit 132 changes input/output characteristics so that the R′, G′ and B′ signals subjected to the white balance adjustment have desired gamma characteristics, and outputs the R′, G′ and B′ signals to the YC signal generation circuit 134 . The YC signal generation circuit 134 generates a luminance signal Y and chroma signals Cr and Cb from the R′, G′ and B′ signals subjected to gamma correction. These luminance signal Y and chroma signals Cr and Cb (YC signals) are stored in the memory 136 located in the same memory space as the memory 124 . [0071] Here, when the YC signals in the memory 136 are read and outputted to the LCD monitor 152 , pass-through images (live-view images), shot still images or the like can be displayed on the LCD monitor 152 . [0072] Moreover, the YC signals after the shooting are compressed in a predetermined format by a compression/expansion circuit 154 , and subsequently recorded in a recording medium such as a memory card by a recording section 156 . Furthermore, in a replaying mode, image data recorded in the memory card or the like is subjected to an expansion process by the compression/expansion circuit 154 and subsequently outputted to the LCD monitor 152 , and a replayed image is displayed on the LCD monitor 152 . [0073] The CPU 138 controls the respective circuits in an integrated manner based on input from a camera operation section 140 including the mode dial 101 , the shutter release button 102 , the menu button 104 , the cross button 105 and the like shown in FIGS. 1 and 2 , and also controls auto focus, auto exposure control, the white balance and the like. This auto focus control is, for example, a contrast AF which moves the shooting lens 110 so that a high frequency component of the G signal becomes maximum, and the shooting lens 110 is moved to a focus position via a driving section 142 so that the high frequency component of the G signal becomes maximum when the shutter release button 102 is half-pressed. [0074] Moreover, in the auto exposure control, the R, G and B signals are captured, luminance of a subject (shooting EV value) is obtained based on an integrated value obtained by integrating these R, G and B signals, and based on this shooting EV value, an aperture value and the shutter speed at the time of shooting are determined. Next, when the shutter release button 102 is fully pressed, the aperture 112 is driven via an aperture driving section 144 so that the aperture value becomes the above described determined aperture value, and also the charge storage time is controlled by the electronic shutter so that the shutter speed becomes the determined shutter speed, and then one frame of the image data is captured, subjected to required signal processing and subsequently recorded in the recording medium. [0075] Next, a white balance correction method will be described. [0076] Although white balance correction is also performed in the auto shooting mode, if the white balance correction is manually performed, the manual shooting mode is set with the mode dial 101 , and furthermore, the menu button 104 is operated to display a menu for setting the white balance on the LCD monitor 152 as shown in FIG. 7 . Here, a cursor is moved up and down with the cross button 105 to select an item for the white balance correction (M, icons showing light source types or AUTO). [0077] Here, a method of measuring a color temperature of a subject field (light source type) measured in the case of the auto shooting mode or the case of setting the white balance to “AUTO” will be described. [0078] One screen is split into multiple areas (8×8), and for each split area, an average integrated value for each color of the R, G and B signals is obtained from the R, G and B signals which have been temporarily stored in the memory 124 shown in FIG. 4 . These average integrated values of the R, G and B signals for each split area are calculated by an integration circuit 148 and added to the CPU 138 . Multipliers 150 R, 150 G and 150 B are provided between the integration circuit 148 and the CPU 138 , and an adjustment gain value for adjusting variation in equipment is added to the multipliers 150 R, 150 G and 150 B. [0079] Based on the above described average integrated values of the R, G and B signals for each split area, the CPU 138 determines the light source type such as daylight (fine), shaded area-cloudy, fluorescent light, tungsten bulb and the like. In this light source type determination, ratios of the average integrated values for each color of the R, G and B signals, R/G and B/G, are obtained for the above described each split area, and subsequently, a detection frame showing a range of color distribution corresponding to each light source type is set on a graph having a horizontal axis of R/G and a vertical axis of B/G. Next, based on the above described obtained ratios R/G and B/G for each area, the number of areas to be put in the above described detection frame is obtained, and the color source type is determined based on a luminance level of the subject and the number of the areas to be put in the detection frame (see Japanese Patent Application Laid-Open No. 2000-224608). In addition, a method of automatically obtaining the light source type (the color temperature of the subject field) is not limited to this embodiment, and the color temperature may be obtained by calculating the color temperature based on a ratio of luminance information on the R, G and B signals obtained from the CCD 114 , and the like. [0080] When the light source type (the color temperature of the subject field) is obtained as described above, the CPU 138 determines the white balance correction value suitable for the light source type, and outputs the determined white balance correction value (gain value) to the multipliers 130 R, 130 G and 130 B. Thereby, the multipliers 130 R, 130 G and 130 B output the R′, G′ and B′ signals subjected to white balance adjustment, to the gamma correction circuit 132 . [0081] Here, if the white balance has been set to “M”, the color temperature which has been previously stored based on an operation of storing the color temperature is read out, the white balance correction value is determined depending on the color temperature, and the white balance correction is performed similarly. [0082] Moreover, if the white balance has been set to the icon showing the light source type, the white balance correction value suitable for the selected light source type is determined and the white balance correction is performed. [0083] In addition, although a white balance process is performed in the digital signal processing circuit 126 in this embodiment, the white balance process may be performed in an analog signal processing circuit including the CDS circuit 118 , a gain control amplifier which is not shown in the figure and the like. Moreover, although the white balance process is performed by varying the ratios of R/G and B/G based on an independent gain process for each of R, B and G, there is also a method of performing the white balance process by adding or subtracting one value with respect to color difference signals C r and C b by an independent addition/subtraction process for each of the color difference signals C r and C b . [0084] Next, a method of controlling the strobe device 146 according to the present invention will be described. [0085] FIG. 5 is a block diagram showing details of the strobe device 146 built in or externally attached to the above described electronic camera 100 . [0086] As shown in FIG. 5 , in this strobe device 146 , a light receiving sensor for strobe light control 34 , an LED group 38 , a battery 40 , a voltage up-converter 42 , a high capacity condenser 44 , operational amplifiers 46 , 48 and 50 , a system controller 52 , a light control circuit 54 and a temperature sensor 56 are provided. [0087] The system controller 52 controls the strobe device 146 in an integrated manner, and a light emission signal synchronized with the shutter release is inputted from the CPU 138 , or strobe light emission amount information or strobe color temperature information is inputted from the CPU 138 via serial communication. The system controller 52 controls the voltage up-converter 42 to increase voltage (for example, 6 V) of the battery 40 to approximately 10 V, and charges the condenser 44 with this increased voltage. In addition, the condenser 44 is charged, for example, in a long time such as 2 to 5 seconds, and also can continuously supply current to the LED group 38 for more than or equal to 1/60 seconds (approximately 16 milliseconds). [0088] Electric energy accumulated in this condenser 44 is supplied to LEDs of R, G and B 38 R, 38 G and 38 B via the operational amplifiers 46 , 48 and 50 . The system controller 52 controls the above described operational amplifiers 46 , 48 and 50 based on the strobe light emission amount information or the strobe color temperature information from the CPU 138 to control a light emission time and a light emission amount of each of the LEDs of R, G and B 38 R, 38 G and 38 B. [0089] In addition, since the light amount of the LED varies depending on an ambient temperature, the temperature sensor 56 which detects the ambient temperature of the LED group 38 is provided, and based on the ambient temperature of the LED group 38 detected by this temperature sensor 56 , the system controller 52 controls the current with respect to the LED group 38 so that a required light emission amount can be obtained regardless of the ambient temperature. [0090] Next, operations of the above described system controller 52 will be described with reference to timing charts shown in FIGS. 6A , 6 B, 6 C and 6 D. [0091] The system controller 52 previously operates the voltage up-converter 42 at a timing of turning on the camera which is not shown in the figure, and charges the condenser 44 . [0092] Subsequently, when the shutter release button 102 is half-pressed, a standby state occurs ( FIG. 6A ) and information for determining a strobe light emission amount such as a guide number is captured. [0093] Here, if the item for the white balance correction is “M”, the CPU 138 reads the color temperature which has been previously stored, or in the case of the auto shooting mode or the case where the item for the white balance correction is “AUTO”, the CPU 138 automatically obtains the light source type (the color temperature of the subject field) based on the R, G and B signals obtained from the CCD 114 , and sets the color temperature for the white balance correction. [0094] The CPU 138 has outputted this above described color temperature for the white balance correction, and the system controller 52 captures the color temperature outputted from the CPU 138 ( FIG. 6B ). [0095] The system controller 52 determines the strobe light emission amount based on the above described captured information and outputs a reference value for adjusting the light emission amount in order to obtain the strobe light emission amount, to the light control circuit 54 , and also, determines a ratio of the light emission amounts of the LEDs of R, G and B 38 R, 38 G and 38 B so that the light of the same color temperature is emitted based on the color temperature of the subject field, and sets R, G and B light emission levels corresponding to this ratio ( FIG. 6C ). [0096] Next, when the shutter release button 102 is fully pressed and a shutter opens, the system controller 52 inputs the light emission signal synchronized with the opening of the shutter, and outputs control signals showing the above described set R, G and B light emission levels to positive inputs of the operational amplifiers 46 , 48 and 50 , respectively. On the other hand, signals corresponding to values of the current flowing through the respective LEDs 38 R, 38 G and 38 B are applied to negative inputs of the operational amplifiers 46 , 48 and 50 , and the operational amplifiers 46 , 48 and 50 control constant current corresponding to the above described set R, G and B light emission levels to flow through the respective LEDs 38 R, 38 G and 38 B. [0097] Thereby, strobe light of the color temperature which is the same as the color temperature of the subject field as a whole is emitted from the LED group 38 ( FIG. 6D ). [0098] When the strobe light is emitted from the LED group 38 , the light control circuit 54 senses the light emission amount via the light receiving sensor for the strobe light control 34 . If this sensed light emission amount matches the reference value for adjusting the light emission amount, the light control circuit 54 outputs a light emission stop signal to the system controller 52 in order to stop the light emission. When the light emission stop signal is inputted from the light control circuit 54 , the system controller 52 outputs a control signal for stopping the light emission of the LED group 38 to the operational amplifiers 46 , 48 and 50 . Thereby, the current flowing into the LED group 38 is broken and the light emission of the LED group 38 is stopped. [0099] Next, a method of controlling the color bracketing shooting according to the present invention will be described by using FIGS. 8 , 9 and 10 . [0100] FIG. 8 is a flowchart showing operations of the camera at the time of the color bracketing shooting, FIG. 9 is a view representing a display inside the finder 103 at the time of the color bracketing shooting, and FIG. 10 is a timing chart showing the operations of the system controller 52 at the time of the color bracketing shooting. [0101] First, a case of setting a color temperature selection for color bracketing to automatic selection “AUTO” will be described. [0102] When a shooter turns on the camera, the system controller 52 previously operates the voltage up-converter 42 and charges the condenser 44 (S 1 in FIG. 8 ). [0103] Next, the shooter uses the mode dial 101 , the menu button 104 and the cross button 105 of the camera 100 to perform mode setting for performing the color bracketing shooting such as shooting mode selection or strobe shooting selection (S 2 in FIG. 8 ). [0104] When the color bracketing shooting is selected, next, a bracketing width showing how many steps plus or minus of bracketing are performed is selected (S 3 in FIG. 8 ). [0105] Although the steps will be described later, here, it is assumed that plus or minus one step has been selected. [0106] Next, the number of bracketing frames showing how many frames of the bracketing are performed is selected (S 4 in FIG. 8 ). Here, it is assumed that three frames have been selected. [0107] When the selection of the bracketing width and the selection of the number of the bracketing frames are completed, the color temperature selection is set next (S 5 in FIG. 8 ). [0108] The color temperature selection includes two kinds of the automatic selection “AUTO” and manual selection “M”, and here, the color temperature selection is set to the automatic selection “AUTO”. [0109] When “AUTO” is set, an operation of the shutter release button 102 is waited for (S 6 in FIG. 8 ). [0110] Here, when the shutter release button 102 is half-pressed (S 7 in FIG. 8 ), the CPU 138 obtains the light source type (the color temperature of the subject field) similarly to the case of the white balance correction (S 8 in FIG. 8 ), determines a white balance correction value (first correction value) suitable for the obtained color temperature of the subject field (first color temperature), and also determines a white balance correction value (second correction value) suitable for a color temperature which is lower than the above described obtained color temperature of the subject field by one step (second color temperature) and a white balance correction value (third correction value) suitable for a color temperature which is higher than the above described obtained color temperature of the subject field by one step (third color temperature). [0111] When the measurement of the color temperature of the subject field is completed, a color temperature measurement completion display lamp 201 is turned on, on the display within the finder 103 shown in FIG. 9 (S 9 in FIG. 8 ). [0112] Next, strobe light emission information is read (S 10 in FIG. 8 ), and subsequently, when the shutter release button 102 is fully pressed, strobe shooting for the three frames is performed at predetermined intervals (S 11 in FIG. 8 ). The details thereof will be described by using the timing chart of FIG. 10 . [0113] When the measurement of the color temperature is completed (timing (a) in FIG. 10 ), the CPU 138 outputs the first color temperature (timing (b) in FIG. 10 ), the second color temperature (timing (c) in FIG. 10 ) and the third color temperature (timing (d) in FIG. 10 ) along with the light emission amount information. [0114] This information is inputted to the system controller 52 , and the system controller 52 determines the strobe light emission amount based on the above described captured light emission amount information, and outputs the reference value for adjusting the light emission amount in order to obtain the strobe light emission amount, to the light control circuit 54 . [0115] Moreover, RGB ratio data with respect to the color temperature has been stored in a memory 25 . First, the system controller 52 reads an RGB ratio corresponding to first color temperature information from the memory 25 (timing (e) in FIG. 10 ), and sets the R, G and B light emission levels of the LEDs 38 R, 38 G and 38 B so that the strobe light is emitted at the read RGB ratio (timing (f) in FIG. 10 ). [0116] Subsequently, when the shutter release button 102 is fully pressed, the shooting with the strobe light emission with the light emission amount and an emitted light color based on the set information, that is, the strobe light emission shooting at the first color temperature is performed (timing (g) in FIG. 10 ). [0117] As described above, image data of a first frame obtained by performing the shooting in this way is outputted via the correlated double sampling circuit (CDS circuit) 118 from the A/D converter 120 , and temporarily stored in the memory 124 . In normal shooting, subsequently, digital signal processing is performed in the digital signal processing circuit 126 . However, in the case of the color bracketing shooting mode, since the shooting is prioritized, the digital signal processing is performed in the digital signal processing circuit 126 after the image data of the shooting of all of the number of the bracketing frames (here, the three frames) has been inputted to the memory 124 . [0118] When the shooting of the first frame is completed, the system controller 52 immediately reads an RGB ratio corresponding to second color temperature information from the memory 25 (timing (h) in FIG. 10 ), and sets the R, G and B light emission levels of the LEDs 38 R, 38 G and 38 B so that the strobe light is emitted at the read RGB ratio (timing (i) in FIG. 10 ). [0119] When the setting of the light emission levels is completed, the strobe light emission shooting at the second color temperature is performed (timing (j) in FIG. 10 ). [0120] When the shooting of the second frame is completed, the system controller 52 immediately reads an RGB ratio corresponding to third color temperature information from the memory 25 (timing (k) in FIG. 10 ), and sets the R, G and B light emission levels of the LEDs 38 R, 38 G and 38 B so that the strobe light is emitted at the read RGB ratio (timing (l) in FIG. 10 ). [0121] When the setting of the light emission levels is completed, the strobe light emission shooting at the third color temperature is performed (timing (m) in FIG. 10 ). [0122] When the shooting of the third frame is completed, shooting data for the three frames stored in the memory 124 is applied with desired digital processing by the digital signal processing circuit 126 . Here, the shooting data of the first, second and third frames is subjected to the white balance correction with the first, second and third correction values, respectively. Subsequently, the shooting data for the three frames is recorded in the recording medium by the recording section 156 (timing (n) in FIG. 10 ). [0123] As described above, if the color temperature selection for the color bracketing shooting is set to the automatic selection “AUTO”, the color bracketing shooting is realized in which the shooting is continuously performed so that the first frame is shot with the strobe light emission at the first color temperature, the second frame is shot with the strobe light emission at the second color temperature, and the third frame is shot with the strobe light emission at the third color temperature. [0124] In addition, although the color temperature information for the shooting of the three frames has been previously inputted to the system controller 52 in this embodiment, the color temperature information may be inputted for the shooting of each frame. Moreover, in this embodiment, although the strobe light emission is performed in an order of the color temperature of the subject field, the color temperature lower than the color temperature of the subject field, and the color temperature higher than the color temperature of the subject field, this order may be different. [0125] Moreover, in this embodiment, although a different value is also used for the white balance correction value for each shooting, a white balance value may be constant and only the color temperature of the strobe may be different. Moreover, although the shot image data is collectively recorded in the recording medium after the shooting of all frames has been completed, the shot image data may be recorded one by one for each shooting. Moreover, the number of times of the bracketing shooting is not limited to three and may be any number of times. [0126] Next, a case of setting the color temperature selection for the color bracketing to the manual selection “M” will be described. [0127] As shown in FIG. 7 , in the setting of “M”, a user can set a center of the color temperature for the color bracketing. [0128] In FIG. 8 , since the operations from S 1 to S 4 are similar to the case of “AUTO”, descriptions thereof are omitted. However, it is assumed that plus or minus one step has been selected as a bracketing correction width and three frames have been selected as the number of the bracketing frames. [0129] In the setting of the color temperature selection, the color temperature selection is set to “M” at this time (S 5 in FIG. 8 ). [0130] When the color temperature selection is set to “M”, the process proceeds to a step of manually setting the color temperature (S 6 in FIG. 8 ). [0131] After the manual setting of the color temperature (S 12 in FIG. 8 ) is completed, when the shutter release button 102 is half-pressed (S 13 in FIG. 8 ), the strobe light emission information based on the manually set color temperature information is read (S 10 in FIG. 8 ), and subsequently, when the shutter release button 102 is fully pressed, the strobe shooting for the three frames is performed at the predetermined intervals (S 11 in FIG. 8 ). [0132] Here, the manual setting of the color temperature will be described by using FIG. 11 . [0133] FIG. 11 is a detailed flowchart of the manual setting of the color temperature shown in S 12 in FIG. 8 . [0134] When the color temperature selection is set to “M”, the CPU 138 measures the color temperature of the subject field (S 21 in FIG. 11 ). When the measurement of the color temperature is completed, the color temperature measurement completion display lamp 201 is turned on and also a color temperature set value mark 202 shown in FIG. 9 is displayed within the LCD finder 103 (S 22 in FIG. 11 ). [0135] Here, the color temperature set value mark 202 will be described by using FIGS. 12A , 12 B and 12 C. [0136] FIGS. 12A , 12 B and 12 C are enlarged views of the color temperature set value mark 202 of FIG. 9 , in which seven rectangles are laterally aligned and one of the rectangles is displayed in black. [0137] A central rectangle, that is, a rectangle under a circle mark shows a current color temperature of the subject field, the rectangles show color temperatures which can be set, and the rectangle displayed in black shows the color temperature which is currently set. [0138] Moreover, when the rectangle displayed in black is set to a middle position (under the circle mark), display of the circle mark is changed from white to black for showing that the subject field has matched the set color temperature. [0139] In other words, FIG. 12A represents that the center of the color temperature for the color bracketing has been set to the color temperature of the subject field, FIG. 12B represents that the center of the color temperature for the color bracketing has been set to the color temperature which is lower than the color temperature of the subject field by one step, and FIG. 12C represents that the center of the color temperature for the color bracketing has been set to the color temperature which is higher than the color temperature of the subject field by two steps. [0140] When the setting of color temperature is changed by using the camera operation section 140 (S 23 in FIG. 11 ), a position of the rectangle displayed in black is changed (S 24 in FIG. 11 ), and the user can set a desired color temperature while seeing this position. [0141] Moreover, the CPU 138 compares the set color temperature with the color temperature of the subject field (S 25 in FIG. 11 ), and when the set color temperature matches the color temperature of the subject field, that is, when the rectangle displayed in black is set to the middle position, displays the circle mark which has been previously displayed in white, in black, and displays an announcement that the set color temperature has matched the color temperature of the subject field (S 26 and S 27 in FIG. 11 ). [0142] In this way, the user can freely set the center of the color temperature for the color bracketing in a range of plus or minus by three steps with respect to the color temperature of the subject field, while seeing the color temperature set value mark 202 , by using the camera operation section 140 . [0143] Here, if the shutter release button 102 is half-pressed in a state of setting as shown in FIG. 12C (S 12 in FIG. 8 ), the CPU 138 determines a white balance correction value (first correction value) suitable for the color temperature higher than the color temperature of the subject field, which has been already measured, by two steps (first color temperature), and also determines a white balance correction value (second correction value) suitable for a color temperature which is lower than the above described first color temperature by one step (second color temperature) and a white balance correction value (third correction value) suitable for a color temperature which is higher than the above described first color temperature by one step (third color temperature). [0144] Subsequently, this color temperature information is inputted from the CPU 138 to the system controller 52 , and the bracketing shooting is realized as described above. [0145] In this way, similarly to the case of setting the color temperature selection for the color bracketing shooting to “AUTO”, also in the case of setting the color temperature selection for the color bracketing shooting to “M”, the color bracketing shooting is realized in which the shooting is continuously performed so that the first frame is shot with the strobe light emission at the first color temperature, the second frame is shot with the strobe light emission at the second color temperature, and the third frame is shot with the strobe light emission at the third color temperature. [0146] Here, a bracketing correction step and the memory 25 will be described by using FIG. 13 . [0147] FIG. 13 is a graph representing a relationship between the color temperature and a ratio of three primary colors RGB, in which a horizontal axis shows an absolute temperature (K) and a vertical axis shows relative intensity of each of R, G and B components. In FIG. 13 , relative intensity at color temperature of 5000K is used as a reference. [0148] As is apparent from FIG. 13 , the RGB ratio varies precipitously in an area of the low color temperature, while the RGB ratio varies gradually in an area of the high color temperature. [0149] Hence, if a bracketing amount (correction step) for the color bracketing is equally set both when the central color temperature for the bracketing shooting is the low color temperature and when the central color temperature for the bracketing shooting is the high color temperature, a magnitude of an effect (visual variation) differs even when the color bracketing shooting has been performed with the same step amount. [0150] In this embodiment, a step of splitting the color temperature is varied depending on a range of the color temperature. Specifically, the splitting step is 100K/step (100K per step) in a range of 4500K and below, the splitting step is 250K/step in a range of 4500K to 6500K, and the splitting step is 500K/step in a range of 6500K and above. [0151] In this way, the variation of the color in one step becomes visually equal regardless of a color temperature zone at which the bracketing shooting is performed. [0152] Moreover, as described above, the RGB ratio data with respect to the color temperature is stored in the memory 25 . If the color temperature is equally split both at the time of the low color temperature and at the time of the high color temperature and the data is stored, since the RGB ratio varies gradually with respect to the color temperature on the high color temperature side, the memory is wastefully used. [0153] In this embodiment, the step of splitting the color temperature in data to be stored is varied depending on the range of the color temperature so that the memory can be efficiently used. [0154] As described above, the system controller 52 reads the RGB ratio corresponding to a desired color temperature from the memory 25 . More specifically, the system controller 52 reads an RGB ratio corresponding to a color temperature closest to the desired color temperature among color temperature steps stored in the memory. [0155] In this way, in this embodiment, although the RGB ratio corresponding to the closest color temperature is read, the RGB ratio corresponding to the closest color temperature on the low temperature side may be read, or conversely, the RGB ratio corresponding to the closest color temperature on the high temperature side may be read. [0156] Moreover, the RGB ratio corresponding to the closest color temperature on the low temperature side and the RGB ratio corresponding to the closest color temperature on the high temperature side may be read respectively, an RGB ratio in which these two read RGB ratios are interpolated with the desired color temperature may be calculated, and this calculated RGB ratio may be used to perform the strobe light emission. For example, if the desired color temperature is 4220K, since the RGB ratio corresponding to the color temperature is stored in the memory in 100K/step in the range of 4500K and below as described above, the RGB ratio at 4200 k, which is the closest color temperature on the low temperature side, and the RGB ratio at 4300K, which is the closest color temperature on the high temperature side, may be read respectively, and an RGB ratio in which these two RGB ratios have been interpolated at 4:1 may be used. Second Embodiment [0157] As a second embodiment related to the present invention, a camera not including a dedicated display related to the color temperature such as the color temperature measurement completion display lamp 201 or the color temperature set value mark 202 will be described. [0158] FIGS. 14A and 14B are displays in the LCD finder 103 of the camera not including the dedicated display related to the color temperature of the second embodiment related to the present invention. [0159] A frame for a focus is displayed in the LCD finder 103 . FIG. 14A is the display at a normal time and FIG. 14B is the display when the subject is in focus. [0160] Here, the case of setting the color temperature selection for the color bracketing shooting to “M” (S 12 in FIG. 8 ) will be described. [0161] In the camera of the second embodiment related to the present invention, the frame for the focus in the LCD finder 103 is also used for the display of the matching of the color temperature of the subject field and the set color temperature (S 27 in FIG. 11 ). In other words, the display becomes as shown in FIG. 14A when the color temperature of the subject field does not match the set color temperature, and the display becomes as shown in FIG. 14B when the color temperature of the subject field has matched the set color temperature. [0162] In order to avoid confusion with the focus display, FIGS. 14A and 14B at the time of the color temperature display may be blinked. [0163] Moreover, blink speed of FIG. 14A when the color temperature of the subject field does not match the set color temperature may be varied depending on a difference between the color temperature of the subject field and the set color temperature, instead of the color temperature position display at the time of setting the color temperature (S 24 in FIG. 11 ). [0164] Moreover, the display may be constantly as shown in FIG. 14A during setting the color temperature, and the display may be blinked only when the color temperature of the subject field has matched the set color temperature. [0165] Moreover, instead of the display of the focus frame, another display may be also used for the matching display. [0166] Moreover, instead of the display in the LCD finder 103 , another display in the LCD monitor 152 may be also used. [0167] Moreover, instead of the visual display, a sound announcement may be used. Third Embodiment [0168] The camera of a third embodiment related to the present invention will be described by using FIGS. 15 and 16 . [0169] FIG. 15 is a flowchart representing operations of the camera of the third embodiment related to the present invention, and FIG. 16 is a display screen on the LCD monitor 152 of the camera of the third embodiment according to the present invention. [0170] In the camera 100 of the third embodiment related to the present invention shown in FIG. 1 , the mode dial 101 can be rotated to set to any shooting mode among the manual shooting mode, the auto shooting mode and a shooting scene selection mode. [0171] When the mode dial 101 is set to the shooting scene selection mode (S 31 in FIG. 15 ), a shooting scene selection screen shown in FIG. 16 is displayed on the LCD monitor 152 . [0172] A shooting scene can be selected among a person mode, a landscape mode, a sport mode, a night scene mode, an evening scene mode and a beach mode, and the cursor is moved up and down with the cross button 105 to select a desired item. [0173] Here, the evening scene mode is a mode for shooting morning glow or evening glow vibrantly in red, and the beach mode is a mode for shooting at a beach under strong sunshine. [0174] When the evening scene mode is selected with the cross button 105 (S 32 in FIG. 15 ) and further the menu button 104 is used, the color bracketing shooting mode in the evening scene mode can be set (S 33 in FIG. 15 ). [0175] As described above, since the evening scene mode is the mode for shooting in red, it is conceivable that the strobe light is also preferably emitted in a color close to red, that is, at the low color temperature. [0176] Hence, if the color bracketing shooting mode in the evening scene mode has been set, the color temperature for the strobe light emission is previously set to the low color temperature so that, for example, the above described first color temperature is 3000K, the above described second color temperature is 2900K, and the above described third color temperature is 3100K (S 34 in FIG. 15 ). [0177] Moreover, when the beach mode is selected with the cross button 105 (S 35 in FIG. 15 ) and further the menu button 104 is used, the color bracketing shooting mode in the beach mode can be set (S 36 in FIG. 15 ). [0178] As described above, although the beach mode is the mode for shooting at the beach under the strong sunshine, since the beach includes a lot of ultraviolet rays and also blue sky is often reflected, it is conceivable that the strobe light is also preferably emitted in a color close to blue, that is, at the high color temperature. [0179] Hence, if the color bracketing shooting mode in the beach mode has been set, the color temperature for the strobe light emission is previously set to the high color temperature so that, for example, the above described first color temperature is 10000K, the above described second color temperature is 9500K, and the above described third color temperature is 10500K (S 37 in FIG. 15 ). [0180] When the shooting scene other than the evening scene mode and the beach mode is selected with the cross button 105 and further the menu button 104 is used, the color bracketing shooting mode in that mode can be set. [0181] In the shooting scene other than the evening scene mode and the beach mode, since it is conceivable that the color temperature of the subject field is normal, it is conceivable that the strobe light is also preferably emitted at a normal color temperature. [0182] Hence, if the color bracketing shooting mode in the mode other than the evening scene mode and the beach mode has been set (S 38 in FIG. 15 ), the color temperature for the strobe light emission is set to the normal color temperature so that, for example, the above described first color temperature is 5000K, the above described second color temperature is 4750K, and the above described third color temperature is 5250K (S 39 in FIG. 15 ). [0183] Based on this information, the operational amplifiers 46 , 48 and 50 and the light control circuit 54 are set, and the color bracketing shooting is realized in which the shooting is continuously performed so that the first frame is shot with the strobe light emission at the first color temperature, the second frame is shot with the strobe light emission at the second color temperature, and the third frame is shot with the strobe light emission at the third color temperature.

A camera which continuously performs shooting at predetermined time intervals in conjunction with one shutter release operation, comprises: a strobe light source which emits strobe light whose color temperature is adjustable; a light emission control device which controls the strobe light source to emit the strobe light in synchronization with each shooting in the continuous shooting; and a color temperature adjustment device which adjusts the color temperature of the strobe light emitted from the strobe light source for each shooting in the continuous shooting to vary color temperature with each shooting within a predetermined color temperature variable range which has been previously set. Thereby, even in a situation where the strobe light emission at a right color temperature is difficult, it is possible to perform the shooting with the strobe light emission at the color temperature intended by the shooter.

CROSS-REFERENCE TO RELATED APPLICATIONS This patent application is a divisional of and claims priority to U.S. application Ser. No. 10/608,113, filed on Jun. 30, 2003, and further claims priority to Japanese Patent Application No. 2000-192422, filed Jul. 1, 2002. The contents of these applications are incorporated herein by reference in their entirety. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for using a shared library in a microprocessor having a function for supporting the multi-task program execution environment and program and data encryption/decryption function so as to realize the protection of secrecy and the prevention of alteration for the execution codes of the programs and the processing target data. 2. Description of the Related Art In the computer systems of recent years, the open system constructed by combining hardware and software of various makers has been widespread, as in the case of PCs. In the open system, the information on hardware and system program (or operating system (OS)) is publicly disclosed so that it is in principle possible for an end user to modify or alter the system program according to this information In the application program to be executed in such an environment, it is difficult for a provider of the application program to completely protect the program from the analysis and the alteration. The application program is operated under the management of the OS, so that there is no way of escaping from the attack when the OS itself is altered and used as means for attacking. For this reason, there is a method to encrypt the application program in advance, in order to prevent the analysis of the application program to be operated in the open system. When the program is encrypted, not only the analysis becomes difficult but also the prediction of the operation in the case where the program is altered also becomes difficult so that it is also effective for the prevention of the alteration. However, the encrypted application program cannot be executed as it is by the existing computer, so that there is a need for a microprocessor which can execute the program while decrypting the program. This microprocessor must protect the secrecy of the program on the presumption that the OS may carry out hostile operations against the application program. A microprocessor that can satisfy these requirements includes one proposed in commonly assigned co-pending U.S. patent application Ser. Nos. 09/781,158 and 09/781,284, and one disclosed in Lie et al., “Architectural Support for Copy and Tamper Resistant Software”, Proceedings of ASPLOS-IX 2000, November 2000. These proposed microprocessors have a function for encrypting not just programs but also information and data to be handled by the programs as a protection against the analysis and the alteration. They also provides the multi-task program execution environment for executing a plurality of programs simultaneously in a pseudo-parallel manner. In the following such a microprocessor will be referred to as a tamper resistant microprocessor. In the conventionally proposed tamper resistant microprocessor, it is assumed that the application program is operated singly and all the necessary processing can be realized by its execution code alone. A method for sharing the data region in order to realize the cooperative operations by a plurality of programs has also been proposed in commonly assigned co-pending U.S. patent application Ser. No. 10/028,794. However, even in this case, the programs that are carrying out the cooperative operations are mutually independent individual programs. On the other hand, the current OS often utilizes the shared library. Here, the library is a collection of sub-programs such as a sub-routine (a group of instructions which have a certain function in the program) which constitute the program. The programmer of the application program can rely on the sub-programs provided in the library for a part of functions of the application program, instead of implementing in the application program all the functions necessary for the operation of the application program. The library and the application program can be separately developed and then freely combined later on for use, so that they can make the software development more efficient. The classic library is linked to the application program at a time of producing the application program, and the sub-programs of the library are distributed integrally with the application program. On the other hand, the shared library that is widely in use today is distributed as a separate file independent from the application program. In the case of the shared library, the link to the application program is made when the user actually executes the program. Also, this linking operation is carried out with respect to an image of the application program on memory, rather than with respect to the executable object file of the application program. Once the linking between the application program and the shared library is carried out, it becomes possible to use the sub-programs of the shared library by freely calling them up from the application program, similarly as the sub-programs of an ordinary library. One of the advantages for using the shared library is that the necessary memory region can be reduced. A total size of one application program and the shared library to be used by that application program is always larger than the size in the case of not utilizing the shared library. However, when there are a plurality of application programs which use the same shared library, it suffices to have one copy of the shared library so that the necessary memory region can be reduced overall. This reduction of the necessary memory region is effective for both the secondary memory (external memory device such as disks) on which the distributed file of the application program is stored and the main memory of the computer on which the application program is stored at a time of its execution. Among the shared libraries, those known as a dynamic link type (dynamic link shared libraries) have a feature that the shared library can be changed without changing the application program. When the dynamic link shared library is used, it is possible to change a part of the functions of the application program or correct errors in the application program, without changing the application program itself, by replacing one shared library with another shared library. Also, in the case where the application program searches the available shared library after the execution starts and loads the shared library found by the search, it is possible to add functions to the application program without changing the application program itself, by separately providing the shared library alone. The shared library designed to be used in this manner is often referred to as a plug-in. So far there has been no proposition for an architecture that can enable the use of the shared library on the tamper resistant microprocessor described above. In order to implement the shared library on the tamper resistant microprocessor, there is a need to satisfy the following requirements. Namely, it is required that the routines of the shared library can be called up from the application program, and that data may be passed to the routine at a time of calling up the routine, and data of the processing result can be returned to the called source when the processing returns from the routine. In addition, in order to maintain the protection function for data, etc. that is provided by the tamper resistant microprocessor effectively functional, there is a need to protect the secrecy of the information to be exchanged between the application program and the shared library from the OS, etc. In the case of exchanging data to be kept secret at a time of calling up the routine, there is a need to authenticate the correspondent in order to check whether it is a trustworthy correspondent or not (Whether the shared library has been replaced with another malicious shared library by the OS, etc. or not). There is also a need to prevent a secret substitution of another routine into the call up target routine after this authentication is finished. In the case where the shared library are to be used simultaneously from a plurality of application programs, the leakage of a secret of one program to another program by the shared library must be prevented. Also, the shared library must be usable from arbitrary application. In other words, if the shared library is usable only from a specific application program as a result of the authentication, it would be insufficient as the shared library because its use is limited. On the other hand, from a viewpoint of the application program that uses the shared library, it is preferable to be able to confirm that the shared library will not leak data to the others, before giving data to be kept secret to the shared library. For these reasons, there is a need to provide a mechanism by which the application program can authenticate the shared library. The operation of the shared library is to receive data from the application program, apply some processing on the data, and return the processing result to the application program. Here, the data received from the application program and the processing result should not be leaked to the third party other than the application program and the shared library. Namely, not only the data exchange must be carried out by applying the encryption, but there is also a need to check that the program to which the processing result corresponding to the received data is going to be returned is the same application program which originally provided the data. Also, anyone can write an application program that uses the shared library, so that there is a possibility of being used from a malicious application program. Even in such a case, it must be capable of protecting the internal operation of the shared library from the analysis. In other words, it must be capable of preventing the reading of the execution code of the shared library by the application program and the peeping of the intermediate data during the processing of the data given to the shared library by the application program. BRIEF SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a method for using a shared library and a computer program product for such a method, which are capable of enabling the use of the shared library on the tamper resistant microprocessor which has been impossible conventionally, while satisfying the above described requirements and providing the above described advantages. According to one aspect of the present invention there is provided a method for using a shared library called up from a calling source program in a tamper resistant microprocessor which has a function for decrypting and executing encrypted codes and a table formed by a plurality of regions for storing a plurality of encryption keys corresponding to at least one program and at least one shared library to be called up by the at least one program, the method comprising: creating a task for the shared library; allocating a task identifier to the task; acquiring an instruction key from a header of the shared library; storing the instruction key into a region of the table corresponding to the task identifier allocated to the task for the shared library in the microprocessor; initializing by executing a loader in the shared library; and returning a control to the calling source program via an entry point in the shared library. According to another aspect of the present invention there is provided a computer program product for causing a tamper resistant microprocessor which has a function for decrypting and executing encrypted codes and a table formed by a plurality of regions for storing a plurality of encryption keys corresponding to at least one program and at least one shared library to be called up by the at least one program, to use a shared library called up from a calling source program, the computer program product comprising: a first computer program code for causing the tamper resistant microprocessor to create a task for the shared library; a second computer program code for causing the tamper resistant microprocessor to allocate a task identifier to the task; a third computer program code for causing the tamper resistant microprocessor to acquire an instruction key from a header of the shared library; a fourth computer program code for causing the tamper resistant microprocessor to store the instruction key into a region of the table corresponding to the task identifier allocated to the task for the shared library in the microprocessor; a fifth computer program code for causing the tamper resistant microprocessor to initialize by executing a loader in the shared library; and a sixth computer program code for causing the tamper resistant microprocessor to return a control to the calling source program via an entry point in the shared library. Other features and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a configuration of a microprocessor in which a shared library is to be used according to one embodiment of the present invention. FIG. 2 is a diagram showing a key value table provided inside the microprocessor of FIG. 1 . FIG. 3 is a diagram showing an application program used in one embodiment of the present invention. FIG. 4 is a diagram showing a shared library used in one embodiment of the present invention. FIG. 5 is a flow chart showing a procedure for task execution start according to one embodiment of the present invention. FIG. 6 is a flow chart showing a procedure for shared library loading according to one embodiment of the present invention. FIG. 7 is a sequence chart showing a procedure for calling up a sub-routine of a shared library according to one embodiment of the present invention. FIG. 8 is a diagram showing a sub-routine call up parameter block according to one embodiment of the present invention. FIG. 9 is a flow chart showing a procedure of a shared library side at a time of using a shared library from a program according to one embodiment of the present invention. FIG. 10 is a flow chart showing a procedure of a program side at a time of using a shared library from a program according to one embodiment of the present invention. FIG. 11 is a diagram showing an arrangement of memory address spaces of a program and a shared library according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION Referring now to FIG. 1 to FIG. 11 , one embodiment of a method for using a shared library according to the present invention will be described in detail. FIG. 1 shows a basic hardware configuration of a microprocessor (tamper resistant microprocessor 1 to which the present invention is applied. The microprocessor 1 has a processor core 10 , a code and data encryption/decryption processing unit 11 , a key value table 13 , a task ID storing register 14 , a random number generation unit 15 , and an external bus interface 12 . The microprocessor 1 to be used as the tamper resistant microprocessor differs significantly from the ordinary microprocessor in that it internally has the code and data encryption/decryption processing unit 11 . The execution code and data to be inputted into the processor core 10 are inputted after being decrypted by the code and data encryption/decryption processing unit 11 . Also, when the data flows out on the bus from the processor core 10 , the data are outputted after being encrypted by the code and data encryption/decryption processing unit 11 . The code and data encryption/decryption processing unit 11 uses an encryption key in the encryption processing and the decryption processing. This encryption key is acquired from the key value table 13 inside the same microprocessor 1 . Also, the task ID storing register 14 is used in selecting and acquiring the encryption key to be used among those in the key value table 13 . FIG. 2 shows a configuration of the key value table 13 . In the key value table 13 , a plurality of key value table entries 130 formed by registers for storing values of the encryption keys are arranged. The key value table entries can be provided as many as the number (n+1) of task IDs ranging from 0 to n as will be described below. The key value table entries 130 are identified each other as 130 0 , 130 1 , 130 2 , . . . 130 n for different task IDs. The key value table entry 130 i (0≦i≦1) can store an instruction key k 1 which is a key for encrypting/decrypting the execution code 32 of the program 3 , a data key k 2 which is a key for encrypting/decrypting data to be handled by the program 3 , and an address information 13 a which indicates a memory range to which the instruction key k 1 and the data key k 2 will be applied. As a plurality of key value table entries 130 0 , 130 1 , 130 2 , . . . 130 n are arranged in the key value table 13 , the instruction keys of different programs 3 can be stored into different key value table entries 130 i (0≦i≦1). In this way, it is possible to deal with the multi-task operation in which instances (processes or the like) of a plurality of programs encrypted by different encryption keys are operated in a pseudo-parallel manner. The task ID storing register 14 is a register for storing one task ID. The task ID storing register 14 will be used in identifying the task that is currently executed by the microprocessor 1 in multi-task operation, in which multiple tasks are operated in a pseudo-parallel manner. A task may be an instance of a single-threaded process, or one thread within a multi-threaded process, or an instance of a shared library that is being called by another task. The random number generation unit 15 provides a different random number with respect to each occasion of reading from the processor core 10 . This random number generation unit 15 can be used in generating a random number that is necessary for the key by which the program carries out the encryption or for the authentication. The software operated on the microprocessor to which the present invention is applied comprises a system software (OS), the application program 3 (hereafter simply referred to as program), and the shared library 4 . In the following, the configurations of the program 3 and the shared library 4 will be described. FIG. 3 shows a configuration of the program 3 in this embodiment. The program 3 is formed by a header 31 , an execution code 32 , an initialized data 33 , and an import table 34 . The header 31 contains the instruction key K 31 for decrypting the execution code 32 of the program 3 . The import table 34 specifies the shared library 4 to be used by the program 3 and symbols contained in the shared library 4 (symbols are identifiers for identifying sub-routines or the like contained in the shared library as will be described below), which are information necessary in loading the shared library 4 . FIG. 4 shows a configuration of the shared library 4 in this embodiment. The shared library 4 is formed by a header 41 , an execution code 42 , an initialized data 43 , and an import table 44 , similarly as the program 3 . The import table 44 of the shared library 4 contains information necessary in the case where this shared library 4 itself uses another shared library. The execution code 42 of the shared library 4 is formed by a bootstrap routine 42 a , an entry point code 42 b , and a number of sub-routines 42 c having respective functions. In FIG. 4 , a plurality of sub-routines are distinguished by a subscript i (1≦i≦n) as 42 c 1 , 42 c 2 , . . . 42 c n . The bootstrap routine (loader) 42 a is used in carrying out the processing necessary when the shared library 4 is loaded by the calling source program 3 . The entry point code 42 b indicates an entry point of the shared library 4 with respect to the program 3 which will be a call up target when the shared library 4 is to be used from the calling source program 3 . The other sub-routines 42 c i (1≦i≦n) of the shared library 4 are codes implementing functions to be actually used by the program 3 . Each sub-routines 42 c i (1≦i≦n) of the shared library 4 is assigned with an identifier for identifying it in the shared library 4 . Also, the execution code 42 of the shared library 4 contains the data key K 42 for encrypting data to be used in carrying out the requested processing, when the shared library 4 carries out a processing according to the call from the program 3 as will be described below. (Start of the Task) Next, with reference to FIG. 5 , a procedure by which the OS starts the execution of the task in response to a request for executing the program from the user or a request for creating a new process or a new thread from the existing process will be described. First, the OS creates the task (step S 51 ). This includes a securing of a memory region and a creation of a data structure for the purpose of managing the task. The OS also carries out the allocation of a task ID to the new task. Next, the OS acquires the instruction key K 31 from the header 31 of the program 3 , and stores the instruction key K 31 into the key value table entry 130 i (0≦i≦1) corresponding to the task ID allocated earlier (step S 52 ). Also, the OS refers to the import table 34 of the program 3 and loads each shared library 4 described therein by using a mechanism to be described below (step S 53 ). Any number of shared libraries 4 may be described in the import table 34 . Consequently, the OS carries out the loading operation separately for each shared library 4 described in the import table 34 . Note that the shared library 4 may be loaded in response to a request from the task after the task is started, instead of loading the shared library 4 before the task starts. When the loading of all the requested shared libraries 4 is completed, the OS carries out the switching of the context to the new task (here the context is data in which the processing state and the environment of the process are described), and starts the execution of the task (step S 54 ). At a time of this task switching, the task ID of the program is stored into the task ID storing register 14 . In the tamper resistant microprocessor 1 , the execution code 32 of the program is executed as follows. When the external bus interface acquires the instruction code from the external memory, the code and data encryption/decryption processing unit 11 refers to the content of the key value table 13 corresponding to the task ID stored in the task ID storing register 14 , and decrypts the execution code 32 by using the instruction key K 31 of the program 3 stored there. Then, the decrypted execution code 32 is given to the processor core 10 and executed there. (Loading of the Shared Library) FIG. 6 shows a procedure by which the OS loads the shared library. The ordinary microprocessor does not create another task for the shared library separately from the calling source program. However, the tamper resistant microprocessor 1 creates another task for the shared library 4 , in order to account for the security in the case where the program 3 or the shared library 4 happens to be malicious. For this reason, the first operation to be carried out by the OS at a time of loading the shared library 4 is the creation of a task and the allocation of the task ID to the new task (step S 61 ). Next, the OS acquires the instruction key K 41 from the header 41 of the shared library 4 , and stores the instruction key K 41 into the key value table entry 130 (0≦i≦1) corresponding to the task ID allocated earlier (step S 62 ). By this step, it becomes possible for the microprocessor 1 to decrypt the shared library 4 that is encrypted by using the instruction key K 41 in advance, and the different instruction keys K 41 are stored into different key value table entries 130 i (0≦i≦1). Consequently, even when a plurality of the shared libraries 4 exist, it becomes possible to identify them so that it is secure. Also, the OS refers to the import table 44 of the shared library 4 according to the need, and loads the other shared library 4 described therein (step S 63 ). The procedure of this loading is the same as the procedure in the case of loading the shared library 4 according to the import table 34 of the program 3 . Next, the OS executes the bootstrap routine (loader) 42 a of the shared library 4 (step S 64 ). The bootstrap routine 42 a carries out the necessary initialization processing, and then gives the control to the entry point code 42 b (step S 65 ). Then, the entry point code 42 b returns the control to the OS. When the control is returned to the OS, the shared library 4 is shifted into a standby state (step S 66 ). Note that, even in the case where the shared library 4 to be loaded is currently used by the other task already in a process of its execution, the loading of the shared library 4 is carried out at each occasion for each calling source task. As a result, as many task IDs as the number of calling source tasks are allocated with respect to the same shared library 4 . Here the execution code 42 of the shared library 4 can be loaded into the memory only once even when there are a plurality of calling source tasks, by utilizing the mechanism of the virtual memory of the microprocessor 1 and the OS. (Call Up of the Sub-Routine in the Shared Library) When there is a need to call up the sub-routine 42 c i (1≦i≦n) of the shared library 4 in a middle of the execution of the task, the processing for calling up the sub-routine 42 c i (1≦i≦n) is carried out according to a sequence shown in FIG. 7 . FIG. 8 shows a structure of a sub-routine call up parameter block 8 . The calling source task stores a shared library identifier 81 of the call up target shared library 4 , a subroutine identifier 82 of the sub-routine 42 c i (1≦i≦n) to be called up, and parameters 83 to be given to the sub-routine 42 c i (1≦i≦n), into the sub-routine call up parameter block 8 . After producing the sub-routine call up parameter block 8 , the calling source task gives the sub-routine call up parameter block 8 and makes a request for the sub-routine call up to the OS, by using a system call. Upon receiving this request, the OS stops the calling source task, selects the task of the call up target shared library 4 by referring to the shared library identifier 81 of the sub-routine call up parameter block 8 , and carries out the switching of the task to that shared library 4 . At this point, the sub-routine call up parameter block 8 is given to the task of the shared library 4 . When the switching of the task to the shared library 4 is carried out, the task ID of the shared library 4 is stored into the task ID storing register 14 . Then, the execution of the entry point code 42 b of the shared library 4 that has been in the standby state until then is resumed. The procedure for executing the encrypted execution code 42 of the shared library 4 is the same as the procedure for executing the program execution code 32 described above. When the execution is resumed, the entry point code 42 b of the shared library 4 refers to the content of the sub-routine call up parameter block 8 , and calls up the sub-routine 42 c i (1≦i≦n) corresponding to the sub-routine identifier 81 specified therein. The called up sub-routine 42 c i (1≦i≦n) refers to the parameters 83 in the sub-routine call up parameter block 8 , and carries out the requested processing. The data to be returned as the processing result is stored into the sub-routine call up parameter block 8 , and when the processing is completed, the processing returns to the entry point code 42 b and then to the OS from there. When the processing returns to the OS, the shared library 4 is set back to the standby state, and the OS returns the sub-routine call up parameter block 8 to the calling source task and resumes the execution of the calling source task. (Multi-Thread Operation) In the case where the program 3 that is the calling source of the shared library 4 carries out the multi-thread operation, a plurality of threads cannot use the task of the shared library 4 simultaneously. For this reason, when the calling source program 3 requests a creation of a new thread during its execution, the OS carries out the processing for loading once again for all the shared libraries 4 used by the calling source program 3 . As a result, each shared library 4 is allocated with as many task IDs as the number of threads of the respective calling source program 3 . When the call up of the sub-routine 42 c i (1≦i≦n) of the shared library 4 is requested from the thread, the OS selects an unused task ID that is allocated to that shared library 4 , and calls up the sub-routine 42 c i (1≦i≦n) of the shared library 4 by using this task ID. Also, in order to reduce the number of task IDs to be used, the OS may carry out the loading of the shared library 4 when there is a shortage of the task IDs at a time of calling up the sub-routine 42 c i (1≦i≦n), rather than at a time of creating the task. (Method for Maintaining Secret Data Unique to the Shared Library) The sub-routine 42 c i (1≦i≦n) of the shared library 4 maintains the secret data such as a processing progress and a processing method inside the shared library 4 as follows. The creator of the shared library 4 produces one data key K 42 which is an encryption key for encrypting the secret data, and embeds the data key K 42 into the execution code 42 (see FIG. 4 ). A value of this data key K 42 is embedded in the execution code 42 , and the execution code 42 is encrypted by using the instruction key K 41 , so that those who do not know the instruction key K 41 of the shared library 4 cannot take out the data key K 42 from the shared library 4 . In order to encrypt the data to be kept secret, a value of this data key K 42 and an address of the memory region to be encrypted are stored into the key value table 13 . Then, the data to be read/written with respect to the specified memory region is encrypted/decrypted by the code and data encryption/decryption processing unit 11 . It is also possible to distribute the data encrypted by using this data key K 42 in advance as the initialized data 43 of the shared library 4 , such that the sub-routine 42 c i (1≦i≦n) of the shared library 4 uses it by decrypting it as described above. After the data are written into the above described memory region and the processing is returned to the calling source once, when there is a need to read this data upon being called up again, it suffices to store the same data key K 42 into the key value table 13 again. However, according to the above described method, as long as the same shared library 4 is used, the data key K 42 of the same value will be used every time no matter how many times the shared library 4 is loaded. In other words, When the same data key K 42 is used, it becomes possible to store the encrypted data at a time of the one program execution, and write this data into the same memory region at a time of the another program execution, such that the state at a time of the previous execution can be reproduced. If such a re-utilization of the data is allowed, there is a possibility that this fact may be used as a way of attacking against the operation of the shared library 4 , so that this fact can be inconvenient in some cases. In such a case, as described in the commonly assigned co-pending U.S. patent application Ser. No. 09/984,407, it suffices to use the random number generated by the random number generation unit 15 of the microprocessor 1 as the data key K 42 , by regarding the instruction key and the data key as a key pair. The task of the shared library 4 acquires the random number from the random number generation unit 15 at a time of the execution, and stores this as the data key K 42 along with an address of the memory region to be encrypted by using this data key K 42 , into the key value table 13 . When the data key K 42 which is generated by the random number generation unit 15 for each task of the shared library 4 is used, the data key K 42 of different values will be used for different tasks. Consequently, it becomes impossible to re-utilize the data encrypted by using the data key K 42 which is obtained as described above. The content of the pair of the instruction key K 41 and the data key K 42 will not be lost even when the processing returns to the calling source, so that when the sub-routine of the shared library 4 is called up again, it is still possible to read the data encrypted by using this data key K 42 . (Exchange of Data) The shared library 4 and its calling source (program or another shared library) can exchange data with each other by using the sub-routine call up parameter block 8 described above. However, the content of this sub-routine call up parameter block 8 is not encrypted, so that there is a possibility for the OS to peep its content. In order for the shared library 4 and its calling source to exchange the secret data with each other, as proposed in commonly assigned co-pending U.S. patent application Ser. No. 10/028,794, it suffices to carry out the key generation using the Diffie-Hellman key exchange sequence between them. The key generated by the Diffie-Hellman key exchange sequence can be calculated only by two sides which carried out the key exchange. Namely, even the OS which can observe the exchange between them cannot learn the value of this key. In the following, this key will be referred to as a common key ck. As a memory region for exchanging the secret data, a memory region shared between them is allocated by the memory sharing mechanism provided by the OS. When each of the shared library 4 and the calling source registers the common key into the key value table entry 130 i (0≦i≦1) of the respective task, for this memory region, it becomes possible for each of them to decrypt and read the content encrypted and written into this memory region by the other one of them. The memory region prepared in this way will be referred to as a shared encrypted data region in the following. In the case where there is a need for the shared library 4 and its calling source to authenticate each other as an intended correspondent program 3 or shared library 4 , this can be done by attaching a signature according to the public key cryptosystem to a message of the above described key exchange sequence. For example, in the case where there is a need for the program 3 to authenticate the shared library 4 , a pair of the public key and the secret key is given to the shared library 4 in advance, and the public key of the shared library 4 is distributed to the creator of the program 3 in advance. The authentication is realized by attaching the signature based on the secret key of the shared library 4 to the message to be sent by the shared library 4 to the program 3 for the purpose of the key exchange, and verifying this signature at the program 3 by using the public key of the shared library 4 . On the other hand, in the case where there is a need for the shared library 4 to authenticate the program 3 , a pair of the public key and the secret key is given to the program 3 in advance, and the public key of the program 3 is distributed to the creator of the shared library 4 in advance. The authentication is realized by attaching the signature based on the secret key of the program 3 to the message to be sent by the program 3 to the shared library 4 for the purpose of the key exchange, and verifying this signature at the shared library 4 by using the public key of the program 3 . Note that the authentication and the key exchange are carried out simultaneously in these schemes, because if they are carried out separately, there would be no method for confirming that the correspondent with whom the authentication is carried out and the correspondent with whom the key exchange is carried out are the same one, so that the pretending of the correspondent by the malicious program would become possible and the authentication could not be done correctly. (Operation of the Shared Library) Using the basic operation of each part described above, the operation of the actual shared library 4 according to this embodiment will be described. FIG. 9 shows an operation on the shared library 4 side in a procedure by which the program 3 to be described here uses the shared library 4 . FIG. 10 shows an operation on the program 3 side at that time. Also, FIG. 11 shows an arrangement of memory address spaces of the program 3 and the shared library 4 at that time. The shared library 4 to be described here provides a routine for the operation to receive data from the program 3 , carry out some processing and return the processing result. Besides that, an assistant routine for carrying out the Diffie-Hellman key exchange sequence is also available from the program 3 . Also, it is assumed that the public key and the secret key for the authentication described above are given to the shared library 4 in advance, such that the shared library 4 can be authenticated from the program 3 side. Among them, the public key is distributed along with the shared library 4 such that a programmer who wishes to use this shared library 4 can incorporate this public key into the program to be created by the programmer. When the program 3 that uses the shared library 4 is executed, the loading of the shared library 4 is carried out, as described above with reference to FIG. 6 (step S 91 ). At a time of the loading, the bootstrap routine 42 a (see FIG. 6 ) of the shared library 4 is executed. At this point, the random number is acquired from the random number generation unit 15 of the microprocessor 1 , and the data key K 42 is generated by using the random number and stored into the key value table 13 as the data key K 42 of the shared library 4 . When the loading is completed, the shared library 4 is set in the standby state, and the execution of the program 3 is started. Similarly as the shared library 4 , the program 3 also acquires the random number from the random number generation unit 15 in order to encrypt the memory region to be used by the program 3 , and the data key K 32 is generated and stored into the key value table 13 as the data key K 32 of the program 3 (step S 101 ). Before using the function of the shared library 4 , the program 3 prepares the shared encrypted data region 115 for the purpose of the data exchange (step S 102 ). Then, the routine of the shared library 4 for carrying out the Diffie-Hellman key exchange sequence is called up (step S 103 ). In conjunction with this, the shared library 4 side also executes the Diffie-Hellman key exchange sequence (step S 92 ). At a time of the key exchange, the signature using the secret key for the authentication of the shared library 4 is attached to the message to be sent from the shared library 4 to the program 3 , and this authentication information is sent to the program 3 (step S 93 ). The program 3 receives this authentication information from the shared library 4 (step S 104 ). Here, the verification of the signature by using the public key for the authentication of the shared library 4 is carried out (step S 105 ). The key exchange sequence is finished only when this authentication succeeds (step S 106 ). By this verification of the signature, it is possible to confirm that the shared library 4 which is the correspondent with whom the key exchange is carried out is the intended correct shared library 4 . On the program 3 side, the value of the common key ck generated as a result of the key exchange is encrypted by using the data key K 32 of the program 3 and written into the secret data region 112 which cannot be read by anything other than the program 3 . Similarly, on the shared library 4 side, the above described common key ck is encrypted by using the data key K 42 of the shared library 4 and written into the secret data region 114 which cannot be read by anything other than the shared library 4 (step S 94 ). Next, the program 3 makes a request to the OS and secures the shared memory region for the purpose of the data exchange, and sets the common key ck in the key value table 13 such that it is applied to this shared memory region (step S 107 ). Also, the address of this shared memory region is notified to the shared library 4 , and the shared library 4 side also sets the common key ck in the key value table 13 such that it is applied to the same shared memory region. On the other hand, the shared library 4 receives the address of this shared memory region and carries out the key setting (step S 95 ). As a result, it becomes possible to use this shared memory region as the shared encrypted data region 115 . When the program 3 actually calls up the sub-routine 42 c i (1≦i≦n) of the shared library 4 for carrying out the desired processing, the data to-be given is entered into the shared encrypted data region 115 , and a checksum 111 of this data is calculated and attached to the data. Then, the sub-routine 42 c i (1≦i≦n) of the shared library 4 is called up (step S 109 ). When this call up signal is received (step S 96 ), the sub-routine 42 c i (1≦i≦n) of the shared library 4 checks the checksum 111 first (step S 97 ). When the checksum 111 does not match the data content, the processing is finished as an error (step S 971 ). When the checksum matches, the data and the request from the calling source side are read out from the shared encrypted data region 115 next (step S 98 ), In the case where a work memory region is necessary in a process of this processing, the shared library 4 may create and use its own memory region (work region) 116 which is encrypted by using the data key K 42 (step S 99 ). Next, the processing requested for this data is carried out (step S 990 ). When the requested processing is completed, the processing result is stored into the shared encrypted data region 115 , the checksum 111 is attached, and the processing returns to the program 3 (step S 991 ). When the processing returns, the program 3 checks the checksum 111 (steps S 110 , S 111 ). When the checksum matches the data content, the processing is continued by using the returned data (step S 112 ). When the checksum does not match, the error is returned and the processing is finished (step S 113 ). As long as the procedure for the key exchange and the format of the data exchange are disclosed publicly, anyone can create the program 3 that uses the shared library 4 described above. The fact that this shared library 4 satisfies the requirements regarding the security can be confirmed as follows. The secrecy of the data given from the program 3 can be guaranteed by the fact that the shared encrypted data region 115 shared between the program 3 and the shared library 4 is encrypted by using the common key ck. Here, the common key ck used for the encryption is generated by the Diffie-Hellman key exchange. Consequently, the value of the common key ck will not be known by anything other than the program 3 and the shared library 4 , unless either one of them intentionally or accidentally disclose this common key ck publicly. Also, the same shared encrypted data region 115 is used at a time of returning the processing result, so that this content can be viewed only by the program 3 and the shared library 4 . Even if the other program attempts to read the processing result, the other program does not know the value of the common key ck according to the original Diffie-Hellman key exchange so that the content cannot be decrypted. It is possible to consider an attack in which the OS fraudulently substitute another program into the calling source program 3 , and the program 3 after the substitution steals the processing result returned from the shared library 4 , However, the calling source program would be the program 3 of the instruction key K 31 which is different before and after the fraudulent substitution so that the contents of the instruction key K 31 and the data key K 32 that are managed as a pair in the key value table 13 would both be changed, The common key ck is stored in the shared encrypted data region 115 which is encrypted by the data key K 32 before the fraudulent substitution, but the value of the data key K 32 in the key value table 13 after the fraudulent substitution is changed so that the program 3 after the fraudulent substitution cannot read the common key ck. For this reason, it is in principle impossible for the program 3 after the fraudulent substitution to decrypt the data returned from the shared library 4 . It is also possible to consider another attack in which the erroneous operation is induced as another program 3 alters the content of the data exchanged between the program 3 and the shared library 4 in a course of the data exchange between them. However, the program 3 on the side of altering the data does not know the value of the common key ck used in encrypting this data so that it cannot predict a result of decrypting the altered result. Consequently, the decrypted result of the data becomes random if the alteration is made and the alteration will be detected by the checking of the compatibility according to the checksum 111 . Even in the case where a plurality of tasks are using the same shared library 4 simultaneously, a different task is allocated to the shared library 4 for a different calling source task, so that a respective shared library 4 will use a respectively different data key K 42 . For this reason, the case of erroneously giving the data received by each shared library 4 from some calling source to another calling source will not occur. It is impossible for the program 3 that calls up the shared library 4 itself to see the execution code 42 of the shared library 4 because the shared library 4 is encrypted by its own unique instruction key K 41 . Also, the content of the work memory used in a process of the processing by the shared library 4 uses the secret data region 114 which is encrypted by using the data key K 42 that is known only by the shared library 4 , so that it is impossible to peep this content. Note that the shared library 4 described above has the secret key for the authentication in advance. For this reason, the third party who does not know this secret key cannot create the shared library that can be substituted into this shared library 4 at his own will. This goes against the characteristic that the shared library compatible with the existing shared library can be created freely, which is an advantage of the dynamic link shared library. However, this is the limiting factor which is indispensable in guaranteeing the security of the operation of the shared library 4 to the program 3 . When a developer other than the original provider of the shared library 4 needs to create a new shared library 4 which is compatible with this shared library 4 in order to add some function, it suffices to ask the provider of the original shared library 4 to confirm the security of the new shared library 4 and ask him to embed the secret key into the new shared library 4 . As described above, according to the present invention, it becomes possible to use the protected shared library from a protected application program operated on the tamper resistant microprocessor. By using the shared library, it becomes possible to improve the program development efficiency and the ability to enhance the function of the program. It is also possible to protect the secrecy of the data such as the processing result, and the processing method inside the encrypted program and the shared library, by enabling the exchange of the secret data and the mutual authentication. According to the method for using the shared library realized in this way, the execution code of the shared library is protected because the shared library itself is processed as a task which has a single identifier, and the instruction key for encrypting/decrypting the shared library is recorded at a location within the microprocessor corresponding to that identifier. In such a shared library, the processing result and the data of the processing result are encrypted by using the data key of the shared library when the shared library carries out the processing requested from the program. For this reason, in addition to the encrypting of the code of the shared library itself, it is possible to prevent the leakage to the external of the internal processing method and processing result. Also, it is possible to surely protect the processing content and the processing result within the shared library even in the case where the calling source is changed before and after the processing by the OS or the like, as the checksum matches or nor is checked each other when the request for processing is received and the processing result is returned to the calling source. In addition, it is also possible to use one shared library from a plurality of calling sources because the loading is carried out as many times as the number of the calling sources. It is also to be noted that, besides those already mentioned above, many modifications and variations of the above embodiments may be made without departing from the novel and advantageous features of the present invention. Accordingly, all such modifications and variations are intended to be included within the scope of the appended claims.

A computer readable storage medium encoded with computer instructions for causing a tamper resistant microprocessor which has a function for decrypting and executing encrypted codes and a table formed by a plurality of regions for storing a plurality of encryption keys corresponding to at least one program and at least one shared library to be called up by the at least one program, to use a shared library called up from a calling source program, the instructions including the steps of causing the tamper resistant microprocessor to create a task for the shared library, causing the tamper resistant microprocessor to allocate a task identifier to the task, causing the tamper resistant microprocessor to acquire an instruction key from a header of the shared library, causing the tamper resistant microprocessor to store the instruction key into a region of the table corresponding to the task identifier allocated to the task for the shared library in the microprocessor, causing the tamper resistant microprocessor to initialize by executing a loader in the shared library, and causing the tamper resistant microprocessor to return a control to the calling source program via an entry point in the shared library.

REFERENCE TO RELATED APPLICATION The application is a continuation-in-part application and claims priority to U.S. patent application entitled “SAFETY BED HAVING ELEVATING MATTRESS,” Ser. No. 11/857,263, filed Sep. 18, 2007, now U.S. Pat. No. 7,681,260 which claims priority to U.S. Provisional Application 60/845,476, filed Sep. 18, 2006, both of which are incorporated herein by reference in their entirety. FIELD OF THE INVENTION The present invention is directed to a safety bed primarily for use in care for patients with physical and developmental disabilities where special circumstances require a bed designed to reduce the possibility of injury to the patient. Specifically, a bed is required which would prevent falls and entrapment for individuals who need care. DESCRIPTION OF THE PRIOR ART Safety beds are well known and described in the field, such as those which are commonly found in certain medical and geriatric facilities. Generally, these beds include a guard member assembly which can be raised to prevent the patient from falling out of the bed and lowered to allow the patient ingress and egress from the bed. Known guard member assemblies, such as those described in U.S. Pat. No. 5,742,959, typically include a top and a bottom horizontal member as well as a series of spaced vertical bars there between. Such assemblies are therefore a lattice type of structure having a number of associated gaps. Other safety or guard member assemblies for cribs, such as described in U.S. Pat. No. 5,926,870, have similarly “gapped” structures. In spite of fairly strict governmental standards that have been specifically mandated for the construction of safety beds, there have been numerous reported instances in which a patient has fallen not only through gaps in a guard member assembly, but also between other gaps often created between the lateral side of the mattress and box spring and the guard member assembly, and between various portions of the bed frame itself. These injuries can not only be traumatic but also catastrophic, producing entrapment and possibly death. Therefore, there is an urgent need in the field to provide a safety bed which all but eliminates the probability of such injuries as those described above. Reference is specifically made to U.S. Pat. No. 6,453,491 to Wells et al. which describes a safety bed having a releasable guard member assembly. The guard member assembly includes at least one guard member sized to extend over an entire lateral side of the frame of the bed. In addition, there is a means for releasably attaching the guard member to the bed frame. The means includes a hinge for attaching the lower end of the guard member to the bed frame. The guard member can then be selectively pivotally moved between a first raised position and a second lowered position. When the guard member is in the first position, the guard member is in compressive contact with a lateral side of the mattress to minimize the existence of gaps between the bed frame, the guard member, and the mattress. When the guard member is in the second position, the guard member permits a patient ingress and egress from the bed. When the guard member is secured in the first position the patient is prevented from falling out of the bed. At the same time, the guard member also prevents or at least substantially minimizes the incidences of gap-related injuries which can occur using standard known guard member assemblies. Although safety beds have been improved to prevent entrapment of a patient between the mattress and the side board, none of the prior art has addressed the problem of patients crawling out of the bed. A restless patient can easily climb over top of the side boards and potentially fall to the floor. Potential solutions to this problem are included in U.S. Pat. No. 5,926,870, which includes unusually high end and side panels. The high end and side panels create a higher barrier, which is harder for the patient to climb over. A similar solution has been proposed in U.S. Pat. No. 4,811,436, which creates a higher barrier for a patient. The design of these two patents places the patient in a fixed location and with the side boards up, out of reach of the health practitioner. In order to access the patient, the health practitioner must fold down the guard member and likely bend over to reach the patient. These designs both create an uncomfortable work environment for the practitioner, as well as a potential safety risk for the patient. A safety bed should not only attend to the patient's needs, but also create a more efficient work space for the health practitioner. A safety bed should combine the safe enclosure of high side walls for the patient, as well as a high mattress position to assist the health practitioner. Therefore, a need exists to combine safety features for the patient and assist the practitioner in caring for the patient. SUMMARY OF THE INVENTION The present invention is directed to a safety bed for patients with physical and developmental disabilities. The safety bed comprises a bed frame of substantially rigid construction to prevent gaps from forming between the bed frame and a mattress positioned within the bed frame. The bed frame includes a headboard, a footboard, and a pair of opposing side boards which interconnect the headboard and the footboard. Disposed within the bed frame is a mattress support frame that is connected to the pair of opposing side boards for supporting the mattress and for independently raising and lowering the mattress within the bed frame without causing any corresponding vertical movement on the part of the headboard, footboard and pair of opposing side boards. The headboard and footboard extend below the mattress and the mattress is in compressive contact within the bed frame such that there are no gaps between the mattress and the bed frame. The present invention is also directed to a safety bed which comprises a bed frame of substantially rigid construction to prevent gaps from forming between the bed frame and a mattress positioned within the bed frame. The bed frame includes a headboard, a footboard, and a pair of opposing side boards which interconnect the headboard and the footboard. In addition, a mattress support frame is connected to the pair of opposing side boards and is disposed within the bed frame for supporting the mattress for independently raising and lowering the mattress within the bed frame without causing any corresponding vertical movement on the part of the headboard, footboard and pair of opposing side boards. The headboard and footboard extend below the mattress and the mattress is in compressive contact within the bed frame such that there are no gaps between the mattress and the bed frame. Further, the safety bed includes at least one pair of rotatable guard members disposed on an opposing lateral side of the bed frame. The guard members are sized to occupy the entirety of the lateral space between the footboard and the headboard such that there are no gaps between the guard members, the footboard and the headboard. The primary patentable feature is the combination of the safety bed described in the '491 patent to Wells et al. and the adjustable (hi-lo) feature allowing for the electronic elevation and lowering of the mattress within the safety bed. The bed of the present invention allows seamless, remote control high and low mattress adjustment without any movement of the bed frame. In other words, the mattress support frame can be raised and lowered within the bed frame without any corresponding movement on the part of the side boards, headboard or footboard of the bed frame. Further advantages of the present invention include an adjustable mattress height. The mattress height, surface-to-floor, can be remotely controlled and be positioned at any height from 17 inches to 34 inches; thus, allowing for more comfort for the user and the caregiver. The adjustable mattress height allows the distance from the surface of the mattress to the top of the safety rail to be varied from 1 inch to 36 inches, preferably 8 inches to 25 inches. Varying the height of the mattress within the frame does not compromise the geometry of the bed and frame and maintains the minimal gaps between frame and mattress throughout the full range of motion. The articulated mobility of the mattress easily allows for the raising of the back portion and/or knee portion. The bed frame includes adaptable, full-length safety rails that combine the strength of solid wood with clear non-breakable plastic or polyethylene terepthalate glycol (PETG) panels. The bed includes a rigid construction with a high-low bed frame, which utilizes tubular steel or aluminum, preferably the lighter weight aluminum, to maximize strength and stability of the sleep surface in all positions. The present invention includes a full-electric hand-held remote operation that uses ultra whisper quiet, rapid-moving DC motors. Preferably, the motor has a dynamic operating capacity of 400 pounds and meets all necessary UNDERWRITER LABORATORY (UL) safety standards for medical beds. The present invention helps the patient because caregivers have full view for easy monitoring. The bed's user can see his environment, thus reducing the chance of claustrophobia and encouraging a comfortable rest. The headboard and footboard extend below the mattress and box spring reducing the risk of entrapping an arm and leg. The advantage of the safety bed of the present invention is that not only is it visually appealing, but it also addresses safety issues in a variety of ways, including providing clear windows incorporated in the safety rails to prevent the opportunity for entanglement in contrast to traditional institutional beds. The present invention also virtually eliminates entrapment issues. The space between side boards, headboard and footboard is nearly nonexistent even with compression. The aesthetics and hardwood construction of the bed promote a “homey” atmosphere for the benefit of not only the resident whose self-esteem may be an issue, but also for family members and caregivers who appreciate a more normalized setting. Another advantage of the present invention is that the guard member when secured in the first position will prevent the patient from falling out of the bed, while also preventing or at least substantially minimizing the incidence of “gap-related” injuries, which can occur using standard guard rail assemblies. The present guard rail adapter and the safety bed using the adapter are in compliance with the strict governmental standards which are required for facility safety beds. A further advantage of the present invention is that the guard member is easily movable between the first and second position for a caregiver, but not for the patient. In addition, the adapter can be adapted to be removed from the bed frame without requiring tools or intensive labor or modifications. In addition, no part of the mattress support structure touches the ground as it is attached to the side boards of the bed frame. This facilitates easier movement of the bed from one location to another. It is also within the scope of the present invention to include a second or upper guard member on each side of the safety bed. With the addition of the upper guard member, the height of the entire bed and frame can be increased, while the mattress can still be raised and lowered as in the single guard rail safety bed. By adding an upper guard member and increasing the overall height of the bed, the patient is more fully enclosed inside the bed frame. The extra height of the bed frame creates a safe enclosure for a taller patient, who may be able to crawl out of a lower safety bed, with only a single guard member assembly. The objects and advantages of the invention will appear more fully from the following detailed description of the preferred embodiment of the invention made in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top-perspective illustration of the safety bed with a single guard member assembly and the mattress in the upper position. FIG. 2 is a top-perspective illustration of the safety bed with a single guard member assembly and the mattress in the lower position, which is visible in the cut-away. FIG. 3 is a top-perspective illustration of the safety bed with a single guard member assembly and the mattress in the upper position. The guard member assembly is in the lowered position. FIG. 4 is a top-perspective illustration of the safety bed with a single guard member assembly and the mattress in the lower position, which is visible in the cut-away. The guard member assembly is in the lowered position. FIG. 5 is a top-perspective illustration of the safety bed with a double guard member assembly. FIG. 6 is a top-perspective illustration of the safety bed with a double guard rail assembly. The upper guard rail assembly is detached and the lower guard rail assembly is folded down. FIG. 7 is an exploded, perspective, view of the safety bed of the present invention illustrating the mechanism by which the mattress is raised and lowered, and by which the mattress is actuated. FIG. 8 is an exploded, perspective, partial view of the safety bed of the present invention illustrating the mattress support structure between the two parallel opposing side boards of the bed frame. DETAILED DESCRIPTION OF THE INVENTION The following description relates to a safety bed design according to a specific embodiment. It will be readily apparent from the following discussion, however, that certain variations and modifications can easily be imagined within the inventive concepts as claimed herein. Furthermore, certain terms are used throughout this discussion such as “upper,” “lower,” “lateral” and the like which assist in providing a frame of reference with regard to the accompanying drawings. These terms, however, should not necessarily be construed as limiting of the present invention, except as otherwise stated herein. Referring to FIG. 1 , there is illustrated a safety bed 10 , with the mattress 26 in the upper position in accordance with the preferred embodiment of present invention. The safety bed includes a wooden bed frame 14 , the frame including a headboard 30 , a footboard 34 , and a pair of side boards 38 (only one of which is shown in FIG. 1 ), which interconnect the headboard 30 and the footboard 34 . The bed frame 14 and each of the preceding components collectively define a supporting structure for a stacked mattress 26 and box spring (not shown). Each of the headboard 30 and footboard 34 extend above an upper surface 46 of the mattress 26 , the headboard 30 and footboard 34 each including a pair of bed posts 48 which are secured to a unitary member 50 , 54 , respectively, the posts being secured thereto using conventional furniture fastening techniques, such as a knockdown fitting having an eccentric cam so as to reduce forward play in each of the interconnected components. Referring to FIGS. 1 and 2 , a guard member adapter 60 according to the preferred embodiment includes a pair of guard members 64 , 68 , each of the guard members being disposed on an opposing lateral side of the bed frame 14 . For purposes of the discussion which follows, only details specific to one of the guard members 64 are provided, though it should be understood that the remaining guard member 68 is identical in appearance and function. More specifically, and referring to FIGS. 1-6 , the guard member 64 includes an upper end 72 and a lower end 76 . The guard members 64 are substantially planar members made from wood having a grain preferably like that of the bed frame 14 . Each guard member 64 is sized to occupy the entirety of the lateral space between the footboard 34 and the headboard 30 ; that is, the length of a side board 38 without any gaps there between. The guard member 64 has a corresponding height dimension such that the upper end 72 of the member can pivot about the lower end 76 between a first or raised position, such as shown in FIG. 1 , and a second or lowered position, such as shown in FIG. 3 . The axis defining the pivot axis of the lower end 76 is stationary throughout the pivoting action, this axis always being beneath the upper surface 46 of the mattress 26 . Each of the first and second positions assumable by the guard member 64 as shown in FIGS. 1 and 3 , respectively, are substantially in the same lateral plane as the side board 38 . Each of the guard members 64 , 68 include a set of preferably unbreakable transparent windows 100 made from PLEXIGLAS, polycarbonate, PETG or other suitable material, the windows being disposed between the upper and lower ends 72 , 76 , and permitting a caregiver to monitor a resting patient from a sitting position without having to first look over the guard member 64 . Though three windows are shown, any number of windows can be provided; for example, a single window (not shown) extending over the length of the guard member 64 could be substituted. Referring to the figures in general and in operation, the guard member 64 is attached to the bed frame 14 and in the first position assumed in FIG. 1 . In this raised position, the patient (not shown) cannot fall out of the bed in that the upper end 72 of the guard member 64 is substantially above the upper surface 46 of the mattress 26 . Furthermore, because the guard member 64 extends along the entire lateral side of the bed frame 14 and includes no gaps, either within the guard member itself or between the lateral side of the mattress 26 and the guard member 64 , the risk of injury is greatly minimized. Retraction of each of the locking members 80 located at the upper end 72 of the guard member adapter 60 is accomplished by pulling each of the levers 90 against the bias of springs 88 and placing the lever 90 within respective unlocked slot positions 94 , thereby releasing the upper end and permits the guard member 64 to pivot downwardly about the lower end 76 from the first position, shown in FIG. 1 , to the second position, as shown in FIG. 3 . In this lowered position, the patient (not shown) can easily get into and out of the bed as needed. The guard members 64 , 68 can be permanently, albeit rotatably attached to the bedposts 48 of both the headboard 30 and the footboard 34 at location 75 by means of a locking pin (not illustrated) which joins the guard members 64 , 68 to the bedposts 48 in rotatable fashion. Alternatively, the guard members 64 , 68 can be removably attached to the bed frame 14 . In order to remove the guard member adapter 60 from the bed frame 14 from the first position, as shown in FIGS. 1 and 2 , the guard member 64 is first pivoted to the second position, as shown in FIGS. 3 and 4 , as described above, by releasing the locking members 80 at each opposing side of the upper end 72 . Once the member 64 has been pivoted, the locking members 80 at the lower end 76 of the guard member 64 can also be retracted in a similar manner by pulling each of the levers 90 against the biasing of springs 88 to unlock the lower end and remove the guard member from the bed frame 14 . Though not shown, guard member 68 can be similarly removed. As noted and upon removal of the guard member adapter 60 , the safety bed 10 looks no different than a standard twin size bed and can be used for that purpose. Additionally, FIG. 1 shows the mattress 26 in the raised position, and close to the top of the bed frame 14 . In the raised position, a patient lying on the mattress 26 can easily be attended to by a health practitioner. The transparent windows 100 in the guard members 64 , 68 allow the patient to look out into the environment. With the guard member 64 in the upper position, the patient is still safely enclosed in the safety bed 10 . If the practitioner needs to have better access to the patient, the guard member 72 can be lowered as shown in FIG. 3 . Referring to FIG. 2 , the mattress 26 can be lowered within the confines of the bed frame 14 , so that the upper surface of the mattress 46 is well below the top of the guard members 64 , 68 . With the mattress 26 in the lowered position, the patient is safely held within the walls of the safety bed 10 . The windows 100 in the guard members 64 , 68 allow light into the safety bed 10 , even when the mattress 26 is in the lowered position. This adds to the comfort of the patient. As shown in FIG. 4 , a health provider can still access the patient when the mattress 26 is in the lowered position. The guard member 64 can be lowered to allow greater access to the patient. However, even when the guard member 64 is lowered, the top of the mattress 46 is still below the lower end 76 of the guard member 64 . Even when the mattress 26 is in the lowered position, there is still a significant barrier for the patient to escape from the safety bed 10 . The second embodiment of the present invention is shown in FIG. 5 . The second embodiment includes a double set of guard members 64 , 68 on each side of the safety bed 10 . The addition of double guard members 64 , 68 increases the overall height of the bed frame 48 , and is appropriate for taller patients. When the mattress 26 is in the lowered position, even a patient of significant height will be safely enclosed in the safety bed 10 . In order to access the patient, the mattress 26 can be raised and the guard members either removed and/or lowered. Referring now to FIG. 7 , the mattress support structure 200 is illustrated. The mattress support structure 200 is supported by support brackets 202 which attach to the pair of side boards 38 by bolts or other means known to art and suspend the mattress support structure 200 within the bed frame 14 . The mattress support structure 200 is preferably made of tubular steel or aluminum to maximize the strength and stability of the sleep surface in all positions. Referring to FIG. 8 , the lower substructure 212 which is illustrated as a pair of tubular posts 214 remains fixed on top of the support brackets 202 . The upper substructure 216 is connected above the lower substructure 212 by telescoping columns (not illustrated) actuated electrically within the tubular posts 214 . The electric motor 222 is controlled by a remote control 220 . The action of raising and lowering the mattress support structure 200 is well known to art and can include any of a number of electronic, pneumatic or other types of elevating mechanisms. Reference is made to the OKIMAT and DUOMAT line of bedding motors produced by OKIN America LLC (Shannon, Miss.) and actuators produced by Precision Technology, Inc. (Roanoke, Va.) for an example of a suitable mechanism for use here. It is within the scope of this invention to use additional mechanisms to accomplish the same task. Additionally, although a column elevation system 214 is shown, other linkages such as a parallelogram or scissor linkage could also be used. As shown in FIGS. 7 and 8 , the mattress support structure 200 has articulating joints 230 which separate the head section 202 , the thigh section 204 , and the foot section 206 . The articulating joints 230 allow the head section 232 , thigh section 234 and foot section 236 to raise and lower independently. This allows for greater patient comfort. The remote control 220 can control additional DC motors (not illustrated) to operate actuating pistons 235 to raise and lower the sections 232 , 234 , and 236 . In operation, the electric motor 222 is plugged into a standard wall outlet by an electric cord (not illustrated). The upper substructure 216 of the mattress support structure 200 is operated typically using a corded remote control 220 . It is also within the scope of the present invention to provide a backup battery system (not illustrated) in the event of a power outage. For example, the mattress support structure 200 can be provided with a 9 volt backup battery designed to allow the operator to lower the head section 232 and/or foot section 236 or the entire upper substructure 216 . It is understood that the invention is not confined to the particular construction and arrangement of parts herein illustrated and described, but embraces such modified forms thereof as come within the scope of the following claims. Thus, the invention encompasses all different versions that fall literally or equivalently within the scope of these claims.

A safety bed including a bed frame with a head board, side boards and a footboard, pivotally attached guard members, and a vertically adjustable mattress support structure which is attached to the side boards. The mattress support structure is capable of being lowered within the confines of the bed frame to prevent a patient from crawling out of the safety bed. The mattress support structure capable of being raised within the bed frame to grant a health care provider access to the patient. The raising and lowering of the mattress support frame does not affect height of the side boards or guard members.

BACKGROUND OF THE INVENTION The present invention relates to new acylamino acid derivatives with valuable pharmacological properties, especially properties favorably affecting nitrogen metabolism, to the use of these acylamino acid derivatives as pharmaceuticals and dietetics, especially for the treatment and prophylaxis of, for example, disturbances of nitrogen metabolism caused by liver and/or kidney damage in relatively large mammals, especially humans, to pharmaceuticals and dietetics which contain acylamino acid derivatives as active ingredients, and to the preparation of the acylamino acid derivatives. It is known that the corresponding α-keto analogs of essential amino acids are possible substitutes for the essential amino acids. After enzymatic transamination, the α-keto analogs are, with a few exceptions, available as building blocks for proteins in the body (J. H. Close, N. Engl. J. Med. 290 (1974), pp. 663-667). Leucine and its α-keto analog 4-methyl-2-oxovaleric acid (α-ketoleucine) play a special part in protein synthesis because the modes of action of the two substrates complement each other synergistically. On the one hand, protein synthesis is stimulated by leucine, and on the other hand, protein breakdown is inhibited by α-ketoleucine (M. E. Tischler, M. Desantels, A. L. Goldberg, J. Biol.-Chem. 257 (1982), pp. 1613-1621). Furthermore, nitrogen is consumed in the synthesis of α-amino acids from their corresponding α-keto analogs in the body, which leads additionally to a reduction in the amount of nitrogen compounds excreted in the urine. This knowledge has been applied by utilizing the effects of α-keto and α-amino acids in a wide variety of metabolic situations, especially in catabolic states as occur in connection with hepatic and renal insufficiencies, trauma, sepsis and fasting states. Compositions which contain α-amino carboxylic acids and α-keto analogs of amino carboxylic acids are disclosed, for example, in French Patent Application No. FR 2,556,593 or are already marketed in the form of preparations for oral administration, such as, for example, the commercial product ULTRAMINE (manufactured by Pfrimmer). Although these products have been used successfully in therapy, there are still various problems associated both with their manufacture and with their oral and parenteral use. Thus, for example, when administered orally, these amino acids and α-keto analogs are, unfortunately, not utilized optimally because of the absorption behavior. When administered parenterally as described, for example, for leucine and ketoleucine by G. Francois et al. (Clin. Nutr., 3 (1984), pp. 99-101), the advantageous effect of a reduction in nitrogen excretion can only be achieved if substrates of carbohydrate metabolism are administered concurrently. However, infusion solutions which are manufactured to contain substrates of carbohydrate metabolism in addition to amino acids and their α-keto analogs have the disadvantage that when reducing sugars such as, for example, glucose are used, Maillard products may form in completely assembled infusion solutions either during the necessary heat sterilization or during storage. SUMMARY OF THE INVENTION An object of the invention is to prepare new amino acid derivatives with valuable pharmacological and dietetic properties, which permit the aforementioned disadvantages of the prior art to be overcome. Another object of the invention is to provide new pharmaceuticals and/or dietetics which can be used in amino acid replacement therapy and for treating or preventing disturbances of nitrogen metabolism and which do not have the aforementioned disadvantages of the state of the art. These and other objects of the invention are achieved by providing a compound corresponding to the formula I: ##STR2## in which R 1 represents an organic radical A ##STR3## in which Y represents hydrogen or another bond, R 20 represents hydrogen or methyl, and if R 20 is hydrogen, R 21 denotes isopropyl and, if R 20 is methyl, R 21 denotes methyl or ethyl, R 2 represents the organic radical A' ##STR4## in which R 20 and R 21 have the above meanings, R 3 represents hydroxy or lower alkoxy or an amino group B ##STR5## in which R 5 denotes hydrogen or lower alkyl, and R 6 denotes hydrogen, lower alkyl or, if R 5 is hydrogen, R 6 may be the deamino radical of a biogenic amino acid, or R 5 and R 6 together with the N atom to which they are bonded form a 3- to 6-membered heterocycle, and Z 1 and Z 2 together represent oxygen or a physiologically acceptable alkylenedioxy group O--(CH 2 ) n --O in which n is 1 to 4, or Z 1 and Z 2 each represent a physiologically acceptable R 7 --O-- group in which R 7 denotes lower alkyl, or Z 1 represents an R 7 --O-- group in which R 7 has the above meaning, and Z 2 together with Y represents a bond, or a salt thereof in which R 3 represents hydroxy with a physiologically acceptable cation. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS The invention relates to new acylamino carboxylic acid derivatives of formula I ##STR6## in which R 1 represents an organic radical A ##STR7## in which Y represents hydrogen or another bond and, if R 20 is hydrogen, R 21 denotes isopropyl and, if R 20 is methyl, R 21 denotes methyl or ethyl, R 2 represents the organic radical A' ##STR8## in which R 20 and R 21 have the above meanings, R 3 represents hydroxy or lower alkoxy or an amino group B ##STR9## in which R 5 denotes hydrogen or lower alkyl, R 6 denotes hydrogen, lower alkyl or, if R 5 is hydrogen, R 6 may be the deamino radical of a biogenic amino acid, or R 5 and R 6 together with the N atom to which they are bonded form a 3- to 6-membered heterocycle, and Z 1 and Z 2 together represent oxygen or a physiologically acceptable alkylenedioxy group O--(CH 2 ) n --O in which n is 1-4, or Z 1 and Z 2 each represent a physiologically acceptable R 7 --O-- group in which R 7 denotes lower alkyl, or Z 1 represents an R 7 --O-- group in which R 7 has the above meaning, and Z 2 together with Y represents a bond, and salts of those compounds of formula I in which R 3 represents hydroxy with a physiologically acceptable cation. Where the substituents in the compounds of formula I represent or contain lower alkyl groups, these can be straight-chain or branched and preferably contain 1 to 4, particularly 1 to 2, carbon atoms. In the compounds of formula I, Z 1 and Z 2 preferably together represent oxygen, so that the resulting compounds have the general formula Ia ##STR10## in which R 1 to R 3 have the meanings indicated above. These are referred to hereinafter as "ketopeptides". Besides the ketopeptides of formula Ia, the invention also includes their physiologically acceptable derivatives in which the keto group is derivatized by ketal formation, that is to say, compounds of formula I in which Z 1 and Z 2 each represent a physiologically acceptable R 7 --O-- group. The lower alkyl group R 7 in such groups is an alkyl group with, for example, 1 to 4, particularly 2 to 3, carbon atoms, which is preferably straight chain. R 7 preferably represents ethyl. A diol can also be used for the ketal formation. Z 1 and Z 2 in compounds which result in this case together represent an alkylenedioxy group. In the case of cyclic ketals, those particularly preferred are the ones in which the alkylene chain contains 2 or 3 carbon atoms. The ketal derivatives of compounds of formula Ia also include compounds in which the enol form of these compounds is derivatized by ketal formation, that is to say compounds in which Z 1 represents an R 7 --O-- group, and Z 2 together with Y forms a bond. These are referred to hereinafter as "enol ether derivatives". A radical A' present in R 1 and/or R 2 represents the radical X of a biogenic α-amino carboxylic acid X--CHNH 2 --COOH selected from the group consisting of valine, leucine and isoleucine. Biogenic amino acids are preferably those L-α-amino carboxylic acids found in biological material. Such groups of formula A' are then the radical (CH 3 ) 2 CH-- derived from valine, the radical (CH 3 ) 2 CH--CH 2 -- derived from leucine and the radical CH 3 --CH 2 --CH(CH 3 )-- derived from isoleucine. To simplify the naming of the L-α-amino carboxylic acids the three-letter symbols recommended by the IUPAC nomenclature commission are used. The symbols used in the present application are listed in the following table. ______________________________________Amino acid Symbol______________________________________Valine ValLeucine LeuIsoleucine IleLysine LysArginine ArgHistidine HisOrnithine Orn______________________________________ R 1 is advantageously an organic radical which can be derived in the manner described from L-amino acids selected from the group consisting of valine and leucine. R 2 is likewise advantageously a corresponding radical which can be derived from L-amino acids selected from the group consisting of valine and leucine. The carbon atom to which R 3 is bonded in the compounds of formula I is at the oxidation state of a carboxylic acid C atom. This means that the compounds represent acids (R 3 =OH) and their salts with physiologically acceptable cations, or their esters and amides. Acids of formula I in which R 3 =OH and their salts with physiologically acceptable cations prove to be particularly advantageous. Examples of suitable pharmaceutically acceptable cations include metal cations such as cations of alkali metals such as sodium or potassium, alkaline earth metals such as calcium or magnesium, or zinc. Another advantageous physiologically acceptable cation is an ammonium group C ##STR11## in which the substituents R 8 to R 11 denote, independently of one another, hydrogen or lower alkyl, or two of the substituents R 8 to R 11 together denote a C 4 - or C 5 -alkylene chain, and the other substituents denote hydrogen, or one of the radicals R 8 to R 11 represents the deamino radical of a basic biogenic α-amino carboxylic acid, and the other radicals denote hydrogen. Lower alkyl radicals R 8 to R 11 can be straight-chain or branched, but only one of the radicals can be tert. butyl, or only two of the radicals can be isoalkyl radicals. As used herein, the term "a deamino radical of a basic biogenic α-amino carboxylic acid" refers to a radical which results from a basic amino acid when the basic amino group is removed. Preferred ammonium radicals of formula C include NH 4 + and ammonium ions which contain the deamino radicals of lysine, arginine, histidine or ornithine. Where R 3 denotes a lower alkoxy group, this can contain 1 to 4 carbon atoms and be straight-chain or branched. If R 3 denotes an amino group B, the radicals R 5 and R 6 can, independently of one another, be hydrogen or lower alkyl. Lower alkyl groups R 5 or R 6 can be straight-chain or branched and preferably contain 1-4, particularly 1-2, carbon atoms. R 5 and R 6 can also form, together with the nitrogen atom to which they are bonded, a 3- to 6-membered heterocycle. Examples of suitable heterocycles include aziridine, pyrrolidine, piperidine. It is furthermore possible, if the radical R 5 is hydrogen, for R 6 also to be the deamino radical of a biogenic amino acid. Such compounds of formula I represent tripeptide derivatives. The naming of the ketopeptides of formula Ia and their derivatives in the present application is consistent with the IUPAC nomenclature rules using the three-letter symbols already defined above, in such a way that an α-keto carboxylic acid, which is derived from a biogenic α-amino carboxylic acid by replacing the α-amino group and the hydrogen atom bonded to the α-carbon atom with an oxo group, is named by the three-letter symbol of the base α-amino carboxylic acid being prefixed by "keto". For example, the keto analog of leucine is called "ketoleucine" (=4-methyl-2-oxovaleric acid). A ketodipeptide acid of formula Ia which is derived from ketoleucine (R 1 =isopropylmethyl) and the amino acid valine (R 2 =isopropyl) is called, for example, "ketoleucylvaline" or, when the configuration of the amino acid valine is also named, "ketoleucyl-L-valine". The abbreviated name is "CO--Leu--Val" or "ketoleu--Val". The corresponding methyl ester of ketoleucylvaline is accordingly, for example, "ketoleucylvaline methyl ester" and, in abbreviated form, for example, "CO--Leu--Val--OMe" or "ketoleu--Val--OMe". Preferred compounds according to the invention are: ketoleucylleucine or ketovalylvaline, and their salts with physiologically acceptable cations of the type indicated above. The invention also relates to the use of the compounds of formula I according to the invention as pharmaceuticals and dietetics in relatively large mammals, especially humans. The compounds according to the invention have valuable pharmacological properties, they are suitable as substitutes for essential amino acids and are distinguished, in particular, by a favorable effect on disturbances of nitrogen metabolism and good absorption and good stability in pharmaceutical preparations. By reason of their physiological and pharmacological properties, the amino acid derivatives of formula I and their salts with physiologically acceptable cations are suitable for use as pharmaceuticals and dietetics in amino acid replacement therapy. In particular, the compounds can be used for the treatment and prophylaxis of disturbances in the nitrogen balance, for example of metabolic disorders caused by hepatic and/or renal insufficiency and catabolic disorders which may occur in connection with trauma, sepsis and fasting states. Due to their chemical stability, even in the presence of carbohydrates, they can be incorporated in any desired manner into dietetic and/or pharmaceutical preparations and are outstandingly suitable for manufacturing infusion solutions, even infusion solutions containing reducing carbohydrates. The invention furthermore relates to pharmaceuticals and dietetics, especially for use as amino acid substitutes and/or for the treatment and prophylaxis of disturbances of nitrogen metabolism, which contain as active ingredient compounds of formula I or their salts with a physiologically acceptable cation, in addition to customary physiologically acceptable adjuvants and/or vehicles. According to the invention, the compounds of formula I and their physiologically acceptable salts can be present together with customary pharmaceutical adjuvants and/or vehicles in solid or liquid pharmaceutical preparations. As used herein, the term "pharmaceutical compositions" is intended to refer to both to the usual pharmaceutical preparations and to dietetics. Products which can be administered orally, such as capsules, tablets, granules or coated tablets, may be mentioned as examples of solid preparations. Solid products can contain customary inorganic and/or organic pharmaceutical vehicles such as, for example, talc, starch or lactose in addition to customary pharmaceutical adjuvants, for example lubricants such as magnesium stearate or tablet disintegrating agents. Liquid products such as solutions, suspensions or emulsions can contain the customary diluents such as water and/or oils, for example triglyceride mixtures of saturated vegetable fatty acids and/or suspending agents such as, for example, polyethylene glycols and the like, or other dissolved nutrients, for example carbohydrates such as glucose. If desired, other adjuvants can be added, such as, for example, preservatives, stabilizers, flavorings and the like. The active substances can be mixed and formulated with the pharmaceutical adjuvants and/or vehicles in a known manner. To manufacture solid drug forms, the active substances can be mixed with the vehicles and granulated wet or dry in a customary manner. Granules or powders can be used directly to fill capsules or single-portion sachets or compressed to tablet cores in a conventional manner. The latter can be coated, if desired, in a known manner. To manufacture liquid preparations, the compounds can be dissolved or suspended in the liquid vehicle in a known manner. Solutions or suspensions intended for parenteral administration can be sterilized in a known manner. Solutions intended for parenteral administration represent a particularly preferred embodiment of liquid preparation containing a compound of formula I, or a salt thereof with a physiologically acceptable cation, as the active ingredient. These solutions which can be administered parenterally, i.e. infusion solutions, can be manufactured in a known manner. For this purpose, the desired amount of one or more of the compounds of formula I according to the invention, or their physiologically acceptable salts, is dissolved with stirring in distilled water (for injections), ensuring exclusion of atmospheric oxygen to the maximum extent by simultaneously introducing a suitable protective gas, for example nitrogen. In the manufacture of these aqueous infusion solutions, care must be taken that the solutions are adequately isotonic. In exceptional cases (for example where the solubility is insufficient) it is also possible where appropriate to add limited amounts of known co-solvents which are miscible with water and/or other known auxiliaries for infusion solutions. The resulting solutions are subsequently pumped through a suitable series of filters with a final filter of, for example, about 0.2 μm pore diameter to remove particles and reduce the microbe count. The manufactured infusion solutions are subsequently packaged in a known manner, that is to say, for example, introduced into rinsed glass bottles, after which the headspace of these filled glass bottles is evacuated, the bottles are sealed with rubber stoppers, and finally crimp-capped. The filled and sealed bottles are then also heat-treated in an autoclave under conditions which ensure the sterility of the product. The compounds of formula I and their physiologically acceptable salts, and pharmaceutical preparations containing them, are absorbed extremely well and, at least in part, enter the blood plasma intact even after oral administration. Their administration leads not only to a build up of favorable blood plasma concentrations of intact ketopeptides of formula Ia, but also to a distinct and long-lasting increase, in a surprising and advantageous manner, of the natural blood plasma levels of the corresponding α-amino acids and of the α-keto analogs. Besides pharmacological advantages, the compounds of formula I and their physiologically acceptable salts also display technological advantages over corresponding mixtures of α-amino acids and α-keto acids. Acids of formula I are, for example in the form of their ornithine or lysine salts, readily soluble in water and prove to be extremely heatstable, even under extreme conditions. They can therefore be readily subjected to the heat sterilizing conditions necessary for preparing parenteral infusion solutions without decomposing. Their high long-term stability ensures that the pharmaceutical preparations of the invention have a good shelf life. Furthermore, compared with mixtures of α-amino acids and α-keto acids, the compounds of formula I offer special advantages in the preparation of complete infusion solutions which additionally contain metabolizable carbohydrate materials. Whereas, for example, in preparing a glucose-containing, heat-sterilized solution of α-amino acids and α-keto acids, the usefulness of the sterilized solution may be impaired by Maillard reactions, Maillard reactions do not occur when compounds of formula I are processed together with glucose to produce heat-sterilized solutions. The advantageous properties of pharmaceutical preparations containing compounds of formula I are demonstrated in the following experiments. EXPERIMENT 1 The absorption kinetics of compounds of formula I were demonstrated using the example of ketoleucylleucine in rats. Twelve rats (Sprague Dawley, 400 g) were each given 1 g of ketoleucylleucine orally in the form of the bis-ornithate in 5% by weight glucose solution. Blood samples were taken after defined time intervals and tested for α-ketoleucylleucine, α-keto acids and α-amino acids. The results are reported in the following table: ______________________________________ Blood Concentration in μmol/liter after 0 15 30 60 120 180 min min min min min min______________________________________CO--Leu--Leu 0 20 26 15 9 6CO--Leu 20 91 135 91 77 58Leu 185 715 795 715 715 610______________________________________ The experimental results listed in the table show, using the example of oral administration of ketoleucylleucine, that at least some of the compound of formula I is absorbed intact, and that there is a drastic increase in the plasma concentration of the corresponding α-amino acid, in this example leucine, and of the corresponding α-keto acid, in this example α-ketoleucine, over an extended period. EXPERIMENT 2 To demonstrate the surprisingly high resistance of the ketopeptides of formula Ia to the Maillard reaction, from the group of ketopeptides the magnesium salt of ketoleucylvaline (CO--Leu--Val) and the calcium salt of ketoisoleucylleucine (CO--Ile--Leu) were each tested in comparison with the mixture of the corresponding amino acids under the following conditions. The ketopeptide--or an equimolar sample of the base amino acid for comparison--in a concentration of 1% by weight in 20% strength glucose solution is kept at a constant temperature of 121° C. for 60 minutes. The browning caused by Maillard reactions is measured by the decrease in transmission at 420 nm. ______________________________________ % transmission at 420 nm after 0 min 10 min 30 min 60 min______________________________________CO--Leu--Val 97.0 90.5 77.9 55.6(Mg salt)Leu + Val mixture 100.2 65.6 12.4 0CO--Leu--Ile 99.5 95.6 84.2 62.8(Ca salt)Leu + Ile mixture 97.8 66.4 5 0______________________________________ The results listed in the foregoing table demonstrate the greater Maillard reaction resistance of ketopeptides compared with simple mixtures of the amino acids. EXPERIMENT 3 To test their stability, selected ketopeptides of formula Ia were heated in an aqueous medium at pH 7 under a protective nitrogen atmosphere at 121° C. for periods of time up to 60 minutes. After the time periods indicated in the table for the heat treatment, the remaining, undecomposed ketopeptide content was determined in % (relative to the initial amount of ketopeptide employed). The analysis was carried out by high resolution liquid chromatography (HPLC) with the following: Column: Nucleosil™ 5 C18* length=20 cm internal diameter 4.6 mm; Eluent: 0.05 M NaH 2 PO 4 with 50 to 60% methanol; Detection: UV spectrophotometer at 225 nm, range 0.08. The results are listed in the following table: ______________________________________ Percentage content remaining after 10 min 30 min 60 min______________________________________CO--Leu--Leu 97.0% 100% 99.2%(Mg salt)Purity: 97.6%CO--Leu--Val 101.5% 103.6% 102.0%(Mg salt)Purity: 99.3%CO--Ile--Leu 100% 100% 99.5%(Ca salt)Purity: 88.5%______________________________________ It is evident from the test that the ketodipeptides are very stable on exposure to heat. The variations around the 100% value are within the range of accuracy of the measurement. The compounds of formula I can be prepared in a known manner, such that a) to prepare compounds of formula Ia ##STR12## in which R 1 , R 2 and R 3 have the above meanings, the CZ 3 Z 4 group in compounds of formula II ##STR13## in which R 1 , R 2 and R 3 have the above meanings, and Z 3 and Z 4 denote alkoxy or alkylthio or together represent alkylenedioxy or alkylenedithio, or in which Z 3 denotes alkoxy or alkylthio, and Z 4 together with Y represents a bond, is converted into a keto group, or b) to prepare acids of formula Ib ##STR14## in which R 1 , R 2 , Z 1 and Z 2 have the above meanings, an ester of formula Ic ##STR15## in which R 1 , R 2 , Z 1 and Z 2 have, the above meanings, and R 4 denotes lower alkyl, is hydrolyzed, or c) to prepare compounds of formula Id ##STR16## in which R 1 , R 2 , Z 1 and Z 2 have the above meanings, and R 3 ' represents lower alkoxy or an R 5 'R 6 'N- group in which R 5 ' and R 6 ' have the same meanings as R 5 and R 6 with the exception of hydrogen, a compound of formula III ##STR17## in which R 1 , Z 1 and Z 2 have the above meanings, and U is a reactive radical, is reacted with a compound of formula IV ##STR18## in which R 2 and R 3 ' have the above meanings, or d) to prepare compounds of formula IE ##STR19## in which R 20 , R 21 , R 2 and R 3 ' have the above meanings, a compound of formula V ##STR20## in which R 20 , R 21 , R 2 and R 3 ' have the above meanings, and R 12 denotes lower alkyl, phenyl, trifluoromethyl or trichloromethyl, is cleaved, or e) an acid of formula Ib or a reactive acid derivative thereof is reacted with an amine of formula VI ##STR21## in which R 5 and R 6 have the above meanings, to yield a compound of formula If ##STR22## in which R 1 , R 2 , R 5 , R 6 , Z 1 and Z 2 have the above meanings, and, if desired, acids of formula Ib are converted into corresponding salts with physiologically acceptable cations, or salts of acids of formula Ib are converted into corresponding free acids. The conversion of compounds of formula II into compounds of formula Ia by process variant a) can be carried out by conventional methods for hydrolytically cleaving ketal and enol ether groups. The hydrolytic cleavage can be carried out in an aqueous solution or suspension of the compound of formula II under acidic reaction conditions, optionally diluted with a solvent which is inert under the reaction conditions. Aqueous solutions of organic and inorganic acids are suitable for the acid hydrolysis. Organic acids which can be used for the hydrolysis include lower alkane carboxylic acids such as formic acid, acetic acid etc., haloalkane carboxylic acids such as chloroacetic acid, or organic sulfonic acids such as p-toluenesulfonic acid. Inorganic acids which can be used include mineral acids such as hydrochloric acid or phosphoric acid. Oxoketals of formula II in which Z3 and Z4 represent alkoxy or together represent alkylenedioxy, or Z3 represents alkoxy and Z4 together with Y represents a bond, are cleaved particularly well and straightforwardly by reaction with an organic or inorganic acid in aqueous medium. Dilute to concentrated aqueous mineral acids, especially hydrochloric acid, are preferably used for this. If thioketals of formula II in which Z3 and Z4 represent alkylthio or together represent alkylenedithio, or Z3 represents alkylthio and Z4 together with Y represents a bond, are to be cleaved, it is advantageous to carry out the acid hydrolysis in ethers, preferably in cyclic ethers such as dioxane. Although it is also possible to cleave the thioketal group straightforwardly by reaction with HgO/HgCl 2 /H 2 O, this route is of only minor importance for obtaining highly pure compounds suitable for pharmaceutical uses. Conversion of the ketals of formula II into compounds of formula Ia can be carried out at temperatures between room temperature and the boiling point of the solvent, with the alcohol which forms in the reaction being distilled out where appropriate. To prepare acids of formula Ib by process variant b), esters of formula Ic can be hydrolyzed by conventional methods for hydrolyzing ester groups in an alkaline or acidic aqueous medium. The hydrolysis can be carried out in an aqueous solution or suspension of the compounds of formula Ic in the presence of acid or alkali, optionally diluted with a solvent which is inert under the reaction conditions. Acids which can be used include aqueous solutions of organic or inorganic acids. Organic acids suitable for this purpose include lower alkane carboxylic acids such as formic acid, acetic acid etc., haloalkane carboxylic acids such as chloroacetic acid or organic sulfonic acids such as p-toluenesulfonic acid. Suitable inorganic acids include mineral acids such as hydrochloric acid or phosphoric acid. Alkalis which can be used include aqueous solutions or suspensions of oxides, hydroxides or carbonates of alkali metals or alkaline earth metals. The hydrolysis of the esters of formula Ic is advantageously carried out under alkaline reaction conditions using aqueous alkali metal hydroxides. The hydrolysis is preferably carried out with aqueous sodium hydroxide solution. It is possible and preferable to employ the methoxy (R4=CH 3 ) or ethoxy (R4=C 2 H 5 ) ester as compound Ic. The esters of formula Ic can be converted into compounds of formula Id at temperatures between room temperature and the boiling point of the solvent, where appropriate removing the alcohol which forms in this reaction by distillation. The preparation of compounds of formula Id by process variant c) can be carried out by reacting reactive acid derivatives of formula III in which U represents a reactive radical with amines of formula IV by conventional peptide chemistry methods for forming amide groups by aminoacylation. Particularly suitable reactive derivatives of formula III include acid halides, preferably chlorides, esters and mixed anhydrides, for example compounds of formula III in which the reactive group U denotes halogen, especially chlorine or bromine, lower alkoxy, especially alkoxy with 1 to 4 carbon atoms, or a group O-W in which W represents a lower alkylcarbonyl or lower alkoxycarbonyl group or an organic sulfonic acid radical, especially the radical of a lower alkanesulfonic acid such as, for example, methanesulfonic acid or of an aromatic sulfonic acid such as benzenesulfonic acid or benzenesulfonic acids substituted by lower alkyl or halogen. It is also possible to start from the base acid of formula III (U=OH) of the reactive acid derivative itself. Before the actual reaction with the amine of formula IV, the acid is first converted in situ by known methods into the reactive acid derivative which is subsequently used without further isolation or purification, for reaction with the amine of formula IV. The in situ formation of the reactive acid derivative can advantageously be carried out at temperatures from -30° C. to room temperature using solvents such as halogenated hydrocarbons, ethers, preferably cyclic ethers such as tetrahydrofuran, and/or aromatic solvents. Acid halides, especially acid chlorides, or mixed acid anhydrides, especially mixed anhydrides obtained from reaction of the base acids of formula III (U=OH) with an organic sulfonyl chloride such as methane sulfonyl chloride or with chloroformate esters, are preferably used as compounds of formula III. In a preferred procedure acid derivatives are used which, before the actual reaction, were first prepared in situ from the base acid of formula III (U=OH) and which are reacted without previous isolation or purification, directly with the amine of formula IV to form an amide. The reaction of the amine IV with the acid halide or anhydride of formula III is carried out in the presence of an inert organic solvent, for example a halogenated hydrocarbon such as methylene chloride, a cyclic or open ether such as dioxane or diethyl ether, dimethylformamide, sulfolane, tetramethylurea or mixtures of these solvents and, where appropriate, aromatic hydrocarbons such as benzene or toluene. Where acid halides or anhydrides of formula III are used, it is advantageous to carry out the reaction in the presence of an acid-binding agent. Suitable acid-binding agents include inorganic bases, for example alkali metal carbonates, or alkali metal hydroxides or organic bases, especially tertiary lower alkylamines, for example triethylamine or pyridines. It is also possible to use an excess of the amine of formula IV in place of an alien base. Organic bases used in excess can also simultaneously act as solvent. It may furthermore be advantageous to add catalytic amounts of basic pyridines such as 4-dimethylaminopyridine or 4-pyrrolidinopyridine. The reaction is advantageously carried out at temperatures between -30° C. and the boiling point of the reaction mixture. The chosen temperature can vary depending on the starting compounds used, for example when acid halides or anhydrides of formula III are used, low temperatures up to about room temperature, especially temperatures from about -20° C. to 0° C., are preferred. It is especially advantageous to react a solution of the acid derivative of formula III at a very low temperature with a solution of the amine of formula IV. Process variant c) is particularly suitable for reacting compounds of formula III in which Z 1 and Z 2 represent alkoxy or together represent alkylenedioxy, or Z 1 represents alkoxy and Z 2 together with Y represents a bond. However, keto compounds of formula III (Z 1 and Z 2 together=oxygen) can also be reacted with amines of formula IV to yield compounds of formula Id. In process variant d) the compounds of formula V undergo hydrolytic cleavage. This hydrolytic cleavage of the enamide compounds of formula V can be carried out by conventional peptide chemistry methods for cleaving enamide groups. The hydrolysis of the enamide compounds of formula V is advantageously carried out in an aqueous medium under acidic reaction conditions, where appropriate in the presence of a water-miscible organic solvent. Examples of suitable solvents include lower alcohols, acetone or cyclic ethers such as dioxane or furan, preferably lower alcohols such as methanol or ethanol. It is possible and desirable to employ compounds of formula V in which R 12 represents trifluoromethyl. The enamide group can be cleaved straightforwardly by treatment with an aqueous solution of an organic or inorganic acid. Suitable organic acids include lower alkane carboxylic acids such formic acid, acetic acid etc. or halocarboxylic acids such as chloroacetic acid. Examples of suitable inorganic acids include hydrochloric acid or phosphoric acid. Aqueous mineral acids, especially hydrochloric acid, are preferably used. The hydrolysis of the enamide compounds can be carried out at temperatures between room temperature and the boiling point of the solvent. The reaction of the acids of formula Ib or their reactive acid derivatives with amines of formula VI by process variant e) can be carried out by conventional peptide chemistry methods for forming amide groups by aminoacylation, for example under the conditions indicated above for reacting a compound of formula III with a compound of formula IV. Process variant e) is particularly suitable for reacting compounds of formula Ib in which Z 1 and Z 2 represent alkoxy or together represent alkylenedioxy, or Z 1 represents alkoxy and Z 2 together with Y represents a bond. However, keto compounds of formula Ib (Z 1 and Z 2 together=oxygen) can also be reacted with amines of formula VI to give compounds of formula If. If, in the amine of formula VI used, R 5 represents hydrogen and R 6 represents the deamino radical of a biogenic α-amino carboxylic acid, it is advantageous for the free carboxyl group contained therein to be provided, before the above reactions, in a known manner with a protective group which can easily be removed again afterward. Suitable protective groups are known, for example, from E. McOmie, "Protective Groups in Organic Chemistry", Plenum Press (1971). For example, ester groups such as, for example, methyl ester, benzyl ester, p-nitrophenyl esters etc. are suitable for protecting carboxyl groups present in amino carboxylic acids. Where the deamino radical of the amino carboxylic acid contains further functional groups in addition to the carboxyl group, these can also be provided where appropriate with protective groups during the foregoing reactions. The compounds of formula I can be isolated from the reaction mixture and purified in a known manner. Salts of acids of formula I can be converted in a customary manner into the free acids, and the latter can, if desired, be converted in a known manner into pharmacologically acceptable salts of these acids. The pharmacologically acceptable salts of acids of formula I with metal cations and ammonium ions of formula C are prepared by customary methods of salt formation. Salts with metal cations are obtained, for example, by dissolving the acids of formula I in a water-miscible organic solvent, in particular in a lower alcohol such as methanol or ethanol; reacting with solid, powdered metal hydroxide or with a solution or suspension of the oxide or hydroxide of the metal cation in water, and subsequently isolating and purifying the corresponding metal salt of the acid in a known manner. For example, some salts of acids of formula I with metal cations crystallize out of the reaction solution even at room temperature, it being possible to complete the crystallization by additional cooling to about 4° C. Other salts of acids of formula I with metal cations can be precipitated out of the reaction solution by addition of suitable solvents, for example organic solvents which are miscible with water, such as ethyl acetate or acetone or other ketones, or hydrocarbons, such as petroleum ether or hexane, optionally with cooling where appropriate. Salts of acids of formula I with ammonium ions of formula C are obtained, for example, by dissolving the acid in a water-miscible organic solvent, particularly a lower alcohol, acetone or ethyl acetate, and adding dropwise an amine on which the ammonium group C is based or an ammonium salt containing the ammonium group C dissolved in an organic solvent such as a halogenated hydrocarbon, particularly methylene chloride, or a hydrocarbon, particularly hexane. In particular, if a salt of an acid of formula I with a cation of a basic amino acid (R 8 , R 9 and R 10 =hydrogen, and R 11 =a deamino radical of the basic amino acid) is desired, it can be obtained, for example, by dissolving the acid in a water-miscible organic solvent, particularly a lower alcohol such as methanol; reacting with a solution of the basic amino acid in a lower alcohol, particularly methanol, and subsequently isolating and purifying the corresponding salt of the acid with the basic amino acid in a known manner. In some cases salts of acids of formula I with basic amino acids crystallize out of the reaction solution even at room temperature. Otherwise, salts of acids of formula I with basic amino acids can also be precipitated out of the reaction solution by adding suitable solvents, for example water-miscible solvents such as ethyl acetate or acetone or other ketones, optionally with additional cooling. The starting materials for preparing the compounds of formula I can be obtained by known processes. The ketal and enol ether compounds of formula II to be used in process variant a) can be obtained by reacting an acid or an acid derivative of formula VII ##STR23## in which Z 3 and Z 4 have the above meanings, and U represents hydroxy or a reactive radical, with an amine of formula IV by conventional peptide chemistry methods for forming amide groups by aminoaoylation, for example under the conditions indicated above for reacting a compound of formula III with a compound of formula IV. Compounds of formula VII can be prepared by ketalization of the base α-keto acid compounds of formula IIIa R.sup.1 --CO--CO--U IIIa in which R 1 and U have the above meanings, by conventional methods. For example, the ketalization may be carried out under catalysis by anhydrous organic or inorganic acids by reacting an α-keto acid or derivative thereof with an alcohol, alkylenediol, thiol or alkylene dithiol. The water formed in the ketalization reaction with alcohols or alkylenediols may be trapped by water-binding agents, for example with dialkyl sulfites in the preparation of dialkyl oxoketals. The water formed in the reaction can also be removed by azeotropic distillation. It is also possible to use corresponding trialkyl orthoformates, for example trimethyl or triethyl orthoformate, in place of the alcohols as ketalizing agents. The amines of formula IV are known or can be prepared in a known manner from the base amino acid by conventional methods for forming esters or amides. The compounds of formula III for use in process variant c) can be obtained by conventional methods. The keto acids of formula IIIa (U=OH) are known or can be obtained in a known manner, for example by first reacting the base amino acid of formula XIIIa ##STR24## in which R 1 has the above meaning, with trifluoroacetic anhydride (formula XIV, R 12 =CF 3 ) to give the 4-substituted 2-trifluoromethyl-5-oxazolone of formula XIa, ##STR25## in which R 1 has the above meaning, by heating either without a solvent or else in the presence of a solvent such as, for example, methylene chloride. The resulting oxazolone of formula XIa can subsequently be converted into the keto acid of formula IIIa by basic hydrolysis, during which an intramolecular oxidation-reduction reaction simultaneously occurs. Alkalis such as, for example, sodium or potassium hydroxide are suitable for this hydrolysis reaction. To convert the amino acid isoleucine (R 1 =--CH(CH 3 )CH 2 CH 3 in formula XIIIa) into the corresponding keto acid, it is advantageous to carry out the hydrolysis of the corresponding oxazolone (R 1 =--CH(CH 3 )CH 2 CH 3 in formula XIa) in a buffer at about pH=6.8 in order to avoid racemization of the asymmetric carbon atom present in the isoleucine radical R 1 =--CH(CH 3 )CH 2 CH 3 . The acids of formula IIIa can be converted into their reactive derivatives in a known manner. Ketals and enol ketals of formula III (Z 1 and Z 2 each=alkoxy or together=alkylenedioxy, or Z 1 =alkoxy and Z 2 together with Y=a bond) can be prepared by ketalization of the base keto compounds of formula IIIa with alcohols or alkylenediols by conventional methods, for example under the conditions described for preparing compounds of formula VII. The starting compounds of formula V for use in process variant d) can be obtained by reacting substituted, unsaturated oxazolones of formula VIII ##STR26## in which R 20 , R 21 and R 12 have the above meanings, with amines of formula IV. The reaction of a compound of formula VIII with a compound of formula IV is carried out under conditions customary in peptide chemistry, for example under the conditions described above for reacting a compound of formula III with a compound of formula IV. Two routes are available for preparing oxazolones of formula VIII. The first way to prepare unsaturated oxazolones of formula VIII starts from keto compounds of formula IX ##STR27## in which R 20 and R 21 have the above meanings. These are condensed with N-acylglycine derivatives of formula X ##STR28## in which R 12 has the above meaning, in a known manner (Erlenmeyer synthesis). For this, for example, a compound of formula IX is reacted with a compound of formula X in a suitable solvent such as, for example methanol, with the addition of a tertiary base such as pyridine or in the presence of sodium acetate and acetic anhydride. The condensation can be carried out at temperatures between room temperature and the boiling point of the solvent. The second way of preparing unsaturated oxazolones of formula VIII starts in a known manner from substituted, saturated oxazolones of formula XI ##STR29## in which R 20 , R 21 and R 12 have the above meanings. These are first halogenated, preferably brominated, to give compounds of formula XII ##STR30## in which R 20 , R 21 and R 12 have the above meanings, and Hal represents halogen, preferably bromine. The halogenation of compounds of formula XI is carried out under know conditions by reacting a compound of formula XI in a solvent which is inert under the reaction conditions, for example 1,2-dichloroethane, with the halogen, preferably bromine, to yield a compound of formula XII. The halogenated derivatives XII are subsequently dehydrohalogenated by treatment with an organic base, preferably triethylamine, to yield the unsaturated oxazolones of the formula VIII. For this purpose a compound of formula XII can be reacted in a known manner in a solvent which is inert under the reaction conditions, such as an ether, for example a cyclic ether such as tetrahydrofuran, by treatment with a tertiary organic base, preferably triethylamine, to yield a compound of formula VIII. The oxazolones of formula XI can be prepared in a known manner, for example by reacting an α-amino carboxylic acid of formula XIII ##STR31## in which R 20 and R 21 have the above meanings, by heating with an acid anhydride of formula XIV R.sup.12 --CO--O--CO--R.sup.12 XIV in which R 12 has the above meaning, optionally diluting with a solvent which is inert under the reaction conditions; or, for example, by reacting an N-acylated α-amino carboxylic acid of formula XV ##STR32## in which R 20 , R 21 and R 12 have the above meanings, with an inorganic acid halide such as phosphorus trichloride, phosphorus pentachloride, phosphorus oxychloride or thionyl chloride, preferably phosphorus oxychloride, in the presence of a tertiary organic base such as, for example, pyridine, optionally diluting with a solvent which is inert under the reaction conditions; or, for example, by reacting an N-acylated α-amino carboxylic acid of formula XV with isopropylmethyl chloroformate in the presence of a tertiary organic base such as triethylamine, optionally diluting with a solvent which is inert under the reaction conditions. In a special variant for preparing enamide compounds of formula V by reacting an unsaturated substituted oxazolone of formula VIII with an amine of formula IV, the unsaturated oxazolone of formula VIII can also be formed in situ from the corresponding brominated oxazolone of formula XII. For this purpose, a compound of formula XII is added directly to a solution of the amine IV and of a tertiary organic base such as, for example, triethylamine. The following examples are intended to illustrate the preparation of the new compounds of formula I in detail without restricting the scope of the invention in any way. The structures of the new compounds were verified by elemental analysis and spectroscopic investigations, in particular by analysis of the NMR, mass and/or IR spectra. EXAMPLE 1 Ethylene ketal of ketoleucylleucine methyl ester a) Ten g of ketoleucine were reacted with 16.7 g of ethylene glycol with the addition of 0.15 g of p-toluenesulfonic acid in 160 ml of toluene at the boiling point for 16 hours, during which the water that formed in the reaction was continuously removed from the reaction mixture by distillation and collected in a water trap. After the reaction was complete, the reaction mixture was washed with water and dried over sodium sulfate. The toluene solvent was subsequently removed under reduced pressure. 16.8 g of the ethylene ketal of ketoleucylglycol ester were obtained as residue. b) A solution of 16.0 g of the ethylene ketal of ketoleucylglycol ester obtained in step a) in 100 ml of methanol was, after addition of 91.5 ml of a 2N sodium hydroxide solution, stirred at room temperature for 1 hour. The methanol solvent was subsequently removed under reduced pressure, and the remaining aqueous solution was adjusted to pH 1 with concentrated hydrochloric acid. After the acidic solution had been stirred for 15 minutes, the free acid of the ethylene ketal of ketoleucine which had formed was extracted with methylene chloride, and the methylene chloride extract was dried over sodium sulfate. Removal of the methylene chloride solvent under reduced pressure yielded 11.4 g of the ethylene ketal of ketoleucine. c) 11.4 g of the ethylene ketal of ketoleucine obtained under b) and 8.7 g of dimethylaminopyridine were dissolved in 600 ml of tetrahydrofuran and, after addition of 13.2 g of triethylamine, cooled to -20° C. Subsequently, at this temperature, a solution of 8.2 g of mesyl chloride (methylsulfonyl chloride) in 25 ml of tetrahydrofuran was added dropwise, resulting in a solution of a derivative activated at the acid group of the ethylene ketal of ketoleucine. To this solution was added, for peptide formation, 11.8 g of leucine methyl ester hydrochloride, after which the reaction mixture was warmed to room temperature. To isolate the peptide derivative which formed in this reaction, the precipitates which had formed were filtered out with suction, and the solvent was removed under reduced pressure. The remaining oily residue was dissolved in methylene chloride and washed with water, and the resulting methylene chloride solution was then dried over sodium sulfate. Removal of the methylene chloride under reduced pressure left an oily product which was purified by column chromatography (silica gel; mobile phase hexane/ethyl acetate 2:1). 18.4 g of the ethylene ketal of ketoleucylleucine methyl ester were isolated in the form of a yellow oil. The infrared spectrum (film) of the product compound had absorption bands at the following wave numbers (in cm -1 ): 1740, 1680, 1520. EXAMPLES 2-4 The ethylene ketals listed in Table 1 were prepared by procedures analogous to Example 1. TABLE 1______________________________________Example Ethylene ketal of IR data______________________________________2 Ketoleu--Val--OMe 1740 1720 1670 15203 Ketoval--Leu--OMe 1740 1680 15154 Ketoval--Val--OMe 1740 1650 1530______________________________________ EXAMPLE 5 Ethylene ketal of ketoleucylleucine 240 mmol of sodium hydroxide in the form of an aqueous 2N sodium hydroxide solution were added to a solution of 18.4 g of the ethylene ketal of ketoleucylleucine methyl ester obtained in Example 1 in 50 ml of methanol, and the reaction solution was stirred at room temperature for 2 hours. Removal of the solvent under reduced pressure yielded the crude title compound in the form of its sodium salt. Although the crude product obtained in this way can be converted into the free acid and subsequently purified, it can also be used directly for further reactions. EXAMPLE 6 Ketoleucylleucine The crude product obtained in Example 5 was adjusted to pH 1 with concentrated hydrochloric acid, and the resulting mixture was stirred for 15 minutes. It was subsequently extracted with methylene chloride, and the methylene chloride extract was dried over sodium sulfate. Removal of the methylene chloride solvent under reduced pressure and purification of the residue by column chromatography (silica gel; mobile phase hexane/ethyl acetate 1:1) resulted in 12.2 g of ketoleucylleucine in the form of the free acid as a pale yellow oil. The infrared spectrum (film) of the prepared compound exhibited absorption bands at the following wave numbers (in cm -1 ): 1720, 1710, 1670, 1530. The following resonances were found in the 13 C--NMR spectrum (in ppm): 201.5; 160.0; 57.2; 175.5. EXAMPLES 7-9 The free ketodipeptide acids shown in the following Table 2 were obtained by procedures analogous to Examples 5 and 6. TABLE 2______________________________________ IR Data .sup.13 C-NMRExample Product (cm.sup.-1) Data (ppm) Notes______________________________________7 Ketoleu--Val 1733 197.9 Melting 1718 160.3 point 1661 57.2 174-178° C. 1539 175.78 Ketoval--Leu 1720 1710 1650 15259 Ketoval--Val 1710 201.5 1660 160.0 1550 57.2 175.5______________________________________ EXAMPLE 10 Ketovalylleucine methyl ester a) 44 ml of concentrated hydrochloric acid were added to a solution of 20.0 g of the calcium salt of ketovaline in 100 ml of distilled water, and the mixture was stirred for 20 minutes. The mixture was subsequently extracted with dichloromethane, and the collected organic phases were dried over sodium sulfate. Removal of the solvent under reduced pressure left 13.1 g of ketovaline in the form of the free acid. b) 15.1 g of dimethylaminopyridine were added to a solution of 13.0 g of the ketovaline obtained in step a) in 100 ml of tetrahydrofuran. While stirring, 22.7 g of triethylamine were added dropwise, and the reaction mixture was cooled to -20° C. Subsequently a solution of 14.1 g of mesyl chloride in 50 ml of tetrahydrofuran was added dropwise, and the mixture was stirred for a further 20 minutes. Then a solution of 20.4 g of leucine methyl ester hydrochloride in 150 ml of dichloromethane was added dropwise, and the mixture was again stirred for 20 minutes. The mixture was then allowed to warm slowly to room temperature, undissolved constituents were separated by filtration, and the solvent was removed from the filtrate under reduced pressure. The residue was taken up in distilled water and extracted with dichloromethane. The collected organic phases were then dried over sodium sulfate and, after filtration, the solvent was removed under reduced pressure. 14.7 g of the title compound remained as a yellow oil. The infrared spectrum (film) of the prepared compound exhibited absorption bands at the following wave numbers (in cm -1 ): 1740, 1720, 1685, 1520. EXAMPLE 11 Ketovalylleucine 113.5 ml of a 2N sodium hydroxide solution were added to a solution of 22.1 g of the ketovalylleucine methyl ester obtained in Example 10 in 200 ml of methanol, and the mixture was stirred for 1 hour. The methanol solvent was subsequently removed under reduced pressure, and the resulting aqueous solution was buffered with saturated ammonium chloride solution. After the mixture had been adjusted to pH 2 with 6N hydrochloric acid, it was extracted with dichloromethane. The collected organic phases were dried over sodium sulfate, and after filtration, the solvent was removed under reduced pressure. 15.0 g of the title compound were obtained in the form of an oil. The compound proved to have properties identical to those of the product obtained in Example 8. EXAMPLE 12 Ketoisoleucylleucine Ketoisoleucylleucine was prepared by a procedure analogous to Examples 10 and 11. The title compound was obtained in the form of an oil. The resulting compound had bands at the following wave numbers (in cm -1 ) in the IR spectrum (film): 1725, 1710, 1680, 1540. Ketoleucylleucine, ketoleucylvaline and ketovalylvaline were also prepared by procedures analogous to Examples 10 and 11. These compounds proved to have properties identical to those of the corresponding products obtained in Examples 6, 7 and 9, respectively. EXAMPLE 13 Ketovalylvaline methyl ester a) 314 mmol of triethylamine were added to a solution of 46.4 g of valine methyl ester hydrochloride in 500 ml of tetrahydrofuran, and the mixture was then stirred for 15 minutes. Subsequently a solution of 73.9 g of α-bromooxazolone in 750 ml of tetrahydrofuran was added, and the mixture was then stirred at room temperature for 24 hours. The solvent was subsequently removed under reduced pressure, the residue was taken up in ethyl acetate, and the solution was washed twice with water and once with dilute hydrochloric acid. The ethyl acetate solution was subsequently dried over sodium sulfate, and then the solvent was removed under reduced pressure. RecrystalIization of the remaining residue from methanol/water resulted in 95.4 g of N-trifluoroacetyldehydrovalylvaline methyl ester as yellowish-white crystals with a melting point of 152°-155° C. b) 70 ml of 4N hydrochloric acid were added to a solution of 10.0 g of the N-trifluoroacetyldehydrovalylvaline methyl ester obtained in step a) in 80 ml of methanol, and the mixture was heated under reflux for 3 hours. The solvent was then removed under reduced pressure, and the remaining residue was neutralized with dilute sodium hydroxide solution and extracted with dichloromethane. The dichloromethane extract was dried over sodium sulfate. Removal of the dichloromethane solvent under reduced pressure yielded 6.5 g of ketovalylvaline methyl ester in the form of a yellow oil. The infrared spectrum (film) of the prepared compound exhibited absorption bands at the following wave numbers (in cm -1 ): 1740, 1720, 1680, 1510. The compounds shown in the following Table 3 were prepared by procedures analogous to Example 13. TABLE 3______________________________________ IR data .sup.13 C-NMRExample Product (cm.sup.-1) Data (ppm) Notes______________________________________14 Ketoval-- 1740 Substance Leu--OMe 1720 properties 1685 identical 1520 to product obtained in Example 1015 Ketoleu-- 1740 198.2 Leu--OMe 1715 160.0 1660 51.0 1550 170.7______________________________________ EXAMPLE 16 Diethylamide of ketoleucylleucine A solution of 5.8 g of ketoleucylleucine methyl ester obtained in Example 15 and 1 g of ammonium chloride in 20 ml of diethylamine was heated under reflux for 1.5 hours. The reaction mixture was then taken up in water/methylene chloride, and the organic phase was separated, washed twice with water and subsequently twice with 0.1N hydrochloric acid, and then dried over sodium sulfate. Removal of the solvent under reduced pressure yielded 3.9 g of the title compound as a yellow oil. The resulting compound showed bands at the following wave numbers (in cm -1 ) in the IR spectrum (film): 1720, 1660, 1650, 1540. EXAMPLE 17 Calcium salt of ketoleucylleucine 2.9 g of calcium hydroxide were added to a solution of 19.1 g of the ketoleucylleucine obtained in Example 2 in 100 ml of methanol, and the mixture was briefly heated under reflux. After addition of ethyl acetate to the cooled reaction solution, 15 g of the calcium salt of ketoleucylleucine crystallized out in the form of a colorless crystalline solid with a melting point of 236 to 237° C. The resulting compound showed the following resonances in the 13 C--NMR spectrum (in ppm): 198.8; 160.3; 52.9; 180.1. EXAMPLE 18 Calcium salt of ketoisoleucylleucine The ketoisoleucylleucine obtained in Example 12 was converted into the calcium salt by a procedure analogous to Example 17. The crystalline title compound was obtained having a melting point of 232°-236° C. The resulting compound showed bands at the following wave numbers (in cm -1 ) in the IR spectrum (KBr): 1715, 1650, 1550, 1405. EXAMPLE 19 Magnesium salt of ketoleucylleucine A suspension of 3.4 g of magnesium hydroxide in 150 ml of water was added to a solution of 28.5 g of the ketoleucylleucine obtained in Example 2 in 300 ml of methanol, and the mixture was heated under reflux for 2 hours. After the mixture had been slowly cooled to room temperature, it was stirred while cooling with an ice bath for 1 hour. The crystallized colorless product was filtered out with suction, washed with water and subsequently dried. 17.6 g of the title compound were obtained with a melting point of 271° C. The prepared compound showed the following resonances in the 13 C--NMR spectrum (in ppm): 199.3; 161.9; 54.2; 179.1. EXAMPLE 20 Sodium salt of ketoleucylleucine A solution of 8.3 g of the ketoisoleucylleucine obtained in Example 2 in 150 ml of ethanol was adjusted to pH 7 with aqueous 1N sodium hydroxide solution. Subsequently petroleum ether was added until inception of turbidity, and the mixture was then stirred while cooling with an ice bath for 2 hours. The precipitated product was filtered out with suction, washed with diethyl ether, and dried over phosphorus pentoxide in vacuo. 4.4 g of the highly hygroscopic title compound were obtained with a melting point above 200° C. The prepared compound showed the following resonances in the: 13 C--NMR spectrum (in ppm): 200.2; 162.0; 53.9; 178.7. EXAMPLE 21 Bis-ornithate of ketoleucylleucine A solution of 16.2 g of the basic amino acid 15 ornithine in 200 ml of methanol was added to a solution of 28.9 g of the ketoleucylleucine obtained in Example 2 in 300 ml of methanol, and the mixture was briefly heated under reflux. Subsequently ethyl acetate was added to the solution at the boiling point until inception of turbidity. After slow cooling to room temperature it was stirred while cooling with an ice bath for 1 hour. The precipitated product was filtered out with suction, washed with ethyl acetate and subsequently dried. 26.6 g of the title compound which contained ketoleucylleucine and ornithine in the molar ratio 1:2 were obtained in the form of a colorless crystalline salt with a melting point of 134° to 139° C. The compound exhibited the following resonances in the 13 C--NMR spectrum (in ppm): 200.8; 162.5; 54.5; 179.6. EXAMPLES 22 AND 23: The crystalline salts of ketodipeptides with the basic amino acid lysine which are shown in the following Table 4 were prepared by a procedure analogous to Example 21. TABLE 4______________________________________ Molar ratio Lysinate IR data Melting ketodipeptideExample of (cm.sup.-1) point to lysine______________________________________22 Ketoleu-- 1735 167° C. 1:1.25 Leu 1720 1675 152023 Ketoval-- 3400 179-181° C. 1:1 Val 1720 1710 1680 1510 1400______________________________________ EXAMPLE 24 Infusion solution as supplement for parenteral nutrition regimes To prepare a solution which can be administered parenterally, ketoisoleucylleucine in the form of the calcium or ornithine salt and ketovalylvaline in the form of the lysine salt were dissolved while stirring in distilled water (for injections), care being taken that atmospheric oxygen was substantially excluded by introducing nitrogen. The solution was pumped through a series of filters with a final filter of 0.2 μm pore diameter to remove particles and reduce the microbe count. Sufficient amounts of the ketoisoleucylleucine and ketovalylvaline salts were used to provide the following concentrations in the finished solution calculated on the basis of the free ketodipeptide acids corresponding to the salts which were used: CO--Ile--Leu 10.95 g/100 ml, and CO--Val--Val 7.53 g/10 ml. The resulting solutions having this composition were suitable for parenteral administration as a parenteral nutrition supplement. Thus, they were packaged by dispensing them directly into rinsed glass bottles; the headspaces of the filled glass bottles were evacuated, and the glass bottles were thereafter sealed with rubber stoppers and crimp-capped. The sealed and crimp-capped glass bottles were subsequently sterilized in an autoclave at 121° C. for 8 minutes. The foregoing description and examples have been set forth merely to illustrate the invention and are not intended to be limiting. Since modifications of the described embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the scope of the invention should be construed to include all variations falling within the ambit of the appended claims and equivalents thereof.

Acylamino carboxylic acid derivatives corresponding to the formula I ##STR1## in which the groups R 1 , R 2 , R 3 , Z 1 and Z 2 represent functional groups specified in the claims. The acylamino carboxylic acid derivatives have valuable pharmacological properties which, in particular, favorably influence nitrogen metabolism. The compounds are useful as active ingredients in pharmaceutical and/or dietetic compositions for treatment or prevention of nitrogen metabolism disturbances in large mammals caused, for example, by liver or kidney damage.

CROSS REFERENCE TO RELATED APPLICATIONS This application is related to U.S. application Ser. No. 07/464,278 filed Jan. 12, 1990, by Vandenberg et al; to U.S. application Ser. No. 07/464,042 filed Jan. 12, 1990 by Pitek et al; to U.S. application Ser. No. 07/485,413 filed Feb. 27, 1990 by Dey et al; to U.S. application Ser. No. 07/485,182 filed Feb. 27, 1990 by Humbel et al; to U.S. application Ser. No. 07/496,732 filed Mar. 21, 1990, by Vandenberg et al; to U.S. application Ser. No. 07/500,640 filed Mar. 28, 1990, by Humbel et al; and, to U.S. application Ser. No. 07/531,988 filed May 31, 1990 to Dey, which is being filed contemporaneously with this application. The entire disclosures of each of these applications are incorporated by reference herein. Each of these applications is copending and commonly assigned. FIELD OF THE INVENTION This invention relates to a method for testing an imaging device. INTRODUCTION TO THE INVENTION As disclosed in the above referenced applications, a Foucault knife-edge test has been traditionally understood to be perhaps the classic optical test for an imaging device, for example, a lens or a mirror. Attention is directed to FIG. 1, which shows a typical optical assembly 10 for demonstrating the basic principles of the Foucault knife-edge test. The assembly 10 includes a conventional imaging device, i.e., a lens 12, the lens 12 comprising a pair of optical surfaces 14 and 16; a radiation source 18; a collector lens 20; and a conventional photodetector 22 comprising the human eye. The components of the assembly 10 are aligned to a reference axis 24, as further evidenced by an x, y, z coordinate system. For this optical assembly 10, one may employ the knife-edge test for qualitatively detecting (at the eye/photodetector 22) the presence of transverse aberrations that may have been introduced into the assembly 10 by the lens optical surfaces 14, 16. Accordingly, a knife-edge 26 may be gradually introduced into the assembly 10 (shown by way of the FIG. 1 staggered arrows), so that the knife-edge 26 sequentially cuts and blocks the image of the radiation source 18 at a plane of convergence 28. This action, in turn, removes source rays from their expected trajectories, so that a variable intensity pattern may be registered by the eye. Finally, a comparison of this intensity pattern with a theoretical intensity pattern for an ideal optical surface, can become a qualitative measure of the presence or transverse aberrations introduced by the optical surfaces 14, 16. SUMMARY OF THE INVENTION So far, we have stressed that the Foucault knife-edge test can provide a qualitative measure of the presence of transverse aberrations that may have been introduced by the imaging device 12. Attention is now directed to FIGS. 2 and 3, which figures help explain what we mean by a qualitative test. In particular, FIGS. 2A, B, C, D show, in sequence, what the eye can qualitatively perceive when an ideal imaging device is subjected to the Foucault knife-edge test, and the knife-edge is sequentially advanced through four successive knife-edge positions viz: FIG. 2A: knife-edge position 1=total non-occlusion of the radiation (no shadow); FIG. 2B: knife-edge position 2=partial occlusion of the radiation (light, uniform shadowing); FIG. 2C: knife-edge position 3=further occlusion of the radiation (darker, uniform shadowing); FIG. 2D: knife-edge position 4=total occlusion of the radiation (total shadow). In summary, FIGS. 2A-D show that, for the ideal imaging device, the eye can qualitatively perceive an ever increasing and uniform shadow pattern. We can say, moreover, that the FIG. 1 collector lens 20 can provide images of the imaging device 12 at a photodetector plane, that is, at the eye, which images are the FIGS. 2A-D shadow patterns. Now we turn our attention to FIGS. 3A-D, which sequentially show what the eye can qualitatively perceive when a non-ideal imaging device is substituted for the FIG. 2 ideal imaging device, and is subjected to the Foucault knife-edge test. In particular, as the knife-edge is sequentially advanced through four successive knife-edge positions, the eye can sequentially and qualitatively perceive: FIG. 3A: knife-edge position 1=total non-occlusion of the radiation (no shadow); FIG. 3B: knife-edge position 2=partial occlusion of the radiation (light, non-uniform shadowing); FIG. 3C: knife-edge position 3=further occlusion of the radiation (darker, more obscure shadowing); FIG. 3D: knife-edge position 4=total occlusion of the radiation (total shadow). In summary, FIGS. 3A-D show that, for the non-ideal imaging device, the eye can qualitatively perceive an ever increasing shadow pattern: the FIGS. 3A-D shadow patterns, in contrast to that of FIGS. 2A-D, are marked by salients consisting of various dark zones with different radii of curvature, and different centers of curvature. Comparing, therefore, the shadow patterns provided in FIGS. 3A-D, versus those provided in FIGS. 2A-D, one skilled in the art may be enabled to say, based upon his subjective experience, that the FIG. 3 non-ideal imaging device has introduced some transverse aberrations into the assembly 10. A skilled optician may indeed be able to say more, for example, that the FIG. 3 shadow pattern suggests that the aberration is trefoil, or quatrefoil, or astigmatism. However, the skilled optician would not be able to ascertain, based on his eye's perception of the FIG. 3D shadow pattern, what quantitative measure of the transverse ray has been introduced by the non-ideal imaging device. As a first of two examples of this predicament, one's eye perception alone may preclude the optician from answering quantitative questions such as: how many waves of quatrefoil? or, how many waves of trefoil? etc. With reference to this first example, it has now been discovered, and disclosed in the above-referenced U.S. patent application Ser. No. 07/500,640, a quantitative Foucault knife-edge test. The test disclosed in this application complements the traditional qualitative test, by developing a quantitative interpretation of the imaging device's characteristics. An important advantage of this discovery is that the skilled optician is now enabled to quantitatively answer the questions posed above by the first example: that is, the optician can now say, "the imaging device has 0.05 waves of trefoil, or 0.75 waves of quatrefoil." As a second example, and one not addressed by the above-referenced U.S. patent application, one's eye perception alone may preclude the optician from quantitatively assessing an imaging device in terms of what is conventionally known as an "encircled energy test". Here, the optician is asked to realize, by way of the encircled energy test, the following design specifications for an imaging device: Example A: A desired transverse ray aberration tolerance for an imaging device is such that an energy circle of 80.0 micron diameter contains 95% of the energy imaged by the imaging device; or, Example B: A desired transverse ray aberration tolerance for an imaging device is such that an energy circle of 100.0 micron diameter contains 98% of the energy imaged by the imaging device. The significance of the second example, as compared to the first example, includes the following. I have realized that for many practical, commercial operations, it may be a sufficient objective to know whether or not a focused beam emerging from the imaging device is within or without the energy circle. This fact alone, may be an important indicia of the imaging device's characteristics. Restated, it may be a sufficient objective, for certain applications, to know whether or not the imaging device simply passes or fails the energy circle test, in contrast to quantitatively knowing exactly how many waves of a particular aberration characterize the imaging device. Thus, if an imaging device passes, say, a 98% energy circle test, that is sufficient, and one does not care that the implicit aberration comprises, say, 0.08 waves of coma. At the same time, it would be a desirable objective to quantitatively know exactly what percentage of energy is imaged by the imaging device (pass or fail), and to know this by a quick and efficient testing procedure. I have now discovered two novel methods for assessing an imaging device in terms of the encircled energy test. The first novel method is disclosed in U.S. patent application Ser. No. 07/531,988, filed contemporaneously with the present application. The first novel method provides a quantitative assessment of an imaging device, in terms of the encircled energy test. In particular, the first novel method includes an adaptation of the Foucault knife-edge test, to the end of providing a pass/fail test for quantitatively ascertaining exactly what percentage of energy may be sharply imaged by an imaging device. The second and present novel method complements my first novel method, in the following way. I have recognized the desirability of being able to further exploit the advantages provided by the first novel method pass/fail test, to the end of being able to locate and specify, precisely and uniquely, those discrete portions of the imaging device which pass the energy encircled test, and those discrete portions of the imaging device which fail the energy encircled test. The advantages of the present novel method are manifold. For example, the specified discrete portions of the imaging device which fail the energy encircled test, can now be efficiently and directly operated upon, to the end of correcting and/or lessening the transverse ray aberrations induced by these discrete portions. In other words, one can directly concentrate attention on the failed portions of the imaging device, without jeopardizing the integrity of the acceptable (pass) portions of the imaging device. Accordingly, for example, position and/or force correction actuators may be applied directly to the specified failed portions of the imaging device. Moreover, and in this spirit, for the case of an imaging device comprising a plurality of discrete segments, one can now isolate the failed discrete segments, and simply replace and/or correct them, without compromising the remaining acceptable discrete segments. Additionally, since my method provides the identity or signature of a failed portion of an imaging device, one can selectively mask it off, for example, by way of an aperture stop or iris, to thus lessen the introduction of transverse ray aberrations into an optical system. The present invention, accordingly, provides a method suitable for locating and specifying the regions of origination of unacceptable transverse ray aberrations in an imaging device, as indicated by an encircled energy pass/fail test. The imaging device is tested in a modified Foucault knife-edge test assembly. The assembly comprises: a) an imaging device to be tested; b) a source of radiation energy that can be directed along a reference axis to the imaging device; c) a photodetector aligned on the source reference axis, for detecting and measuring the radiation energy imaged by the imaging device; and d) a knife-edge capable of being positioned in a series of knife-edge position steps, for cutting the radiation imaged by the imaging device, thereby producing a variable radiation energy function, as measurable by the photodetector, the knife-edge comprising a substrate comprising an opaque region. The novel method comprises the steps of: 1) normalizing radiation energy levels of the assembly; 2) positioning the knife-edge opaque region in three degrees of freedom, for reducing the radiation energy measured by the photodetector; 3) positioning the knife-edge opaque region in three degrees of freedom, until the photodetector measures a minimum radiation energy; and 4) generating a conjugate image of the imaging device under the last step (3) condition, which conjugate image comprises discrete dark and light regions, which discrete regions correspond to a unique mapping of pass/fail portions of the imaging device under test. BRIEF DESCRIPTION OF THE DRAWING The invention is illustrated in the accompanying drawing, in which: FIG. 1 shows an optical assembly for using the Foucault knife-edge test; FIGS. 2A-D show shadow patterns generated by an ideal imaging device undergoing the FIG. 1 knife-edge test; FIGS. 3A-D show shadow patterns generated by a non-ideal imaging device undergoing the FIG. 1 knife-edge test; FIGS. 4A-C show preferred knife-edges of the present invention; FIG. 5 shows curves indicative of the pass/fail status of an imaging device, generated in accordance with the method of the present invention; FIG. 6 shows the basic elements of the FIG. 1 optical assembly, as modified in accordance with the requirements of the present invention; FIGS. 7A-C show cyclic descent optimization curves generated in accordance with a Step 2 of the present invention, for the case of a "Passed" imaging device; FIGS. 8A-C show cyclic descent optimization curves generated in accordance with a Step 3 of the present invention, for the case of a "Passed" imaging device; FIGS. 9A-C show cyclic descent optimization curves generated in accordance with a Step 2 of the present invention, for the case of a "Failed" imaging device; FIGS. 10A-C show cyclic descent optimization curves generated in accordance with a Step 3 of the present invention, for the case of a "Failed" imaging device; and FIG. 11 shows the FIG. 6 assembly at a frozen moment of time, when Step 3 of the present invention has been concluded. DETAILED DESCRIPTION OF THE INVENTION As summarized above, the method of the present invention requires a knife-edge comprising a substrate, the substrate comprising an opaque region. Preferably, the knife-edge comprises a transparent substrate, and a coating material that can adhere to at least a portion of the transparent substrate, thereby forming the opaque region. The transparent substrate of the present invention preferably has a high precision plano-shape, i.e., a flat shaped configuration, e.g., flat to within one micron over the area which is coated by the coating material. The transparent substrate preferably comprises a conventional glass. It may, alternatively, comprise a conventional plastic, or an equivalent transparent material, and one that is substantially self-supporting. A suitable transparent substrate has an index of transmittance that distinguishes it from a metal, for example, a transmittance preferably greater than 10 percent. An advantage of the present invention is that the thickness of the transparent substrate may be variable, but, for example, for a glass substrate, is preferably from 0.5 mm to 5 mm in thickness. Further, the transparent substrate may have, for example, a circular, square or trapezoidal shape, but preferably defines a rectangular shape, the latter preferably having dimensions of approximately 3 to 50 mm length, by 3 to 50 mm width. The coating material of the present invention preferably is such that, in combination with the transparent substrate and the source of radiation, at least one portion of a knife-edge element may be defined that qualitatively differentiates a substantially opaque region from a substantially transparent region. Restated, the transmittance of the substantially opaque region in ratio to the transmittance of the substantially transparent region, is preferably less than 10 percent. To this end, the coating material preferably comprises silver, or chrome, or aluminum, or conventional paints, or combinations of these coating materials. A particularly preferred coating material comprises a conventional photoemulsion. This material is preferred because (1) it provides a desired opacity for a typical employment of the Foucault method, (2) it inherently and readily adheres to a typical transparent substrate, for example, glass, and (3) it has a preferred coating thickness, typically less than 10 microns. On this last point, thickness, the coating material preferably has a thickness less than 25 microns, especially less than 0.25 microns. Control of the thickness of the coating material directly translates into the "sharpness" of the knife-edge, hence directly translating into an enhanced Foucault method accuracy. A selected coating material can adhere to the transparent substrate either indirectly, as in paints, or inherently by way of conventional adhesion processes including, for example, the conventional high vacuum evaporative processes, or sputtering processes, or chemical vapor deposition processes. As indicated above, the coating material can adhere to at least a portion of the transparent substrate, thereby forming the opaque region. The pattern adhesion may be realized by way of conventional mask techniques, or lithographic film or plate techniques. A preferred technique employs conventional photographic techniques, for example, photolithographic films and plates. Attention is now directed to FIGS. 4A-C, which show preferred knife-edge opacity regions of the present invention, and suitable for employment in the Foucault method. FIG. 4A shows a knife-edge 30. The knife-edge 30 comprises a white crown glass substrate 32, and an opacity region comprising a coating material 34 comprising blue chrome. The transition from opacity to transparency is abrupt, that is, the transmittance of the opaque region in ratio to the transmittance of the transparent region, is 0.01 percent. The thickness of the coating material 34 is 500 angstroms. The FIG. 4A knife-edge opacity region is meant to represent an energy circle of 80.0 microns diameter. The diameter of other circular energy circles (not shown) is typically from 1.0 micron to 200.0 microns. The circle geometry is preferred when the total transverse ray aberration of an imaging device is specified, independent of the FIG. 1 x and y coordinates. The FIG. 4B embodiment shows a knife-edge 36. The knife-edge 36 comprises a white crown glass substrate 38, and an opacity region comprising a coating material 40 comprising photoemulsion. The coating material 40 adheres to the glass substrate 38 by way of an evaporative process. The transition from opacity to transparency is abrupt, and the coating material is several microns in thickness. The FIG. 4B knife-edge opacity region comprises an energy rectangle having a length of 100.0 microns and a width of 40.0 microns. The energy rectangle geometry is preferred when the FIG. 1 x and y transverse ray aberrations are specified, and they are separate and unequal. Attention is next directed to FIG. 4C, which shows a knife-edge 42 formed in substantially the same way as FIG. 4B, but comprising an opacity region 44 in the form of an energy square having a length of 70.0 microns. This geometry is preferred when the x and y transverse ray aberrations are specified separately, to the same tolerance. For the sake of illustration, the FIG. 4A knife-edge 30 comprising a circular opaque geometry, is now used to demonstrate preferred aspects of the steps of the method of the present invention, for each of three imaging devices to be tested. FIG. 5 develops this point, for the following common specification: Specification For FIG. 5: A desired transverse ray aberration tolerance for an imaging device is such that an energy circle of 80.0 micron diameter contains 95% of the energy imaged by the imaging device. FIG. 5 shows the three possible curves that can be generated in accordance with the method of the present invention, for each of three different imaging devices, i.e., the first imaging device fails (curve A); the second imaging device meets specification (curve B); the third imaging device exceeds specification (curve C). For the FIG. 5 third imaging device that exceeds specifications (curve C), its curve may be generated in accordance with the following four steps. Step 1: Normalizing radiation levels of the Foucault Assembly. Step 1 is preferably realized by way of a modified FIG. 1 optical assembly 10, of the type shown in FIG. 6. To this end, the FIG. 1 photodetector 22 comprising the human eye, is preferably replaced by a solid state (E-O) camera, for example, a CIDTEC Corporation Model No. TN2250A2, as shown in FIG. 6 as numeral 46. Alternatively, the photodetector may comprise a conventional camera including a camera lens and conventional photographic film. The FIG. 6 E-O photodetector 46 may be normalized (in the presence of the FIG. 6 imaging device 12) by making two separate camera readings, namely, (1) with a mask or knife-edge opaque region completely blocking the radiation passing through the imaging device 12 from the source 18 to the E-O camera 46; and, (2) with the knife-edge transparent portion allowing substantially all of the radiation source 18 energy to reach the E-O camera 46. These two readings comprise first and second endpoints, demarking 0 to 100% normalization. Step 2: Positioning the knife-edge opaque region in three degrees of freedom, for reducing the radiation energy measured by the E-O camera. Step 2 is preferably realized in the following way. The knife-edge comprising the opaque region is positioned in three degrees of freedom Δx, Δy, Δz (see FIG. 6's coordinate system), for reducing the radiation energy measured by the E-O camera 46. Such a positioning of the knife-edge initiates a process comprising cyclic descent optimization, to the end of minimizing the E-O camera 46 energy reading. An example of the cyclic descent optimization is shown in FIG. 7A-C. Note that each of the coordinates Δx, Δy, Δz is individually optimized unto itself. Step 3: Positioning the knife-edge opaque region in three degrees of freedom, until the E-O camera measures a minimum energy. Step 3 corresponds to a continuation of the Step 2 cyclic descent optimization process. That is, the knife-edge opaque region is further positioned for gradual increments of Δx, Δy, Δz, until the E-O camera 46 now measures a minimum, quantified energy. FIGS. 8A-C provide examples of Step 3, for each of the coordinates Δx, Δy, Δz, respectively. Note that although each of the coordinate movements Δx, Δy, Δz, is individually optimized unto itself, the final descent to a minimum energy is such that the photon energy intensity measured by the E-O camera 46, for each of the coordinates Δx, Δy, Δz, is the same. Step 4: Comparing the Step 3 minimum energy against a test specification value. Step 4 may be explained by reference to FIGS. 8A-C. These figures show that the minimum energy measured by the E-O camera 46 is less than the specification value. The imaging device being tested, accordingly, exceeds the specification line poised above with reference to FIG. 5 (curve C). This imaging device therefore passes the encircled energy test. Finally, the method of the present invention is illustrated for the case where an imaging device fails a specification, as exemplified above in FIG. 5, curve A. Such an imaging device, when subjected to the second step of the method, generates a family of curves of the type shown in FIGS. 9A-C. FIGS. 9A-C show that when the knife-edge opaque region is moved in three degrees of freedom, the E-O camera 46 generates energy curves, for each of the coordinate movements Δx, Δy, Δz, above the specification line. Further, FIGS. 10A-C show that when the knife-edge is further positioned in accordance with the Step 3 of the method, so as to generate a minimum E-O camera 46 energy of known intensity, the minimum remains above the specification line, for each of the coordinate movements Δx, Δy, Δz. This last fact demonstrates that the imaging device fails the specification, i.e., the encircled energy test. OBSERVATIONS ON STEPS ONE THROUGH FOUR: The steps 1-3 disclosed above provide a pass/fail test for quantitatively ascertaining exactly what percentage of energy may be sharply imaged by an imaging device, in terms of the encircled energy test (step 4). Attention is now turned to a complementary capability; namely, locating and specifying, precisely and uniquely, those discrete portions of the imaging device 12 which pass the encircled energy test, and those discrete portions of the imaging device 12 which fail the encircled energy test. Step 5: Generating a conjugate image of the imaging device under the step 3 condition, which conjugate image comprises discrete dark and light regions, which discrete regions correspond to a unique mapping of pass/fail portions of the imaging device under test. Step 5 may be realized by way of an E-O camera, or a conventional camera. As an example, step 5 is realized by way of the FIG. 11 assembly, which includes a conventional camera 48 comprising a lens 50, and a sheet of photographic film 52. FIG. 11, otherwise, includes the components of FIG. 6 supra, and in particular, shows FIG. 6 as it would be if "frozen" at the end of the step 3 cyclic descent optimization process. Note in FIG. 11 that the illustrative pattern developed on the photographic film 52 by the camera 48 comprises discrete light and dark regions, numerals 54, 56 respectively. These discrete light and dark regions 54, 56 are a conjugate image 54', 56' of the imaging device 12 under test. Moreover, since these light and dark regions 54, 56 are generated by the camera 48, by way of the above delineated cyclic descent optimization process of steps 1-3 supra, the discrete light and dark regions 54', 56' correspond to a unique mapping of fail/pass portions of the imaging device 12 under test.

A novel method for quantitatively assessing an imaging device in terms of the classical encircled energy test is disclosed in a contemporaneously filed Application. The present invention complements this capability, and discloses a method which can specify, precisely and uniquely, those discrete portions of an imaging device which pass the encircled energy test, and those discrete portions of the imaging device which fail the encircled energy test. Advantages of the present invention include a capability to direct efficient correction procedures towards those discrete portions of the imaging device which fail the encircled energy test, without compromising discrete portions of the imaging device which pass the encircled energy test.

TECHNICAL FIELD [0001] The invention relates to magnetic resonance imaging, in particular to magnetic resonance imaging systems with multiple radio-frequency transmit channels. BACKGROUND OF THE INVENTION [0002] A magnetic field is used in Magnetic Resonance Imaging to align the nuclear spins of atoms as part of the procedure for producing images within the body of a patient. This magnetic field is referred to as the B0 field. During an MRI scan, Radio Frequency (RF) pulses generated by a transmitter or amplifier and an antenna cause perturbations to the local magnetic field and can be used to manipulate the orientation of the nuclear spins relative to the B0 field. RF signals emitted by the nuclear spins are detected by a receiver coil, and these RF signals are used to construct the MRI images. [0003] Parallel Transmit Magnetic Resonance Imaging (MRI) systems may have multiple transmit and receive channels. The antenna may comprise multiple antenna elements, each of which is connected to a transmitter and/or receiver. [0004] U.S. Pat. No. 7,282,915 discloses a receive only RF imaging coil. The RF imaging coil has a plurality of distributed capacitors positioned selectively about each coil element. The values of the distributed capacitors are adjusted so as to tune each coil element to the MRI frequency with all the coil assemblies assembled and with the sample or subject present in the sample space. SUMMARY OF THE INVENTION [0005] The invention relates to a magnetic resonance imaging system, a computer program product, a method, and a radio-frequency antenna in the independent claims. Embodiments are given in the dependent claims. [0006] In Magnetic Resonance Imaging there is a clear trend to design antenna arrays for the RF transmission and reception. The power efficiency of such arrays depends on the loading, i.e. on the size of the patient and the body region to be imaged. Currently multi-element antennas are tuned so that it functions with a variety of subjects. However, the positioning and size of a particular subject relative to the antenna elements may affect their scattering matrix S, i.e., input reflections and transmission coefficients with respect to the feeding ports. Embodiments of the invention may solve this problem and others by actively modifying or impedance matching the transmit array or antenna depending on the loading condition to achieve an efficient use of the power applied. [0007] There is also radio-frequency coupling between the individual antenna elements. The radio-frequency power applied to one antenna element may couple to another element. To compensate for this, embodiments of the invention may characterize the radio-frequency antenna. This characterization of the radio-frequency antenna constitutes a set of radio-frequency properties which can then be used with a radio-frequency model to calculate how the impedance matching network should be adjusted. The radio-frequency model may either be a model which uses the set of radio-frequency properties to model the impedance matching network and radio-frequency antenna or it may be a set of parameters which characterize the present state of the antenna and its matching network. [0008] In another embodiment execution of the instructions causes the processor to acquire a magnetic field map using the magnetic resonance imaging system. For instance the magnetic field map may be a B1 field map for each antenna element that was acquired using the magnetic resonance imaging system. The radio-frequency properties are at least partially measured using the magnetic field map. For instance the strength of the B1 field generated by a coil element may be proportional to or related to the radio-frequency current through the coil element. As a result, the B1 field could be used to determine the current or even the voltage applied to the coil element. [0009] In multi channel magnetic resonance imaging systems, each antenna element may be driven with radio-frequency power that has a different amplitude and phase. The amplitude and phase may be selected to perform among other things like B1 shimming, i.e. improving the B 1+ homogeneity, or reduction of the Specific Absorption Ration (SAR) for whole body imaging. This amplitude and phase may be referred to as a drive vector, B1 shim setting, or shim setting. The appropriate drive vector may change depending upon the subject, the subject position, and the type of magnetic resonance imaging procedure performed, in particular the region being imaged. Each of the antenna elements are impedance matched to a radio-frequency channel using an impedance matching network. For each drive vector the impedance matching network may need to be adjusted. [0010] A ‘computer-readable storage medium’ as used herein encompasses any tangible storage medium which may store instructions which are executable by a processor of a computing device. The computer-readable storage medium may be referred to as a computer-readable non-transitory storage medium. The computer-readable storage medium may also be referred to as a tangible computer readable medium. In some embodiments, a computer-readable storage medium may also be able to store data which is able to be accessed by the processor of the computing device. Examples of computer-readable storage media include, but are not limited to: a floppy disk, a magnetic hard disk drive, a solid state hard disk, flash memory, a USB thumb drive, Random Access Memory (RAM), Read Only Memory (ROM), an optical disk, a magneto-optical disk, and the register file of the processor. Examples of optical disks include Compact Disks (CD) and Digital Versatile Disks (DVD), for example CD-ROM, CD-RW, CD-R, DVD-ROM, DVD-RW, or DVD-R disks. The term computer readable-storage medium also refers to various types of recording media capable of being accessed by the computer device via a network or communication link. For example a data may be retrieved over a modem, over the internet, or over a local area network. References to a computer-readable storage medium should be interpreted as possibly being multiple computer-readable storage mediums. Various executable components of a program or programs may be stored in different locations. The computer-readable storage medium may for instance be multiple computer-readable storage medium within the same computer system. The computer-readable storage medium may also be computer-readable storage medium distributed amongst multiple computer systems or computing devices. [0011] ‘Computer memory’ or ‘memory’ is an example of a computer-readable storage medium. Computer memory is any memory which is directly accessible to a processor. Examples of computer memory include, but are not limited to: RAM memory, registers, and register files. References to ‘computer memory’ or ‘memory’ should be interpreted as possibly being multiple memories. The memory may for instance be multiple memories within the same computer system. the memory may also be multiple memories distributed amongst multiple computer systems or computing devices. [0012] ‘Computer storage’ or ‘storage’ is an example of a computer-readable storage medium. Computer storage is any non-volatile computer-readable storage medium. Examples of computer storage include, but are not limited to: a hard disk drive, a USB thumb drive, a floppy drive, a smart card, a DVD, a CD-ROM, and a solid state hard drive. In some embodiments computer storage may also be computer memory or vice versa. References to ‘computer storage’ or ‘storage’ should be interpreted as possibly being multiple storage. The storage may for instance be multiple storage devices within the same computer system or computing device. The storage may also be multiple storages distributed amongst multiple computer systems or computing devices. [0013] A ‘processor’ as used herein encompasses an electronic component which is able to execute a program or machine executable instruction. References to the computing device comprising “a processor” should be interpreted as possibly containing more than one processor or processing core. The processor may for instance be a multi-core processor. A processor may also refer to a collection of processors within a single computer system or distributed amongst multiple computer systems. The term computing device should also be interpreted to possibly refer to a collection or network of computing devices each comprising a processor or processors. Many programs have their instructions performed by multiple processors that may be within the same computing device or which may even be distributed across multiple computing devices. [0014] A ‘user interface’ as used herein is an interface which allows a user or operator to interact with a computer or computer system. A ‘user interface’ may also be referred to as a ‘human interface device.’ A user interface may provide information or data to the operator and/or receive information or data from the operator. A user interface may enable input from an operator to be received by the computer and may provide output to the user from the computer. In other words, the user interface may allow an operator to control or manipulate a computer and the interface may allow the computer indicate the effects of the operator's control or manipulation. The display of data or information on a display or a graphical user interface is an example of providing information to an operator. The receiving of data through a keyboard, mouse, trackball, touchpad, pointing stick, graphics tablet, joystick, gamepad, webcam, headset, gear sticks, steering wheel, pedals, wired glove, dance pad, remote control, and accelerometer are all examples of user interface components which enable the receiving of information or data from an operator. [0015] A ‘hardware interface’ as used herein encompasses a interface which enables the processor of a computer system to interact with and/or control an external computing device and/or apparatus. A hardware interface may allow a processor to send control signals or instructions to an external computing device and/or apparatus. A hardware interface may also enable a processor to exchange data with an external computing device and/or apparatus. Examples of a hardware interface include, but are not limited to: a universal serial bus, IEEE 1394 port, parallel port, IEEE 1284 port, serial port, RS-232 port, IEEE-488 port, Bluetooth connection, Wireless local area network connection, TCP/IP connection, Ethernet connection, control voltage interface, MIDI interface, analog input interface, and digital input interface. [0016] Magnetic Resonance (MR) data is defined herein as being the recorded measurements of radio frequency signals emitted by atomic spins by the antenna of a Magnetic resonance apparatus during a magnetic resonance imaging scan. A Magnetic Resonance Imaging (MRI) image is defined herein as being the reconstructed two or three dimensional visualization of anatomic data contained within the magnetic resonance imaging data. This visualization can be performed using a computer. [0017] In one aspect the invention provides for a magnetic resonance imaging system for acquiring magnetic resonance data. The magnetic resonance imaging system comprises a radio-frequency transmitter with multiple transmit channels for generating radio-frequency pulses during acquisition of the magnetic resonance data. In acquiring the magnetic resonance data typically a large magnetic field is used to align magnetic spins in atoms or molecules. Next, magnetic gradient coils are used to generate gradient fields which are used for spatially encoding the spins. Finally the radio-frequency antenna is used to transmit radio-frequency pulses which are used for manipulating the orientation of the magnetic spins. The same or a different antenna may be used to receive radio-frequency emissions from the spins. [0018] The magnetic resonance imaging system comprises or includes an impedance matching network adapted for impedance matching the radio-frequency transmitter to a radio-frequency antenna. The matching network may comprise or include several matching circuits for each antenna port to control the impedance at each port, or to control the S-matrix. [0019] The radio-frequency antenna comprises multiple antenna elements. The impedance matching network is adjustable remotely. By adjustable remotely it is meant that the impedance matching network may be controlled from a distance. This may include electronic control of the impedance matching network and also remote mechanical adjustment of components of the impedance matching network. For instance an impedance matching network could be controlled by such things as a pin diode which would be an example of electronic control or it may be controlled for instance by adjustable capacitors which would be an example of a mechanical adjustment of the impedance matching network. [0020] The radio-frequency transmitter, the impedance matching network, and the radio-frequency antenna may all have the same number of channels or elements. In other embodiments the radio-frequency transmitter, the radio-frequency antenna and the impedance matching network have a different number of channels or elements. For instance a multiplexer may be connected between the radio-frequency transmitter and the impedance matching network and/or a multiplexer may be connected between the impedance matching network and the radio-frequency antenna. The magnetic resonance imaging system further comprises a memory for storing machine executable instructions. [0021] In another embodiment the matching network may have interconnections between at least two ports allowing a defined (in magnitude and phase) transfer of power among channels. [0022] The magnetic resonance imaging system further comprises or includes a processor for executing the machine executable instructions. The processor is adapted for controlling the magnetic resonance imaging system. [0023] Execution of the instructions causes the processor to measure a set of radio-frequency properties of the radio-frequency antenna. That is to say a signal is transmitted using the radio-frequency transmitter and measurements are made which allow the processor to measure a set of radio-frequency properties. The radio-frequency properties characterize the multi-element antenna. The radio-frequency properties may be measured in different ways in different embodiments. For instance a radio-frequency receiver could be used to simultaneously measure the transmitted signals while the radio-frequency transmitter is emitting. Alternatively the reflection may be measured using directional couplers. In this case the magnetic resonance imaging system may have a network analyzer-like functionality. In other embodiments sensors are distributed within the radio-frequency chain and are used to measure the set of radio-frequency properties. The MRI system could also acquire magnetic field information using MR-methods to be used as radio frequency properties. [0024] Execution of the instructions further causes the processor to calculate a matching network command using the set of radio-frequency properties and a radio-frequency model. The radio-frequency model is descriptive of the impedance matching network and the radio-frequency antenna. For instance the radio-frequency model may be a SPICE or other model which allows the precise modeling of the impedance (matrix) properties and field generator of the radio-frequency coil. The matching network command is a command or instruction, possibly a set of commands or set of instructions, which cause the impedance matching network to be adjusted remotely. Execution of the instructions further cause the processor to adjust the impedance matching network by sending the matching network commands to the impedance matching network. [0025] This embodiment may be particularly beneficial because it is advantageous to impedance match the radio-frequency antenna when acquiring magnetic resonance data. The measurement of the radio-frequency properties and the calculation of the matching network commands using the measured set of radio-frequency properties and the radio-frequency model enables the accurate adjustment of the impedance matching network. In a magnetic resonance imaging system with multiple transmit and/or receive channels the transmission and matching of one channel affects the transmissions and matching of other channels (due to residual coupling). The apparatus as outlined enables the accurate impedance matching network in spite of these changes and transmissions on other channels. [0026] In another embodiment the magnetic resonance imaging system further comprises a radio-frequency receiver for acquiring the magnetic resonance data using the radio-frequency antenna. The radio-frequency receiver has one or multiple receive channels. The multiple receive channels may have the same number as the multiple transmit channels or they may be a different number. For instance a multiplexer may be used where there is a different number of transmit and receive channels. If B1 mapping is used to measure the magnetic field generated by a coil only a single receiver is needed. [0027] In another embodiment the magnetic resonance imaging system further comprises a radio-frequency generator. The radio-frequency properties are at least partially measured using radio-frequency transmitter. The radio-frequency generator may be used to generate radio-frequency signals which can be detected by a radio-frequency receiver, external sensors, field probes, or B1 measurements of the magnetic field using the magnetic resonance imaging system. In some embodiments the radio-frequency generator is identical with the radio-frequency transmitter. In other embodiments the radio-frequency generator is a generator that is separate from the radio-frequency frequency transmitter. The radio-frequency generator may also be a component of a network analyzer. [0028] In another embodiment the magnetic resonance imaging system further comprises a network analyzer. The radio-frequency properties are at least partially measured using the network analyzer. The network analyzer may be for instance connected into the radio-frequency chain using a switch. [0029] In another embodiment the magnetic resonance imaging system further comprises a radio-frequency properties measuring means for measuring the radio-frequency properties. The radio-frequency properties are at least partially measured using the radio-frequency measuring means. A radio-frequency properties measuring means as used herein in encompasses any means which may be used for characterizing the radio-frequency properties of the antenna. This may include, but is not limited to: a network analyzer, radio-frequency test equipment, sensors distributed within the RF chain, magnetic field sensors, and/or the magnetic resonance imaging system itself. [0030] The radio-frequency transmitter and the radio-frequency receiver are configured for simultaneous transmissions on at least one of the multiple transmit channels and simultaneous receptions on at least one of the multiple receive channels. The set of radio-frequency properties comprise an S-matrix or scattering matrix measured using the at least one of the multiple transmit channels and using the at least one multiple receive channels. This embodiment may be advantageous because the simultaneous transmission and reception enables the magnetic resonance imaging system to function in a network analyzer-like way and measure the S-matrix. In conjunction with a radio-frequency model the S-matrix may be used to accurately calculate the matching network command. [0031] In another embodiment the impedance matching network is further adapted for impedance matching the radio-frequency receiver to the radio-frequency antenna. [0032] In another embodiment the magnetic resonance imaging system comprises a set of radio-frequency sensors. The radio-frequency properties are measured at least using the set of radio-frequency sensors. This embodiment may be beneficial because the measurement of the radio-frequency properties using the radio-frequency sensors allows the radio-frequency properties of the radio-frequency antenna to be characterized. The radio frequency sensors could for instance be used when the radio-frequency transmitter or a radio-frequency generator is generating a radio-frequency signal. [0033] In another embodiment the magnetic resonance imaging system uses B1 mapping techniques to measure the response of the multi element transmit coil. [0034] In another embodiment execution of the instructions further causes the processor to determine a B1 shim settings for the radio-frequency transmitter using the magnetic resonance imaging system. A B1 shim setting as used herein encompasses is a complex vector comprising amplitudes and phases of all excitations in each transmit channel. The processor may send commands to the magnetic resonance imaging system which cause it to acquire data which may be used to calculate B1 shim settings for i.e. homogeneous excitation in a given field of interest (FOI). Execution of the instructions further causes the processor to calculate a power loss using the set of radio-frequency properties and the B1 shim settings. Execution of the instructions further causes the processor to choose a matching network adjustment. The matching network is adjustable. The matching network adjustment is a change in the settings or mechanical position of matching network components. [0035] Execution of the instructions further causes the processor to transform the set of radio-frequency properties and the B1 shim settings using the radio-frequency model and the matching network adjustment. A change in the matching network will change the radio-frequency properties and the B1 shim settings. Using the radio-frequency model these changes may be calculated. Execution of the instructions further causes the processor to calculate a changed power loss using the transformed set of radio-frequency properties and the transformed B1 shim settings. The matching network command is calculated in accordance with the matching network adjustment if the changed power loss is smaller than the power loss. This embodiment may be beneficial because it provides a means of determining matching network settings which lead to the efficient radio-frequency emissions from the antenna. [0036] In another embodiment execution of the instructions further causes the processor to re-determine the B1 shim settings and re-measure the set of radio-frequency properties. The model was used to calculate the transformed value of the radio-frequency properties and the transformed B1 shim settings. After the final matching network adjustment is determined or even during an iterative process these calculated values can be checked against measurements made using the magnetic resonance imaging system. [0037] In another embodiment the power loss is a relative power loss and the changed power loss is a changed relative power loss. [0038] In another embodiment execution of the instructions causes the processor to iteratively repeat the choosing of a matching network adjustment and calculation of the changed power loss. For instance the matching network adjustment may be repeatedly calculated until the change in the power loss is below a predetermined threshold. [0039] In another embodiment the impedance matching network is configured to couple at least one pair of the multiple antenna elements. The coupling between the at least one pair is remotely adjustable. This embodiment may be beneficial because transmissions on one antenna element may affect other antenna elements. The coupling may be adjusted in different ways. For instance there may be a resistance or real impedance, a capacitive or capacitor may be used to provide the coupling, an adjustable impedance may be used to adjust the coupling, or combinations thereof may be used. For instance a simple network may be used to join pairs of channels going to the multiple antenna elements. This embodiment may be beneficial because it may provide better impedance matching of the radio-frequency antenna. [0040] In another embodiment the step of calculating the matching network command comprises instructions for adjusting the coupling between the at least one pair. This embodiment may be beneficial because the adjustable coupling between the multiple antenna elements is modeled in the radio-frequency model and this is used to properly adjust the impedance matching network. This may be performed as an iterative process where the matching network is adjusted, including adjusting the coupling, is alternated with acquiring magnetic resonance data for reconstructing images. [0041] In another embodiment the instructions for adjusting the coupling between the at least one pair cause the coupling between the at least one pair to be changed. The coupling has an amplitude and a phase. Changing the amplitude and/or the phase will change the degree of coupling between two channels. [0042] In another embodiment the magnetic resonance imaging system comprises the radio-frequency antenna. [0043] In another embodiment the magnetic resonance imaging system comprises a magnet with a main field. A main field as used herein encompasses a magnetic field which is strong enough and uniform enough to perform magnetic resonance imaging. The impedance matching network is located outside of the main field. This may for instance include the instance where a portion of the impedance matching network is located on or near the antenna. For instance a half or quarter wavelength transmission line may be used to connect an element of the radio-frequency antenna to a matching network or a sub-matching network. [0044] In another embodiment the impedance matching network is integrated into the radio-frequency coil. [0045] In another embodiment the impedance matching network comprises a set of separate matching networks each connected between one of the multiple transmit and receive channels and one of the multiple antenna elements. In this embodiment the impedance matching network for the multi-channel system is comprised of individual and possibly simpler matching networks. This may enable the expanding of the number of radio-frequency channels used in the magnetic resonance imaging system. [0046] In another embodiment execution of the instructions further causes the processor to acquire the magnetic resonance data using the magnetic resonance imaging system. The magnetic resonance data is acquired after the impedance matching network has been adjusted. This is advantageous because the images or the magnetic resonance data that has been acquired was acquired after the radio-frequency antenna has been properly impedance matched. This may improve the image quality. In some embodiments the acquisition or measurement of the radio-frequency properties and the acquisition of magnetic resonance data is iterative. Periodically during the use of the magnetic resonance imaging system the set of radio-frequency properties may be measured or re-measured to ensure that all of the magnetic resonance data acquired is of the best quality. [0047] The invention provides for a magnetic resonance imaging system for acquiring magnetic resonance data. The magnetic resonance imaging system comprises or includes a radio-frequency transceiver for generating radio-frequency pulses during acquisition of magnetic resonance data. The radio-frequency transceiver has multiple transmit and receive channels. The radio-frequency transceiver is adapted for simultaneous transmission and reception on each of the multiple transmit and receive channels. Alternatively, the radio-frequency properties may be measured with an other piece of hardware or sensors. [0048] The magnetic resonance imaging system further comprises an impedance matching network adapted for impedance matching the radio-frequency transceiver to a radio-frequency antenna. The radio-frequency antenna comprises multiple antenna elements. The radio-frequency transceiver has a channel chosen from the multiple transmit and receive channels for each of the multiple antenna elements. In alternative embodiments, the number of channels in the antenna might also be higher than the number of transmission channels. In this case, power splitters and/or combiners can be used for example. The impedance matching network is adjustable remotely. [0049] In another embodiment the magnetic resonance imaging system further comprises a memory for storing machine executable instructions in a processor for executing the machine executable instructions. The processor is adapted for controlling the magnetic resonance imaging system. Execution of the instructions causes the processor to measure an S-matrix (scattering matrix) for the radio-frequency antenna using e.g. the radio-frequency transceiver. In alternative embodiments, the invention may be realized without measuring the S-matrix. For examples field maps acquired with MRI-techniques may be used instead. Important information may also be provided for or measured by at least one data set of: Field maps (B1-maps) of the single coil elements, S-matrix of the coil, Field probe measurements of the individual elements (Field sensitivity matrix), and Current measurements of the individual elements (current sensitivity matrix) [0054] Execution of the instructions further causes the processor to calculate a matching network command using the S-matrix and a radio-frequency model. The radio model is descriptive of the impedance matching network and the radio-frequency antenna. Execution of the instructions further causes the processor to adjust the impedance matching network by sending the matching network command to the impedance matching network. [0055] In another aspect the invention provides for a computer program product comprising machine executable instructions. The machine executable instructions are for execution by a processor controlling the magnetic resonance imaging system for acquiring magnetic resonance data. The magnetic resonance imaging system comprises a radio-frequency transmitter for generating radio-frequency pulses during acquisition of the magnetic resonance data. The radio-frequency transmitter has multiple transmit channels. The magnetic resonance imaging system further comprises an impedance matching network adapted for impedance matching the radio-frequency transmitter to a radio-frequency antenna. The radio-frequency antenna comprises multiple antenna elements. The impedance matching network is adjustable remotely. [0056] Execution of the instructions causes the processor to measure a set of radio-frequency properties of the radio-frequency antenna. Execution of the instructions further causes the processor to calculate a matching network command using the set of radio-frequency properties and a radio-frequency model. The radio-frequency model is descriptive of the impedance matching network and the radio-frequency antenna. Execution of the instructions further causes the processor to adjust the impedance matching network by sending the matching network command to the impedance matching network. In another aspect the invention provides for a method of operating a magnetic resonance imaging system for acquiring magnetic resonance data. The magnetic resonance imaging system comprises a radio-frequency transmitter for generating radio-frequency pulses during acquisition of the magnetic resonance data. The radio-frequency transmitter has multiple transmit channels. [0057] The magnetic resonance imaging system further comprises an impedance matching network adapted for impedance matching the radio-frequency transmitter to a radio-frequency antenna. The radio-frequency antenna comprises multiple antenna elements. The impedance matching network is adjustable remotely. Execution of the instructions causes the processor to measure a set of radio-frequency properties of the radio-frequency antenna. Execution of the instructions further causes the processor to calculate a matching network command using the set of radio-frequency properties and a radio-frequency model. The radio-frequency model is descriptive of the impedance matching network and the radio-frequency antenna. Execution of the instructions further causes the processor to adjust the impedance matching network by sending the matching network command to the impedance matching network. [0058] In another embodiment the magnetic resonance imaging system comprises a magnet with an imaging zone. The magnetic resonance imaging system is acquired from the imaging zone. The method further comprises the step of placing a subject at least partially within the imaging zone before measuring the set of radio-frequency properties. This embodiment may be particularly beneficial because when a subject is placed within the imaging zone in the vicinity of the radio-frequency antenna this may cause the impedance of the radio-frequency antenna to change. Matching the impedance of the radio-frequency antenna to the radio-frequency transmitter while the subject is in place may result in better impedance matching and therefore higher image quality. [0059] It should be noted that the magnetic resonance data is primarily acquired from the imaging zone. However, Fourier methods are used typically for image construction using the magnetic resonance data. For this reason magnetic spins outside of the imaging zone may affect the image. Therefore, although the region of interest for imaging is within the imaging zone magnetic spins outside of the imaging zone also have their magnetic resonance data acquired. [0060] In another aspect the invention provides for a radio-frequency antenna configured for acquiring magnetic resonance data. The radio-frequency antenna comprises multiple antenna elements. The multiple antenna elements are configured for transmitting. In some embodiments the multiple antenna elements are configured for transmitting and receiving. The radio-frequency antenna comprises or includes an impedance matching network. The impedance matching network is remotely controllable. The impedance matching network is configured to connect to a radio-frequency transmitter with multiple transmit channels. BRIEF DESCRIPTION OF THE DRAWINGS [0061] In the following preferred embodiments of the invention will be described, by way of example only, and with reference to the drawings in which: [0062] FIG. 1 shows a flow diagram which illustrates a method according to an embodiment of the invention; [0063] FIG. 2 shows a flow diagram which illustrates a method according to a further embodiment of the invention; [0064] FIG. 3 shows a magnetic resonance imaging system 300 according to an embodiment of the invention [0065] FIG. 4 shows a plot with calculated power levels at the radio-frequency antenna and the matching network for a first volunteer; [0066] FIG. 5 shows a plot with calculated power levels at the radio-frequency antenna and the matching network for a second volunteer; [0067] FIG. 6 shows a plot with calculated power levels at the radio-frequency antenna and the matching network for a third volunteer; [0068] FIG. 7 shows a plot with calculated power levels at the radio-frequency antenna and the matching network for a fourth volunteer; [0069] FIG. 8 shows a plot with calculated power levels at the radio-frequency antenna and the matching network for an empty coil; [0070] FIG. 9 shows the data plotted FIG. 6 to illustrate the benefit of a tunable controlled coupling/decoupling network between coil elements; [0071] FIG. 10 shows the same data as FIG. 9 with the addition of the forward power at the antenna with only decoupling and without adjusting the matching network; [0072] FIG. 11 illustrates an example of a hydrodynamically tuned capacitor; [0073] FIG. 12 illustrates an example of direct tuning of a frequency coil; [0074] FIG. 13 shows a block diagram which illustrates the functioning of a software tool according to an embodiment of the invention; [0075] FIG. 14 shows an example of a radio-frequency system for a magnetic resonance imaging system according to an embodiment of the invention; [0076] FIG. 15 shows an example of a radio-frequency system for a magnetic resonance imaging system according to a further embodiment of the invention; [0077] FIG. 16 shows an example of a radio-frequency system for a magnetic resonance imaging system according to a further embodiment of the invention; [0078] FIG. 17 shows an example of an l-matching network which may be used in an embodiment of the invention; [0079] FIG. 18 shows a further example of an l-matching network which may be used in an embodiment of the invention; [0080] FIG. 19 shows an inductive matching network which may be used in an embodiment of the invention; [0081] FIG. 20 shows a pi-matching network which may be used in an embodiment of the invention; [0082] FIG. 21 shows a t-matching network which may be used in an embodiment of the invention; [0083] FIG. 22 shows a matching network which uses a transmission lines and which may be used in an embodiment of the invention; [0084] FIG. 23 shows a dual-frequency matching network that may be used for more than one frequency which may be used in an embodiment of the invention; [0085] FIG. 24 illustrates a set of radio frequency sensors according to an embodiment of the invention; [0086] FIG. 25 illustrates a set of radio frequency sensors according to a further embodiment of the invention; [0087] FIG. 26 illustrates a set of radio frequency sensors according to a further embodiment of the invention; and [0088] FIG. 27 illustrates a set of radio frequency sensors according to a further embodiment of the invention. DETAILED DESCRIPTION OF THE EMBODIMENTS [0089] Like numbered elements in these figures are either equivalent elements or perform the same function. Elements which have been discussed previously will not necessarily be discussed in later figures if the function is equivalent. [0090] FIG. 1 shows a flow diagram which illustrates a method according to an embodiment of the invention. In step 100 a set of radio-frequency properties of the radio-frequency antenna are measured using at least the radio-frequency transmitter. Next in step 102 a matching network command is calculated using the set of radio-frequency properties and a radio-frequency model. Finally in step 104 the matching network command is sent to the matching network. The matching network command then causes the impedance matching network to be adjusted. [0091] FIG. 2 shows a flow diagram which illustrates a method according to a further embodiment of the invention. First in step 200 a set of radio-frequency properties of the radio-frequency antenna are measured using at least the radio-frequency transmitter. Next in step 202 a matching network command is calculated using the set of radio-frequency properties and a radio-frequency model. Next in step 204 the matching network command is sent to the impedance matching network. This causes the impedance matching network to be adjusted. Finally in step 206 magnetic resonance data is acquired using the magnetic resonance imaging system. For instance the processor may generate commands which cause the magnetic resonance imaging system to acquire the magnetic resonance data. In FIG. 2 this method is optionally iterative. After the magnetic resonance data has been acquired the method may repeat itself by going to step 200 . [0092] FIG. 3 shows a magnetic resonance imaging system 300 according to an embodiment of the invention. The magnetic resonance imaging system 300 comprises a magnet 302 . The magnet 302 is a cylindrical type superconducting magnet with a bore 304 through the center of it. The magnet 302 has a liquid helium cooled cryostat with superconducting coils. It is also possible to use permanent or resistive magnets. The use of different types of magnets is also possible for instance it is also possible to use both a split cylindrical magnet and a so called open magnet. A split cylindrical magnet is similar to a standard cylindrical magnet, except that the cryostat has been split into two sections to allow access to the iso-plane of the magnet, such magnets may for instance be used in conjunction with charged particle beam therapy. An open magnet has two magnet sections, one above the other with a space in-between that is large enough to receive a subject: the arrangement of the two sections area similar to that of a Helmholtz coil. Open magnets are popular, because the subject is less confined. Inside the cryostat of the cylindrical magnet there is a collection of superconducting coils. Within the bore 304 of the cylindrical magnet 302 there is an imaging zone 328 where the magnetic field is strong and uniform enough to perform magnetic resonance imaging. [0093] Within the bore 304 of the magnet 302 there is also a set of magnetic field gradient coils 306 which are used for acquisition of magnetic resonance data to spatially encode magnetic spins within an imaging zone of the magnet. The magnetic field gradient coil is connected to a magnetic field gradient coil power supply 308 . The magnetic field gradient coils 306 are intended to be representative. Typically magnetic field gradient coils contain three separate sets of coils for spatially encoding in three orthogonal spatial directions. A magnetic field gradient power supply supplies current to the magnetic field gradient coils. The current supplied to the magnetic field coils is controlled as a function of time and may be ramped or pulsed. [0094] Adjacent to the imaging zone 328 is a radio-frequency antenna 310 . In this example the radio-frequency antenna 310 comprises a first antenna element 312 , a second antenna element 314 , a third antenna element 316 , and a fourth antenna element 318 . The antenna elements 312 , 314 , 316 , 318 are all connected to an impedance matching network 320 . The impedance matching network 320 is connected to transceiver 322 . The transceiver 322 comprises a transmitter 324 and a receiver 326 . In alternative embodiments the matching network is connected to only the transmitter 324 . The receiver 326 may also be connected to a separate receive coil. A subject 330 is reposing on a subject support 332 and is partially within the imaging zone 328 . When the subject 330 is within the imaging zone 328 the subject 330 affects the impedance of the antenna elements 312 , 314 , 316 and 318 . [0095] The matching network 320 , the transceiver 322 , and the magnetic field gradient coil power supply 308 are all connected to a hardware interface 338 of computer 334 . The computer further comprises a processor 336 which is connected to the hardware interface 338 as well as a user interface 340 , computer storage 342 , and computer memory 344 . The hardware interface 338 , the processor 336 is able to send and receive data to the various components and control the magnetic resonance imaging system 300 . [0096] Within the computer storage 342 is stored magnetic resonance data 346 . The magnetic resonance data 346 was acquired using the magnetic resonance imaging system 300 . The computer storage 342 is further shown as containing a magnetic resonance image 348 reconstructed from the magnetic resonance data 346 . The computer storage 342 is further shown as containing a pulse sequence 350 . A pulse sequence as used herein encompasses a set of commands for a magnetic resonance imaging system 300 which enables it to acquire the magnetic resonance data 346 . The pulse sequence may be stored as a timeline descriptive of sequential commands or it may be stored in a machine executable form. Pulse sequences 350 may be displayed on a user interface 340 in the form of a timeline. [0097] The computer storage 342 is further shown as containing a set of radio-frequency properties 352 that have been measured. The radio-frequency properties 352 may for instance be an s-matrix or other measurements which have been acquired using radio-frequency sensors. Radio-frequency sensors are not illustrated in this diagram. The simultaneous use of the transmitter 324 and the receiver 326 with appropriate software may enable the processor 336 to use the transceiver 322 to measure an s-matrix. The computer storage 342 is further shown as containing a matching network command 354 . The matching network command 354 is a command or set of commands which the processor 336 may send to the impedance matching network 320 to adjust the impedance matching of the antenna elements 312 , 314 , 316 and 318 . [0098] The computer memory 344 is shown as containing a control module 360 . The control module 360 contains computer executable code which enables the processor 336 to control the operation and function of the magnetic resonance imaging system 300 . The computer memory 344 is further shown as containing an image reconstruction module 362 . The image reconstruction module 362 contains computer executable code which enables the reconstruction of magnetic resonance data 346 into a magnetic resonance image 348 . The computer memory 344 further contains a radio-frequency measurement module 364 . The radio-frequency measurement module 364 contains computer executable code which enables the processor 336 to use components of the magnetic resonance imaging system 300 to measure the set of radio-frequency properties 352 . The computer memory 346 is further shown as containing a radio-frequency model 366 . The radio-frequency model 366 is a model which uses the radio-frequency properties 352 as input and enables accurate radio-frequency modeling of the impedance matching network 320 and/or the radio-frequency antenna 310 . The computer memory 344 is shown as further containing a matching network command generation module 368 . The matching network command generation module 368 uses the radio-frequency model 366 and the measured set of radio-frequency properties 352 to generate the matching network command 354 . [0099] In Magnetic Resonance Imaging there is a clear trend to array designs for the Radio-Frequency (RF) transmission and reception. Today, the clinical application of multi channel transmission is the RF-shimming at 3 Tesla since wave propagation effects generate too much B1 field inhomogeneity in many patients. RF shimming enables clinical investigation with even with wave propagation effects present in the volume of interest. Basic idea of RF-shimming is to superimpose various transmit fields with different shapes, phases and amplitudes such, that the resulting transmit field amplitude becomes homogeneous inside a desired FOV. Those transmit fields are typically generated by a transmit coil array. One of the challenges in the development of such a transmit coil array is to increase the power efficiency of such a coil. [0000] In particular two efficiency values are of interest: [0000] sp max =  B   1 P n , max =  B   1 max  ( P n ) sp sum =  B   1 P total =  B   1 ∑ n = 1   …   N  P n [0000] B1: the RF magnetic field at reference point(s) required for spin excitation P n : the peak power applied via channel n P n,max : is the maximum power on a single channel P n,max =max(P n , n=1 . . . N) N: the number of channels available sp: the corresponding efficiency values It is beneficial to design for a high value of sp sum , but also sp max is important. The maximum power does not always occur at the same channel for different patient and FOV, so that all RF amplifiers have to be designed for P n,max . In case of a big deviation of the power values used, this leads to an inefficient use of the installed RF power. Both values can be already considered in the RF-shimming calculation, by regularization it is possible to find a reasonable trade off between homogeneity achieved, the total and the maximum power. [0100] However, there are remaining imperfections of the coil which should be addressed as follows. There are two reasons for the inefficiency of an array: Power is reflected at the ports of the coil since the coil elements are not properly matched to the impedance of the feeding system (e.g. 50 Ohm) Power is coupled from one element of the array to the others and leaves the array elsewhere [0103] This lost power has two disadvantages: Firstly, it has to be generated so that multi channel systems often require more powerful RF-amplifiers (more total RF-power). Secondly, this power propagates in the wrong direction, it can also disturb the operation of the RF-amplifiers. Therefore, expensive isolators (each one build from a circulator and dummy load) have to be used to protect the amplifiers. [0104] Normally, tuning, decoupling and matching of the transmit coil array is optimized for a fixed geometry and an assumed typical loading like an average weight patient in abdominal imaging. Different loading or changes of the coil geometry (flexible arrays) have impact on the efficiency of such a coil. [0105] Furthermore, reflection and coupling can superimpose, so that the power efficiency of such an array also depends on the relative amplitudes an phases applied. More in detail, a coil array with strong mismatch and strong coupling can be very efficient in at least a special feeding situation as long as a magnitudes and phases applied lead to a cancellation of the sum signals (reflected and coupled signals) leaving the coil. [0106] Embodiments of the invention may provide for a method and corresponding hardware to adjust matching/tuning/decoupling of the coil array so that the power is efficiently used. [0107] Let the wave amplitude vector (“shim setting” resulting from the RF shimming calculation) be described with a complex vector a. with N components (number of channels/coil elements). [0108] The unit of a is the square root of Watt and a H a describes the transmit power, which is to be generated by the amplifiers (a H means the complex conjugate transpose of a). The reflection and transmission of the coil is described by the so called scattering matrix S: The signals leaving the coil are than characterized by a wave vector b=Sa and the lost power is given by b H b=a H S H Sa. Today, the RF-coil is made such that all the entries in S are as small as possible so that the reflected/transmitted power b H b becomes low. However, a perfect matching and decoupling is not possible and also depends on the individual patient. With this invention, we use variable matching of each individual coil channel to reduce the relative power loss (b H b)/(a H )= — (a H S H Sa)/(a H a). The basic feature is a variable matching network for each individual channel. With such a set of matching networks, it can be shown to be possible to match always such that there is no power reflected/transmitted at all. Such a matching network transforms the coil scattering matrix S to a new matrix S t as well as the feeding vector a is to be transformed to a new vector a t . It is worth mentioning that this method is independent from the pattern to be excited. Finding a compromise between achievable homogeneity and power efficiency is not required. However finding such a compromise is not excluded. [0109] Methods for tuning the matching network are discussed next. The matching has to be performed such that the transformed wave amplitude vector a t is an eigenvector to the eigenvalue 0 of the (singular) matrix S t H S t . A scalar, i.e., one channel, general lossless reciprocal matching network has three degrees of freedom. However, a phase shift along the matching network does not change the power levels, therefore there are only two relevant parameters. These can be characterized by the complex reflection coefficient at the output side of the matching network (which is to be connected to the coil input). By choosing these by r n =(b n /a n ) H the reflection at the input sides of the matching vanishes. This reduces both, single and overall power level. [0110] FIGS. 4-7 show this effect for four volunteers in a the current MBC60 (8-channel Body coil multi-transmit system). The coil was initially tuned and matched for volunteer D (cf. FIG. 7 ), yielding a low effect for that loading. However, for other volunteers, all single power levels could be reduced and the overall power was decreased up to 20% (HWC). In the figures the relative forward powers are plotted. Due to matching, there is no reflected power in the ideal matched case and the forward power was decreased. The figures were calculated for optimized abdominal shim settings, however, the effect is very similar also in the HWC. (HWC means “Hardware Compatibility Mode” and is related to a constant amplitude and constant phase difference in neighbouring channels.) [0111] FIG. 4 shows power levels at the radio-frequency antenna and the matching network for volunteer A. The x-axis labeled 400 shows eight different channels. The y-axis 402 shows either the forward or reflected power. The curve labeled 406 is the forward power at the radio-frequency antenna. The curve labeled 408 is the forward power at the antenna using the method of matching the matching network. The curve labeled 410 shows the reflected power at the matching network. The curve labeled 412 shows the reflected power at the matching network applying a method according to an embodiment of the invention. It can be seen in this Fig. that the reflected power decreased by appropriate 12.8%. [0112] FIG. 5 shows the forward and reflected power for a second volunteer B. The x-axis 500 again shows the eight channels and the y-axis 502 shows the forward and reflected power. The curve labeled 506 is the forward power at the antenna. The curve labeled 508 is the forward power of the antenna applying a method according to an embodiment of the invention. The curve labeled 510 shows the reflected power at the matching network. The curve labeled 512 shows the reflected power at the matching network applying a method according to an embodiment of the invention. [0113] FIG. 6 shows the power levels for a third volunteer, volunteer C. The x-axis is labeled 600 and again shows the forward reflected power 602 for eight different channels. The curve labeled 606 shows the forward power at the antenna 506 . Curve 508 shows the forward power at the antenna applying a method according to an embodiment of the invention. The curve labeled 610 shows the reflected power at the matching network. The curve labeled 612 shows the reflected power at the matching network applying a method according to an embodiment of the invention. It can be seen in this Fig. that the reflected power decreased by appropriate 17.9%. [0114] FIG. 7 shows the power levels for a fourth volunteer, volunteer D. Again the x-axis 700 shows the forward and reflected power 702 for eight different channels. The curve labeled 706 is the forward power of the antenna. The curve labeled 708 is the forward power of the antenna applying a method according to an embodiment of the invention. The curve labeled 710 shows the reflected power at the matching network. The curve labeled 712 shows the reflected power of the matching network using a method of matching according to an embodiment of the invention. In this case, the power levels for the reflected power decrease by approximately 8.3%. [0115] FIG. 8 shows a simulation of the same system used with the simulation shown in FIGS. 4-7 but in this case therefore an empty coil. The x-axis 800 shows the power level 802 for each of the eight channels. The curve 806 shows the forward power at the antenna. The curve 808 shows the forward power of the antenna applying a method of matching according to an embodiment of the invention. The curve 810 shows the reflected power of the matching network. The curve 812 shows the reflected power of the matching network applying a method of matching according to the embodiment of the invention. In this case the reflected power decreased by appropriate 32.8%. [0116] As FIGS. 4 to 7 illustrate, the reflected power may be reduced but the remaining power levels are still varying. This cannot be solved by the adopted matching alone. However, some embodiments of the invention may provide for a tuneable controlled coupling/decoupling network (one parameter per element). Assuming only one more free parameter per element for controlled coupling, we can adjust the coil such, that the power is equally distributed along the coil elements. This is illustrated in FIGS. 9 and 10 . [0117] FIG. 9 illustrates the benefit of having a tunable controlled coupling/decoupling network between coil elements. FIG. 9 shows the data for volunteer C as was shown in FIG. 6 again. In this case both decoupling between the various channels and matching was applied. Curve 908 shows the forward power at the antenna applying decoupling and matching according to an embodiment of the invention. Curve 912 shows the reflected power at the matching network using decoupling and matching according to an embodiment of the invention. In this case it can be seen that curve 908 has a constant forward power as opposed to the curve 608 in FIG. 6 . This illustrates the benefit of coupling pairs of the multiple antenna elements in the impedance matching network. [0118] FIG. 10 shows the same data as FIG. 9 except that in this Fig. the forward power at the antenna is shown only with decoupling before matching. Curve 1012 shows the reflected power of the matching network using only decoupling and not applying matching according to an embodiment of the invention. FIG. 10 illustrates the benefit of performing both the decoupling and adjustable matching. [0119] With the insight as described above, it is possible to reduce the nominal power required, and to even omit circulators in the RF chain. However, tuning, matching and decoupling components of the transmit coil have to adjustable. This can be achieved by several different means. [0120] First, varactor diodes may be used to adjust the impedance matching to the transmit coil. For these components the capacitance can be adjusted in the desired range by adjusting the bias voltage. In opposite to the reception case where additional noise from the diodes ohmic resistance is undesired, added losses in the transmit case are negligible (at least compared to the gain which can be achieved). Normally the usage of varactor diodes is limited due to the high peak power required, but with increasing channel number the pear power per channel reduces (with it currents and voltages through the actuator). [0121] Mechanically tuneable devices may also be used to adjust the impedance matching to the transmit coil. The impedance of capacitors and inductances can be changed mechanically. Tunable cylinder capacitors or inductances with adjustable (non)magnetic cores are widely known. [0000] As drive mechanisms can be e.g. used: Linear or radial motors directly at the component to be tuned or connected via Bowden cables over longer distances Bimetal actuators Optically variable capacitors OVC Piezo actuators Hydrodynamic actuators Adjusting by using the B0 field to generate a torque to at least a second electromagnet. [0128] FIG. 11 shows an example of a hydrodynamically tuned capacitor to be used for adjusting a matching network according to an embodiment of the invention. The capacitor 1100 has a first chamber 1102 and a second chamber 1104 . By adjusting the relative pressure in the two chambers 1102 , 1104 a dielectric 1106 is moved back and forth between two capacitor plates 1108 . A tube is placed between the electrodes 1108 of the capacitor 1100 . By adjusting the pressure p1 and p2 the dielectric can be moved in and out to adjust the capacitance C. Several variations may also be implemented: The dielectric can be metallic also changing the capacitance The method also works for (non)magnetic cores of inductances The tube can be closed on one side of p2, space of p2 can be filled with compressible gas. (then only p1 has to be adjusted) The tube can be open on side p2, resetting force (instead of compressible gas) can be realized with a spring [0133] Instead of modifying lumped elements as described above, modifications can directly be made on the RF coil. For example, FIG. 12 shows an example of direct tuning of a frequency coil 1200 . In this example a piezo actuator 1202 moves in the direction indicated 1204 . The movement of the piezo actuator 1202 causes the TEM element 1206 to move and thereby change the tuning of the element 1206 . [0134] As described above, tuning matching and decoupling of the coil can be directly modified within the coil itself or on its lumped components. However, it has been shown that tuning, matching and decoupling is also possible from remote. The references given below describe two methods to where the decoupling network is connected to the coil via n*lambda/4 cables. Furthermore, with the advent of amplifier integration into the coil, the actuators or a part of the active tuning can be subcomponents of the amplifier itself, e.g. output matching. [0135] Measuring the S-matrix and the optimization can be done within seconds with hardware already present on the system. No MRI measurements, just like B1 mapping, are required. [0136] FIG. 13 shows a block diagram which illustrates the functioning of a software tool for performing an embodiment of the invention. In step 1300 the scattering matrix of a loaded coil is measured. In step 1302 a multichannel coil drive set for MRI demands is determined. The drive set comprises the magnitude and phase of RF to be applied to the radio-frequency coil. In step number 3 the current matching network setting is determined. In step number 4 the adjustment in the tuning of the matching network is determined. 1306 represents a s-matrix or model of the s-matrix of the adaptable network such as the tuning network. The block labeled 1308 represents the s-matrix of the loaded coil. In step number 5 the tuning demand is translated into an actuator signal. Finally in step number 6 the actuators for the matching network receive their signal and are changed to a different position. The steps 1303 , 1304 , 1310 , 1312 may be repeated in a loop. These steps can further be summarized as: [0137] 1. Measurement 1300 of the coils scattering matrix (S-matrix), this already known from other applications. The measurement consists of linearly independent multi-channel RF pulses which are send via the transmit chain and monitored by dedicated receive channels. A advanced version of this step considers not only the S-matrix itself but also the magnetic field B1 inside the coil. Recent measurements show that having properly adjusted S-parameters at the ports fed by the amplifier does not necessarily indicate efficient function of the system. To measure this, the S-matrix can be measured during, for instance, B1 mapping or FID sampling experiments while applying linearly independent drive sets [0138] 2. The demand drive set results 1302 from imaging requirements, can be considered as predefined [0139] 3. The status 1303 of the adaptable matching network has to be known, or to be set to a predefined state. [0140] 4. According to the input parameters 1304 , and the known topology of the adaptable network the tuning demand, i.e. the amount of increase or decrease of a capacitor or an inductor is calculated. [0141] 5. The tuning demand 1310 is translated into actuator signal, e.g. the voltage required to reach a certain capacitance of a varactor diode is determined. Can be realized as a Look up table (LUT). [0142] 6. The actual actuators 1312 receive their tuning signal and change the network properties as required. [0143] 1 to 6 can be done prior to measurements or in parallel to an MRI experiment. [0144] FIG. 14 shows an example of a radio-frequency system for a magnetic resonance imaging system according to an embodiment of the invention. There is shown a collection of radio-frequency transmitters 1400 . Each radio-frequency transmitter 1400 is connected to a separate matching network 1402 . Each matching network 1402 is connected to a separate radio-frequency coil element 1404 . The adaptive matching networks 1402 are placed between amplifier 1400 and coil 1404 . Each coil channel 1404 has its own matching network 1402 . The networks act independently, though being centrally controlled. [0145] FIG. 15 shows another radio-frequency system for a magnetic resonance imaging system according to an embodiment of the invention. In FIG. 15 there is a collection of radio-frequency transmitters 1500 . Each radio-frequency transmitter 1500 is connected to a separate input of a multi-port matching network 1502 . The matching network 1502 is connected via a collection of individual cables to a multi-element magnetic resonance antenna 1504 . The individual RF amplifiers 1500 are connected to a common matching network 1502 here also interconnections to other channels within the network are possible. [0146] FIG. 16 shows another radio-frequency system for a magnetic resonance imaging system according to an embodiment of the invention. In FIG. 16 there is a collection of radio-frequency transmitters 1600 . The individual radio-frequency transmitters 1600 are connected to a combined matching network and multi-element magnetic resonance antenna 1602 . Matching network and coil 1602 are joined cannot be distinguished. This version considered that it can be advantageous to adapt the coil itself instead of adding an additional (possibly lossy or resistive) component. [0147] FIG. 17 shows an example of an L-matching network 1700 to be used as an embodiment of the invention. The matching network has inputs 702 and outputs 704 . [0148] FIG. 18 shows an alternative embodiment of an L-matching network 1800 . The matching network 1800 has inputs 802 and outputs 804 . [0149] FIG. 19 shows a general (compensated) inductive matching network 1900 . The matching network 1900 has inputs 1902 and outputs 1904 . The matching network 900 may be used in an impedance matching network according to an embodiment of the invention. [0150] FIG. 20 shows a pi-matching network 2000 with three reactive elements according to an embodiment of the invention. The matching network 2000 may be used in an impedance matching network according to an embodiment of the invention. The matching network 2000 has inputs 2002 and outputs 2004 . [0151] FIG. 21 shows a T-matching network 2100 with three reactive elements. The matching network 2100 may be used in an embodiment according to an embodiment of the invention. The matching network 2100 has inputs 2102 and outputs 2104 . [0152] FIG. 22 shows a matching network 2200 using a series of transmission lines typically a quarter wavelength long. The matching network 2200 has inputs 2202 and inputs 2204 . The matching network 2200 may be used for building a matching network according to an embodiment of the invention and may be used for splitting components between two locations. [0153] FIG. 23 shows a dual-frequency matching network that may be used for more than one frequency: for instance for hydrogen and phosphor. The matching network 2300 has an input 2302 and an output 2304 . [0154] In the matching networks shown in FIGS. 17-23 one or more inductors or capacitors are replaced with adjustable inductors or capacitors to make the respective matching networks adjustable so that a variety of impedances may be matched. FIGS. 24-27 show different examples of radio-frequency centers according to an embodiment of the invention. [0155] In FIG. 24 a radio-frequency source 2400 is shown as being connected to an antenna 2404 through a radio-frequency chain 2402 . The radio-frequency source 2400 may be a radio-frequency transmitter and/or radio-frequency generator. A radio-frequency chain is the components between a transmitter and the antenna 2404 . This may include transmission lines, matching networks and other components. In FIG. 24 there is an example of a forward power directional coupler 2006 and a reflected power directional coupler 2408 mounted near the radio-frequency source 2400 . These two directional couplers 2406 and 2408 are examples of radio-frequency sensors. The measurements may be placed on the output of all radio-frequency sources 2400 . [0156] The characterization of the RF properties of the antenna and matching network can be characterized in several different ways. The S-Matrix or scattering matrix can be measured. [0157] Additionally the forward and reflected power are measured for linearly independent drive sets until the response matrix is fully known. This is realizable with a directional coupler and/or RF switches. If the chain attenuation and phase is known FWD and REFL power coupler do not need to be at the same position. From the S-Matrix well known impedance, admittance or ABCD matrices can be calculated. [0158] Other hybrid type matrices may also be measured. Unlike typical definitions one can measure the forward power at the amplifier and the resulting currents in the antenna elements. There is also a linear relation between both. The relation can be written in matrix form. We call this matrix the “System Matrix”, elements do not have to have the typical units of Ohm, Siemens or W(sqrt(W)). [0159] The element currents can be measured using small loop antennae attached to the MRI antennae (such pick-up coils are known in MRI). Coupling between small loop and MRI antenna is week but of defined level. Furthermore measurement can be done using a coupler directly within the antenna (e.g. a voltage/current divider) to couple a small amount of the current/voltage to an AD converter. [0160] FIG. 25 shows an embodiment similar to that shown in FIG. 24 . However in this embodiment the reflected power directional coupler is distributed. The reflected power directional coupler 2506 is mounted near the antenna 2404 instead of near the radio-frequency source 2400 . [0161] FIG. 26 shows an alternative set of radio-frequency sensors according to an embodiment of the invention. FIG. 26 is similar to FIG. 24 . In this case the reflected power directional coupler 2406 has been replaced with an antenna 2610 near the antenna element 2404 . [0162] FIG. 27 shows an alternative set of radio-frequency sensors according to an embodiment of the invention. The embodiment shown in FIG. 27 is similar to that shown in FIG. 26 . In this case the sensing antenna 2610 has been replaced with a molded measurement directly on the antenna 2710 . For instance a capacitive voltage divider may be used to measure the voltage directly on the antenna. The various embodiments shown in FIGS. 24-27 may be combined to form a more comprehensive set of radio-frequency sensors. In addition the embodiments shown in FIGS. 24-27 may also be combined with the embodiment where the s-matrix is measured using the radio-frequency transmitter and receivers. [0163] It should be noted that multiple element antennae tend to couple mutually. This coupling can be compensated using different methods in coil design, however residual coupling remains, e.g., due to the fact that coupling depends on the patient scanned. [0000] This can be explained as follows: The impedance matrix Z (calculated from, for example, the S-Matrix) looks like the following: [0000] ( U   1 U   2 ) = ( Z   11 Z   12 Z   21 Z   22 )  ( I   1 I   2 ) [0000] where U1 and U2 are the voltages, I1 and I2 are the currents at the feeding ports of the coil. (The impedance matrix is written for just two pots here for the sake of simplicity.) Without coupling, the S-matrix is diagonal. As can be shown the same is true for the corresponding Z-matrix. For case of cancelled coupling: [0000] ( U   1 U   2 ) = ( Z   11 0 0 Z   22 )  ( I   1 I   2 ) [0000] The input impedance is: [0000] Zin =  U   1 I   1 =  Z   11 [0000] and matching Zin to 50 ohm is possible without knowing signals at port 2. In case of coupling present, Zin is [0000] Zin =  U   1 I   1 =  ( Z   11 - Z   21  Z   12 Z   22 ) + U   2  Z   12 I   1  Z   22 [0164] Zin can only be brought to a target Z0 (e.g. 50) ohm if U2 is known. Also Zin changes with U2. The input impedances may be matched depending on the Z matrix (depending on the antenna and patient) and on the drive signals (depending on the imaging settings) at the other ports. [0000] It is also possible to generalize the matching: having not only isolated matching networks at each port, but also having interconnections between the different matching networks. This enables, e.g., to cancel the coupling. [0165] However, coupling can also be changed in a favourable way, eg. To equalize the driving vector. It can happen that U1>>U2 or vice versa, the disadvantage is, that both transmitters have to be capable to provide the maximum signals, even if only one is usually used to the maximum. This can also be rephrased in terms of the incident power. This argument also applies when P1>>P2, where P1 is the power input on channel 1 and P2 is the power input on channel 2. [0166] The input impedance depends on the patient and possibly the position of the patient. Changing the position of the patient may require to measure of the input impedance (or the S-matrix) again. [0167] For different drive signals (here U) the Z-matrix of the coil is constant, there is no need to remeasure it. [0168] Movement of the patient also changes the Z matrix. However in case of breathing the impact may be very small. [0169] In some embodiments any adjustments to the matching network may be an iterative process, i.e. the matching can be adjusted and then the new excitation is tested with low power, reflected power is measured (should vanish in the optimal case) and the field is checked by field- and/or current probes (or MRI field measurements). An error function can be defined and the adjustment can be optimized by checking this error function. [0170] While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments. [0171] Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage. A computer program may be stored/distributed on a suitable medium, such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems. Any reference signs in the claims should not be construed as limiting the scope. LIST OF REFERENCE NUMERALS [0000] 300 magnetic resonance imaging system 302 magnet 304 bore of magnet 306 magnetic field gradient coils 308 magnetic field gradient coil power supply 310 radio frequency antenna 312 first antenna element 314 second antenna element 316 third antenna element 318 fourth antenna element 320 matching network 322 transceiver 324 transmitter 326 receiver 328 imaging zone 330 subject 332 subject support 334 computer 336 processor 338 hardware interface 340 user interface 342 computer storage 344 computer memory 346 magnetic resonance data 348 magnetic resonance image 350 pulse sequence 352 radio-frequency properties 354 matching network command 360 control module 362 image reconstruction module 364 radio-frequency measurement module 366 radio-frequency model 368 matching network command generation module 400 channels 402 power 406 forward power at the antenna 408 forward power at the antenna (with matching) 410 reflected power at the matching network 412 reflected power at the matching network (with matching) 500 channels 502 power 506 forward power at the antenna 508 forward power at the antenna (with matching) 510 reflected power at the matching network 512 reflected power at the matching network (with matching) 600 channels 602 power 606 forward power at the antenna 608 forward power at the antenna (with matching) 610 reflected power at the matching network 612 reflected power at the matching network (with matching) 700 channels 702 power 706 forward power at the antenna 708 forward power at the antenna (with matching) 710 reflected power at the matching network 712 reflected power at the matching network (with matching) 800 channels 802 power 806 forward power at the antenna 808 forward power at the antenna (with matching) 810 reflected power at the matching network 812 reflected power at the matching network (with matching) 908 forward power at the antenna (with matching) 912 reflected power at the matching network (with decoupling and matching) 1008 forward power at the antenna (with only decoupling) 1012 reflected power at the matching network (with only decoupling) 1100 hydronamically tuned capacitor 1102 first chamber 1104 second chamber 1106 dielectric 1108 capacitor plates 1200 radio frequency coil 1202 piezo actuator 1204 direction of movement 1206 TEM element 1400 radio-frequency transmitter 1402 matching network 1404 radio-frequency coil element 1500 radio-frequency transmitter 1502 matching network 1504 multi-element magnetic resonance antenna 1600 radio-frequency transmitter 1602 combined matching network and multi-element magnetic resonance antenna 1700 matching network 1702 input 1704 output 1800 matching network 1802 input 1804 output 1900 matching network 1902 input 1904 output 2000 matching network 2002 input 2004 output 2100 matching network 2102 input 2104 output 2200 matching network 2202 input 2204 output 2300 matching network 2302 input 2304 output 2400 radio-frequency source 2402 radio-frequency chain 2404 antenna 2406 forward directional coupler 2408 reflected power directional coupler 2506 reflected power directional coupler 2610 loop antenna 2710 voltage measurement on antenna

The Magnetic Resonance Imaging (MRI) system includes a radio-frequency transmitter with multiple transmit channels. The MRI system includes an impedance matching network ( 320, 1402, 1502, 1602 ) for matching the radio-frequency transmitter to a remotely adjustable radio-frequency antenna ( 310, 1504, 1602 ) with multiple antenna elements ( 312, 314, 316, 318, 1404 ). The MRI system includes a processor ( 336 ) for controlling the MRI system. The execution of the instructions by the processor causes it to: measure ( 100, 200 ) a set of radio-frequency properties ( 352 ) of the radio-frequency antenna, calculate ( 102, 202 ) a matching network command ( 354 ) using the set of radio-frequency properties and a radio frequency model ( 366 ), and adjust ( 104, 204 ) the impedance matching network by sending the matching network command to the impedance matching network, thereby enabling automatic remote impedance matching.

CROSS-PREFERENCE TO RELATED APPLICATIONS [0001] This application is a divisional application of U.S. Ser. No. 13/414,711 filed on Mar. 7, 2012. [0002] Ser. No. 13/414,711 is a divisional of U.S. Ser. No. 12/055,384 filed on Mar. 26, 2008, now pending, which is a continuation of International Patent Application No. PCT/CN2006/001315 with an international filing date of Jun. 13, 2006, designating the United States, and further claims foreign priority benefits to Chinese Patent Application No. 200510094521.9 filed Sep. 26, 2005. The contents of all of the aforementioned specifications are incorporated herein by reference in their entirety. BACKGROUND OF THE INVENTION [0003] 1. Field of Invention [0004] This invention relates to a method for eradicating weeds using pyrrolidineone derivatives of herbicidal tenuazonic acid (3-acetyl-5-sec-butyl-4-hydroxy-3-pyrrolin-2-one). [0005] 2. Description of the Related Art [0006] Tenuazonic acid (formula name 3-acetyl-5-sec-butyl-4-hydroxy-3-pyrrolin-2-one) is a strong phytotoxin isolated, purified, and identified from metabolites of Alternaria Alternata by Qiang Sheng et al. It is isolated from a crude mixture of metabolites by the extraction of the fermentation fluid. Due to the low yield (0.0005%) and high cost of fermentation, it is very urgent to develop a synthetic process of the compound. [0007] 3-Acetyl-4-hydroxy-5-tert-butylpyrroline-2-ketone is a heterocyclic compound containing carbonyl and hydroxyl functional groups. The lactam that is a part of the heterocyclic ring is the most important functional group. The hydrophobic side chain also plays an important role in its herbicidal activity. [0008] The compound is very effective at killing monocotyledon weeds (such as common crabgrass and barnyardgrass) and dicotyledonous weeds including Crofton weeds at a concentration of 50 μg/mL. It has the potential to become a biological herbicide (CN Pat. Appl. No. 200510038263.2; CN Pat. No. 1644046). However, the low yield and high cost associated with the fermentation process prevents large-scale production of this compound. [0009] A patent (WO1994/01401) discloses 3-benzoylpyrrolidine-2,4-dione derivatives and their herbicidal activity. [0010] CN. Pat. Pub. No. 1676515A made claims based on the fact that some triketones inhibit 4-hydroxyphenylpyruvate dioxygenase (HPPD), which is a key enzyme responsible for biosynthesis of plastoquinone and α-tocopherol. If the biosynthesis of plastoquinone and C-tocopherol is blocked, it will impact the biosynthesis of carotenoids. Therefore, HPPD inhibitor and carotenoid inhibitors have similar functions. This type of compounds has similar structural modification and synthesis, i.e., the existence of N-substituent. The major representative of this type of herbicides is sulfentrazone, isoxazole herbicide, and pyridine type herbicides. It is reported that tenuazonic acid copper salt has a slight inhibition to HPPD (Meazza et al., 2002). With only hydrogen attached to nitrogen, no other substituents, it is obvious that 3-acetyl-4-hydroxy-5-tert-butylpyrroline-2-ketone has a totally different mechanism of action. [0011] Study on the mechanism of action of 3-acetyl-4-hydroxy-5-tert-butylpyrroline 2-ketone has shown that the phytotoxin clearly inhibits the photosynthesis of plants. Its inhibition to Hill reaction is much higher than the typical photosynthetic inhibitor (herbicide), such as 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU). In addition, there is no adverse effect to other parts of the cells. The compound blocks electron flow from Q A to Q B in the photosystem II, but has no effect on the donor of photosystem II, photosystem I and other parts of chloroplasts, which was the first time such effects were observed among known phytotoxins produced by fungus Alternaria alternata. [0012] It is believed that the toxin interacts with D1 protein by competing with Q B for the binding site and thus inhibits the electron transfer. Therefore, it is an inhibitory phytotoxin of photosystem II. Based on the discovery of this mechanism, the molecular structure of tenuazonic acid has heretofore been modified to yield a series of new herbicidal molecules (See CN Appl. Nos. 200510094521.9 and 200610038765.X, and CN Pat Pub No. CN 1752075). [0013] Many photosystem II inhibitors have successfully become commercial herbicides in the field of herbicides, such as s-triazines, triazinones and phenols, etc. There are two advantages associated with the photosystem II inhibitors: first, since photosynthesis is a common phenomenon among plants, and inhibition is specific to the plants, the toxicity to animals is low, thus this type of herbicides possesses the characteristics of high efficacy and low toxicity. Second, with the development oftransgenic technology, there are 67,700,000 hectares of farm land that grow transgenic crops globally and greater than 80% of these crops are herbicide-resistant transgenic (based on Monsanto's 2003 data). [0014] The photosynthetic inhibitors herbicides have a growing share of the herbicides market. With combination of new herbicides and transgenic agricultural products, the chemical pollution to the environment has been greatly reduced. Since the photosynthetic inhibition is the only effect for 3-acetyl-5-sec-butyl-4-hydroxy-3-pyrrolin-2-one on the plant cells, this type of herbicide with high potency, quick action, broad-spectrum, simple structure, and easy synthesis will have a bright future. [0015] There are many types of photosystem II inhibitors according to their chemical structures such as ureas, pyridines, triazinones, pyridazinones, dinitrophenols and cyanophenols, etc. They can be divided into two main groups such as ureas/triazine and phenol. The first type (classical photosystem II inhibitors) can be represented as N—C—X (X stands for O or N atom, not sulfur atom), i.e. atrazine, metribuzin, phemedipham, terbutryand, N-(3,4-dichlorophenyl)-N′-methylurea (DCMU) et al. The second type is phenolic herbicide, including ioxynil, dinoseb and 2-iodo-4-nitro-6-isobutylphenol, etc. [0016] The common feature of the second type of herbicide is that the molecules contain at least one carbonyl oxygen or hydroxy oxygen and a long hydrophobic hydrocarbon side-chain. Most of these herbicides form a hydrogen bond between the carbonyl hydrogen and the D1 protein of photosystem II, which enables them to successfully compete with plastoquinone Q B (secondary electron acceptor), thereby blocking electron transfer from Q A to Q B and leading to the inhibition of photosynthetic process of the plant. [0017] Only a small number of herbicides form hydrogen bond between hydroxyl oxygen and D1 protein and successfully block photosynthetic process. The structure of the hydrophobic hydrocarbon side-chain (number of carbon and chain length) also influences herbicidal activity. Obviously, the binding site, binding manner, and possible binding region of herbicides to D1 protein determine the strength of herbicidal activity. Based on the chemical structure, 3-acetyl-5-sec-butyl-4-hydroxy-3-pyrrolin-2-one belongs to the group of photosystem II inhibitor (containing N—C═O). Unlike the classical herbicides mentioned above, there are no literatures that describe the mechanism of action of this compound to photosynthesis. Therefore, it might be a new type of photosystem II inhibitor. [0018] 3-acetyl-5-sec-butyl-4-hydroxy-3-pyrrolin-2-one has moderate toxicity of 200 mg/kg to rat and moderate level phytotoxicity, which is acceptable in light of its high biological activity. However, its toxicity level may be reduced through modification of its chemical structure. SUMMARY OF THE INVENTION [0019] In one embodiment, the invention provides compounds represented by the general formula (I), or (II), or a salt thereof, [0000] [0020] wherein, R 1 independently and at each occurrence represents H; or —C k H 2k+1 , —OC k H 2k+1 , —(C═O)C k H 2k+1 , —COOC k H 2k+1 , —C k H 2k−1 , —OC k H 2k−1 , —(C═O)C k H 2k−1 , or —COOC k H 2k−1 , each unsubstituted or substituted by one or more substituents selected from a heterocycle, an aryl, a phenylalkyl, a heterocycloalkyl phenyl, a heterocycloalkyl, a heterocycloalkoxyl, a phenoxyl; a phenoxy phenyl; a halogen, a cyano, a nitro, an alkoxyalkyl, an alkoxycarbonyl, and/or an amido. [0021] In a class of this embodiment, R 2 and R 3 independently and at each occurrence represent H, C n H 2n+1 , C n H 2n−1 , a halogen, —CN, a phenyl, a halogenated alkyl, a cyano-alkyl, a phenylalkyl, a halogenoalkenyl, a cyanoalkenyl, or a phenylalkenyl. [0022] In another class of this embodiment, R 2 and R 3 independently and at each occurrence represent H, —CH 3 , —C 2 H 5 , —CH 2 CH 2 CH 3 , —CH(CH 3 ) 2 , —(CH 2 ) 3 CH 3 , —C(CH 3 ) 3 , —CH 2 CH(CH 3 )CH 3 , —CH(CH 3 )CH 2 CH 3 , —(CH 2 ) 4 CH 3 , —CH(CH 3 )CH 2 CH 2 CH 3 , —CH 2 CH(CH 3 )CH 2 CH 3 , —CH 2 CH 2 CH(CH 3 ) 2 , —CH(CH 2 CH 3 ) 2 , —C(CH 2 ) 2 C 2 H 5 , —(CH 2 ) 5 CH 3 , —CH(CH 3 )(CH 2 ) 3 CH 3 , —CH 2 CH(CH 3 )(CH 2 ) 2 CH 3 , —CH 2 CH 2 CH(CH 3 )CH 2 CH 3 , —(CH 2 ) 3 CH(CH 3 ) 2 , —CH(CH 2 CH 3 )CH 2 CH 2 CH 3 , —CH 2 CH(CH 2 CH 3 ) 2 , —C(CH 3 ) 2 (CH 2 ) 2 CH 3 , —C(CH 3 )CH 2 CH 3 ) 2 , —(CH 2 )CH 3 , —CH(CH 2 CH 2 CH 3 ) 2 , —CH 2 CH 2 CH(CH 2 CH 3 ) 2 , —CH(CH 2 CH 3 )(CH 2 ) 3 CH 3 , —CH 2 CH(CH 2 CH 3 )CH 2 CH 2 CH 3 , —CH(CH 3 )(CH 2 ) 4 CH 3 , —CH 2 CH(CH 3 )(CH 2 ) 3 CH 3 , —(CH 2 ) 2 CH(CH 3 )(CH 2 ) 2 CH 3 , —(CH 2 ) 3 CH(CH 3 )CH 2 CH 3 , —(CH 2 ) 7 CH 3 , —CH 2 CH(CH 2 CH 2 CH 3 ), —CH(CH 2 CH 2 CH 3 )(CH 2 ) 3 CH 3 , —CH(CH 3 )(CH 2 ) 5 CH 3 , —CH 2 CH(CH 3 )(CH 2 ) 4 CH 3 , —(CH 2 ) 2 CH(CH 3 )(CH 2 ) 3 CH 3 , —(CH 2 ) 3 CH(CH 3 )(CH 2 ) 2 CH 3 , —(CH 2 ) 4 CH(CH 3 )CH 2 CH 3 , —CH(CH 2 CH 3 )(CH 2 ) 4 CH 3 , —(CH 2 ) 3 CH(CH 2 CH 3 ) 2 , —CH 2 CH(CH 2 CH 3 )(CH 2 ) 3 CH 3 , —(CH 2 ) 2 CH(CH 2 CH 3 )(CH 2 ) 2 CH 3 , —CH═CH 2 , —CH═CHCH 3 , —CH 2 CH═CH 2 , —CH═CHCH 2 CH 3 , —CH 2 CH 2 CH═CH 2 , —CH 2 CH═CHCH 3 , or —CH═CH—CH═CH 2 . [0023] In another class of this embodiment, R 2 and R 3 independently and at each occurrence represent —ON or a phenyl group substituted at positions 1-3 by a substituent selected from: —CHClCH 3 , —CHClCH 2 CH 3 , —CHClC 3 H 7 , —CHClC 4 H 9 , —CHClC 5 H 11 , —CHClC 6 H 13 , —CHClC 7 H 15 , —CHFCH 3 , —CHFCH 2 CH 3 , —CHFC 3 H 7 , —CHFC 4 H 9 , —CHFC 5 H 11 , —CHFC 6 H 13 , —CHFC 7 H 15 , —CHCNCH 3 , —CHCNCH 2 CH 3 , —CHCNC 3 H 7 , —CHCNC 4 H 9 , —CHCNC 5 H 11 , —CHCNC 6 H 13 , —CHCNC 7 H 15 , —CH(C 6 H 5 )CH 3 , —CH(C 6 H 5 )CH 2 CH 3 , —CH(C 6 H 5 )C 3 H 7 , —CH(C 6 H 5 )C 4 H 9 , —CH(C 6 H 5 )C 5 H 11 , —CH(C 6 H 5 )C 6 H 13 , —CH(C 6 H 5 )C 7 H 15 , —CHClCH═CH 2 , —CHClCH 2 CH═CH 2 , or a corresponding isomeric halogenate. [0024] In another class of this embodiment, X is CN, a C 1 to C 5 amido, a benzyl, a naphthalenyl, a phenyl, a pyrrolyl, a furyl, a thiazolyl, a heterocyclic alkyl phenyl; each phenyl or heterocycle being unsubstituted or substituted by a substituent selected from a C 1 to C 6 alkyl, a C 1 to C 4 alkoxy, a halogenated C 1 to C 5 alkyl, a halogen, a C 1 to C 5 amido, a nitro, a cyano, an alkoxycarbonyl, and/or a C 1 to C 5 sulfonyl group. [0025] In another class of this embodiment, the compounds are calcium, magnesium, copper, iron, nickel, sodium, potassium, magnesium, zinc or ammonium salts. [0026] In another class of this embodiment, k represents an integer from 1 to 8. [0027] In another class of this embodiment, n represent an integer from 1 to 15. [0028] In another embodiment, the invention is directed to compounds represented by the general formula (II), (IV), or (V) [0000] [0029] In a class of this embodiment, X independently and at each occurrence represents H; or —C m H 2m+1 , or —OC m H 2m+1 , each unsubstituted or substituted by one or more substituents selected from a heterocyclic alkyl, a heterocyclic aryl, an aryl, a phenylalkyl, a heterocycloalkyl phenyl, a heterocycloalkyl, a heterocycloalkoxyl, a phenoxyl; a phenoxy phenyl; a halogen, a cyano, a nitro, an alkoxyalkyl, an alkoxycarbonyl, and/or an amido. [0030] In another class of this embodiment, R 2 and R 3 independently and at each occurrence represents H, C n H 2+1 , C n H 2−1 , a halogen, —CN, a phenyl, a halogenated alkyl, a cyano-alkyl, a phenylalkyl, a halogenoalkenyl, a cyanoalkenyl, or a phenylalkenyl. [0031] In another class of this embodiment, m represents an integer from 1 to 7. [0032] In another aspect, the invention is directed to a method for preparation of a compound comprising the following steps: a) reacting an amino acid of formula: [0000] with an alcohol under acidic reaction conditions; b) neutralizing with sodium ethoxide; and c) adding a compound of formula XCOCH 2 COY or cyclobutane-1,3-dione in the presence of a sodium alkoxide. [0037] In a class of this embodiment, X independently and at each occurrence represents H; or —C m H 2m+1 , or —OC m H 2m+1 , each unsubstituted or substituted by one or more substituents selected from a heterocyclic alkyl, a heterocyclic aryl, an aryl, a phenylalkyl, a heterocycloalkyl phenyl, a heterocycloalkyl, a heterocycloalkoxyl, a phenoxyl; a phenoxy phenyl; a halogen, a cyano, a nitro, an alkoxyalkyl, an alkoxycarbonyl, and/or an amido. [0038] In another class of this embodiment, m represents an integer from 1 to 7. [0039] In another class of this embodiment, Y is Cl or Br. [0040] In another class of this embodiment, the steps are carried out in situ without purification of intermediates. [0041] In another aspect, the invention is directed to a method of eradicating weeds, comprising applying to the weeds compounds described herein. [0042] In a class of this embodiment, the compound is applied in a solution having a concentration of between 10 and 800 μg of the compound per 1 g of the solution. [0043] In another class of this embodiment, the weeds are broadleaf plants, grassy weeds, or sedge weeds. [0044] In another class of this embodiment, the compound is applied under exposure to sun light. [0045] In another class of this embodiment, the compound inhibits photosynthesis and metabolism of the plant cell, which causes a rapid accumulation of large amounts of reactive oxygen species in cells of the weeds and subsequent death of the cells. [0046] This invention provides a pyrolidineone-type herbicide, which was developed through a modification of tenuazonic acid, a patented herbicidal compound (chemical name: 3-acetyl-5-sec-butyl-4-hydroxy-3-pyrrolin-2-one). The modification provided us a quick and effective way of developing the new herbicides. [0047] It was decided to keep the major functional carbonyl group of 3-acetyl-5-sec-butyl-4-hydroxy-3-pyrrolin-2-one and modify the hydrophobic 5-sec-butyl chain and the 3-acetyl group. A large number of derivatives were synthesized using phosphorous ylides and halogenated amino acids as precursors. Recently, a new synthetic route was developed, which no longer uses phosphor ylides and halogenated amino acids as starting materials. The new process starts from an amino acid and the 4 step reaction sequence is carried out in one pot without isolation and purification of any intermediates. [0048] The synthetic pathway is as follows: [0000] [0049] wherein [0050] X═H; —C m H 2m+1 substituted or unsubstituted; —OC m H 2m+1 substituted or unsubstituted; —CmH 2m−1 substituted or unsubstituted, —OC m H 2m−1 substituted or unsubstituted; a substituted heterocyclic, an aryl, a phenylalkyl, a heterocycloalkyl-phenyl, a heterocycloalkyl, a heterocycloalkoxy, a phenoxy, or a phenoxyphenyl; the substituent groups being a halogen, a cyano, a nitro, an alkyoxyalkyl, an alkyoxycarbonyl, and/or an amido; [0051] m represents from 1 to 7 carbon atoms; and [0052] R 2 , and R 3 independently and at each occurrence represent H, —CH 3 , —C 2 H 5 , —CH 2 CH 2 CH 3 , —CH(CH 3 ) 2 , —(CH 2 ) 3 CH 3 , —C(CH 3 ) 3 , —CH 2 CH(CH 3 )CH 3 , —CH(CH 3 )CH 2 CH 3 , —(CH 2 ) 4 CH 3 , —CH(CH 3 )CH 2 CH 2 CH 3 , —CH 2 CH(CH 3 )CH 2 CH 3 , —CH 2 CH 2 CH(CH 3 ) 2 , —CH(CH 2 CH 3 ) 2 , —C(CH 2 ) 2 C 2 H 5 , —(CH 2 ) 5 CH 3 , —CH(CH 3 )(CH 2 ) 3 CH 3 , —CH 2 CH(CH 3 )(CH 2 ) 2 CH 3 , —CH 2 CH 2 CH(CH 3 )CH 2 CH 3 , —(CH 2 ) 3 CH(CH 3 ) 2 , —CH(CH 2 CH 3 )CH 2 CH 2 CH 3 , —CH 2 CH(CH 2 CH 3 ) 2 , —C(CH 3 ) 2 (CH 2 ) 2 CH 3 , —C(CH 3 )CH 2 CH 3 ) 2 , —(CH 2 ) 6 CH 3 , —CH(CH 2 CH 2 CH 3 ) 2 , —CH 2 CH 2 CH(CH 2 CH 3 ) 2 , —CH(CH 2 CH 3 )(CH 2 ) 3 CH 3 , —CH 2 CH(CH 2 CH 3 )CH 2 CH 2 CH 3 , —CH(CH 3 )(CH 2 ) 4 CH 3 , —CH 2 CH(CH 3 )(CH 2 ) 3 CH 3 , —(CH 2 ) 2 CH(CH 3 )(CH 2 ) 2 CH 3 , —(CH 2 ) 3 CH(CH 3 )CH 2 CH 3 , —(CH 2 ) 7 CH 3 , —CH 2 CH(CH 2 CH 2 CH 3 ) 2 , —CH(CH 2 CH 2 CH 3 )(CH 2 ) 3 CH 3 , —CH(CH 3 )(CH 2 ) 5 CH 3 , —CH 2 CH(CH 3 )(CH 2 ) 4 CH 3 , —(CH 2 ) 2 CH(CH 3 )(CH 2 ) 3 CH 3 , —(CH 2 ) 3 CH(CH 3 )(CH 2 ) 2 CH 3 , —(CH 2 ) 4 CH(CH 3 )CH 2 CH 3 , —CH(CH 2 CH 3 )(CH 2 ) 4 CH 3 , —(CH 2 ) 3 CH(CH 2 CH 3 ) 2 , —CH 2 CH(CH 2 CH 3 )(CH 2 ) 3 CH 3 , —(CH 2 ) 2 CH(CH 2 CH 3 )(CH 2 ) 2 CH 3 , —CH═CH 2 , —CH═CHCH 3 , —CH 2 CH═CH 2 , —CH═CHCH 2 CH 3 , —CH 2 CH 2 CH═CH 2 , —CH 2 CH═CHCH 3 , —CH═CH—CH═CH 2 , —CN, phenyl, —CHClCH 3 , —CHClCH 2 CH 3 , —CHClC 3 H 7 , —CHClC 4 H 9 , —CHClC 5 H 11 , —CHClC 6 H 13 , —CHClC 7 H 15 , —CHFCH 3 , —CHFCH 2 CH 3 , —CHFC 3 H 7 , —CHFC 4 H 9 , —CHFC 5 H 11 , —CHFC 6 H 13 , —CHFC 7 H 15 , —CHCNCH 3 , —CHCNCH 2 CH 3 , —CHCNC 3 H 7 , —CHCNC 4 H 9 , —CHCNC 5 H 11 , —CHCNC 6 H 13 , —CHCNC 7 H 15 , —CH(C 6 H 5 )CH 3 , —CH(C 6 H 5 )CH 2 CH 3 , —CH(C 6 H 5 )C 3 H 7 , —CH(C 6 H 5 )C 4 H 9 , —CH(C 6 H 5 )C 5 H 11 , —CH(C 6 H 5 )C 6 H 13 , —CH(C 6 H 5 )C 7 H 15 , —CHClCH═CH 2 , or —CHClCH 2 CH═CH 2 . [0053] When X is a methyl group, the following synthetic method can also be used: [0000] [0054] 3-acetyl-5-sec-butyl-4-hydroxy-3-pyrrolin-2-one analogs were dissolved in a small amount of methanol and diluted with water to a concentration of 5-100 μg/g. A pathogenic test was conducted by placing the toxic liquid on the slightly wounded leaf of Crofton weed with a needle. The test has shown that the pathogenic capability of 3-acetyl-5-sec-butyl-4-hydroxy-3-pyrrolin-2-one analogs with respect to Crofton weed increases with the increase of concentration. The spot diameter caused on the leaf of Crofton weed after 24 hours was 2 mm at 50 μg/g. [0055] The mechanism of action of 3-acetyl-5-sec-butyl-4-hydroxy-3-pyrrolin-2-one analogs on weeds is to affect plant photosynthesis. Specifically, it significantly reduces the photosynthetic oxygen evolution rate and the apparent quantum efficiency. The main action site of the compounds is the thylakoid membrane, inhibiting the electron transfer reaction of two photosystems, especially photosystem II, but no effect has been observed on the structure and synthesis of the membrane protein: In addition, the active oxygen content significantly has been increased 3 hours after the leaf was treated with 3-acetyl-5-sec-butyl-4-hydroxy-3-pyrrolin-2-one analogs. This may be the cause of cell death and appearance of the brown spots on the leaf. Moreover, it may also block the synthesis of protein in the ribosome. [0056] The main advantages and positive effects of the invention are summarized below: modification of 3-acetyl-5-sec-butyl-4-hydroxy-3-pyrrolin-2-one was carried out, based on (1): its inhibitory activity to photosystem II and its binding mode to D1 protein; and (2): its inhibitory activity and its action sites, combined with chemical synthetic route of 3-acetyl-4-hydroxy-5-sec-butylpyrroline-2-ketone. Focus was placed on the carbonyl oxygen (a few hydroxyl oxygens), which played essential role in the protein binding. The structure of D1 protein from algae was carefully analyzed and of various factors including hydrophobicity, electronegativity and stereo hindrance were considered when designing and selecting the target molecules. It is obvious that such rational design has advantage over the traditional chemical herbicide screening. [0057] A series of herbicidal molecules was prepared through the modification of 3-acetyl-5-sec-butyl-4-hydroxy-3-pyrrolin-2-one, a metabolic phytotoxin of Alternaria alternata . These compounds kill weeds quickly; the weeds treated with the herbicidal agents clearly show symptoms after 24 hours, and the weeds can be killed in about 3 to 5 days. [0058] The method of biocontrolling weeds using the analogues of tenuazonic acid and their salts effectively controls and eradicates the main gramineous weeds in the farmland, such as common crabgrass, barnyardgrass, goosegrass, green foxtail, equal alopecurus , Japanese alopecurus, Beckmannia syzigachne Fern, wild oat, annual bluegrass, keng stiffgrass, common polypogon, and rabbitfoot polypogon; broad leaf weeds, such as Crofton weed, Copperleaf, Yerbadetajo, Redroot pigweed, Tender catchweed bedstraw, Narrowleaf vetch, Sheathed monochoria , Indian rotala , Water ammannia, Purslane, Flixweed tansymustard, Shepherdspurse, Common dayflower, Wild cress, Wormseed mustard, Pennsylvania bittercress, Geminate speedwell, Mouse-ear chickweed; and sedges, such as Needle spikesedge, Difformed galingale, Rice galingale, and Dichotomous dimbristylis. [0059] The compounds of the invention have high activity at concentration as low as from 5 to 50 μg/g. At a concentration of 10 to 800 μg/g (close to 45-360 g/hectare), the compounds can kill a variety of broad-leaf weeds, grassy weeds, and sedge weeds. They are highly potential herbicides. [0060] The analogues disclosed herein have comparable herbicidal activity to the original tenuazonic acid. These molecules are easy to make, thus reducing the manufacturing cost. Because these compounds were obtained through modification of the metabolite of a fungus, a natural product, these analogs have some desirable characteristics of bio-based herbicides: low pollution, few byproducts, high rate of decomposition, and high environmental safety. [0061] The new synthetic process can be carried out in one pot without isolation and purification of the intermediates. This process can reduce the manufacturing cost. DETAILED DESCRIPTION OF THE EMBODIMENTS [0062] The following examples illustrate the products of this invention and the methods for preparing them. However, the examples are not intended in any way to otherwise limit the scope of the invention. The number of compounds that were synthesized and evaluated is far exceeding the number of examples. Example 1 List of Compounds Having Formula (I) and (II) (Table 1) and Herbicidal Activities Thereof (Table 2) [0063] Synthesis of compound 1: A 100 mL three-neck flask was charged with anhydrous alcohol (30 mL), hydrogen chloride (0.055 mol, 2 g) and Isoleucine (0.05 mol, 6.56 g). The mixture was heated to reflux and stirred for 3 h and then left overnight. Ethanol was removed by distillation and the residue was mixed with sodium ethoxide (0.05 mol, 2.6 g, freshly prepared) solution in ethanol. The mixture was stirred for 0.5 h. Cyclobutane-1,3-dione (0.055 mol, 4.62 g) was added over 1 h, with the temperature kept below 10° C., and the reaction was stirred for 2 h. Benzene (20 ml) and sodium ethoxide (0.0575 mol, 3 g, freshly prepared) solution in ethanol were added, and the mixture was stirred at reflux for 3 h and allowed to stand at room temperature overnight. The reaction mixture was poured into 30 mL of water and acidified with 10% sulfuric acid (0.055 mol, 55 g), then extracted with ethyl acetate and dried over sodium sulfate. Ethyl acetate was removed under vacuum and the residue was mixed with concentrated sulfuric acid and toluene. The mixture was refluxed in toluene for 2 h. Compound 1 was obtained as a brown solid after column chromatography in a 55.6% yield. [0064] Synthesis of compound 9: A 100 mL three-neck flask was charged with anhydrous alcohol (30 mL), hydrogen chloride (0.055 mol, 2 g) and Isoleucine (0.05 mol, 6.56 g). The mixture was heated to reflux and stirred for 3 h and then left overnight. Ethanol was removed by distillation and the residue was mixed with sodium ethoxide (0.05 mol, 2.6 g, freshly prepared) solution in ethanol and stirred for 0.5 h. 2-Propionamidoacetyl chloride (0.055 mol, 8.22 g) was added over 1 h and the reaction was stirred for 2 h. Benzene (20 ml) and sodium ethoxide (0.0575 mol, 3 g, freshly prepared) solutions were added, and the mixture was stirred at reflux for 3 h and allowed to stand at room temperature overnight. The reaction mixture was poured into 30 mL of water and acidified with 10% sulfuric acid (0.055 mol, 55 g), then extracted with ethyl acetate and dried over sodium sulfate. Removal of ethyl acetate under vacuum gave crude product which was purified with column chromatography, providing compound 9 as a pale brown oil in a 47.1% yield. [0000] TABLE 1 Physical properties of 3-acetyl-4-hydroxy-5-sec- butylpyrroline-2-ketone analogs with formula (I) and (II) Compound Type R 1 R 2 R 3 Appearance 1 II H Sec-C 4 H 9 H Brown solid 2 II H C 3 H 7 CHCl H Brown solid 3 I H Sec-C 4 H 9 H Light brown viscous liquid 4 I CH 3 CH 2 Sec-C 4 H 9 H Light brown viscous liquid 5 I C 2 H 5 O Sec-C 4 H 9 H Light brown viscous liquid 6 I C 6 H 5 CH 2 CH 2 Sec-C 4 H 9 H Light brown viscous liquid 7 I NH 2 COCH 3 CH 2 Sec-C 4 H 9 H Light brown viscous liquid 8 I Cl(CH 2 ) 3 NH Sec-C 4 H 9 H Light brown viscous liquid 9 I C 2 H 5 CONH Sec-C 4 H 9 H Light brown viscous liquid [0000] TABLE 2 Comparison of the toxicity of 3-acetyl-4-hydroxy- 5-sec-butylpyrroline-2-ketone analogs with formula (I) and (II) Time of disease Avg. diameter of the spot after Treatment spot to occur (h) 24 h (mm) Water control / 0.23 ± 0.02 Methanol control / 0.27 ± 0.14 1 22.3 ± 0.77 1.97 ± 0.04 2 22.0 ± 2.30 2.96 ± 0.01 3 20.9 ± 1.01 2.31 ± 0.09 4 18.5 ± 1.55 2.97 ± 0.01 5 20.7 ± 0.75 2.35 ± 0.14 6 21.2 ± 3.85 2.12 ± 0.08 7 14.9 ± 2.65 4.45 ± 0.22 8 20.0 ± 1.51 2.53 ± 0.18 9 21.9 ± 2.00 2.80 ± 0.33 Example 2 Herbicidal Activity Evaluation of Compounds 10-57 with Formula (III), (IV), and (V) (Table 3) [0065] Synthesis of compound 24: A100 mL three-neck flask was charged with anhydrous alcohol (30 mL), hydrogen chloride (0.055 mol, 2 g) and 2-amino-2-methylbutanoic acid (0.05 mol, 5.85 g). The mixture was heated to reflux and stirred for 3 h and then left for overnight. Ethanol was removed by distillation and the residue was mixed with sodium ethoxide (0.05 mol, 2.6 g, freshly prepared) solution in ethanol and stirred for 0.5 h. Cyclobutane-1,3-dione (0.055 mol, 4.62 g) was added over 1 h maintaining the temperature of the reaction mixture below 10° C., and the reaction was stirred for 2 h. Benzene (20 ml) and sodium ethoxide (0.0575 mol, 3 g, freshly prepared) solution in ethanol were added, and the mixture was stirred at reflux and then allowed to stand for 3 h at room temperature overnight. The reaction mixture was mixed with 30 mL of water and acidified with 10% sulfuric acid (0.055 mol, 55 g), then extracted with ethyl acetate and dried over sodium sulfate. Removal of ethyl acetate under vacuum gave crude product, which was purified with column chromatography, providing compound 24 as a pale brown oil in a 52.9% yield. [0066] Synthesis of Compound 53: A 100 mL of three-neck flask was charged with anhydrous alcohol (30 mL), hydrogen chloride (0.055 mol, 2 g) and 2-amino-3-cyanohexanoic acid (0.05 mol, 7.81 g). The mixture was heated to reflux and stirred for 3 h and then left overnight. Ethanol was removed by distillation and the residue was mixed with sodium ethoxide (0.05 mol, 2.6 g, freshly prepared) solution in ethanol, and stirred for 0.5 h. Cyclobutane-1,3-dione (0.055 mol, 4.62 g) was added over 1 h and maintaining the temperature of the reaction mixture below 10° C., and the reaction was stirred for 2 h. Benzene (20 mL) and sodium ethoxide (0.0575 mol, 3 g, freshly prepared) solution in ethanol were added, and the mixture was stirred at reflux for 3 h and then to allowed to stand at room temperature overnight. The reaction mixture was mixed with 30 mL of water and acidified with 10% sulfuric acid (0.055 mol, 55 g), extracted with ethyl acetate and dried over sodium sulfate. Removal of ethyl acetate under vacuum gave crude product, which was purified with column chromatography, providing compound 53 as a brown oil in 45% yield. [0000] TABLE 3 Physical properties of 3-Acetyl-4-hydroxy-5-sec- butylpyrroline-2-ketone analogues with formula of (III), (IV), and (V) Compound Type X R 2 R 3 Appearance 10 III CH 3 H H Light yellow solid 11 III CH 3 CH 3 H Pale needle crystal 12 III CH 3 CH 3 CH 2 H Light brown solid 13 III CH 3 CH 3 CH 2 CH 2 H Light brown viscous liquid 14 III CH 3 n-C 4 H 9 H Light brown viscous liquid 15 III CH 3 n-C 5 H 11 H Light brown viscous liquid 16 III CH 3 n-C 6 H 13 H Light brown oil 17 III CH 3 n-C 7 H 15 H Light brown oil 18 III CH 3 n-C 8 H 17 H Light brown oil 19 III CH 3 C 6 H 5 CH 2 H Light yellow solid 20 III CH 3 (1-C 6 H 5 )C 4 H 8 H Light yellow solid 21 III CH 3 H 3 C—CH:CH H Brown viscous liquid 22 III CH 3 CH 3 CH 3 Light yellow solid 23 III CH 3 CH 3 CH 2 CH 3 CH 2 Light brown viscous liquid 24 III CH 3 CH 3 CH 2 CH 3 Light brown viscous liquid 25 III CH 3 CH 3 CH 2 CH 2 CH 3 CH 2 CH 2 Light brown viscous liquid 26 III CH 3 CH 3 CH 2 CH 2 CH 3 Light brown viscous liquid 27 III CH 3 CH 3 CH 2 CH 2 CH 3 CH 2 Light brown viscous liquid 28 III CH 3 n-C 4 H 9 n-C 4 H 9 Light brown viscous liquid 29 III CH 3 n-C 4 H 9 CH 3 Light brown viscous liquid 30 III CH 3 n-C 4 H 9 CH 3 CH 2 Light brown viscous liquid 31 III CH 3 sec-C 5 H 11 H Light yellow liquid 32 III CH 3 tert-C 5 H 11 H Light yellow liquid 33 III CH 3 iso-C 5 H 11 H Light yellow liquid 34 III CH 3 OOCCH 2 H Light yellow solid 35 III CH 3 OOCCH 2 CH 2 H Light yellow solid 36 III CH 3 (NH 2 )OCCH 2 H Light yellow solid 37 III CH 3 (NH 2 )OCCH 2 CH 2 H Light yellow solid 38 III CH 3 C 3 H 7 CHCN H Light brown viscous liquid 39 III CH 3 iso-C 3 H 7 H Light brown solid 40 III CH 3 C 3 H 7 CHCl H Light brown viscous liquid 41 III CH 3 CH 3 SCH 2 CH 2 H Light brown solid 42 III C 2 H 5 sec-C 4 H 9 H Light brown viscous liquid 43 III ClC 2 H 4 sec-C 4 H 9 H Light brown viscous liquid 44 III FC 2 H 4 sec-C 4 H 9 H Light brown viscous liquid 45 III C 2 H 5 OC 2 H 5 sec-C 4 H 9 H Light brown viscous liquid 46 III PhCH 2 CH 2 O sec-C 4 H 9 H Light brown viscous liquid 47 III PhOCH 2 CH 2 sec-C 4 H 9 H Light brown viscous liquid 48 III (m-diCl) sec-C 4 H 9 H Light brown viscous liquid PhCH 2 CH 2 49 III PhCH 2 NH sec-C 4 H 9 H Light brown viscous liquid 50 III THF—CH 2 CH 2 sec-C 4 H 9 H Light brown viscous liquid 51 III PhCH 2 sec-C 4 H 9 H Light brown viscous liquid 52 III p-NO 2 PhCH 2 sec-C 4 H 9 H Light brown viscous liquid 53 IV CH 3 C 3 H 7 CHCN H Brown viscous liquid 54 IV CH 3 C 5 H 11 CHCN H Brown oil liquid 55 IV CH 3 C 7 H 13 CHCN H Brown oil liquid 56 IV CH 3 C 7 H 13 CHF H Brown oil liquid 57 V CH 3 CH 3 H Yellow needle crystal [0067] The study results showed different herbicidal activities of the above compounds. The compounds also affect the Hill reaction rate and fluorescence of thechlorophyll. Example 3 [0068] 3-acetyl-5-sec-butyl-4-hydroxy-3-pyrrolin-2-one analogue (Table 3, compounds 10-57) was dissolved in small amount of methanol. The solution was then diluted with distilled water to a concentration of 50 μg/mL. Methanol solution with same concentration and pure distilled water were used as control of the experiment. A pathogenic test was conducted by placing the toxic liquid on the slightly wounded leaf of Crofton weed with a needle. The experiment was carried out at 25° C. under the natural light and each test was repeated 6 times. It was measure the diameter of the spot after 24 h. The experimental results are listed in Table 4. The data indicated that most of the 3-acetyl-5-sec-butyl-4-hydroxy-3-pyrrolin-2-one analogs have high herbicidal activity. The size of the side chain also has an effect on their activity. [0000] TABLE 4 Comparison of the toxicity of 3-acetyl-4-hydroxy- 5-sec-butylpyrroline-2-ketone analogs with formula (III), (IV), and (V) Average diameter Time of Disease spot of spot after 24 h Treatment (h) (mm) Water control / 0.23 ± 0.02 Methanol control / 0.27 ± 0.14 10   29 ± 6.30 1.11 ± 0.16 11 21.5 ± 0   1.80 ± 0.41 12 15.2 ± 0.35 2.77 ± 0.23 13 16.70 ± 0.21  5.21 ± 0.44 14 13.8 ± 0.54 6.37 ± 0.04 15  9.5 ± 1.26 9.61 ± 1.20 16 13.80 ± 0.54  7.61 ± 0.11 17  9.5 ± 2.36 7.94 ± 1.30 18 12.00 ± 0.48  8.27 ± 0.61 19   24 ± 4.00 1.24 ± 0.10 20 21.1 ± 3.56 1.57 ± 0.04 21 16.5 ± 1.30 2.89 ± 0.14 22 20.0 ± 1.63 1.76 ± 0.24 23 18.3 ± 2.17 2.23 ± 0.12 24 16.21 ± 3.55  2.43 ± 0.07 25 15.22 ± 2.00  2.44 ± 0.10 26 13.61 ± 1.35  3.31 ± 0.07 27 14.2 ± 4.15 3.18 ± 0.93 28 16.9 ± 2.25 2.40 ± 0.11 29 12.1 ± 3.75 5.77 ± 1.15 30 13.3 ± 2.00 4.53 ± 1.03 31 10.8 ± 2.00 5.93 ± 1.35 32 12.5 ± 3.75 4.82 ± 1.44 33 13.5 ± 0.75 4.17 ± 1.15 34 24.0 ± 0.02   1 ± 0.86 35 26.4 ± 0.12 1.27 ± 0.02 36 21.9 ± 0.23 1.54 ± 0.07 37   24 ± 0.08 1.64 ± 0.25 38 13.6 ± 0.50 9.82 ± 0.02 39 16.5 ± 2.15 4.89 ± 0.37 40 11.93 ± 0.66  8.10 ± 0.90 41 20.8 ± 3.00 2.45 ± 0.24 42 19.4 ± 2.50 2.24 ± 0.45 43 20.1 ± 1.15 2.30 ± 0.28 44 12.0 ± 1.33 4.07 ± 0.51 45 20.3 ± 0.57 2.73 ± 0.73 46 22.1 ± 1.35 2.31 ± 0.44 47 21.2 ± 1.88 2.12 ± 0.09 48 13.5 ± 2.77 4.33 ± 0.54 49 23.2 ± 2.86 2.47 ± 0.08 50 22.6 ± 0.69 2.66 ± 0.46 51 15.1 ± 1.82 3.28 ± 1.12 52 15.3 ± 1.72 3.83 ± 1.03 53 12.90 ± 0.27  7.334 ± 0.845 54 11.30 ± 0.73  8.211 ± 0.101 55 9.81 ± 0.33 8.931 ± 0.086 56 14.00 ± 1.09  6.927 ± 0.317 57 20.4 ± 0   1.98 ± 0.51 Example 4 [0069] Compounds 1, 2, 3, and 40 were separately dissolved in a small amount of methanol. The solutions were then diluted with distilled water to a concentration of 50 μg/mL. A mixture of methanol and water in the same ratio as the sample solution was also prepared and used as control in the experiment. The solutions were sprayed on leaves and stems of three-leaf-stage Crofton weed seedlings. All the plants were grown in pot in a greenhouse. The leaves were properly wet by the solutions for consistency and the treatment was repeated 3 times. The plant damage assessment was conducted two days later and the results were listed in Table 5. The measurement of the plant damage was calculated by the formula: Damage Index=Σ(damage level×number of plants)×100/4/number of plants in each treatment. The calculated results are listed in Table 6. [0000] TABLE 5 Standard of evaluation of weed damage Damage Level Description 4 Plant completely dead 3 Two thirds of the plant stems and leaves dried out 2 Half of the plant stems and leaves dried out 1 One third of the plant stems and leaves dried out 0 No damage at all [0000] TABLE 6 Weed damage assessment results Treatment Damage Level H 2 O control 0 Methanol control 0 1 2 2 2 3 1 40  4 [0070] The data in the Table 6 suggests that the analogs of 3-acetyl-5-sec-butyl-4-hydroxy-3-pyrrolin-2-one have good herbicidal activity against Crofton weed. Substitution of chlorine on the side chain increases their activity. Example 5 [0071] Compounds 10-57 were dissolved in small amount of methanol. The solutions were then diluted with distilled water to a concentration of 50 μg/mL. A mixture of methanol and water in the same ratio as the sample solution was also prepared and used as control in the experiment. The healthy leaves of Crofton weed were washed in water for 30 minutes and then rinsed with distilled water. The clean and tissue dried leaves were placed in petri dish with the back-side of the leaves facing up. Wet filter paper was also placed in the in petri dish for moisture control. Water, methanol and chemical solutions of the analogues were applied to the back-side of each leaf. Test sample was then placed in vacuum chamber at 25° C. for 15 min followed by exposure to the strong light (400 μM m −2 s −1 ) for 12 hours. The leaf sample went through a series of test, and the Hill reaction rate, the electron transfer activity and fluorescence of chlorophyll were measured. Four leaves were used for each treatment and each test was repeated three times. [0072] The experiment results indicate that compound 10 to 57 can slow the Hill reaction and inhibit the electron transfer of photosystem II, but has no effect in photosystem I. As the experimental data in Table 7 indicated that compounds having chlorinated side-chain have more inhibitory effect on the activity of Hill reaction and electron transfer in photosystem II than the compounds whose side chain are not substituted by halogen. [0000] TABLE 7 Effects to the photosynthesis of Crofton weed PSII Activity of Activity of Hill oxygen The t 1/2 of Reaction evolution of fluorescence Treatment (uMO 2 /mgChlh) (uMO 2 /mgChlh) F v /F m rise (ms) H 2 O control 130.11 65.34 0.83 1339 Methanol 124.38 60.89 0.81 1382 control 1 98.76 50.89 0.82 1184 2 69.41 37.02 0.84 1055 3 62.21 32.14 0.83 1172 4 51.13 28.01 0.83 791 5 52.31 24.10 0.82 826 6 50.04 27.11 0.81 773 7 52.41 29.17 0.82 809 8 49.05 24.65 0.79 725 9 50.12 23.33 0.83 733 10 84.32 47.55 0.79 1176 11 80.00 46.41 0.82 1181 12 70.32 34.54 0.83 925 13 78.19 41.35 0.85 1000 14 67.37 34.01 0.79 910 15 62.77 31.26 0.78 946 16 61.43 30.00 0.83 880 17 57.13 27.04 0.82 917 18 67.27 39.98 0.80 913 19 63.43 40.07 0.79 962 20 57.23 43.40 0.82 876 21 62.34 42.25 0.77 879 22 56.16 38.05 0.82 828 23 63.28 38.24 0.79 855 24 71.37 43.01 0.83 921 25 97.55 57.12 0.82 1197 26 89.15 58.01 0.82 1211 27 91.45 53.24 0.81 1232 28 75.03 31.76 0.82 1124 30 47.33 22.78 0.79 747 32 63.42 32.13 0.82 905 33 51.94 26.54 0.79 791 34 65.73 35.11 0.81 922 38 64.69 40.41 0.81 871 39 62.72 33.79 0.80 884 40 46.20 24.00 0.82 720 41 59.07 41.32 0.83 901 43 63.35 47.80 0.83 880 44 59.15 40.75 0.79 839 45 41.00 27.04 0.79 713 46 58.78 43.67 0.82 899 47 67.99 49.01 0.82 844 51 52.23 32.15 0.81 798 52 53.13 36.86 0.82 814 53 42.72 32.12 0.79 739 54 43.65 31.98 0.81 741 55 42.72 28.63 0.79 727 56 42.72 29.02 0.79 719 57 63.42 35.13 0.82 955 Example 6 [0073] Fourteen salts of 3-acetyl-5-sec-butyl-4-hydroxy-3-pyrrolin-2-one analogs were dissolved in small amount of methanol and diluted with distilled water to a concentration of 50 μg/mL. Methanol/water mixture was also prepared and used as control. Needle puncture method was used for the test on the small pieces of Crofton weed. Each treatment was repeated six times or more. The test samples were kept under natural light at 25° C. for 24 hours. The diameters of damaged spot of the plant leaves were measured by vernier caliper. These fourteen compounds are: (a) Sodium salt of 3-acetyl-4-hydroxy-1H-pyrrol-2(5H)-one [0074] (b) Sodium salt of 3-acetyl-4-hydroxy-5-methyl-1H-pyrrol-2(5H)-one [0075] (c) Sodium salt of 3-acetyl-5-ethyl-4-hydroxy-1H-pyrrol-2(5H)-one [0076] (d) Sodium salt of 3-acetyl-4-hydroxy-5-propyl-1H-pyrrol-2(5H)-one [0077] (e) Sodium salt of 3-acetyl-4-hydroxy-5-(prop-1-enyl)-1H-pyrrol-2(5H)-one [0078] (f) Potassium salt of 3-acetyl-5-ethyl-4-hydroxy-1H-pyrrol-2(5H)-one [0079] (g) Calcium salt of 3-acetyl-5-ethyl-4-hydroxy-1H-pyrrol-2(5H)-one [0080] (h) Magnesium (II) salt of 3-acetyl-5-ethyl-4-hydroxy-1H-pyrrol-2(5H)-one [0081] (i) Manganese salt of 3-acetyl-5-ethyl-4-hydroxy-1H-pyrrol-2(5H)-one [0082] (j) Zinc salt of 3-acetyl-5-ethyl-4-hydroxy-1H-pyrrol-2(5H)-one [0083] (k) Iron salt of 3-acetyl-5-ethyl-4-hydroxy-1H-pyrrol-2(5H)-one [0084] (l) Copper salt of 3-acetyl-5-ethyl-4-hydroxy-1H-pyrrol-2(5H)-one [0085] (m) Sodium salt of 3-acetyl-4-hydroxy-5-(Pentan-2-yl)-1H-pyrrol-2(5H)-one [0086] (n) Zinc salt of 3-acetyl-4-hydroxy-5,5-dimethyl-1H-pyrrol-2(5H)-one [0087] (o) Ammonium salt of 3-acetyl-5-ethyl-4-hydroxy-1H-pyrrol-2(5H)-one [0088] [0000] TABLE 8 Herbicidal activity of 14 salts to Crofton weed Average diameter of the damage spot Treatment Time (h) after 24 h (mm) H 2 O control / 0.227 ± 0.002 Methanol control / 0.273 ± 0.014 a   26 ± 7.30 1.34 ± 0.08 b 19.5 ± 0.5  2.21 ± 0.18 c 14.5 ± 1.8  3.11 ± 0.54 d 10.2 ± 2.50 5.07 ± 0.11 e 16.8 ± 1.85 2.42 ± 0.05 f 14.2 ± 2.00 3.72 ± 0.28 g 18.7 ± 3.00 2.29 ± 0.19 h 17.5 ± 1.50 2.88 ± 0.10 i 14.3 ± 3.15 3.24 ± 0.33 j 15.1 ± 4.00 2.91 ± 0.02 k 17.2 ± 0.95 1.72 ± 0.15 l 21.6 ± 3.05 1.22 ± 0.25 m  8.5 ± 2.00 8.27 ± 1.72 n 18.2 ± 2.50 2.63 ± 0.06 o 10.3 ± 1.50 4.97 ± 1.01 [0089] Compared with the no-salt form (data are listed in Table 2 and Table 4), the salt form of these compounds is much more herbicidal. In addition, the ammonium salt, the sodium salt, the potassium salt, the magnesium salt and the zinc salt have higher activity than the calcium, magnesium and copper salts. Example 7 [0090] Compounds 7, 14, 15, 16, 40, 45, 48 and 53 were dissolved individually in small amount of methanol, and diluted with distilled water to concentration of 50 μg/mL. Methanol water solution and pure water were used as control. A piece of 5 mm leaf was taken from the second leaf of weed sample and was treated with the solution three times. 5 pieces of the leaf were prepared for each treatment. The damage data were collected 4 days later. The measurement of damage level is described in the Table 9. [0000] TABLE 9 Standard of evaluation of weed damage Damage level Description 4 The leaf completely dead 3 Two third of the leaf withered 2 One half of the leaf withered 1 Only edge of the leaf withered 0 Not damage at all [0091] The measurement of the plant damage was calculated by the formula: Damage Index=Σ(damage level×number of plants)×100/4/number of plants in each treatment. The calculated results are listed in Table 10. [0000] TABLE 10 Weed damage assessment results Family Plant species H 2 O Methanol 7 14 15 16 40 44 48 53 Gramineae Goose grass 0 0 4 3 3 3 4 3 3 4 Wild oats 0 0 4 3 3 3 3 3 3 3 Equal alopecurus 0 0 4 3 3 3 3 3 4 4 Japanese alopecurus 0 0 4 3 3 3 3 4 4 3 Keng stiffgrass 0 0 4 3 3 3 3 3 4 4 Common polypogon 0 0 3 3 3 3 3 4 4 4 Green foxtail ( Setaria 0 0 4 3 4 3 3 4 4 3 viridis ) Crabgrass ( Digitaria 0 0 4 4 4 4 4 4 4 4 sanguinalis ) Leptochloa chinensis 0 0 4 4 4 4 4 4 4 4 Barbyardgrass Echinochloa 0 0 4 4 4 4 4 4 4 4 crusgalli Big Bristlegass 0 0 3 2 2 3 3 2 3 3 Amaranthaceae Redroot pigweed 0 0 3 2 2 3 3 2 2 3 ( Amaramthus retroflexus ) Alligator weed 0 0 3 3 2 3 3 4 4 3 ( Alternanthera philoxeroides ) Pigweed ( Amaranthus 0 0 3 2 2 2 2 3 3 3 spinosus ) Malvaceae Malvaceae 0 0 3 2 2 2 2 2 2 3 Abrtilon theophrasti 0 0 2 2 2 3 3 2 3 3 Polygonaceae Polygonum lapathifolium 0 0 2 2 2 2 2 2 2 3 Rumex japonicus 0 0 2 1 2 2 2 3 2 3 Polygonum perfoliatum 0 0 3 2 2 3 3 3 3 3 Polygonum hydropiper 0 0 3 2 2 3 2 3 3 3 Rumex dentatus 0 0 2 2 2 2 2 3 3 2 Euphorbiaceae Acalypha australis 0 0 3 2 2 2 3 3 3 2 Cannabinaceae Humulus scandens 0 0 3 2 2 3 3 2 3 2 Labiatae Perilla frutescens 0 0 2 2 3 2 2 3 2 2 Galeopsis bifida 0 0 3 2 2 2 3 3 2 3 Lamium amplexicaule 0 0 3 2 3 2 3 3 2 2 Mosla scabra 0 0 2 2 2 2 2 2 2 2 scrophulariaceae Veronica didyma 0 0 2 3 2 2 2 3 3 3 Veronica percica 0 0 3 2 2 2 3 3 3 3 commelinaceae Commelina communis 0 0 4 2 2 3 3 2 4 3 Commelina bengalensis 0 0 4 3 3 3 3 3 4 3 convolvulaceae Japanese false bindweed 0 0 4 3 3 4 3 4 4 4 ( Calystegia hederacea ) Dichondra repens 0 0 3 2 2 3 3 2 3 2 Pharbitis nil 0 0 2 2 3 2 2 3 3 3 compositae Lapsana apogonoides 0 0 4 3 2 3 3 3 4 3 Xanthium sibiricum 0 0 3 2 2 2 2 2 3 3 Conyza canademsis 0 0 4 3 3 3 3 4 4 3 Eclipta prostrata 0 0 4 3 4 3 3 4 4 4 Sonchus oleraceus 0 0 4 3 3 3 3 3 4 4 Aster ageratoides var. 0 0 4 3 3 4 3 4 4 4 scaberulus Youngia japonica 0 0 3 3 3 3 3 3 3 4 Sonchus asper 0 0 4 3 3 3 3 3 4 3 Crisium setosum 0 0 3 3 3 3 3 3 4 4 Erigeron annuus 0 0 3 3 4 3 3 4 4 3 Ambrosia artemisiifolia 0 0 3 3 2 3 3 4 3 3 Carpesium abrotanoides 0 0 3 2 2 2 3 3 4 2 Eupatorium adenophorum 0 0 4 3 4 4 4 4 4 4 Trifolium pretense 0 0 3 3 3 3 3 4 4 4 Rosaceae Duchesnea indica 0 0 2 2 3 2 2 3 3 3 Vitaceae Cayratia japonica 0 0 2 2 2 2 2 3 3 3 Parthenocissus tricuspidata 0 0 2 2 3 2 2 3 3 3 Chenopodiaceae Chenopodium serotinum 0 0 3 2 2 2 2 3 3 3 Oxalidaceae Oxalis corniculata 0 0 4 4 3 4 4 4 4 4 Plantaginaceae Plantago asiatica 0 0 3 2 3 2 3 3 2 2 cyperaecae Cyperus rotundus 0 0 2 2 2 2 2 2 2 2 Cyperus difformis 0 0 4 3 3 3 3 3 4 3 Fimbristylis miliacea 0 0 3 2 2 3 3 2 3 2 [0092] The results listed in the table 10 suggest that eight compounds (7, 14, 15, 16, 40, 44, 48, and 53) have potential to be used to control or kill grassy weed such as Common crabgrass, Barnyardgrass, Difformed galingale, broadleaf weeds, Yerbadetajo, Copperleaf, Chenopodium serotinum, Commelina communis , Alligator weed, Redroot pigweed, Japanese false bindweed, Sonchus oleraceus etc. Example 8 [0093] Compounds 1, 2, 3, and 40 were dissolved in small amount of methanol and diluted with distilled water to concentration of 50 μg/mL. The solution was sprayed to the soil sample until the soil was wet but not overflows. After standing at room temperature for 3 hours, the soil sample was washed with water and methanol. The wash solution was collected and concentrated. Such process was repeated three times. The concentrated solutions were used for herbicidal activity test using the method of needle puncture on Crofton weed. Methanol water solution and pure water were used as control. The experiment for every sample was repeated six times. The spot diameters were measured with vernier caliper after the plant was kept under natural light at 25° C. for 24 hours (Table 11). [0000] TABLE 11 Evaluation compound toxicity after they were treated with soil Average diameter of the spot after 24 h (mm) Treatment H 2 O wash Methanol wash H 2 O control 0.234 ± 0.045 Methanol control 0.288 ± 0.024 1 0.223 ± 0.077 0.292 ± 0.041 2 0.280 ± 0.030 0.362 ± 0.012 3 0.273 ± 0.062 0.334 ± 0.082 40 0.336 ± 0.050 0.416 ± 0.024 [0094] Based on data listed in Table 11, it is clear that the herbicidal activity of all 4 compounds were completely lost after the soil treatment.

A compound represented by formula (I), or (II), or a salt thereof, for eradicating weeds.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority from U.S. Provisional Application No. 62/162,215 filed on May 15, 2015, entitled “Route Based Vehicle Speed Optimization for Fuel Efficiency”, which is hereby fully incorporated by reference. This application also claims priority from U.S. Provisional Application No. 62/162,258 filed on May 15, 2015, entitled “Route Aware Speed Control for Fuel Efficiency”, which is hereby fully incorporated by reference. This application further claims priority from U.S. Provisional Application No. 62/162,287 filed on May 15, 2015, entitled “Elevation Querying System”, which is hereby fully incorporated by reference. [0002] Further, this application is related to co-pending U.S. application Ser. No. 15/152,326, (Attorney Docket Number MGL-1601-US) filed May 11, 2016, entitled “System and Methods for Vehicular Route Optimization”, which is hereby fully incorporated by reference. [0003] Further, this application is related to co-pending U.S. application Ser. No. 15/152,344, (Attorney Docket Number MGL-1602-US) filed May 11, 2016, entitled “Elevation Query Systems for Vehicular Route Optimization and Methods thereof”, which is hereby fully incorporated by reference. BACKGROUND [0004] The present invention relates to systems and methods for efficiently deploying valuable resources, such as cost and duration, especially during extended vehicular trips. [0005] While many vehicles available today offer conveniences such as cruise control, they provide few options for assisting drivers interested in dynamically optimizing fuel efficiency. For example, cruise control works reasonably well for maintaining a constant speed on a straight and flat interstate freeway with moderate traffic. In newer and better equipped vehicles, adaptive cruise control enables these drivers to maintain appropriately safe spacing between vehicles when the vehicle ahead changes speed, while lane departure warning system alerts inattentive drivers who drift from their intended lane of traffic. However, the general goal of the current vehicular control systems is to minimize driver workload and/or to enhance driver safety. [0006] Some driver-agnostic and route-agnostic attempts at reducing fuel consumption do exist, and they include “one-size-fits-all” strategies such as capping the rate of acceleration or shifting gears at more efficient preset speeds, often marketed as “ECO” driving mode. However these “ECO” modes substantially compromise vehicular performance, and also ignore individual driver preferences and actual routes driven, thereby adversely impacts drivers' overall experience. [0007] It is therefore apparent that an urgent need exists for systems and methods targeted at increasing efficiency of vehicles while dynamically taking into consideration real-time route characteristics. With the average cost of new cars in the United States now exceeding $30,000, existing vehicles are expected to remain in service for ten or more years. Hence, in addition to improving the dynamic efficiency of new vehicles, such improved systems and methods enable a large number of existing vehicles to be retrofitted and transformed into dynamically efficient vehicles. SUMMARY [0008] To achieve the foregoing and in accordance with the present invention, systems and methods for dynamically and efficiently control vehicular speed and acceleration is provided. [0009] In one embodiment, a glide controller includes a glide solver and a glide control interface. The glide solver generates at least one vehicular glide schedule including a plurality of discretized targets. The solver generates a plurality of vehicular glide control outputs corresponding to the plurality of discretized targets. The glide control interface outputs the plurality of vehicular glide control outputs, intended to result in a performance adjustment of a vehicle. [0010] Note that the various features of the present invention described above may be practiced alone or in combination. These and other features of the present invention will be described in more detail below in the detailed description of the invention and in conjunction with the following figures. BRIEF DESCRIPTION OF THE DRAWINGS [0011] In order that the present invention may be more clearly ascertained, some embodiments will now be described, by way of example, with reference to the accompanying drawings, in which: [0012] FIGS. 1-4 are block diagrams illustrating one embodiment of a dynamic vehicular resource optimization system in accordance with the present invention; [0013] FIGS. 5-7 are flowcharts illustrating the embodiment of the dynamic vehicular resource optimization system of FIGS. 1-4 ; [0014] FIGS. 8A-8C are block diagrams illustrating three alternative implementations of a glide controller for the dynamic vehicular resource optimization system of FIGS. 1-4 ; [0015] FIGS. 9 and 10A-10B illustrate one embodiment of an elevatier for the dynamic vehicular resource optimization system of FIGS. 1-4 ; and [0016] FIGS. 11-13 are screenshots illustrating the embodiment of the dynamic vehicular resource optimization system of FIGS. 1-4 . DETAILED DESCRIPTION [0017] The present invention will now be described in detail with reference to several embodiments thereof as illustrated in the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the present invention. It will be apparent, however, to one skilled in the art, that embodiments may be practiced without some or all of these specific details. In other instances, well known process steps and/or structures have not been described in detail in order to not unnecessarily obscure the present invention. The features and advantages of embodiments may be better understood with reference to the drawings and discussions that follow. [0018] Aspects, features and advantages of exemplary embodiments of the present invention will become better understood with regard to the following description in connection with the accompanying drawing(s). It should be apparent to those skilled in the art that the described embodiments of the present invention provided herein are illustrative only and not limiting, having been presented by way of example only. All features disclosed in this description may be replaced by alternative features serving the same or similar purpose, unless expressly stated otherwise. Therefore, numerous other embodiments of the modifications thereof are contemplated as falling within the scope of the present invention as defined herein and equivalents thereto. Hence, use of absolute and/or sequential terms, such as, for example, “always,” “will,” “will not,” “shall,” “shall not,” “must,” “must not,” “first,” “initially,” “next,” “subsequently,” “before,” “after,” “lastly,” and “finally,” are not meant to limit the scope of the present invention as the embodiments disclosed herein are merely exemplary. [0019] The present invention relates to systems and methods for optimizing a vehicle's route and Glide schedule using information related but not limited to traffic, time, cost, weather, vehicular sensor data, cost, and refueling/recharging. In particular, the present invention is directed to the novel methods and systems to optimize the route of a transportation vehicle based on optimization preferences, and provide the vehicle user and the vehicle with an optimized route based on the optimization preferences. Additionally, the present invention is directed to the novel methods and systems that enable a user to temporarily relinquish acceleration and braking (regenerative deceleration, engine braking, and friction braking) to the present invention for the purpose of increasing a vehicle's efficiency and optimizing one or more of a vehicle route's parameters (e.g. time, cost); this could be thought of as an advanced or “smart” cruise control. Additionally, the present invention is directed to the novel methods and systems that enable a transportation infrastructure (namely vehicular) to optimize one of many parameters, including but not limited to, traffic flow, total throughput, and lane avoidance/clearance, by providing vehicles with instructions directed at how to manipulate driving behaviors. [0020] The following discussion serves to explain the methods and systems of the present invention. There are multiple examples throughout the discussion that aid in the explanation of certain features or methods the present invention has or uses. For example, this discussion is primarily centered on the automotive transportation industry and movement in 2-dimensional space (constrained to roads). This should not limit the scope of application for the present invention. The systems and methods described here may be applied to planes, boats, submersibles, and spacecraft. Many of these modes of transportation are not limited in movement to 2-dimensions; it follows that the discussion should not limit the present invention to operating in the vehicle transportation sector, nor in 2-dimensional space. [0021] FIG. 1 shows one possible embodiment of the Glide System 100 . Communication between the Glide Servers 110 , 170 and Glide enabled devices 131 , 132 . . . 139 , 140 , 150 may occur over a WAN (Wide Area Network) 120 . Although FIG. 1 depicts Glide enabled devices 131 , 132 . . . 139 , 140 , 150 as motorized vehicles and traffic related infrastructure, this should not limit the scope of Glide enabled devices. [0022] There may be multiple instances of the Glide Servers 110 , 170 . These different instances of the servers may serve different purposes or may store different data. As an example, one set of Glide Servers 110 may be responsible for data pertaining to route optimization, while another instance of the Glide Servers 170 may be responsible only for providing firmware updates to Glide Controllers 144 . This may mean that a Glide Controller 144 will access Glide Servers 110 exclusively when performing route optimization. It would then follow that, when requesting firmware updates or periodic (monthly, quarterly, yearly) data refreshing, a Glide Controller 144 may only access Glide Server 170 . [0023] Throughout the rest of this discussion, Glider Servers 110 in FIG. 1 will be referenced when route data is being discussed, and Glider Servers 170 in FIG. 1 will be referenced when firmware updates and locally stored data refreshing are being discussed. This distinction between the two different blocks of FIG. 1 should in no way limit the number or responsibilities of different instances of the Glide Servers. [0024] Communication 160 in the Glide System 100 may happen between Glide enabled devices 131 , 132 . . . 139 , 140 , 150 and the Glide Servers 110 , 120 or between Glide enabled devices 131 , 132 . . . 139 , 140 , 150 . Communication 160 should not be limited to the above two cases. Communication 160 in the Glide System 100 may include but is not limited to, 4G and 5G cellular communication, DSRC, WiFi, ZigBee, and Bluetooth. [0025] There may be multiple mode variations that a Glide Controller 144 may operate in. These may include but are not limited to, a subscription-based model; a stand-alone configuration; and OEM licensed software. The mode variation that a Glide Controller 144 is operating in may determine the Glide Servers 110 , 170 that specific Glide Controller 144 has access to. [0026] In the subscription-based model, the Glide Controller 144 in a Glide enabled device 131 , 132 . . . 139 , 140 , 150 may send and receive pertinent data to and from the Glide Servers 110 to be used to optimize a route for the desired parameters. The subscription based model may allow Glide Controllers 144 to communicate 160 in real-time with the Glide Servers 110 to gain new information pertinent to solving the route optimization. This model may be similar to OnStar systems where the user 141 may pay a subscription fee for continuous use of the Glide Servers 110 . [0027] In the stand-alone application, the Glide Controller 144 in the Glide enabled device 131 , 132 . . . 139 , 140 , 150 may not communicate 160 with the Glide Servers 110 , but may rather solve the route optimization using data included locally on the Glide Controller 144 . In this way, the Glide Controller 144 would not receiver data from the Glide Servers 110 that is pertinent to solving the route optimization. This stand-alone configuration may allow for a Glide Controller 144 to download firmware updates from the Glide Servers 170 . These firmware updates may include firmware that runs on a Glide Controller 144 as well as updates to the data stored locally on the Glide Controller 144 that the controller uses to solve the route optimization. This model may be compared to a GPS unit where the unit periodically downloads updates, but it relies on internal data for functionality. [0028] A third possibility is for the Glide Controller 144 to be licensed to OEM (Original Equipment Manufacturers) for use in propriety or “in-house” developed products. An example of this may be the Glide software being installed directly into the electronic vehicular control unit (e.g. ECU) 142 of an OEM vehicle instead of as an after-market add-on. In this realization, the Glide functionality may operate in either the connected or stand-alone mode. [0029] These three models should not be considered the only embodiment variations that Glide Controllers 144 may operate in. It should be noted that all embodiments of the Glide System 100 may include the ability to solve the route optimization problem, regardless of if it is a connected system, stand-alone, licensed to an outside party or any other embodiment the system might assume. [0000] I. User and/or Vehicle Interfaces [0030] FIG. 1 shows the Glide System 100 with Glide enabled devices 131 , 132 . . . 139 , 140 , 150 . Glide enabled vehicle 140 shows that the Glide Controller 144 may include a Glide User Interface 143 . The Glide User Interface 143 may refer generally to a module capable of providing the user 141 a way to import route information into the Glide Controller 144 . More specifically, the Glide User Interface 143 may be a visual feedback device with tactile or virtual buttons capable of reading data in and outputting data. [0031] The Glide User Interface 143 may be a user's 141 cellular device, tablet or laptop computer. The Glide User Interface 143 may not necessarily be installed in the Glide enabled device 140 , but may be a device that is connected via a wireless communications protocol and WAN to the Glide Controller 144 , the Glide enabled device 140 , or the Glide WAN 120 . In this way, the Glide Controller 144 may be controlled remotely (outside of the Glide enabled device 140 ). [0032] The Glide User Interface 143 may be used to receive route parameters, preferences and general data from the User 141 ; it may also be used to display information to the User 141 . Information that the Glide User Interface 143 may report the user may include but is not limited to, trip duration; estimated time of arrival (ETA); trip cost (tolls, fuel consumption cost, etc.); current vehicle speed; next target speed; next target location; trip efficiency normalized by distance relative to other trips taken; trip efficiency normalized by distances relative to the same trip taken without the Glide System 100 ; the next driving instruction; or warning of hazards along the route. [0033] The information that the Glide User Interface 143 may display should in no way be limited by the above list. The Glide User Interface 143 may also be integrated into the vehicle's infotainment suite. In this realization, the Glide User Interface 143 may be tasked with displaying other vehicle related information including but not limited to, navigation maps and directions; maintenance alerts; and entertainment related information. [0034] FIG. 2 shows how a Glide Controller 144 may interface with the Glide enabled device 131 , 132 . . . 139 , 140 , 150 that it is installed into and the user 141 of that device (if applicable). The Glide Controller may communicate with multiple vehicle peripheral systems 145 , 142 , 210 , 143 including but not limited to, vehicular sensors (e.g. GPS, radar, optical sensors, wheel speed sensors, accelerometers, gyroscopes and strain gauges) 145 ; the electronic vehicular control unit (e.g. ECU and cruise control specific controller) 142 ; and the vehicular control interface (e.g. accelerator and brake pedals and cruise controls) 210 . [0035] FIG. 2 depicts the data between the Glide Controller 144 and vehicle's peripherals 145 , 142 , 210 , 143 may be bidirectional. In this case, the Glide Controller 144 may take information from the peripherals while also sending data to or manipulating them. [0036] The Glide Controller 144 may integrate into the Glide enabled device 131 , 132 . . . 139 , 140 , 150 in multiple ways. The following discussion is specific to integration into a vehicle but may also apply for integration into other devices; further, it should not be concluded that these are the only ways the Glide Controller 144 may integrate into a physical system. [0037] FIG. 3 shows one way the Glide Controller 144 may be integrated into the electronics of a vehicle. The Glide Controller 144 may be connected to any of or multiple of the vehicle's CAN busses 360 , which means it may be able to take data from and inject data onto the vehicle's communication bus 360 . In this way, the Glide Controller 144 may be able to manipulate the throttle request of the vehicle by adding specific messages onto the CAN bus 360 . In addition to manipulating the throttle request, the Glide Controller 144 may be able to manipulate other sensors or modules in the vehicle. Other information the Glide Controller 144 may manipulate may include but is not limited to, Batter Management System information (tractive battery voltage, tractive battery current, output and input tractive battery power); cylinder activation; braking (regenerative deceleration, engine braking, friction braking); gear and neutral selection; 4 wheel, 2 wheel, and all-wheel drive selection; enabling and disabling manufacturer eco modes; and specifying a power plant to use (electric or gas) in hybrid systems. This may also allow the Glide Controller 144 to collect information from the vehicular sensors 310 , 320 , 330 , 340 , 350 , 370 . The vehicular sensors shown in FIG. 3 are representative only and should not limit the quantity or scope of the sensors that a Glide Controller 144 may take information from or give information to. [0038] The Glide Controller 144 may physically connect to the vehicle's accelerator pedal 210 . FIG. 4 shows the functional blocks for the Speed Control Interface 440 interacting with the vehicle's user interface (pedals) 210 . In this way, the accelerator pedal 210 may be physically actuated by the Glide Controller 144 to adjust the acceleration of the vehicle to match the route optimization that the Glide Controller 144 has been tasked with carrying out. [0039] The Glide Controller 144 may physically actuate the vehicle's accelerator pedal by using a vacuum servomotor that is driven by a microcontroller. In this way, the Glide Controller 144 may directly actuate the vehicle's accelerator pedal 210 through an electro-mechanical output. This is just an example of one way to interface with the vehicle's pedal and should not be considered an exclusive or limiting example. [0040] The Glide Controller 144 may physically connect to the vehicle's throttle cable. It may connect to the cable that is physically connected to the accelerator pedal, or it may connect to the throttle cable controlled by the vehicle's cruise control system. In this way, the Glide Controller 144 may physically actuate the vehicle's accelerator cable, which will influence the vehicle's speed. [0041] The Glide Controller's 144 Speed Control Interface 440 may actuate the throttle cable(s) via a vacuum servomotor and microcontroller, similar to the connection to the accelerator pedal that was just discussed. This is just an example of one way to interface with the throttle cable(s) and should not be considered an exclusive or limiting example. [0042] The Speed Control Interface 440 may be responsible for processing the Glide Schedule received from the Glide Solver 410 . This Glide Schedule may be a set of discretized points that pertain to locations along the requested route. These points may be the same optimization points that the Glide Solver 410 produces. The Speed Control Interface 440 may not be the only method for manipulating the performance of the vehicle. The Speed Control Interface 440 may also be responsible for producing Glide control messages. These control messages may be electronic and used to interface with the vehicular electronic communications. [0043] In an embodiment where the Speed Control Interface 440 is not used to manipulate the vehicle, or the vehicular controls, a User 141 may be presented with instructions or a Glide Schedule. In this way, the Glide Schedule may be presented to the User 141 via instructions pertaining to how to operate the vehicle to adhere to the optimization produced by the Glide Controller 144 . [0044] This set of instructions (manual carrying out of the Glide Schedule) may be presented visually to the User 141 via the Glide User Interface 143 , or the instructions may be presented audibly to the User 141 , or the instructions may be presented via the vehicular GPS unit. The Glide Controller 144 should not be limited by these examples in how it may present instructions to the User 141 . [0045] The Speed Control Interface 440 may receive the Glide Schedule from a plurality of sources. In the embodiment where the Glide Controller 144 is present in the vehicle, the Speed Control Interface 440 may receive the Glide Schedule locally from the Glide Controller 144 . In the embodiment where the Glide Controller 144 and its functionality is carried out remotely (non-locally—e.g., on the Glide Servers), the Speed Control Interface 440 may receive the Glide Schedule from a remote device (Glide Servers). These two examples serve to explain that the Glide Schedule may be received from a plurality of sources and does not server to exclude sources that may provide the Glide Schedule. [0046] The Glide Schedule and Glide Schedule messages may be communicated via a plurality of methods. The messages may be communicated via one or multiple copper wire busses and protocols including but not limited to, UART, USART, I2C, EIA-232, CANbus, CANopen, and LIN. The messages may be communicated via one or multiple wireless communications protocols including but not limited to, cellular 3G, 4G and 4GLTE; WiFi; Bluetooth; and ZigBee. The Glide Schedule messages may also be communicated via an optical communications bus and protocol. These physical busses and messaging protocols serve as examples and should not serve as exclusive lists, but examples of possibilities. [0047] The Glide control messages may be sent via the same busses and protocols listed above. Again, this does not serve as an exclusive list for how glide control messages may be communicated, but an example of possibilities. [0048] While the example carried through in this description looks at manipulating the accelerator pedal of the vehicle, it should be noted that the Speed Control Interface 440 may manipulate a plurality of vehicle controls. These vehicular controls may include but are not limited to throttle (accelerator), brake, regenerative braking, de-acceleration, transmission controller, and power-train selection control. The Speed Control Interface 440 may receive Glide Schedules pertaining to the manipulation and control of any number of these or more vehicular controls. The Speed Control Interface 440 may produce any number of Glide control messages pertaining to and aimed at the control of any number of these or more vehicular controls. The Speed Controller 440 may manipulate multiple vehicular controls using multiple different methods (mechanical actuation and electronic control). [0049] While FIG. 3 shows the Glide Controller 144 interfacing with the vehicle electrically (by the vehicle's electronics communications bus 360 —e.g. CANbus), there are other electrical methods for the Glide Controller 144 to interact with the vehicular sensors 310 , 320 , 330 , 340 , 350 , 360 and the electronic vehicular control unit (e.g. ECU) 142 . The Speed Control Interface 440 may inject or send Glide control messages via the vehicular electronics communication bus 360 (e.g. CANbus). II. Glide Solver [0050] FIG. 8B shows one possible block diagram of the route processing side of the Glide System 100 . The Requesting Device 811 a may send a route request to the Request Manager 812 . The requested route may be defined by start, end and waypoints; start and end; or simply start or end. The Requesting Device 811 a may also define the route as GPS coordinates spaced at regular intervals along the route. [0051] The Requesting Device 811 a may be a User 141 , an application (via a smartphone, table, or computer). The Requesting Device 811 a may be the Glide User Interface 143 . Additionally, the Requesting Device 811 a could be the Glide WAN 120 , if a User 141 is accessing a Glide Controller 144 via the Glide WAN 120 . [0052] In the standalone embodiment of the system, all of the blocks shown in FIG. 8B may be present in the Glide Controller 144 that is installed in the Glide enabled device 131 , 132 . . . 139 , 140 , 150 ; in the connected embodiment, some, all, or none of these blocks may be present in Glide Controller 144 with the others present on the Glide Servers 110 . [0053] Returning to FIG. 8B , the request manager may then interact with both the Glide Solver 410 and the constraint databases 815 , 816 , 816 . . . 819 to provide the Glide Solver 410 with the information it needs to successfully complete the requested route optimization. [0054] The constraint databases 815 , 816 , 817 . . . 819 may include information related to but not limited by, elevation, drag force, road speed, road curvature, road conditions, traffic, and weather. The Glide Solver 410 may request data from these databases to aid in the optimization of the requested route. [0055] The constraint databases 815 , 816 , 817 . . . 819 may be stored on the Glide Servers 110 , locally on the Glide Controller 144 or in other locations accessible via the Glide System WAN 120 . Additionally, it may be possible to import constraint databases 815 , 816 , 817 . . . 819 into the Glide Controller 144 . An example of this could be data pertaining to a foreign country. The constraint data may be read from a media storage device that is connected to the Glide Controller 144 . [0056] In addition to the constraint databases 815 , 816 , 817 . . . 819 , the Glide Solver 410 and/or Request Manager 812 may request other information from the Glide Servers 110 , 170 , onboard memory or infrastructure servers. [0057] Infrastructure servers and their databases may provide the information related but not limited to current traffic conditions, traffic light timing, current throughput, current throughput goals, current lane throughput, current lane throughput goals, traffic accidents, accident avoidance instructions, and emergency vehicle avoidance instructions. [0058] Other Glide enabled vehicles 131 , 132 . . . 139 , 140 may be a source of additional information that the Glide Solver 410 or Request Manager 812 may request data from. [0059] Since the breadth of information the Glide Solver 410 and Request Manager 812 has access to is large, the data resources are clearly not limited to those mentioned above. [0060] Referring back to FIG. 8B , the Request Manager 812 receives a route from the Requesting Device 811 a, and then requests the necessary constraint information from the constraint databases 815 , 816 , 817 . . . 819 for the requested route. The Request Manager 812 sends the constraint information and any route parameters provided by the Requesting Device 811 a or other parameter sources to the Glide Solver 410 . [0061] The Glide Solver 410 , shown in FIG. 4 as part of the Glide Controller 144 , may include multiple algorithm blocks. Two of these blocks, shown in FIG. 4 , may be the Route Optimizer 420 and the Elevatier 430 . [0062] The Route optimizer 420 may be used in all variations of the Glide System 100 . As stated above, these may include, systems installed in vehicles, systems installed in transportation infrastructures, and systems operating in any of the modes discussed in this specification. [0063] When installed in a vehicle, the Route Optimizer 420 may work by minimizing any number of parameter vectors of the vehicle from the starting point to the ending point of the route. The flow diagrams presented in the figure set use the positive direction acceleration vector as an example; this should not serve as a limiting or exclusive example. In minimizing this positive acceleration vector, the Glide Solver 410 minimizes the energy consumption necessary to complete the requested route. The Glide Solver 410 may minimize the norm-2 of the positive acceleration for each point along the route, or the Glide Solver 410 may minimize a piecewise linear function of the acceleration for each point along the route. The method for optimization should not be limited to the two previously mentioned methods. Any method of optimization may be applied in the Glide Solver 410 . From these discrete acceleration points, the Glide Solver 410 may extrapolate and send discrete speeds that the vehicle should reach at predetermined points along the route to the Glide Controller 144 and Speed Control Interface 440 . [0064] The acceleration example carried through this discussion is just one of many parameters that the Glide Solver 410 and the Glide System 100 may optimize for. The discretized points that the Glide Solver 410 produces may be generally called a Glide Schedule. This Glide Schedule may include discretized points for any number of vehicle parameters. The Glide Schedule may pertain to but is not excluded by, acceleration, engine revolutions-per-minute (RPM), motor RPM, gear selection, powertrain selection, braking, and regeneration (regenerative braking). [0065] The acceleration example carried throughout this description should not limit the scope of the parameters that the Glide Solver 410 or the Glide System 100 may solve for, but rather the example should illustrate how the Glide Solver 410 and Glide System 100 go about optimizing for a given parameter. [0066] The Glide Solver 410 may minimize for multiple parameters. In this case, the Glide Solver 410 may minimize a weighted function of the multiple parameters. [0067] In addition to minimizing the necessary energy for the route, the Glide Solver 410 may use user-configurable options and vehicle type to optimize for other route metrics including but not limited to, monetary cost, temporal trip duration, and travel time spent idle. [0068] The monetary cost or a trip may include but is not limited to, vehicular operating cost, fuel cost, charging cost, and maintenance cost. [0069] When installed in the transportation infrastructure, the Route optimizer 420 may work much in the same way. It may also optimize for other metrics including but not limited to, vehicle throughput, traffic latency and prioritization for special/emergency vehicles. [0070] The Glide Schedule should not be thought of as a fixed solution. The Glide Controller 144 and Glide Solver 410 may continually adjust the Glide Schedule based on new or different data received. This data may be sensor data from one or more of the vehicular sensors, or this data may be received from the constraint databases 815 , 816 , 187 . . . 819 . In this way, the Glide System 100 is continually working, optimizing, and adjusting the Glide Schedule [0071] FIG. 5 and FIG. 6 show possible flow paths for the Glide System 100 from route request to route delivery. FIG. 5 shows a possible flow path for a Glide System 100 that is operating in the connected mode. This mode, as explained above, may denote that the Glide Controller 144 in the Glide enabled device 131 , 132 . . . 139 , 140 , 150 is connected to the Glide Servers 110 via the WAN 120 . FIG. 4B shows a possible flow path for a Glide System 100 that is operating without a final destination. This mode may denote that the Glide Controller 144 is simply looking a certain distance ahead of the current location and continually optimizing the route for the next x-miles. [0072] Step 511 in FIG. 5 describes the Requesting Device 811 a, 811 b sending route information and configuration data to the Request Manager 812 . The Requesting Device 811 a, 811 b may be any of a plethora of possible devices. In the simplest realization, the Requesting Device 811 a, 811 b may be a User 141 . The User 141 may input the route and configuration data via a Glide User Interface 143 . [0073] The User 141 may be prompted for different pieces of information related to the route to be requested. These pieces of information could include but are not limited to, starting and ending points of the route; waypoints throughout the route; and parameters to be optimized for. The Glide Controller 144 may provide (via the Glide User Interface 143 suggestions to the User 141 based on past routes or even other Glide Users with similar habits or destinations. [0074] The Glide Controller 144 may also predict the User's 144 routes and route preferences. An example of this may be predicting a route that is taken at 7:00 am every weekday morning with the starting point being the User's 141 home address, the ending point being the User's 141 work address and a waypoint at the local coffee shop. The Glide Controller 144 may predict this route and have the User's 141 typical preferences for this route auto-filled when the User 141 starts the system at 6:55 am. [0075] The Glide User Interface 143 may refer generally to a module capable of providing the User 141 a way to provide route information and parameters into the Glide Controller 144 . More specifically, the Glide User Interface 143 may be a visual feedback device with tactile or virtual buttons capable of reading data in and outputting data. [0076] The Glide User Interface 143 may be a user's 141 cellular device, tablet or laptop computer. The Glide User Interface 143 may not necessarily be installed in the Glide enabled device 140 , but may be a device that is connected via a wireless communications protocol and the Glide WAN 160 to the Glide Controller 144 , the Glide enabled device 140 , or the Glide WAN 120 . In this way, the Glide Controller 144 may be controlled remotely (outside of the Glide enabled device 140 ). This Glide User Interface 143 may be any device capable of accepting information from a User 141 . The Glide Use Interface 143 may include cellular phones, tablets, laptop computers or any other module capable of accepting inputs and communicating those inputs to the Request Manager 812 . [0077] In other realizations, the Requesting Device 811 a, 811 b may be a device similar to that of the Glide User Interface 143 . A User's 141 cellular phone, tablet, or laptop may be more than just the Glide User Interface 143 . The Requesting Device 811 b may not necessarily be installed in the Glide enabled device 131 , 132 . . . 139 , 140 , 150 , or it may not be integrated into the Glide Controller 144 . The Requesting Device 811 a , 811 b may be connected via a wireless communications protocol and the Glide WAN 160 to the Glide Controller 144 or directly to the Request Manager 812 . [0078] In other realizations or embodiments, the Requesting Device 811 a, 811 b may be the traffic infrastructure 150 , or the Glide Servers 110 . [0079] Referring back to FIG. 5 , step 511 , the Requesting Device 811 a, 811 b (discussed above) may send the route configuration data to the Request Manager 812 . The route information from the Requesting Device 811 a, 811 b may be defined in a plurality of manners. [0080] The route information may be sent as a set of locations, starting, ending and waypoints in between; starting and ending; simply starting or simply ending. The route information may also be sent as a list of GPS points spaced along the desired route. [0081] Step 512 of FIG. 5 describes the Request Manager 812 inserting points along the route to gain the necessary granularity to accurately optimize the route. The purpose of this step is to create more data points for the Glide Solver 410 to calculate. More data points along the route means the Glide Solver 410 will be able to solve for more acceleration points, and this means the speed targets will have finer resolution. [0082] In step 512 of FIG. 5 , the Request Manager 812 may or may not insert additional points along the route. If the route data from step 511 was provided as a list of GPS points, and the Request Manager 812 determines the GPS points provide an adequate level of resolution (granularity), step 512 may not be carried out. [0083] Step 512 in FIG. 5 should not be limited to just the Request Manager 812 . In some embodiments of the Glide System 100 , the data insertion may be carried out by another functional block (e.g. the Glide Solver 410 ). [0084] In step 513 in FIG. 5 , the Request Manager 812 may fetch the necessary data from the constraint databases 815 , 816 , 817 . . . 819 . The constraint databases 815 , 816 , 817 . . . 819 may include information related to but not limited by, elevation, road speed, and road curvature. The Request Manager 812 may request data from the constraint databases 815 , 816 , 817 . . . 819 for each point along the requested route. These points may be the points created in step 512 , or they may be points provided by the Requesting Device 811 a, 811 b. [0085] The constraint databases 815 , 816 , 817 . . . 819 may be stored on the Glide Servers 110 , locally on the Glide Controller 144 , or in other locations accessible via the Glide System WAN 120 . Additionally, it may be possible to import constraint databases 815 , 816 , 817 . . . 819 into the Glide Controller 144 . The constraint data may also be read in from a media storage device that is connected to the local Glide Controller 144 . [0086] In addition to the constraint databases 815 , 816 , 817 . . . 819 , the Glide Solver 410 and/or Request Manager 812 may request other information from the Glide Servers 110 , 170 , onboard memory or infrastructure servers. [0087] Infrastructure servers and their databases may provide the information related but not limited to current traffic conditions, traffic light timing, current throughput, current throughput goals, current lane throughput, current lane throughput goals, traffic accidents, accident avoidance instructions, and emergency vehicle avoidance instructions. [0088] The Request Manager 812 may request data points from all necessary constraint data bases 815 , 816 , 817 . . . 819 and other data sources for all points along the request route. The Request Manager 812 may request data in parallel from all or some of the necessary constraint databases 815 , 816 , 817 . . . 819 and other data sources, or the Request Manager 812 may que the data requests. If the Request Manager 812 ques the data requests, only one constraint database 815 , 816 , 817 . . . 819 may be queried at a time. [0089] Other Glide enabled vehicles 131 , 132 . . . 139 , 140 may also be a source of additional information that the Request Manager 812 may request data from. [0090] In step 514 in FIG. 5 , the constraint data collected by the Request Manager 812 from the constraint databases 815 , 816 , 817 . . . 819 and other data sources may be sent to the Glide Solver 410 . The Request Manager 812 may also send the route information, parameters and preferences that it received from the Requesting Device 811 a, 811 b to the Glide Solver 410 . [0091] The Glide Solver 410 may receive all of the data pertaining to the route from the Request Manager 812 at once (in bulk), or the Glide Solver 410 may receive all of the data from the Request Manager 812 in a stream as the Request Manager 812 requests the data from the constraint databases 815 , 816 , 817 . . . 819 . [0092] In step 515 in FIG. 5 , the Glide Solver 410 may use the data it received in step 514 from the Request Manager 812 to calculate the coefficient matrices of the constraints. [0093] In step 516 in FIG. 5 , the Glide Solver 410 may use the coefficient matrices constructed in step 515 to minimize the acceleration vector. The Glide Solver 410 may be an inequality constrained norm-2 solver that uses the coefficients calculated in step 515 to minimize the norm-2 of the acceleration for each point along the route. [0094] The norm-2 solver referenced above is depicted in FIG. 4 . With reference to FIG. 4 , the Glide Solver 410 , may include multiple algorithm blocks 420 , 430 . One of these blocks may be an Route optimizer 420 . This Route optimizer 420 may be the norm- 2 solver referenced above. The acceleration vector that is being minimized is proportional to the energy vector. Minimizing the acceleration vector corresponds to minimizing the energy vector. [0095] Included as part of step 516 in FIG. 5 may be the Glide Solver 410 producing a set of acceleration points that constitute the solution to the minimized acceleration vector. [0096] In step 517 in FIG. 5 , the Glide Solver 410 may use the set of acceleration points created in step 516 to create a set of speed points along the route. This set of speeds along the route may serve as targets for the Glide Controller 410 to aim for as the vehicle progresses through the route. [0097] The target speed points along the route may be calculated via the minimized acceleration vector and any other factors that are vehicle, road or driver specific that might influence the movement of the vehicle. Two examples of factors that may be taken into account when the Glide Solver 410 creates the set of target speed points are the vehicle's drag coefficient as well as any load the vehicle might be carrying or pulling. [0098] In step 518 in FIG. 5 , the Request Manager 812 may receive the route results from the Glide Solver 410 , and the Request Manager 812 may send the Glide Solver's 410 results to the Requesting Device 811 a, 811 b. The Request Manager 812 may also send the inputs used for the Glide Solver 410 . [0099] If applicable, the Requesting Device 811 a, 811 b may display the results from the Glide Solver 410 on the Glide User Interface 143 . The Glide User Interface 143 may display information related but not limited to, estimated trip duration; estimated trip cost; estimated time spent moving versus idle or in traffic; total estimated energy consumption; and estimated refueling/recharging locations. [0100] Additionally, the User 141 may be able to view the results from the Glide Solver 410 and make changes to any of the input parameters that were previously provided. If the User 141 makes changes to the proposed route/trip, the Glide Request Manager 812 and Glide Solver 410 may recalculate the proposed route/trip with the new preferences or parameters proposed by the User 141 . The Request Manager 812 and Glide Solver 410 may return the edited results to the Requesting Device 811 a, 811 b and the Glide User Interface 143 . The new results may be displayed along with the previous results for the User 141 to compare. [0101] It may follow that the User 141 could input a range of route/trip parameters and preferences and the Request Manager 812 and Glide Solver 410 may return multiple different routes for the User 141 to pick from. In this way, the User 141 may be able to see how different parameters affect the results of the trip optimization. [0102] The flow diagram in FIG. 5 should not serve as an exclusive method for the Glide System 100 to complete a route request and optimization. FIG. 5 merely serves as an example for one possible way for the Glide System 100 to fulfill a route request. [0103] FIG. 6 shows a flow diagram for another possible mode of operation for the Glide System 100 . In FIG. 5 , the flow diagram depicted the possible steps the Glide System 100 may take when given route parameters. These route parameters may include starting, ending, and waypoint destinations. The flow diagram in FIG. 6 shows possible steps for the Glide System 100 operating without and final destination. [0104] In another mode, the User 141 may simply enable the Glide Controller 144 in a Glide enabled device 131 , 132 . . . 139 , 140 , 150 . In doing this, the Glide Controller 144 may look ahead for the next x-miles along the current route and optimize the route for the next x-miles. This is a functionally different mode from the previous example in that the end point is continuously moving. The Glide Controller 144 may continuously look ahead for the next x-miles, so the Glide Controller 144 is constantly updating its “end” destination. [0105] In step 611 in FIG. 6 , the Requesting Device 811 a, 811 b may enable the Glide Controller 144 . The Requesting Device 811 a, 811 b may be any of a plethora of possible devices. In the simplest realization, the Requesting Device 811 b may be a User 141 . The User 141 may enable the Glide Controller 144 via the Glide User Interface 143 . [0106] The Glide User Interface 143 may refer generally to a module capable of providing the User 141 a way to enable the Glide Controller 144 . In other modes of operation, the Glide User Interface 143 may refer generally to a module capable of providing the User 141 a way to provide route information and parameters into the Glide Controller 144 . More specifically, for all modes of operation, the Glide User Interface 143 may be a visual feedback device with tactile or virtual buttons capable of reading data in and outputting data to and from the Glide Controller 144 . [0107] The Glide User Interface 143 may be a user's 141 cellular device, tablet or laptop computer. The Glide User Interface 143 may not necessarily be installed in the Glide enabled device 140 , but may be a device that is connected via a wireless communications protocol and the Glide WAN 160 to the Glide Controller 144 , the Glide enabled device 140 , or the Glide WAN 120 . In this way, the Glide Controller 144 may be controlled remotely (outside of the Glide enabled device 140 ). This Glide User Interface 143 may be any device capable of accepting information from a User 141 . The Glide Use Interface 143 may include cellular phones, tablets, laptop computers or any other module capable of accepting inputs and communicating those inputs to the Request Manager 812 . [0108] In other realizations, the Requesting Device 811 a, 811 b may be a device similar to that of the Glide User Interface 143 . A User's 141 cellular phone, table, or laptop may be more than just the Glide User Interface 143 . The requesting Device 811 b may not necessarily be installed in the Glide enabled device 131 , 132 . . . 139 , 140 , 150 , or it may not be integrated into the Glide Controller 144 . The Requesting Device 811 a , 811 b may be connected via a wireless communications protocol and the Glide WAN 160 to the Glide Controller 144 or directly to the Request Manager 812 . [0109] In other realizations or embodiments, the Requesting Device 811 a, 811 b may be the traffic infrastructure 150 , or the Glide Servers 110 . [0110] Referring back to FIG. 6 , step 611 , the Requesting Device 811 a, 811 b (discussed above) may enabled the Glide Controller 144 . In the connected embodiment, this may enabled the Glide Service 100 as well. [0111] The User 141 may be able to use a quick select menu to choose parameters that the Glide Controller 144 and Glide Solver 410 should optimize for. An example of this could be: the User 141 enables the Glide Controller 144 and uses the quick select menu on the Glide User Interface 143 to tell the Glide Controller 144 to optimize for time. The Glide Controller 144 may then continuously optimize the next x-miles ahead of the current position for time. [0112] In step 612 in FIG. 6 , the Request Manager 812 may insert points along the route for the next x-miles in order to create the granularity necessary to accurately optimize the next x-miles along the current route. The purpose of this step is to create more data points for the Glide Solver 410 to calculate. More data points along the route means the Glide Solver 410 will be able to solve for more acceleration points, and this means the speed targets will have finer resolution. [0113] Step 612 in FIG. 6 should not be limited to just the Request Manager 812 . In some embodiments of the Glide System 100 , the data insertion may be carried out by another functional block (e.g. the Glide Solver 410 ). [0114] In step 513 in FIG. 6 , the Request Manager 812 may fetch the necessary data from the constraint databases 815 , 816 , 817 . . . 819 . The constraint databases 815 , 816 , 817 . . . 819 may include information related to but not limited by, elevation, road speed, and road curvature. The Request Manager 812 may request data from the constraint databases 815 , 816 , 817 . . . 819 for each point along the requested route. These points may be the points created in step 512 , or they may be points provided by the Requesting Device 811 a, 811 b. [0115] The constraint databases 815 , 816 , 817 . . . 819 may be stored on the Glide Servers 110 , locally on the Glide Controller 144 , or in other locations accessible via the Glide System WAN 120 . Additionally, it may be possible to import constraint databases 815 , 816 , 817 . . . 819 into the Glide Controller 144 . The constraint data may also be read in from a media storage device that is connected to the local Glide Controller 144 . [0116] In addition to the constraint databases 815 , 816 , 817 . . . 819 , the Glide Solver 410 and/or Request Manager 812 may request other information from the Glide Servers 110 , 170 , onboard memory or infrastructure servers. [0117] Infrastructure servers and their databases may provide the information related but not limited to current traffic conditions, traffic light timing, current throughput, current throughput goals, current lane throughput, current lane throughput goals, traffic accidents, accident avoidance instructions, and emergency vehicle avoidance instructions. [0118] The Request Manager 812 may request data points from all necessary constraint data bases 815 , 816 , 817 . . . 819 and other data sources for all points along the request route. The Request Manager 812 may request data in parallel from all or some of the necessary constraint databases 815 , 816 , 817 . . . 819 and other data sources, or the Request Manager 812 may que the data requests. If the Request Manager 812 ques the data requests, only one constraint database 815 , 816 , 817 . . . 819 may be queried at a time. [0119] Other Glide enabled vehicles 131 , 132 . . . 139 , 140 may also be a source of additional information that the Request Manager 812 may request data from. [0120] In step 514 in FIG. 6 , the constraint data collected by the Request Manager 812 from the constraint databases 815 , 816 , 817 . . . 819 and other data sources may be sent to the Glide Solver 410 . The Request Manager 812 may also send the route information, parameters and preferences that it received from the Requesting Device 811 a, 811 b to the Glide Solver 410 . [0121] The Glide Solver 410 may receive all of the data pertaining to the route from the Request Manager 812 at once (in bulk), or the Glide Solver 410 may receive all of the data from the Request Manager 812 in a stream as the Request Manager 812 requests the data from the constraint databases 815 , 816 , 817 . . . 819 . [0122] In step 515 in FIG. 6 , the Glide Solver 410 may use the data it received in step 514 from the Request Manager 812 to calculate the coefficient matrices of the constraints. [0123] In step 516 in FIG. 6 , the Glide Solver 410 may use the coefficient matrices constructed in step 515 to minimize the acceleration vector. The Glide Solver 410 may be an inequality constrained norm-2 solver that uses the coefficients calculated in step 515 to minimize the norm-2 of the acceleration for each point along the route for the next x-miles along the current route. [0124] The norm-2 solver referenced above is depicted in FIG. 4 . With reference to FIG. 4 , the Glide Solver 410 , may include multiple algorithm blocks 420 , 430 . One of these blocks may be an Route optimizer 420 . This Route optimizer 420 may be the norm- 2 solver referenced above. The acceleration vector that is being minimized is proportional to the energy vector. Minimizing the acceleration vector corresponds to minimizing the energy vector. [0125] Included as part of step 516 in FIG. 6 may be the Glide Solver 410 producing a set of acceleration points that constitute the solution to the minimized acceleration vector. [0126] In step 517 in FIG. 6 , the Glide Solver 410 may use the set of acceleration points created in step 516 to create a set of speed points along the route for the next x-miles along the current route. This set of speeds along the route may serve as targets for the Glide Controller 410 to aim for as the vehicle progresses through the next x-miles of the route. [0127] The target speed points along the route for the next x-miles may be calculated via the minimized acceleration vector and any other factors that are vehicle, road or driver specific that might influence the movement of the vehicle. Two examples of factors that may be taken into account when the Glide Solver 410 creates the set of target speed points are the vehicle's drag coefficient as well as any load the vehicle might be carrying or pulling. [0128] In step 518 in FIG. 6 , the Request Manager 812 may receive the route results from the Glide Solver 410 , and the Request Manager 812 may send the Glide Solver's 410 results to the Requesting Device 811 a, 811 b. The Request Manager 812 may also send the inputs used for the Glide Solver 410 . [0129] It should be noted that the Glide Solver 410 may provide multiple different routes for the same starting and ending destinations. These multiple different routes may be displayed to the User 141 , and the User 141 may be able to choose the preferred route. In addition to providing multiple routes, the Glide Solver 410 may provide estimations for time of arrival, energy usage, and necessary refueling or recharging. The estimations or additional information provided by the Glide Solver 410 should not be limited to the above listed data. [0130] In other embodiments, third party routing services may be used to provide the multiple different routes. In this embodiment, the Glide Solver 410 may then be applied to the multiple different routes provided by the third party routing services. [0131] If applicable, the Requesting Device 811 a, 811 b may display the results from the Glide Solver 410 on the Glide User Interface 143 . The Glide User Interface 143 may display information related but not limited to, estimated running cost since the Glide Controller 144 has been enabled; estimated and running totals of time spent moving versus idle or in traffic; total estimated energy consumption since the Glide Controller 144 has been enabled; and estimated refueling/recharging locations based on the needs of the vehicle for the next x-miles of the route. [0132] Additionally, the User 141 may be able to view the results from the Glide Solver 410 and make changes to the quick select optimization selections that were originally made. If the User 141 makes changes to the quick select optimization selections, the Glide Request Manager 812 and Glide Solver 410 may recalculate the next x-miles of the current route with the new quick select selections provided by the User 141 . The Request Manager 812 and Glide Solver 410 may return the edited results to the Requesting Device 811 a, 811 b and the Glide User Interface 143 . The new results may be displayed along with the previous results for the User 141 to compare. Ultimately, the User 141 may be asked to select from one of the possible optimizations of the next x-miles, or the Glide Controller 144 may default to a preset optimization setting for the next x-miles if one is not chosen. [0133] The flow diagram in FIG. 6 should not serve as an exclusive method for the Glide System 100 to complete a route optimization for the next x-miles of the current route. FIG. 6 merely serves as an example for one possible way for the Glide System 100 to fulfill a request to optimize the next x-miles of the current route. III. Elevatier (Elevation Finder) [0134] FIG. 4 shows a possible functional block for the Glide Controller 144 and Glide Solver 410 . The Glide Solver 410 may include specific algorithms designed to complete tasks in the Glide System 100 . The Elevatier 430 may be one of these algorithms. [0135] The Elevatier 430 may describe an algorithm specifically designed for finding a point of data (related geographically) from a very large database of information. While not limiting the scope of application for this algorithm, the Glide System 100 may use this algorithm for quickly finding data related to elevation along the requested route. The general algorithm used in the Elevatier 430 may be applied to any rapid search function tasked with querying large databases for data points. [0136] The index and indexing algorithm used by the Elevatier 430 may include any of a wide range of algorithms and indexing methods. Specifically, an rtree indexing scheme and data structure may be used to organize data. It may also follow that an rtree spatial indexing algorithm may be used by the Elevatier 430 to search a database. The spatial data structure index and the spatial indexing algorithm should not be limited to one of an rtree nature; the rtree example serves only to show one possibility for the structure and algorithm. [0137] FIG. 9 shows how elevation data may be organized to allow for the Elevatier 430 to quickly extract data need by the Glide Solver 410 . The configuration file 910 for the given data may be broken into N regions 921 . . . 929 . An example of the regional level 921 . . . 929 could be sections of the continental United States (west, central, and east). These regions may then be broken down into sub-regions 931 , 932 . . . 939 , 940 . An example of this could be states within the larger region (Washington, Oregon, California, Arizona, Nevada and Idaho could be in the west region). FIG. 9 depicts two levels of data (regions 921 . . . 929 and sub-regions 931 , 932 . . . 939 , 940 ), but data organization should not be limited to two levels. Data organization levels may extend as many levels as necessary. To continue with the above example, the next layer could be regions within each state, then counties within each region, then cities within each county. [0138] All files for a given region may be stored in the same directory, and they may be indexed spatially. This may hold true for any region 921 . . . 929 or sub-region 931 , 932 . . . 939 , 940 level in the data organization scheme. Organization may include regions 921 . . . 929 and sub-regions 931 , 932 . . . 939 , 940 being stored in the same hierarchical level. The regions 921 . . . 929 and sub-regions 931 , 932 . . . 939 , 940 may also not be hierarchical. [0139] FIG. 10A shows how data may be manipulated between the raw data 1011 stored in memory (be it local or on a server) and the data that is accessed 1013 for delivery to the Request Manager 812 and eventually the Glide Solver 410 . [0140] Before the data point(s) 1014 being requested are found in the data base 1013 , the Elevatier 430 algorithm may rasterize the raw elevation data 1012 to produce and even spaced matrix 1013 of data points 1014 . FIG. 10A shows the matrix 1011 of un-rasterized (raw) data points 1012 . The Elevatier 430 algorithm may rasterized the raw data 1012 to produce a rasterized matrix 1013 of the rasterized data points 1014 . [0141] The Request Manager 812 may request a data point that already exists in the elevation database. If this is the case, the Elevatier 430 algorithm may simply rasterize the data and select the data point 1014 from the rasterized matrix 1013 . [0142] If the Request Manager 812 requests a data point that is not already in the elevation database, the Elevatier 430 may have to extrapolate the data point from the existing points in the database. [0143] There may be a functional block, included with the Elevatier that is an elevation request manager for the Elevatier. This elevation request manager may be different from the Request Manager 812 . While the Request Manager 812 may handle data between the Elevatier 430 , constraint databases 815 , 816 , 817 . . . 819 , the Glide Solver 410 , and the Requesting Device 811 a, 811 b, the elevation request manager may be a front end function of the Elevatier 430 that may handle incoming data point requests. [0144] To obtain the extrapolated point 1015 , that the Request Manager 812 has requested, a polygon 1016 may be created around the requested point 1015 . The points that make up the polygon vertices may include the polygon vertices' locations as well as the elevation information at the polygon points. The point of interest 1015 (the queried elevation point) may then be extrapolated from the points surrounding it (the vertices of the polygon). [0145] FIG. 10A serves only to illustrate how a data point that is not already in the database may be extrapolated from surrounding data points. It should in no way serve as a limiting or exclusive situation. For example, the polygon formed by already existing, surrounding data points may be a hexagon or other polygon. [0146] In addition to querying data points, the Elevatier 430 algorithm may also add points 1023 to the existing databases. FIG. 10B shows the un-rasterized (raw) data matrix 1021 including the raw data points 1022 . FIG. 10B also shows a new data point 1023 may be added to the existing data set. In this way, the Glide System 100 may take data collected from Glide enabled devices 131 , 132 . . . 139 , 140 , 150 and increase the size and accuracy of the Glide databases with this gathered information. [0147] FIG. 7 shows a possible flow path for the Elevatier 430 algorithm. FIG. 7 should in no way serve as a limiting or exclusive flow path; its purpose is simply to illustrate how a database querying algorithm like the Elevatier 430 could work. [0148] In step 710 in FIG. 7 , an elevation point may be queried by the Request Manager 812 . This requested data point could correspond to the geographic location of one of the route points created in step 512 or 612 in FIG. 5 and FIG. 6 , respectively. [0149] In step 720 a, the Elevatier 430 algorithm may search the configuration file 910 for the region(s) 921 . . . 929 that include the queried point. [0150] To complete step 720 a, the Elevatier 430 algorithm will cycle through two nested loops. The first loop may cycle through the regions 921 . . . 929 , and the second loop may cycle through the sub-regions 931 , 932 . . . 939 , 940 . [0151] In step 720 b in FIG. 7 , the region counter may be set to 0. Step 730 a may enter the second nested loop of the Elevatier 430 algorithm. The initial condition of the second nested loop is to set the sub-region counter to 0 730 b. [0152] In step 740 in FIG. 7 , the polygon contacting the queried point in a particular region and sub-region is stored. The information stored during this step may include but is not limited to the elevation data and the accuracy associated with the elevation data. [0153] Steps 750 and 760 in FIG. 7 may serve as loop checks to allow the Elevatier 430 algorithm to decide when to exit one of the loops. The loop indexes may be positively index each loop iteration to cycle through all sub-regions 931 , 932 . . . 939 and all regions 921 . . . 929 . [0154] In step 770 in FIG. 7 , all of the elevation points stored from step 740 may be compared, and the one(s) with the highest accuracy are saved. [0155] In step 780 in FIG. 7 , the polygon 1016 surrounding the point of interest 1015 may be formed, and the single point of interest 1015 can be extrapolated from the polygon 1016 . IV. Glide Controller Variations [0156] A Glide Controller 144 may have different configurations within the Glide System 100 . Three possible variations will now be discussed. These three variations should in no way limit the variation possibilities of the Glide Controller 144 within or outside of the Glide System 100 . [0157] FIG. 8A depicts one possible variation of the Glide Controller 144 within the Glide System 100 . In FIG. 8A , the Glide Controller 144 may include multiple modules. These modules may include the Requesting Device 811 a, the Request Manager 812 and the Glide Solver 410 . In this configuration, the Glide Controller 144 is also the Requesting Device 811 a. [0158] In FIG. 8A , the Requesting Device 811 a is shown as a sub component of the Glide Controller 144 . In this way, the Glide Controller 144 may be receiving the requested route from the internal Requesting Device 811 a. An example of this situation may include the Glide Controller 144 optimizing for the next x-miles, without receiving an ending destination. [0159] In FIG. 8A , the Request Manager 812 and Glide Solver 410 are hosted locally on the Glide Controller 144 . This means that computation carried out by the Route Optimizer 420 and the Elevatier 430 may occur locally on the Glide Controller 144 . [0160] In FIG. 8A , the constraint databases 815 , 816 , 817 . . . 819 are shown as existing on the Glide Servers 110 . It would follow that in this configuration, the Glide Controller 144 would be operating in the “connected”, subscription-based mode, where a User 141 may pay a temporally regular fee for regular communication 160 with the Glide Servers 110 . [0161] FIG. 8B depicts another possible variation of the Glide Controller 144 within the Glide System 100 . In FIG. 8B , the Glide Controller may include all of the functional blocks that have been previously discussed. This would include the Requesting Device 811 a, the Request Manager 812 , the Glide Solver 410 and the constraint databases 815 , 816 , 817 . . . 819 . In this configuration, like the last, the Glide Controller 144 is also the Requesting Device 811 a. [0162] In FIG. 8B , the Requesting Device 811 a is shown as a sub component of the Glide Controller 144 . In this way, the Glide Controller 144 may be receiving the requested route from the internal Requesting Device 811 a. An example of this situation may include the Glide Controller 144 optimizing for the next x-miles, without receiving an ending destination. [0163] In FIG. 8B , the Request Manager 812 and Glide Solver 410 are hosted locally on the Glide Controller 144 . This means that computation carried out by the Route optimizer 420 and the Elevatier 430 may occur locally on the Glide Controller 144 . [0164] In FIG. 8B , the constraint databases 815 , 816 , 817 . . . 819 are shown as existing locally on the Glide Controller 144 . It would follow that in this configuration, the Glide Controller 144 would be operating in the stand-alone mode, where the Glide Controller 144 may only communicate 160 with the Glide Servers 170 to apply firmware updates and database 815 , 816 , 817 . . . 819 data updates. [0165] FIG. 8C depicts yet another possible variation of the Glide Controller 144 within the Glide System 100 . In FIG. 8C , the Glide Controller may include the function blocks previously discussed, the Request Manager 812 , and the Glide Solver 410 , but may not be the Requesting Device 811 b. [0166] In the FIG. 8C variation, the Requesting Device 811 a may be a module in the Glide Controller 144 (similar to FIG. 8A , FIG. 8B ), or the Requesting Device 811 b may be a User accessing the Glide System 100 via the Glide User Interface 143 , or the Requesting Device 811 b may be a device similar to that of the Glide User Interface 143 (discussed in earlier sections). A User's 141 cellular phone, tablet, or laptop may be used as the Requesting Device 811 b. The Requesting Device 811 b may not necessarily be installed in the Glide enabled device 131 , 132 . . . 139 , 140 , 150 , or it may not be integrated into the Glide Controller 144 . The Requesting Device 811 b may be connected via a wireless communications protocol and the Glide WAN 160 to the Glide Controller 144 or directly to the Request Manager 812 . [0167] FIG. 8A-8C should not serve as limiting or exclusive examples of variations to the Glide Controller. Other examples could include a variation where the Glide Servers 110 hold all of the functional blocks including the Request Manager 812 , the Glide Controller 410 , and the constraint databases 815 , 816 , 817 . . . 819 . In this variation, the computation carried about by the Glide Solver 410 would be carried out on the Glide Servers 110 , and the results would be sent back to the Glide Controller 144 , which may serve simply as a Glide WAN 120 terminal for the Glide User Interface 143 in a Glide enabled device 131 , 132 . . . 139 , 140 , 150 . [0168] It should be noted that the variations discussed above are not mutually exclusive. For one route optimization, the variation shown in FIG. 8A may hold, where the Glide Controller 144 is also the Requesting Device 811 a (e.g., the User 141 enables the Glide Controller 144 to optimize for the next x-miles along the current route). That same Glide Controller 144 for its next route optimization task may assume the variation shown in FIG. 8C where the Requesting Device 811 b is the User's 141 cellular device that is requesting a route optimization from the Glide Controller 144 and the Glide System 100 . V. Operational Modes and Communications [0169] The different modes of operation for the Glide System 100 will now be expanded on. The Glide System 100 may have multiple different modes that a Glide Controller 144 may operate in, and any Glide Controller 144 may operate in multiple different modes at once. These are different from the Glide Controller 144 variations discussed in the previous section. [0170] In the connected, subscription-based mode, a Glide Controller 144 may communicate via the Glide WAN 120 with the Glide Servers 110 to obtain the information necessary for the Glide Solver 410 to optimize the request route for the desired parameters. In this mode, the Glide Solver 410 may use available data; vehicle models; traffic models and vehicle State of Charge models (for hybrid or electric vehicles) to calculate acceleration points; speed targets, optimal lanes when to apply a certain power train (internal combustion versus electric versus both); when to apply regenerative deceleration; and which gears to use for maximum efficiency. This is an example of parameters and solutions the Glide Solver 410 may use and carry out; it should by no means serve as an exclusive list for what the Glide Solver 410 and Glide System 100 may do. [0171] In the stand-alone application, the Glide Controller 144 in the Glide enabled device 131 , 132 . . . 139 , 140 , 150 may not communicate 160 with the Glide Servers 110 , but may rather solve the route optimization using data included locally on the Glide Controller 144 . In this way, the Glide Controller 144 would not receiver data from the Glide Servers 110 that is pertinent to solving the route optimization. This stand-alone configuration may allow for a Glide Controller 144 to download firmware updates from the Glide Servers 170 . These firmware updates may include firmware that runs on a Glide Controller 144 as well as updates to the data stored locally on the Glide Controller 144 that the controller uses to solve the route optimization. This model may be compared to a GPS unit where the unit periodically downloads updates, but it relies on internal data for functionality. [0172] Both the subscription-based mode and the stand-alone mode may be able to carry out the same functionality in terms of route optimization. [0173] Both the subscription-based mode and stand-alone modes may be used with final destinations or simply with the Glide Controller 410 enabled to optimize the next x-miles on the current route. [0174] With infrastructure to vehicle communication 160 , a Glide Controller 144 may be operating on the traffic infrastructure 150 side of the Glide System 100 as well as in a Glide enabled vehicle 131 , 132 . . . 139 , 140 . The infrastructure may solve for parameters including but not limited to vehicle speeds; optimal lanes for traffic flow and throughput; speed smoothing and vehicle spacing; occupancy or vehicle type by lanes; traffic light sequencing based on flow patterns; and traffic behavior alteration for crashes and emergency vehicles. A Glide Controller 144 operating on the traffic infrastructure 150 may send instructions to alter driving behavior to Glide Controllers 144 operating in Glide enabled vehicles 131 , 132 . . . 139 , 140 . [0175] With this communication 160 from the transportation infrastructure to the vehicle, the Glide System 100 may be able to instruct vehicles to switch lanes or slow down to increase or meet a desired throughput of a particular area along a route. Additionally, the traffic infrastructure may be able to send instructions that will allow lane clearing for an accident ahead of a Glide enabled vehicle's 131 , 132 . . . 139 , 140 current location or for an emergency/special vehicle approaching a Glide enable vehicle's 131 , 132 . . . 139 , 140 location. [0176] The infrastructure to vehicle communication 160 may also allow the traffic infrastructure to speed smooth traffic in real-time or space vehicles for optimal travel efficiency. [0177] In vehicle to vehicle communication (Symbiotic Vehicular Synchronizer), one Glide Controller 144 may send notifications about upcoming events to other Glide enabled vehicles 131 , 132 . . . 139 , 140 behind and around it. These notifications may be used by the receiving Glide Controllers 144 to adjust the optimized route in real time. [0178] Vehicle to vehicle communication allows the optimized route to be a fluid solution that adjusts for real time data. This differs from current solutions that may require all information to be routed through system servers before clients may use the information. In allowing for real-time vehicle to vehicle communication, the Glide System may be proactive about route decisions based on information close in time and proximity to a Glide enabled vehicle 131 , 132 . . . 139 , 140 . [0179] Vehicle to vehicle communication may also occur via the Glide Servers. In this communication embodiment, a Glide enabled vehicle 131 , 132 . . . 139 , 140 may communication information to the Glide Servers 110 , 170 , which may then communicate necessary information to other Glide enabled vehicles 131 , 132 . . . 139 , 140 . The communication 160 to and from the Glide Servers 110 , 170 and the Glide enabled vehicles 131 , 132 . . . 139 , 140 may occur via the Glide WAN 120 . In this way, the Glide System 100 may build fluid constraint databases that respond to changing environments. [0180] Information shared by the Symbiotic Vehicular Synchronizer may include but is not limited to, traction failure of preceding vehicles (slippery section of a lane); traffic for the next y-miles along the current route or routes close in proximity to the current location of the vehicle; vertical motion and disturbances (bumps and potholes); breakdowns and accidents, for route and lane avoidance; Glide enabled vehicle locations for convoy opportunities and enhanced diving. [0181] It should be noted that all modes of operation for the Glide System may use the vehicular sensor suite that may be integrated into the vehicle. VI. Modifications and Enhancements [0182] As with any system involved with a complex task, there are always additions that can be made. The following serves as a short list of selected features that the Glide System 100 may employ to increase the completeness of the system. [0183] The Glide System 100 and Glide Controller 144 may include the ability to provide supplemental information regarding the requested or optimized route. This may include functionality to plan out rest stops where the route plan may include when and where to refuel/recharge; which power plant to refuel/recharge (in a hybrid topology); and rest stops and food options. The Glide System 100 and Glide Controller 144 may provide supplemental information including but not limited to, rest-stop information, food services information, refueling and/or recharging information, and lodging information. [0184] The ability of the Glide System 100 to provide recommendations on where to refuel and which power plant to replenish (in a hybrid topology) may be a necessary add-on for hypermiling. The variation in gasoline prices coupled with the sporadic placement of charging stations means there is a large amount of variation in the refueling/recharging plan for a route, especially a lengthy route. [0185] The Glide System 100 may be able to compare gasoline prices for the next z-miles along the route with the availability of charge stations and their costs. This refueling station analysis may then be compared to the length of the route and the current state of the power plant sources (gasoline level and battery charge level). The Glide Controller 144 may then make a decision on the most optimal place to refuel at, given the route preferences. This analysis may change the way the Glide Solver 410 calculates the acceleration schedule for the vehicle [0186] An example of route manipulation due to refueling options could be the following. If the Glide System 100 determines the next gasoline station prices to be expensive relative to another much closer to the final destination, the Glide Controller 144 may choose to have the Glide Solver 410 re-optimize the route, but this time the Glide Solver 410 may be instructed to weight the power plant usage towards a heavier usage of the electric powertrain. In this way, the Glide Controller 144 will save fuel in anticipation of bypassing the more expensive refueling station in favor of the refueling station close to the final destination. [0187] The Glide System 100 may include the ability to optimize for holistic cost versus time balancing which may include HOV/Toll lanes and casual carpool pickups and drop-offs. This could also include a time flexibility parameter for situations like urgent meetings, concerts or other time sensitive activities. [0188] The Glide System 100 may include the ability to estimate and adjust for trailering and other vehicle alterations that may be outside of the standard vehicle models. The Glide System 100 may also include the ability to adjust for weather considerations: snow, rain wind, etc. This may include the consideration of snow-chains or whether or not the vehicle is all-wheel-drive equipped and if a route requires that or not. VII. Glide User Interface [0189] The above discussions have included references to a Glide User Interface 143 . This interface may be embodied in any number of different ways. In a general sense, the Glide User Interface 143 may refer to a module capable of providing the User 141 a way to import route information into the Glide Controller 144 . More specifically, the Glide User Interface 143 may be a visual feedback device with tactile or virtual buttons capable of reading data in and outputting data. [0190] The screen depictions discussed here should not serve as limiting or exclusive matter, but rather they should serve as examples to aid in the explanation of how the Glide User Interface 143 may function and show data. [0191] FIG. 11 depicts a possible screen that a User 141 could be shown while interfacing with the Glide User Interface 143 . 1100 may be generally referred to as the home screen. This is the screen that the User 141 may be returned to, upon requesting so, during operation of the Glide User Interface 143 . [0192] FIG. 11 depicts a possible home screen 1100 with multiple choices for the User 141 . If the User 141 does not want to input a final destination, the User 141 may select choice 1110 , which may request that the Glide System 100 operate without an end destination and rather optimize for the next x-miles. The User 141 may selection choice 1120 which may send the User 141 to a screen FIG. 12 that may prompt the User 141 for more information about the new route 1200 . [0193] FIG. 11 may also have a My Routes selection 1130 that when selected may show the User 141 the previous routes the User 141 has selected as well as routes or destinations the User 141 has saved in an Address Book. The Address Book may hold destinations as well as save routes. An example of this could include the Address Book holding the simple address of the User's 141 office building and holding the saved route to the office building with the route preferences that the User 141 usually selects for the route to the office building. [0194] FIG. 11 may also present the User 141 with a Connect Device selection 1150 , which when selected, may allow the User 141 to connect an eligible device to the Glide Controller 144 . The User 141 may be presented with a System Settings 1150 selection, where the settings for the Glide User Interface 143 and the Glide Controller 144 may be altered. The User 141 may also be presented with a My Glide selection 1160 , which may allow the User 141 to view and their Glide Profile. [0195] FIG. 11 may also present the User 141 with a Map selection 1170 which, when selected, may take the User 141 to a map view that may show the location and current statics of the vehicle. This may not necessarily enabled the Glide System 100 . [0196] FIG. 12 was referenced above when discussing new route information. FIG. 12 depicts a possible screen that may generally be referred to as the New Route Selection screen 1200 . The New Route Selection 1200 may include multiple ways and selections for the User 141 to fill in with regards to the new route. The New Route Selection 1200 may prompt the User 141 with a field 1210 to input the street address of the destination. When 1210 is selected, an on screen keyboard may present itself to aid the User 141 in inputting data. Additionally, the street address 1210 may be taken in using voice commands or the native driver interface that is installed in the vehicle. [0197] The New Route Selection 1200 may present the User 141 with options to access previously stored addresses, trips, and points of interest (POIs) 1220 , 1260 , 1270 . [0198] Selection 1220 in FIG. 12 may allow the User 141 to access previously stored address. After selecting an address from the Address Book, the User 141 may be returned to the New Route Selection screen 1200 to input the preferred optimization for the New Route. [0199] Selection 1260 in FIG. 12 may allow the User 141 to access previously completed or stored trips. After selecting a previously stored trip, the User 141 may be returned to the New Route Selection screen 1200 to input the preferred optimization for the new route. It may also be possible that the previously stored trip selection may include the optimization and route preferences from that trip. These preferences may already be selected or highlighted when the User 141 is returned to the New Route Selection screen 1220 . [0200] Selection 1270 in FIG. 12 may allow the User 141 to access a database of points of interest. After selecting a point of interest, the User 141 may be returned to the New Route Selection screen 1200 to input the preferred optimization for the New Route. [0201] FIG. 12 may also present the User 141 with route optimization selections 1230 a, 1230 b, 1230 c, 1230 d. These choices may include but are not limited to energy 1230 a, time 1230 b, cost 1230 c, and traffic 1230 d. The User 141 may be able to choose any number of optimization strategies for the new route. It may be that the first strategy selected will be the highest priority, and the last strategy selected will be the lowest priority. [0202] FIG. 12 may also present the User 141 with a Route selection 1240 , which when selected may send the selected information from the above discussion to the Glide System as a Requested Route. [0203] FIG. 12 the New Route Selection screen 1200 may also have selections for the Map screen 1170 and the home screen 1250 . The Map selection 1170 which, when selected, may take the User 141 to a map view that may show the location and current statics of the vehicle. This may not necessarily enabled the Glide System 100 . The home selection 1250 , when selected, may return the User 141 to the home screen 1100 . [0204] FIG. 13 shows a possible depiction of the guidance screen for the Glide User Interface 143 . 1300 may be generally referred to as the Guidance Screen. The Guidance Screen 1300 may include information about the vehicle and the current route. [0205] The Guidance Screen 1300 may display the current 1310 and target 1320 speeds for the vehicle. The target speed 1320 may represent the spatially next data point calculated by the Glide Solver 410 along the route. [0206] The Guidance Screen 1300 may display the systems calculated estimated time of arrival to the destination (if applicable). If the Glide System 100 is operating without a final destination, this piece of information may not be displayed. [0207] The Guidance Screen 1300 may display current efficiency of the trip, normalized against similar trips or a best estimated trip that doesn't use the Glide System 100 . The Guidance Screen 1300 may also have a Stats selection 1350 that may take the User 141 to another screen that displays more in depth stats for the trip. [0208] The Guidance Screen 1300 may also display information to alter the driver to the next driving operation that should be carried out as part of the trip plan. The map area 1360 of the Guidance Screen 1300 may display any number of different types of maps (multiple at one time or a single map at a time). [0209] In addition to a map 1360 , the Guidance Screen 1300 may display a Next Step section 1370 for the route. As shown in FIG. 13 this may include written instructions for the next step as well as a visual representation. Additionally, the Glide System may give an auditory message of the next step. [0210] The information the Guidance Screen 1300 displays should not be limited to the above discussion. Other information including battery state of charge, distance to next refueling station, and surrounding vehicles using the Glide System may also be displayed on the Guidance Screen 1300 . VIII. Glide Application and Web Service [0211] The Glide User Interface 143 installed in a Glide enabled device 131 , 132 . . . 139 , 140 , 150 may not be the only device capable of displaying Glide System information. As discussed above, there may be many devices capable of acting as a Glide User Interface 143 that is not necessary installed in a Glide enabled device 131 , 132 . . . 139 , 140 , 150 . [0212] Interaction between the User 141 and a Glide User Interface 143 may occur via a Glide Application or a Glide Web Service. The Glide Application or Web Service may run generally, on a computing device, and specifically, on a device with tactile or virtual buttons capable of receiving input and a method for reading information out to an operator. Devices may include but are not limited to, cellular telephones, tablet computers, laptop computers, desktop computers, and other variations of these devices. [0213] The Glide Application or Web Service may have the same functionality as the Glide User Interface described in the previous section. The Glide Application or Web Service may have a home screen 1100 similar to the one shown in FIG. 11 . It may be possible for the Glide Application or Web Service to take in route information from an operator using a screen similar to the New Route Selection screen 1200 shown in FIG. 12 . The Glide Application or Web Service may then store or send this information to a Glide Controller 144 . Additionally, the Glide Application or Web Service may be able to display real-time information pertaining to an in progress route using a screen similar to the Guidance Screen 1300 shown in FIG. 13 . [0214] The Glide Application or Web Service may connect to the Glide Servers 110 , 170 and directly to a Glide Controller 144 . The device running the Glide Application or Web Service may communicate with the Glide Servers 110 , 170 using any number of communication methods including but not limited to, 3G, 4G, or 5G cellular communication; or WiFi. The device running the Glide Application or Web Service may communicate with the Glide Controller 144 using any number of communication methods including but not limited to, 3G, 4G, or 5G cellular communication; WiFi, DSRC, Bluetooth, or ZigBee. IX. Glide Profile [0215] The Glide System 100 may allow Users 141 to create profiles that may be saved on the Glide Servers 110 , 170 . These profiles may include saved information pertaining to a particular User 141 or driver, or the profiles may include saved information pertaining to a particular vehicle. All types of Glide Profiles may save information pertaining to previous trips, saved addresses, saved settings/preferences, and accumulated statistics. Glide Profiles for either a User 141 or a Glide enabled device 131 , 132 . . . 139 , 140 should not be limited in scope by the current discussion. [0216] A User 141 may be able to access a particular Glide Profile from any number of Glide Controllers 144 . This may allow a User 141 to access a particular Glide Profile from a Glide Controller 144 or Glide User Interface 143 that may not necessarily be installed in a Glide enabled device 131 , 132 . . . 139 , 140 owned by the User 141 . [0217] Two examples of accessing a Glide Profile that may not be owned by the primary account holder may include using the Glide System 100 in a Glide enabled rental car, or using the Glide System 100 in a friend's Glide enabled vehicle. Continuing with the rental car example; a User 141 may be able to access saved routes, saved addresses, saved preferences, and saved statistics via their Glide Profile so that they may use the full extent of the Glide System 100 , while driving a Glide enabled rental vehicle. [0218] It may be possible for a User 141 to temporarily transfer paid Glide services to another Glide Controller 144 . An example of this may include, the rental car company pays only for the stand-alone Glide service, but the current User 141 (renter of the car) pays for the subscription based model with constant access to the Glide Servers 110 . In this example, the Glide Controller 144 in the rental car may be able to access the Glide Servers 110 , while the User's 141 Glide Profile is active on the Glide Controller 144 in the rental vehicle. [0219] It may be possible to access a Glide Profile from devices other than a Glide User Interface 143 . As discussed in the previous section, a Glide Application running on a computing device, may have the capabilities to access the Glide Servers 110 , 170 , to add and retrieve Glide Profile information. In this way, it may be possible for a User 141 to access a Glide Profile from a cellular device to input a destination or route parameters, save the destination or route parameters, and then access this data from a Glide User Interface 143 in a Glide enabled device 131 , 132 . . . 139 , 140 . [0220] In sum, the present invention provides a system and methods for optimizing a vehicle's route and Glide schedule using information related but not limited to traffic, time, cost, weather, vehicular sensor data, and refueling/recharging. The advantages of such a system include the ability to optimize and adjust a travel route based on a limitless number of parameters and inputs that would otherwise not be possible especially if these parameters and inputs were beyond the line of sight of the vehicle's operator. [0221] While this invention has been described in terms of several embodiments, there are alterations, modifications, permutations, and substitute equivalents, which fall within the scope of this invention. Although sub-section titles have been provided to aid in the description of the invention, these titles are merely illustrative and are not intended to limit the scope of the present invention. [0222] It should also be noted that there are many alternative ways of implementing the methods and apparatuses of the present invention. It is therefore intended that the following appended claims be interpreted as including all such alterations, modifications, permutations, and substitute equivalents as fall within the true spirit and scope of the present invention.

A glide controller includes a glide solver and a glide control interface. The glide solver generates at least one vehicular glide schedule including a plurality of discretized targets. The solver generates a plurality of vehicular glide control outputs corresponding to the plurality of discretized targets. The glide control interface outputs the plurality of vehicular glide control outputs, intended to result in a performance adjustment of a vehicle.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toe angle detecting apparatus capable of detecting the individual toe angles of each wheel attached to a vehicle. 2. Description of the Related Art The accurate alignment of vehicle wheels is extremely important for the maintenance of running stability of a vehicle. Therefore, there have been proposed various devices used to measure or check respective states of alignment of the wheels. As an apparatus for measuring toe angles of wheels, for example, there is known one in which a sensor is brought into contact with side portions of a tire of each wheel so as to detect angular displacements of the wheel with respect to the direction in which each wheel runs forward. However, vehicles as objects to be measured vary in size. Therefore, there are proposed wheel supporting means for supporting the wheels, which can be displaced in the directions of the length and width of a vehicle in order to meet the respective sizes. However, there is a tendency for positional displacements of the sensor with respect to the wheel supporting means if the apparatus is constructed in this way. As a result, the sensor cannot be reliably brought into contact with each wheel supported by the wheel supporting means, thereby making it unable to detect the toe angle with high accuracy. On the other hand, any tire varies in shape even when the sensor can be accurately brought into contact with the side portions of the wheel tire. Therefore, the value of the toe angle detected cannot be determined. Even when the tire is temporarily positionally adjusted using the value of the toe angle detected by the sensor, subsequent tire reproducibility is also poor. While the vehicle is running after completion of its adjustment, directional stability characteristics of the vehicle become poor or the angle of a spoke of a steering wheel becomes inappropriate. SUMMARY OF THE INVENTION It is a general object of the present invention to provide a toe angle detecting apparatus capable of detecting a toe angle with high accuracy to thereby adjust a toe angle which gives a vehicle the optimum setting for excellent running characteristics. It is a principal object of the present invention to provide a toe angle detecting apparatus capable of detecting a toe angle with high accuracy even when a tire varies in shape. It is another object of the present invention to provide a toe angle detecting apparatus of a type wherein after a toe angle is adjusted, subsequent tire reproducibility is excellent, and hence the directional stability characteristics of a vehicle under actual driving conditions can automatically be ensured after the adjustment of the toe angle is completed; the spoke angle of the steering wheel is also correct. It is a further object of the present invention to provide a toe angle detecting apparatus comprising: wheel supporting means for supporting thereon each wheel of a vehicle, toe angle detecting means having a pair of detectors brought into contact with predetermined portions of one of the wheels, which portions are spaced a predetermined distance from each other, the toe angle detecting means being rotatably supported on a support shaft, and an angle detector for detecting an angle at which the toe angle detecting means is rotated about the support shaft. It is a still further object of the present invention to provide the toe angle detecting apparatus wherein the wheel supporting means is supported by a first table movable in the direction of the length of the wheel and a second table movable in the direction of the width of the wheel. It is a still further object of the present invention to provide the toe angle detecting apparatus wherein the wheel supporting means has a pair of support rollers for supporting the wheel, and the support rollers are disposed in such a manner that they are displaceably rotated about the support shaft. It is a still further object of the present invention to provide the toe angle detecting apparatus wherein the wheel supporting means includes two pairs of wheel holding mechanisms which are brought into contact with both sides of the wheel so as to hold the wheel. It is a still further object of the present invention to provide the toe angle detecting apparatus wherein the wheel holding mechanisms are coupled to each other by a pantagraph mechanism, and approach each other and move away from each other about the support shaft as a symmetric shaft. It is a still further object of the present invention to provide the toe angle detecting apparatus wherein the wheel holding mechanisms each include a pair of holding rollers brought into contact with the predetermined portions of the wheel which are spaced a predetermined distance from each other, the wheel holding mechanisms being rotatably supported on the support shaft. It is a still further object of the present invention to provide the toe angle detecting apparatus wherein the wheel holding mechanisms include at least one brake mechanism for preventing the mechanisms from being rotated about the support shaft. It is a still further object of the present invention to provide the toe angle detecting apparatus wherein the wheel holding mechanisms each include position adjusting mechanisms for adjusting the vertical position of the pair of holding rollers with respect to the direction of the height of the wheel. It is a still further object of the present invention to provide the toe angle detecting apparatus wherein the toe angle detecting means includes displacing means for causing the pair of detectors to move toward and away from the predetermined portions of the wheel. It is a still further object of the present invention to provide the toe angle detecting apparatus wherein the toe angle detecting means has the pair of detectors which are brought into contact with a rim flange of the wheel. It is a still further object of the present invention to provide the toe angle detecting apparatus wherein the toe angle detecting means has a position adjusting mechanism for adjusting the vertical position of the pair of detectors with respect to the direction of the height of the wheel. It is a still further object of the present invention to provide the toe angle detecting apparatus wherein the angle detector comprises a rotary encoder supported on the support shaft. The above and other objects, features and advantages of the present invention will become apparent from the following description and the appended claims, taken in conjunction with the accompanying drawings in which a preferred embodiment of the present invention is shown by way of illustrative example. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view partly in section showing a toe angle detecting apparatus according to one embodiment of the present invention; FIG. 2 is side view depicting the toe angle detecting apparatus shown in FIG. 1; FIG. 3 is a perspective view showing the four toe angle detecting apparatuses according to the present invention, in relation to a vehicle positioned on them; FIG. 4 is a plan view illustrating each of the toe angle detecting apparatuses shown in FIG. 3; FIG. 5 is a perspective view showing a detector employed in each of the toe angle detecting apparatuses according to the present invention; and FIG. 6 is a side view partly in section showing the detector depicted in FIG. 5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 and 2 are respectively a front view partly in section and a side view showing a toe angle detecting apparatus according to one embodiment of the present invention. As shown in FIGS. 3 and 4, toe angle detecting apparatuses 10A through 10D are disposed in positions where they correspond to four vehicle wheels 14A through 14D mounted on a vehicle 12, respectively. The toe angle detecting apparatuses 10A through 10D are respectively movable in the directions indicated by the arrows a and b according to respective positions where the vehicle 12 is mounted thereon or to the width or length of the vehicle 12 (see Japanese Laid-Open Patent Publication No. 64-72001). A detailed description will now be made of the structure of the toe angle detecting apparatus 10A with reference to FIGS. 1 and 2. Incidentally, other toe angle detecting apparatuses 10B through 10D are structurally identical to the toe angle detecting apparatus 10A and their description will therefore be omitted. The toe angle detecting apparatus 10A is supported on a frame body 16 which can be moved in relation to the vehicle width (i.e., in the direction indicated by the arrow a) through unillustrated guide rails. A first table 20, which is movable in relation to the length of the vehicle 12 (i.e., in the direction indicated by the arrow b), is disposed on the frame body 16 through a pair of guide rails 18a, 18b. Incidentally, the frame body 16 and the first table 20 are positionally adjusted corresponding to the width and length of the vehicle 12 as an object to be measured. A second table 24, which is movable in relation to the width of the vehicle 12 (i.e., in the direction indicated by the arrow a), is disposed on the first table 20 through guide rails 22a, 22b. Incidentally, the second table 24 is used to correct positional displacements of the vehicle 12 produced at the time that the vehicle 12 is moved to reach the toe angle detecting apparatus 10A. A support shaft 26 is supported through bearings 28 by the second table 24 so that it can be rotated in the direction indicated by the arrow c. A rotary encoder 30 (angle detector) for detecting the turning angle of the support shaft 26 is coupled to a lower end of the support shaft 26 through a bracket 32. A third table 36, which is rotatable in the direction indicated by the arrow c, is disposed on the second table 24 through bearings 34. A brake cylinder 40 is mounted on the second table 24 through a bracket 38. A brake plate 44 attached to a cylinder rod 42 of the cylinder 40 is pressed against the third table 36, thereby preventing the rotation of the third table 36 with respect to the second table 24. A pair of opposed wheel clamping means 48a, 48b are disposed on the third table 36 through guide rails 46a, 46b. The wheel clamping means 48a, 48b are coupled to each other by means of a pantagraph mechanism 50. A driving cylinder 51 is actuated to cause the wheel clamping means 48a, 48b to normally move toward and away from the wheel while always being symmetrical about the support shaft 26. The wheel clamping means 48a comprises a support member 52a shaped substantially in the form of an L, a bracket 56a movable in the direction indicated by the arrow d along a guide rail 54a, which is mounted on a side wall of the support member 52a extending in the vertical direction thereof, two clamping rollers 58a, 60a mounted on the bracket 56a, and an up-and-down movable cylinder 62a for moving the bracket 56a in upward and downward directions. As shown in FIG. 2, the clamping rollers 58a and 60a are disposed in such a manner that they are brought into contact with a side wall of a tire 64 of the wheel 14A. Incidentally, since the wheel clamping means 48b is structurally identical to the wheel clamping means 48a, the components associated with the wheel clamping means 48b are denoted by like reference numerals with a suffix b, and its description will be omitted. A wheel support table 68 is displaced on the third table 36 through guide rails 66a, 66b in such a manner that it can be displaced in the direction indicated by the arrow. The guide rails 66a, 66b are supported on the first table 20 by support arms 67a, 67b. A support shaft 72 is supported by the wheel support table 68 through bearings 70 in such a way that it is rotatable in the direction indicated by the arrow c. Wheel support rollers 76a, 76b are supported on the support shaft 72 through a bracket 74. On the other hand, a fourth table 78 is movably placed on an upper end of the support shaft 26, and a toe angle detecting means 82 is disposed on the fourth table 78 through guide rails 80a, 80b. The toe angle detecting means 82 comprises a support member 84 shaped substantially in the form of an L, a driving cylinder 85 (displacing means) for displacing the support member 84 in the direction indicated by the arrow along the guide rails 80a, 80b, a bracket 88 movable in the direction indicated by the arrow d by an up-down movable cylinder 87 along a guide rail 86 which is mounted on a side wall of the support member 84 extending in the vertical direction thereof, and two pairs of contact shoes 90a and 90b mounted on the bracket 88. The contact shoe 90a is constructed as shown in FIGS. 5 and 6. More specifically, the contact 90a has a fifth table 94 mounted through guide rails 92a, 92b on the bracket 88 so that it can be displaced in the direction indicated by the arrow d. Mounted on the fifth table 94 through a bracket 96 are a first roller 102 brought into contact with an upper surface 100a of a rim 98 in the wheel 14A and a second roller 104 brought into contact with a rim flange 100b of the rim 98. In addition, the fifth table 94 has a cylinder 106 mounted thereon. A third roller 112 is mounted through a bracket 110 on a cylinder rod 108 of the cylinder 106. The third roller 112 can be displaced in the direction indicated by the arrow d by means of the cylinder 106. The first to third rollers 102, 104 and 112 have support shafts crossed at right angles to one another respectively. The first roller 102 is disposed so as to provide movement from the rim flange 100b to the upper surface 100a of the rim 98, whereas the second roller 104 is disposed so as to roll along the rim flange 100b. In addition, the third roller 112 is disposed so as to roll along the upper surface 100a of the rim 98. The fifth table 94 has an antenna 114 for detecting a balance weight with a convex portion formed in the rim flange 100b. A sensor such as a pressure sensor is connected to the antenna 114. When the sensor detects that the antenna 114 is brought into contact with the balance weight, the position of the balance weight can be confirmed by the sensor. The toe angle detecting apparatuses 10A through 10D according to the present embodiment are constructed as described above. Operations of the toe angle detecting apparatuses 10A through 10D will now be described. First of all, the toe angle detecting apparatuses 10A through 10D are respectively displaced in the directions indicated by the arrows a and b corresponding to the width and length of the vehicle 12 as the object to be measured. More specifically, the frame body 16 is displaced a predetermined amount in the direction indicated by the arrow a in order to adjust each width of the respective toe angle detecting apparatuses 10A through 10 with respect to the width of the vehicle 12. Then, the first table 20 is displaced a predetermined amount in the direction indicated by the arrow b in order to adjust the length of each of the toe angle detecting apparatuses 10A through 10D with respect to the length of the vehicle 12. The wheel clamping means 48a, 48b and the toe angle detecting means 82 are mounted on the first table 20, and displaced integrally with the wheel support rollers 76a, 76b in the direction of the length of the vehicle 12. Thus, the positional relation between the wheel clamping means 48a, 48b and the toe angle detecting means 82 are held constant at all times in spite of any positional displacement of the first table 20 in the direction of the length of the vehicle 12 (see FIG. 2). Then, the vehicle 12 is caused to approach each of the toe angle detecting apparatuses 10A through 10D, and the wheels 14A through 14D are respectively placed on the wheel support rollers 76a, 76b of each of the toe angle detecting apparatuses 10A through 10D (see FIGS. 1 through 3). In this case, the toe angle detecting apparatuses 10A through 10D are respectively displaced through the second table 24 in the direction indicated by the arrow a in correspondence to displacements in positions where the vehicle 12 approaches the toe angle detecting apparatuses 10A through 10D. In addition, the wheel support rollers 76a, 76b turn completely about in direction by the support shaft 72 in response to the direction of rotation of each of the wheels 14A through 14D, thereby completing the positioning of each of the wheels 14A through 14D. Then, the driving cylinder 51 is actuated to cause the wheel clamping means 48a, 48b to approach relative to each other along the guide rails 46a, 46b, respectively. The clamping rollers 58a, 60a, and 58b, 60b are brought into contact with the side wall of the tire 64 as shown in FIGS. 2 and 3. Incidentally, the clamping rollers 58a, 60a and 58b, 60b are pre-adjusted for their vertical positions by means of the up-and-down movable cylinders 62a and 62b, respectively. The wheel clamping means 48a, 48b are rotated about the support shaft 26 through the bearings 34 in such a way that the clamping rollers 58a, 60a and 58b, 60b are scanned along the side wall of the tire 64. Then, the cylinder 40 is actuated to press the brake plate 44 against the third table 36 so as to couple the second table 24 to the third table 36, thereby fixing the wheel clamping means 48a and 48b. Then, the vertical position of each of the contact shoes 90a, 90b adjusted by means of the up-and-down movable cylinder 87. Thereafter, the driving cylinder 85 is actuated to displace the toe angle detecting means 82 toward the wheel 14A along the guide rails 80a, 80b. In this case, the cylinder 106 is actuated to displace the third roller 112 downwardly. Then, the third roller 112 is brought into contact with the upper surface 100a of the rim 98. The antenna 114 of each of the contact shoes 90a, 90b is brought into contact with the rim 98 of the wheel 14A. The wheel 14A is rotated until the antenna 114 detects the balance weight attached to the rim 98. When the antenna 14 detects the balance weight, the wheel 14A is further rotated through a predetermined amount. Thus, when the first roller 102 and the second roller 104 are brought into contact with the rim 98, the second roller 104 can be prevented from interfering with the balance weight. Then, the cylinder 106 is re-actuated to move the third roller 112 away from the upper surface 100a of the rim 98, and to bring the first roller 102 and the second roller 104 into contact with the upper surface 100a of the rim 98 and the rim flange 100b respectively (see FIG. 6). Since the fifth table 94 can be displaced by means of a spring 95 in the direction indicated by the arrow d along the bracket 88, each of the first roller 102 and the second roller 104 is accurately positioned in a predetermined position of the rim 98. When the contact shoes 90a, 90b of the toe angle detecting means 82 are first brought into contact with the rim 98, the toe angle detecting means 82 is rotated about the support shaft 26 in such a manner that the respective contact shoes 90a, 90b are scanned along the rim 98. The rotary encoder 30 is coupled to the support shaft 26 and detects the turning angle of the toe angle detecting means 82, i.e., a toe angle as an angle at which the wheel 14A is turned, i.e., deflected from the direction in which the wheel 14A travels forward. When the toe angle detecting apparatus 10A is displaced in the direction of the length of the vehicle 12 (i.e., in the direction indicated by the arrow b) to suit the length of the vehicle 12, as described above, the toe angle detecting means 82 is displaced integrally with the wheel support rollers 76a, 76b as the first table 20 is displaced. Thus, the toe angle detecting means 82 is accurately brought into contact with a predetermined portion of the rim flange 100b in the wheel 14A at all times. As a result, the toe angle detecting means 82 can give accurately information about the toe angle as the deflection angle of the wheel 14A to the rotary encoder 30. The toe angle is detected on the basis of the rim 98 having predetermined accuracy without using, as a reference, the tire 64 which varies in shape. As a consequence, the toe angle can be detected with extremely high accuracy. According to the present invention, as has been described above, when it is desired to adjust the position of the toe angle detecting apparatus with respect to the direction of the length of the vehicle, the toe angle detecting means is also displaced together with the wheel supporting means for supporting each of the wheels through each table in the direction of the length of the vehicle. Therefore, the toe angle detecting means can be held in position at all times with respect to each of the wheels. Thus, the toe angle detecting means is brought into contact with the desired portion of each of the wheels regardless of the positional displacements of the wheel supporting means. The detectors of the toe angle detecting means are brought into contact with the two portions of the rim flange of each wheel, which portions are spaced a predetermined distance from each other. In addition, the angle detector detects the turning angle of the toe angle detecting means by scanning each of the wheels with the detectors. In this case, the dimensions of the rim flange are kept constant regardless of the size of each wheel. Thus, the toe angle can be detected with extremely high accuracy. Having now fully described the invention, it will be apparent to those skilled in the art that many changes and modifications can be made without departing from the spirit or scope of the invention as set forth herein.

A toe angle detecting apparatus includes a wheel supporting device for supporting thereon each wheel attached to a vehicle. The wheel supporting device is rotatably mounted on a vertical support shaft. A toe angle detecting device is rotatably mounted on the support shaft and provided with a pair of contact shoes spaced horizontally at a predetermined distance from each other. The toe angle detecting device is rotatable independently of the wheel supporting device. The contact shoes are displaceable vertically and displaceable radially with respect to the support shaft, and are brought into contact with the wheel at predetermined portions thereof to rotate the toe angle detecting device about the support shaft toward a toe direction of the wheel. An angle detector is provided for detecting an angle at which the toe angle detecting device is rotated about the support shaft.

This application is the National Phase of International Application PCT/JP00/05199 filed 3 Aug. 2000 which designated the U.S. and that International Application was published under PCT Article 21(2) in English. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a music reproducing apparatus and a music reproducing method suitable for use in a car telephone or portable telephone. 2. Related Art In portable telephone systems such as PDC (Personal Digital Cellular Telecommunication System) known as analog or digital cellular systems, or PHS (Personal Handy-Phone Systems), a telephone terminal device rings to alert a user at the time of arrival of a call. Conventionally, the alert was made by beeping sound, but it has recently replaced by a melody because the beeping sound is a kind of noise offensive to the ear. The above-mentioned type of conventional telephone terminal device can generate a melody, but the melody is far from satisfactory quality. To solve this problem, the use of a music piece reproducing apparatus with an automatic performance function has been considered effective. Such a conventional music piece reproducing apparatus capable of automatic performance includes a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM) and a tone generator. It reproduces a piece of music as follows: The CPU executes an automatic performance program stored in the ROM to read music data from the ROM or RAM while setting tone generation parameters on the tone generator. Such a telephone terminal device is required to be compact, low priced and multi-functional. The built-in CPU must execute various kinds of operations such as to process incoming and outgoing calls and make a display. In other words, if the music piece reproducing apparatus is used in a portable type of the telephone terminal device, the CPU must carry out reproduction of a music piece in addition to other telephony functions, and this requires a high-speed CPU. The higher the processing speed of the CPU, the more the telephone terminal device costs. The use of a melody IC with a melody reproducing function is also known. The melody IC is constituted of a tone generator, a sequencer, a ROM for storing musical score data, and another ROM for storing timbre data. Upon receipt of a music reproduction instruction from the outside, the melody IC reproduces melody tones along musical score data read from the musical score data ROM with timbres read from the timbre data ROM. If such a melody IC is incorporated into a telephone terminal device, the CPU is not required to perform reproduction of a music piece, and this makes it possible to use an inexpensive, low-speed CPU. The melody IC, however, has a small storage capacity for the timbre data ROM. The storage capacity of the timbre data ROM is so small that the number of parameters and kinds of timbre data are limited, and this makes it difficult to generate tones of high quality or a variety of tones. Further, the melody IC has a small storage capacity for the musical score data ROM such that the number of storable music pieces and the length of a music piece to be reproduced are limited. The storage capacity of the musical score data ROM is so small that a large amount of music data needed for reproducing a music piece of high quality cannot be stored, thereby prohibiting all but some melodies of low quality from being reproduced. OBJECTS AND SUMMARY OF THE INVENTION In consideration of these circumstances, it is an object of the present invention to provide a music piece reproducing apparatus and a music piece reproducing method that enable music pieces to be reproduced with a variety of timbres even though a memory for storing timbre data has a small storage capacity. It is another object of the present invention to provide a music piece reproducing apparatus and a music piece reproducing method that enable music pieces to be reproduced with a variety of timbres even though a memory for storing music score data has a small storage capacity. It is a further object of the present invention to provide a music piece reproducing apparatus, a music piece reproducing method, and a telephone terminal device, by which music pieces with tones of high quality can be reproduced even with a low-speed processing unit. In order to achieve the above noted objects, an inventive music reproducing apparatus comprises a timbre data memory that has a limited capacity for storing timbre data corresponding to a first number of timbres, which is less than a second number of timbres reserved in a data source, an interface that can be operated to transfer the timbre data from the data source to the timbre data memory so that the timbre data memory stores the transferred timbre data, a score data memory that stores score data representing a music piece, a tone generator that is set with a tone generating parameter derived from the score data stored in the score data memory for generating tones of the music piece, and a performance controller that interprets the score data to read out timbre data designated by the score data from the timbre data memory for setting the tone generator with the read timbre data so that the tone generator can generate the tones having timbres specified by the score data. Preferably, the tone generator can concurrently generate a third number of tones allotted to respective parts of the music piece, which are not more than the second number of timbres available by the timbre data memory, and the performance controller reads out timbre data corresponding to the third member of timbres which are assigned to the respective parts according to the score data. An inventive electronic apparatus comprises a processor that processes data to execute a task, a memory device that memorizes data including music data comprised of timbre data and score data to represent music pieces, and a music reproduction device that operates according to the music data under control by the processor to reproduce a music piece in association with the task executed by the processor, wherein the music reproduction device comprises a timbre data memory that has a limited capacity for storing timbre data corresponding to a first number of timbres, which is less than a second number of timbres reserved in the memory device, an interface that can be operated to transfer the timbre data from the memory device to the timbre data memory so that the timbre data memory stores the transferred timbre data, a score data memory that stores score data representing a music piece, a tone generator that is set with a tone generating parameter derived from the score data stored in the score data memory for generating tones of the music piece, and a performance controller that interprets the score data to read out timbre data designated by the score data from the timbre data memory for setting the tone generator with the read timbre data so that the tone generator can generate the tones having timbres specified by the score data. Preferably, the tone generator can concurrently generate a third number of tones allotted to respective parts of the music piece, which are not more than the second number of timbres available by the timbre data memory, and the performance controller reads out timbre data corresponding to the third member of timbres which are assigned to the respective parts according to the score data. Preferably, the inventive electronic apparatus further comprises a communication device that can communicate with an external database to download therefrom music data into the memory device. An inventive telephony terminal apparatus comprises a communication unit that transmits a signal to a remote location and receives a signal from the remote location, and a music reproduction unit that can reproduce a music piece in association with the signal, wherein the music reproduction unit comprises a score data memory that memorizes score data representing a music piece, a tone generator of a frequency modulation type settable with parameters for generating harmonics by frequency modulation to synthesize a tone, and a performance controller that sets the tone generator with parameters according to the memorized score data for enabling the tone generator to synthesize tones of the music piece represented by the score data. Preferably, the music reproduction unit further comprises a timbre data memory that has a limited capacity for memorizing timbre data corresponding to a predetermined number of timbres, and the performance controller interprets the score data to read out timbre data corresponding to a timbre designated by the score data from the timbre data memory, and sets the tone generator according to the read timbre data to thereby enable the tone generator to synthesize the tones of the music piece having the timbre designated by the score data. Preferably, the music reproduction unit further comprises an interface that can transfer data including the timbre data between the music reproduction unit and other units, the interface being operated for transferring the timbre data to the music reproduction unit so as to load the timbre data memory. Preferably, the inventive telephony terminal apparatus further comprises a central processing unit that treats various data and a memory unit that reserves various data including music data composed of score data and timbre data, wherein the interface is operated under control by the central processing unit for transferring the timbre data from the memory unit to the timbre data memory of the music reproduction unit and for transferring the score data from the memory unit to the score data memory of the music reproduction unit. Preferably, the memory unit reserves timbre data corresponding to a first number of timbres, wherein the timbre data memory of the music reproduction unit memorizes timbre data being transferred from the memory unit and corresponding to a second number of timbres which are less than the first number of timbres, wherein the tone generator can concurrently generate a third number of tones allotted to respective parts of the music piece, which are not more than the second number of timbres available by the timbre data memory, and wherein the performance controller reads out timbre data from the timbre data memory corresponding to the third member of timbres which are assigned to the respective parts according to the score data. Preferably, the communication unit can receive a signal representing either of the score data and the timbre data so as to download the same into the memory unit. An inventive music reproducing apparatus comprises a score data memory that has a limited space for storing a part of score data, which represents a music piece and which can be provided from a data source, an interface that can be operated to load the score data from the data source into the score data memory, a tone generator that is set with a variable parameter derived from the score data for sequentially generating tones of the music piece, a performance controller that sequentially retrieves the score data from the score data memory so as to set the tone generator with the variable parameter according to the retrieved score data, and a memory monitor that detects when a vacant area is created in the limited space of the score data memory upon sequential retrieval of the score data for operating the interface to load another part of the score data into the vacant area, thereby enabling the tone generator to continue the generating of the tones of the music piece. Preferably, the inventive music reproducing apparatus further comprises a timbre data memory that stores timbre data corresponding to a number of timbres, wherein the performance controller reads out timbre data corresponding to a timbre designated by the score data from the timbre data memory, and sets the tone generator with the read timbre data, thereby enabling the tone generator to generate the tones of the music piece having the designated timbre. An inventive electronic apparatus comprises a processor that processes data to execute a task, a memory device that memorizes data including score data representative of a music piece, and a music reproduction device that operates according to the score data under control by the processor to reproduce a music piece in association with the task, wherein the music reproduction device comprises a score data memory that has a limited space for storing a part of score data, which represents a music piece and which can be provided from the memory device, an interface that can be operated to load the score data from the memory device into the score data memory, a tone generator that is set with variable parameter derived from the score data for sequentially generating tones of the music piece, a performance controller that sequentially retrieves the score data from the score data memory so as to set the tone generator with the variable parameter according to the retrieved score data, and a memory monitor that notifies the processor when a vacant area is created in the limited space of the score data memory upon sequential retrieval of the score data, so that the processor operates the interface to load another part of the score data from the memory device into the vacant area of the limited space of the score data memory, thereby enabling the tone generator to continue the generating of the tones of the music piece. Preferably, the inventive electronic apparatus further comprises a timbre data memory that stores timbre data corresponding to a number of timbres, wherein the performance controller reads out timbre data corresponding to a timbre designated by the score data from the timbre data memory, and sets the tone generator with the read timbre data, thereby enabling the tone generator to generate the tones of the music piece having the designated timbre. Preferably, the inventive electronic apparatus further comprises a communication device that can communicate with an external database to download therefrom score data into the memory device. According to one aspect of the present invention, timbre data transferred through the interface are stored into the timbre data storage means, the storage capacity of which is available only for required kinds of timbre data, so that the data amount for parameters in the timbre data can be large enough to obtain tones of high quality even if the timbre data storage means has a small storage capacity, thereby reproducing a piece of music with tones of high quality. Further, among the many kinds of timbre data stored in the storage means provided outside the music piece reproducing apparatus, only the timbre data necessary to reproduce a piece of music are transferred to the music piece reproducing apparatus and stored in the timbre data storage means, so that several kinds of timbre data can be selected for tones with which the piece of music is to be reproduced even though the storage capacity of the timbre data storage means is small. In addition, if the timbre data are downloaded to an external storage means through a communication line, a choice of timbre data can be widened. All the data processing means has to do is to read desired timbre data and to send the same to the music piece reproducing apparatus; it is not required to carry out reproduction of a piece of music. This allows music of high quality to be reproduced even with a low-speed processing unit. In addition, if the tone generator of the music piece reproducing apparatus provided in a telephone terminal device is adopting a frequency modulating method, the amount of timbre data required for the frequency modulation type of the tone generator can be extremely reduced compared to that of a waveform memory type of the tone generator (PCM tone generator). Therefore, even if the timbre data is transmitted through a low-speed transmission path, for example, due to low speed of data processing by the data processing means, the telephone terminal device can reproduce a piece of music with a variety of tones of high quality. Further, since the amount of timbre data is reduced, timbre data enough to reproduce a piece of music with tones of high quality can be stored even in a timbre data storage means, the storage capacity of which is smaller. According to another aspect of the present invention, when a vacant area is created in the musical score storing memory, a next portion of the musical score data is subsequently loaded into the memory. By such a construction, a music piece of a high quality requiring a great data volume can be reproduced even though the music score storing memory has a small capacity. Further, the CPU is not required to execute the music reproduction process, but simply executes a data transfer process of feeding a next portion of the music score data when a vacant area is yielded in the memory buffering the music score data. Therefore, the CPU of moderate speed may be sufficient to reproduce the high quality of the melody tones. BRIEF DESCRIPTION OF THE DRAWINGS By way of example and to make the description more clear, reference is made to the accompanying drawings, in which: FIG. 1 is a diagram showing the concept of how to download music data to portable telephones when a music piece reproducing apparatus of the present invention that embodies a music piece reproducing method of the present invention is applied to the portable telephones; FIG. 2 is a diagram showing an embodiment of a music piece reproducing apparatus of the present invention that embodies a music piece reproducing method of the present invention when the music piece reproducing apparatus is applied to a portable telephone; FIG. 3 is a diagram showing an exemplary configuration of a music piece reproducing unit as practiced in the music piece reproducing apparatus of the present invention that embodies the music piece reproducing method of the present invention; FIG. 4 is a diagram showing an example of a musical score data format used in the music piece reproducing apparatus according to the embodiment of the present invention; FIG. 5 is a diagram showing an example of a timbre data format for eight tone colors written in a timbre data storage unit (Voice RAM) in the music piece reproducing apparatus according to the embodiment of the present invention; FIG. 6 is a diagram showing an example of a format of timbre allocation data used in the music piece reproducing apparatus according to the embodiment of the present invention; FIG. 7 is a diagram showing the detailed arrangement of an FIFO in the music piece reproducing apparatus according to the embodiment of the present invention; FIG. 8 is a diagram for explaining the operation of the FIFO in the music piece reproducing apparatus according to the embodiment of the present invention; FIG. 9 is a flowchart showing music piece reproduction support processing executed by a system CPU in a portable telephone to which the music piece reproducing apparatus of the present invention is applied; FIG. 10 is a diagram showing a configuration of a frequency modulation type of tone generator as an example of the tone generator in the music piece reproducing apparatus according to the embodiment of the present invention; FIG. 11 is a diagram showing a configuration of another frequency modulation type of tone generator as an example of the tone generator in the music piece reproducing apparatus according to the embodiment of the present invention; FIG. 12 is a diagram showing an example of a timbre data format for eight tone colors written in the timbre data storage unit (Voice RAM) by using a frequency modulation type of tone generator as the tone generator in the music piece reproducing apparatus according to the embodiment of the present invention; and FIG. 13 is a diagram showing a detailed format of the timbre data shown in FIG. 12 . DETAILED DESCRIPTION OF THE INVENTION FIG. 1 is a diagram showing the concept of how to download music data to portable telephones as telephone terminal devices when a music piece reproducing apparatus of the present invention that embodies a music piece reproducing method of the present invention is applied to the portable telephones. Systems for portable telephones are typically adopting cellular or cell splitting methods that install many radio-zones called cells in a service area. Each radio-zone is managed by one of cell sites or base stations A ( 2 a ) through D ( 2 d ). When users make calls from portable telephones 1 and 101 as mobile stations to ordinary telephones, the calls are first connected to a mobile telephone exchange station through a base station that manages the radio-zone to which the portable telephones now belong, then from the mobile telephone exchange station to a general telephone network. The portable telephones 1 , 101 are connected through radio channels to the base station responsible for the radio-zone so that they can make calls to other telephones. FIG. 1 shows an example of this type of cellular system. Shown in FIG. 1 is a case where the portable telephones 1 , 101 are located within a radio-zone managed by a base station C( 2 c ) in the base stations A( 2 a ) through D( 2 d ). The portable telephones 1 , 101 are connected to the base station 2 c through radio channels so that the base station 2 c will receive and process upward signals when the telephones make calls or perform location registration. Although the base stations 2 a through 2 d are responsible for different radio-zones, the outer edges of the base stations may overlap each other. The base stations 2 a through 2 d are connected to a mobile exchange station 3 through a multiplexing network, and plural mobile exchange stations are consolidated by a gate exchange station 5 a . Plural gate exchange stations 4 provided in this system are connected to each other through a relay transmission line. General telephone exchange stations 5 a , 5 b , 5 c , are located at each local area with a relay transmission line connecting them. Each of the general telephone exchange stations 5 a , 5 b , 5 c , establishes connection with ordinary telephones. Then, in this case, a download center 6 is connected to the general telephone exchange station 5 b. At the download center 6 , new pieces of music are collected at any time and a large number of music data are stored. According to the present invention, music data can be downloaded to the portable telephones 1 , 101 from the download center 6 that is connected to the general telephone network. When the portable telephone 1 downloads music data, the user carrying the portable telephone 1 dials a telephone number of the download center 6 , so that the portable telephone 1 is connected to the download center 6 in a path from the portable telephone 1 to the download center 6 through the base station 20 , the mobile exchange station 3 , the gate exchange station 4 , the general telephone exchange station 5 a and the general telephone exchange station 5 b . Then, the user operates dial buttons and the like on the portable telephone 1 according to the menu indicated on its display to download music data associated to a desired music title. In this case, the music data is composed of musical score data and timbre data. Using the above-mentioned method, only the timbre data indicative of a variety of tones or the musical score data may be downloaded to the portable telephone 1 individually. FIG. 2 illustrates an embodiment of a music piece reproducing apparatus of the present invention that embodies a music piece reproducing method of the present invention when the music piece reproducing apparatus is applied to a portable telephone as a telephone terminal device. In FIG. 2 , the portable telephone 1 includes an antenna 1 a that is generally retractable. The antenna 1 a is connected to a communication unit 13 having modulation and demodulation functions. A central processing unit (CPU) 10 of the system is a system control part that executes telephone function programs to control the operation of each part in the portable telephone 1 . The system CPU 10 has a timer that measures an elapsed time in operation and generates a timer interrupt at certain intervals. Upon receipt of an interrupt request signal, the system CPU 10 executes auxiliary operations to support music piece reproduction processing to be described later. A system RAM 11 is a RAM (Random Access Memory) that provides a storage area for music data composed of musical score data and timbre data downloaded from the download center 6 , a user setting data storage area, a work area for the system CPU 10 , and so on. A system ROM 12 is a ROM (Read Only Memory) that stores several kinds of telephone function programs, such as to handle outgoing and incoming calls, executed by the system CPU 10 , other programs for execution of auxiliary operations to the music piece reproduction processing, and several kinds of preset data such as musical score data and timbre data. The communication unit 13 serves to demodulate a signal received at the antenna 1 a , and to modulate and supply a sending signal to the antenna 1 a . The received signal demodulated at the communication unit 13 is decoded at a voice data processing unit (coder/decoder) 14 . A receiver signal inputted from a microphone 21 is compressed and encoded at the voice data processing unit 14 . The voice data processing unit 14 carries out highly efficient compressive coding/decoding of transmitting voice; it may be coder/decoder of a CELP (Code Excited LPC) or ADPCM (Adaptive Differential PCM Coding) type. A music piece reproducing unit 15 generates sound of the receiver signal from the voice data processing unit 14 and issues the same from a receiver speaker 22 , or reproduces and outputs music data as a calling or holding tone. The calling tone is issued from a speaker 23 for incoming calls. The holding tone is mixed with the receiver signal and issued from the receiver speaker 22 . Suppose that the music piece reproducing unit 15 is reproducing music data. If there occurs a certain amount of available space in an inner storage means for the musical score data, the music piece reproducing unit 15 gives the system CPU 10 an interrupt request signal (IRQ). Upon receipt of the interrupt request signal (IRQ), the system CPU 10 reads a next continued part of music score data from the system RAM 11 or the system ROM 12 , and transfers the read data to the music piece reproducing unit 15 . An interface (I/F) 16 is an interface through which music data composed of musical score data and timbre data are downloaded from external equipment 20 such as a personal computer. An input unit 17 is an input means with dial buttons from ‘0’ to ‘9’ and several other buttons provided on the portable telephone 1 . A display unit 18 is a monitor display that shows a menu of telephone functions and other information changed according to button operations such as to operate dial buttons. A vibrator 19 is to inform the user of arrival of a call by silent vibration instead of calling sound. Each functional block sends and receives data and instructions through a bus 24 . FIG. 3 illustrates an exemplary configuration of the music piece reproducing unit 15 shown in FIG. 2 . In FIG. 3 , an interface 30 is to receive several kinds of data through the bus 24 . The interface 30 separates received data containing musical score data and timbre data from index data (INDEX) indicative of what data is received. The interface 30 outputs the data part from a data output and index data from an index output. An FIFO (First-In First-Out) buffer 31 is a storage means capable of storing a certain amount of musical score data, for example, up to 32 words. The musical score data is read out of the FIFO 31 sequentially from the earliest written part, and when there occurs a certain amount of available area in the FIFO 31 , the FIFO 31 sends the system CPU 10 the interrupt request signal (IRQ). An index decoder 32 decodes the index data, and supplies the FIFO 31 with a write pulse (WP) and a latch pulse (LP) for IRQ point data to be described later. The index decoder 32 also supplies a sequencer 33 with index data AD 1 to inform the sequencer 33 that the data directed to the sequencer 33 has been outputted from the data output of the interface 30 . Further, the index decoder 32 supplies a timbre data storage unit (Voice RAM) 34 with index data AD 2 to inform the timbre data storage unit (Voice RAM) 34 that the timbre data directed to the timbre data storage unit (Voice RAM) 34 has been outputted from the data output of the interface 30 . The sequencer 33 applies a read pulse to the FIFO 31 to read the musical score data sequentially from the FIFO 31 while setting a tone generation parameter s on a tone generator 35 along the musical score data in synchronism with time information of the musical score data. The sequencer 33 also supplies the timbre data storage unit (Voice RAM) 34 with a timbre number for each part specified by timbre allocation data fetched from the data output of the interface 30 so that timbre parameters corresponding to the timbre number are read out of the timbre data storage unit (Voice RAM) 34 and set for each part on the tone generator 35 . The timbre data storage unit (Voice RAM) 34 is a storage means that stores timbre data fetched from the data output of the interface 30 ; it has such a small storage capacity, for example, that it can store only timbre data of eight tone colors. The tone generator 35 can generate music signals, for example, for four parts at the same time. For each part, a timbre read out of the timbre data storage unit (Voice RAM) 34 is set according to the timbre allocation data so that each part will generate a music signal with the pitch and the duration of tone generation determined according to the timbre parameters supplied from the sequencer 33 . The music signals generated for four parts are supplied to a digital/analog converter (DAC) 36 at predetermined reproduction timing to generate an analog music signal. The music signal is then decoded at the voice data processing unit 14 and mixed with a receiver signal by means of a mixer 37 . The following describes the operation of the music piece reproducing unit shown in FIG. 3 . The user carrying the portable telephone 1 as shown in FIG. 2 selects a desired piece of music from information related to music such as music titles displayed on the display 18 in a music piece reproducing mode. Then, music data corresponding to the selected piece are read out of the system RAM 11 and sent to the music piece reproducing unit 15 through the bus 24 . Of the timbre data of eight tone colors in the music data fetched through the interface 30 , index data attached to the timbre data are decoded at the index decoder 32 and supplied and written as index data AD 2 to the timbre data storage unit (Voice RAM) 34 . The timbre data to be written to the timbre data storage unit (Voice RAM) 34 can be selected from many kinds of timbre data stored in the system RAM 11 before transfer. FIG. 5 illustrates an example of a timbre data format for eight tone colors written in the timbre data storage unit (Voice RAM) 34 . As shown in FIG. 5 , timbre data from timbre 1 to timbre 8 are each composed of a waveform parameter, an envelope parameter, a modulation parameter and an effect parameter. Each parameter is peculiar to each of tone 1 to tone 8 . The waveform parameter of each timbre data indicates a waveform of the music piece. For example, if the tone generator 35 is a PCM tone generator having a waveform table, the waveform parameter is to specify one of waveforms on the waveform table. If the tone generator 35 is an FM tone generator, the waveform parameter is to specify the algorithm that defines specific FM operations. The envelope parameter includes an attack rate, a decay rate, a sustain level and a release rate. The modulation parameter includes the depth or velocity of a vibrato or tremolo. The effect parameter includes a reverb, a chorus and a variation. Tempo data (Tempo) and timbre allocation data in the music data fetched through the interface 30 are taken into the sequencer 33 by the index decoder 32 supplying the sequencer 33 with index data attached to the tempo data and the timbre allocation data as index data AD 1 . The sequencer 33 reads out of the timbre data storage unit (Voice RAM) 34 the timbre parameters specified by the timbre allocation data fetched, and sets the same on the tone generator 35 . FIG. 6 illustrates an example of the timbre allocation data configuration. As shown in FIG. 6 , tones allocated for part 1 to part 4 are indicated by timbre numbers. In other words, when the sequencer 33 supplies the timbre number specified for each part to the timbre data storage means 34 , timbre parameters corresponding to the timbre number are read out of the timbre data storage means 34 , and set on the tone generator 35 as a tone for each part. It should be noted that the timbre data for music data to be reproduced are transferred to and written into the timbre data storage unit (Voice RAM) 34 . Therefore, even if the timbre data storage unit (Voice RAM) 34 has such a small storage capacity that it can store only timbre data of eight tone colors in this embodiment, all the timbre data necessary for reproduction of the music data can be stored in the timbre data storage unit (Voice RAM) 34 . In other words, even if the timbre data storage unit (Voice RAM) 34 has a small storage capacity, a piece of music with high sound quality can be reproduced based on the timbre data of high quality with an increased data amount. Further, since desired timbre data are selected from the system RAM 11 and written into the timbre data storage unit (Voice RAM) 34 , a piece of music with a variety of tones can be reproduced. It should be noted that the timbre allocation data and the tempo data can be edited by the user. 32 words of musical score data in the music data fetched through the interface 30 are written into the FIFO 31 by the index decoder 32 decoding the index data attached to the musical score data and supplying a write pulse (WP) to the FIFO 31 . The 32-word musical score data are thus written into the FIFO 31 . The 32 words are part of musical score data of a piece of music; they are considered to be the top block of the musical score data. The musical score data written in the FIFO 31 are composed of note data and rest data. FIG. 4 illustrates an example of such a data format. FIG. 4 shows one word of note data that includes information on an octave code, a note code, a part number to which the note data belong, an interval indicative of a time length to the next note or rest, and the duration of tone generation. FIG. 4 also shows one word of rest data that includes rest data indicative of the kind of rest, a part number to which the rest data belong, and an interval indicative of a time length to the next note or rest. When the tone generator 35 reproduces a piece of music, the note data and the rest data are read sequentially from the FIFO 31 , and therefore, there occurs a certain amount of vacant area in the FIFO 31 as these data are read out one by one. The FIFO 31 has only the top 32-word musical score data, but the next part of the musical score data can be written into the vacant area. Therefore, even if the musical score data requires a large amount of data memory area for reproduction of music of high quality, parts or sections of the score data can be written sequentially into the FIFO 31 as soon as there occurs a certain amount of available space in the FIFO 31 , thus reproducing musical score data of high quality. The music piece reproducing apparatus of the present invention carries out reproduction of music data on such a principle of setting next words when available area in the FIFO 31 occurs at the timing of writing the next part of the musical score data. The IRQ point data is set to give the system CPU 10 an interrupt request signal (IRQ) that instructs the system CPU 10 to write the subsequent part of musical score data into the FIFO 31 . The IRQ point data is set prior to the start of reproduction. If the IRQ point data is set near 0 word, interrupt frequencies increase but the number of words to be written at a time is reduced, resulting in a decrease in load on the system CPU 10 . If the IRQ point data is set near 32 words, interrupt frequencies are reduced but the number of words to be written at a time increases, resulting in an increase in load on the system CPU 10 . Therefore, it is preferable to set the IRQ point data according to the processing speed of the system CPU 10 . Then, when the system CPU 10 instructs the music piece reproducing unit 15 to start reproduction of music data, the sequencer 33 applies a read pulse to the FIFO 31 to read the musical score data sequentially from the FIFO 31 . If the current musical data are note data, the sequencer 33 sets on the tone generator 35 pitch data of an octave code and a note code in the musical score data, part specifying information, and data specifying ‘key-on’ at timing based on the set tempo and interval information. The tone generator 35 generates a musical sound with a pitch specified based on the timbre parameters set for the part specified from the data set in the tone generator register. Then, when time corresponding to the duration of tone generation for the note data has been elapsed, the sequencer 33 sets on the tone generator 35 key-off data with specifying the corresponding part of the music piece. Then, the tone generator 35 silences the musical sound. Such a sequence of operations are repeated each time the musical score data are read out of the FIFO 31 , so that the music signals reproduced from the tone generator 35 are outputted to the DAC 36 . As the piece of music is reproducing, the interrupt request signal (IRQ) is given to the system CPU 10 each time an available area detected in the FIFO 31 becomes equal to the IRQ point data value. Upon receipt of the IRQ, the system CPU 10 reads the next musical score data for a predetermined number of words (31-IRQ point) from the system RAM 11 , and sends the same to the bus 24 . The musical score data are written into the available area in the FIFO 31 through the interface 30 . Such write operation as to write the next musical score data for the predetermined number of words (31-IRQ point) into the FIFO 31 is repeatedly executed. Therefore, even if the musical score data contain many words of data, all the data words can be written in the FIFO 31 after all. The musical score data read out of the FIFO 31 are then reproduced and outputted from the tone generator 35 according to the tempo data. Thus, according to the present invention, a large amount of music data can be treated that allow the music piece to be reproduced with high quality even in a case where the FIFO 31 has such a small storage capacity, for example, only 32 words of music data. Suppose that the music piece reproducing unit 15 is set to reproduce a piece of music when a call arrives at the portable telephone 1 . When a call arrives at the portable telephone 1 , the above-mentioned music piece reproduction processing is so executed that a music signal outputted from the DAC 36 will be issued from the speaker 23 as a calling tone. Suppose further that the music piece reproducing unit 15 is set to reproduce a piece of music as a holding tone when the user carrying the portable telephone 1 places a conversation on hold. When the portable telephone 1 is changed to a holding mode, the above-mentioned music piece reproduction processing is so executed that a music signal outputted from the DAC 36 will be issued from the speaker 22 as a holding tone. Simultaneously, the music signal outputted from the tone generator 35 are also supplied to the voice data processing unit 14 and sent through the communication unit 13 for the purpose of transmitting the holding tone. FIG. 7 illustrates the detailed arrangement of the FIFO 31 . Referring also to FIG. 8 , the following describes the operation of the FIFO 31 . When the IRQ point data is outputted from the interface 30 , a latch pulse (LP) is supplied from the index decoder 32 to a latch circuit 43 , and as a result, the IRQ point data, for example, set to “15” in the latch circuit 43 is latched. Then, when the musical score data are outputted from the interface 30 , the index decoder 32 applies a write pulse (WP) to a write address counter 41 and the up terminal of an up/down counter 45 . The write pulse (WP) is generated each time one word of the musical score data is outputted. In its initial state, the write pulses make progress in the write address counter 41 sequentially from “0” to “31,” so that the top 32 words of musical score data are stored in a RAM 40 that has a storage capacity of at least 32 words. Simultaneously, the up/down counter 45 counts up from “0” to “31.” FIG. 8( a ) shows this state as the start of the first execution. Finally, the RAM 40 reaches the “FULL” state in which the write address W comes to the address “31” and the read address R remains in the address “0.” Under this circumstance, when the start of reproduction of the music data is instructed, the sequencer 33 starts making progress while applying a read pulse (Read) to the read address counter 42 so as to start reading the musical score data sequentially from the top one located at the address “0” on the RAM 40 . The read pulse (Read) is also applied to the down terminal of the up/down counter 45 . Thus, the up/down counter 45 counts up each time the write pulse (WP) is applied, and counts down each time the read pulse (Read) is applied. FIG. 8( b ) shows a state of the RAM in which 16 words of the musical score data have been read out and reproduced. Since 16 words of the musical score data have been read out, it is apparent that the read address counter 42 is at the address “15” and the counter value of the up/down counter 45 is (31−16)=15. As mentioned above, the IRQ point data latched in the latch circuit 43 is “15,” and as a result, a comparison circuit 44 detects that the counter value of the up/down counter 45 and the IRQ point data value of the latch circuit 43 match with each other. Then, the comparison circuit 44 outputs an interrupt request signal (IRQ) to the system CPU 10 . Upon receipt of the IRQ, the system CPU 10 reads the next 16 words (31-IRQ point) of the musical score data from the system RAM 11 , and sends the same to the bus 24 . The musical score data sent to the bus 24 are written from the addresses “0” to “15” that are now available on the RAM 40 . In this case, the index decoder 32 applies the write pulse (WP) to the write address counter 41 and the up terminal of the up/down counter 45 . 16 write pulses (WP) are generated for 16 words, and because of these pulses, the write address counter 41 that is set to count up to a modulus of 31 makes progress and reaches the address “15” while writing the musical score data to each corresponding address. Simultaneously, the up/down counter 45 is incremented by “16.” However, since the up/down counter 45 counts down even in this case due to the read pulses (Read), the count value becomes the balance of the write pulses (WP) and the read pulses (Read). FIG. 8( c ) shows a state of the RAM in which 16 words of the musical score data have been replenished as seen at the time of additional writing of 16 words. Next, the sequencer 33 applies the read pulses (Read) to the read address counter 42 , and as a result, 32 words of the musical score data are read out of the RAM 40 . Such a state of the RAM 40 is shown in FIG. 8( d ). Since the read address counter also counts up to the modulus of 31 , the read address counter 42 is returned to the address “0” here. At this time, since the counter value of the up/down counter 45 is at the address “15” again, the comparison circuit 44 outputs the interrupt request signal (IRQ) again to the system CPU 10 . Then, the above-mentioned operations are so repeated that the subsequent 16 words of the musical score data are written into the addresses “16” to “31” on the RAM 40 . Thus, the next 16 words of the musical score data are replenished until the next 32 words of the musical score data are additionally written in total. Such a state of the RAM 40 is shown in FIG. 8( e ). As discussed above, 16 words of musical score data are additionally written and replenished to the RAM 40 sequentially each time there occurs 16 words of available area on the RAM 40 . Therefore, even if the RAM 40 has a small storage capacity of at least 32 words, any music data having a large amount of musical score data that allow the music data to be reproduced with high quality can be written sequentially onto the RAM 40 while reproducing the same. It should be noted that the counter value of the up/down counter 45 always matches the number of words of the musical score data that remain stored without being read out of the RAM 40 . When reproduced, each part has a timbre allocated according to the timbre allocation data, or the timbre allocation data for each part may be inserted in the musical score data beforehand. During reproduction, the timbre allocation data are read out of the FIFO 31 , so the sequencer 33 supplies the timbre data storage unit (Voice RAM) 34 with a timbre number specified by the timbre allocation data. In this case, the timbre data of eight tone colors that are more than the number of parts, so any timbre can be selected for each part out of eight tone colors of the timbre data. Timbre parameters corresponding to the timbre number are read out of the timbre data storage unit (Voice RAM) 34 , and set in a tone generator register of the tone generator 35 for the part specified by the timbre allocation data. The timbre of the part concerned to be reproduced on the tone generator 35 is thus changed during the reproduction. As discussed above, since the timbre allocation data for each part is inserted in the musical score data, the timbre of each part can be voluntarily changed during the reproduction. Further, the timbre data of eight tone colors stored in the timbre data storage unit (Voice RAM) 34 may be selected by the user out of all the timbre data stored in the system RAM 11 , so that the selected timbre data can be transferred to the timbre data storage unit (Voice PAM) 34 . Since the system RAM 11 has many kinds of timbre data downloaded from the download center 6 or the external equipment 20 , any timbre data from among the timbre data of many kinds can be selectively stored into the timbre data storage unit (Voice RAM) 34 . FIG. 9 is a flowchart illustrating music piece reproduction support processing executed by the system CPU 10 during the reproduction of a piece of music. When the portable telephone 1 is changed to the music piece reproducing mode, a music piece reproducing menu appears on the display 18 . In step S 1 , the user selects a desired piece of music from the music selection menu by operating the dial buttons and the like. In this case, the selection is made from music data stored in the system RAM 11 and the system ROM 12 . The system RAM 11 stores music data downloaded from the download center 6 and the external equipment 20 . After the completion of the selection, timbre data and tempo data are set in step S 2 . In step S 2 , timbre data of eight tone colors for respective parts of the selected music data are transferred to the music piece reproducing 15 and stored in the timbre data storage unit (Voice RAM) 34 . The tempo data for respective parts of the selected music data are also transferred to the music piece reproducing unit 15 and set in the sequencer 33 . The tempo data may be edited on the display 18 by operating the dial buttons and the like. In step S 3 , the IRQ point data is set on the display 18 to a predetermined value by operating the dial buttons and the like. The IRQ data is set by taking into account the processing speed of the system CPU 10 . Then, 32 words of musical score data in the selected music data are read out of the system RAM 11 , transferred to the music piece reproducing unit 15 , and written into the FIFO 31 until the FIFO 31 becomes the “FULL” state. In the next step S 5 , the system waits until start operation is instructed. The start operation is activated at the time of arrival of a call if the music data is to be reproduced as a calling tone, or by operating the holding button if it is to be reproduced as a holding tone. If it is determined in step S 5 that the start operation is instructed, the operating procedure goes to step S 6 in which a start command is forwarded to the music piece reproducing unit 15 . If not determined that the start operation is instructed, it branches to step S 11 in which it is determined whether a button to instruct the start of reproduction is operated. If it is determined that the button is operated, the operating procedure returns to step S 1 so that the operations from step S 1 to step S 4 are repeated. If not determined that the button is operated, it returns to step S 5 and waits until the start operation is instructed. Upon receipt of the start command, the music piece reproducing unit 15 starts the above-mentioned music piece reproduction processing to reproduce the selected music piece. Then, when it is determined in step S 7 that an interrupt request signal (IRQ) is generated to the music piece reproducing unit 15 , the operating procedure goes to step S 8 in which the musical score data for the next (31-IRQ point) words are read out of the system RAM 11 and transferred to the music piece reproducing unit 15 . The operations of steps S 7 and S 8 are repeated until it is determined in step S 9 that stop operation is instructed. The stop operation is activated by operating a talk button if the music data has been reproduced as the calling tone, or by operating a holding tone releasing button if it has been reproduced as the holding tone. If it is determined in step S 9 that the stop operation is instructed, the operating procedure goes to step S 10 in which a stop command is forwarded to the music piece reproducing unit 15 to instruct the music piece reproducing unit 15 to stop the music piece reproduction processing. Then, the operating procedure returns to step S 5 and waits until the start operation is instructed again. As discussed above, the music piece reproduction processing to reproduce the selected music piece is executed at the time of arrival of a call if the selected music piece is to be reproduced as a calling tone, or by operating the holding button if it is to be reproduced as the holding tone. In either case, the music piece to be reproduced is the one that has been selected in the step of music selection. The music selection may be made to select different music pieces for the calling tone and the holding tone so that both music pieces can be reproduced independently when the start of either the calling tone or the holding tone is instructed. Further, since the music selection can be made at any time, any music piece can be selected for both the calling tone and the holding tone. It should be noted that the system CPU 10 executes the main processing for telephony functions, not shown. However, the music piece reproduction support processing only requires such a light load that the system CPU 10 can execute the music piece reproduction support processing together with its main processing without the need of replacing the system CPU 10 by high-speed one. Although in this embodiment the FIFO has such a storage capacity that it can store 32 words of musical score data, the present invention is not limited to this capacity. The storage capacity of the FIFO 31 can vary as long as it is much smaller than that of the system RAM 11 . Further, the timbre data storage unit (Voice RAM) 34 has such a storage capacity that it can store timbre data of eight tone colors, but it is not limited to the capacity as well. The capacity of the timbre data storage unit (Voice RAM) 34 can be extremely reduced, compared to that of the system RAM 11 , as long as the number of tone colors is equal to or more than the number of parts of the music piece corresponding to channels of tone generation. As mentioned above, the tone generator 35 in the music piece reproducing unit 15 can be a frequency modulation type of tone generator, i.e., an FM tone generator. The FM tone generator is designed to use out-of-phase harmonics produced by frequency modulation to synthesize musical sounds; it can generate waveforms having out-of-phase harmonic components like inharmonic tones in a relatively simple circuit configuration. The FM tone generator has the advantage of generating a wide range of musical sounds from a synthesized tone to an electronic tone. FIG. 10 illustrates an example of such a configuration. The FM tone generator uses oscillators called operators that oscillate equivalently to generate a sine wave. As shown in FIG. 10 , the FM tone generator 50 is made of the operator 1 and the operator 2 connected in series. A sine wave oscillated from the operator 1 is supplied to the operator 2 as a modulation signal so that the operator 2 generates a frequency modulated wave FM(t). On one hand, the operator 1 is called a modulator 51 because it generates a modulation signal; on the other hand, the operator 2 is called a carrier 52 because it generates a carrier wave. The operators 1 and 2 are configured in the same manner. In the modulator 51 , a pitch generator 51 c outputs pitch data variable in the form of a sawtooth according to the input of phase angle data ω m . Then, the pitch data and modulation data “0” inputted to the modulator 51 are added at an adder 51 a . The output of the adder 51 a is supplied to a sine wave generator 51 b in which a sine wave table is read according to the pitch data outputted from the adder 51 a as the data that varies in the form of a sawtooth. Then, the sine wave generator 51 b generates a sine wave at frequencies corresponding to varied velocities of the pitch data. The amplitude of the sine wave is controlled by amplitude data B generated from an envelope generator 51 d . For this reason, the sine wave outputted from the sine wave generator 51 b is represented by B·sin ω m t. In the carrier 52 , a pitch generator 52 c outputs pitch data variable in the form of a sawtooth according to the input of phase angle data ω c . Then, the pitch data and the sine wave of modulation signal outputted from the modulator 51 are added at an adder 52 a . The output of the adder 52 a is supplied to a sine wave generator 52 b in which a sine wave table is read according to the added data outputted from the adder 52 a . Then, the sine wave generator 52 b generates a sine wave varied according to the rate of change in the added data. The amplitude of the sine wave is controlled by amplitude data A generated from an envelope generator 52 d . For this reason, the sine wave outputted from the sine wave generator 52 b is represented by A·sin (ω c ) t +B sin ω m t). Thus, the output FM(t) from the carrier 52 is subjected to frequency modulation, and the above equations are basic formulas for the FM tone generator 50 . As shown in FIG. 10 , since the modulator 51 and the carrier 52 have the same circuit configuration, the frequency modulated wave can be generated in such a configuration that either of them feeds back its output as its input. This type of FM tone generator is called a feedback FM tone generator, and an example of such a configuration is shown in FIG. 11 . As shown in FIG. 11 , the feedback FM tone generator 60 is constituted of an operator 61 and a feedback circuit 62 . In the operator 61 , a pitch generator 61 c outputs pitch data variable in the form of a sawtooth according to the input of phase angle data ω m . Then, the pitch data and modulation data “0” inputted to the operator 61 are added at an adder 61 a . The output of the adder 61 a is supplied to a sine wave generator 61 b in which a sine wave table is read according to the added data outputted from the adder 61 a . Then, the sine wave generator 61 b generates a sine wave varied according to the rate of change in the added data. The amplitude of the sine wave is controlled by amplitude data B generated from an envelope generator 61 d . The output of the sine wave generator 61 b is so controlled that a feedback rate β can be obtained in a feedback circuit 62 . Then, it is inputted to the adder 61 a as a modulation signal. The sine wave generator 61 b thus outputs an output FM(t) that is subjected to frequency modulation. The feedback FM tone generator 60 is suitable for generation of a string type of music sound. The FM tone generators 50 and 60 can generate musical sounds of different tones by changing the way or method to connect the circuits on an operator basis. The method of connecting operators is called the algorithm. In the above-described FM tone generators, the tone can vary by controlling the pitch data varied in the form of a sawtooth and outputted from the pitch generator, by controlling the amplitude outputted from the envelope generator, or by changing the algorithm. Timbre data for obtaining desired tone colors on the FM tone generators consist of timbre data for the modulator and timbre data for the carrier. The amount of data for one tone color can be extremely reduced compared to that of the waveform memory type of tone generator. FIG. 12 illustrates an example of a timbre data format for eight tone colors written in the timbre data storage unit (Voice RAM) 34 when the tone generator 35 assumes the form of an FM tone generator. Timbre data of eight tone colors, such as timbre 1 , timbre 2 , . . . written in the timbre data storage unit (Voice RAM) 34 each contain timbre data for the modulator and timbre data for the carrier. Both timbre data for the modulator and the carrier assume the same data format. An example of such a data format is shown in FIG. 13 . As shown in FIG. 13 , each timbre data for the modulator or the carrier may be 32 bits of data containing the following: three bits of multiple setting data (ML 2 –ML 0 ), a bit of vibrato ON/OFF data (VIB), a bit of envelope waveform type data (EGT), a bit of sustain ON/OFF data (SUS), four bits of attack rate setting data (AR 3 –AR 0 ), four bits of decay rate setting data (DR 3 –DR 0 ), four bits of sustain level setting data (SL 3 –SL 0 ), four bits of release rate setting data (RR 3 –RR 0 ), a bit of waveform selecting data (WAV), three bits of feedback amount setting data (FL 2 –FL 0 ), and six bits of total level data (TL 5 –TL 0 ). The multiple setting data (ML 2 –ML 0 ) are adopted to set an oscillator frequency magnification. The pitch generator generates pitch data with a rate of change multiplied by the magnification specified by the multiple setting data. The magnification set by the multiple setting data may range from ±0.5 to ±7, and if the multiple setting data is used in the modulator 51 , the frequency of the modulation signal is changed to vary the timbre. The vibrato ON/OFF data (VIB) are set to determine whether a vibrato is applied or not. The envelope waveform type data (EGT) are set to determine whether the envelope waveform is of an envelope of sustained sound or an envelope of decayed sound. The sustain ON/OFF data (SUS) are data by which the release rate is changed to another release rate tilted at a predetermined gentle angle at timing of terminating the length of tone generation if the sustain ON/OFF data is set ON, or the release rate becomes a set value at timing of terminating the length of tone generation if the sustain ON/OFF data is set OFF. The attack rate setting data (AR 3 –AR 0 ) are used to set the time from when tone generation commences until it reaches the maximum volume. The time set by the attack rate setting data may range from 0.0 ms to 38.1 sec. The decay rate setting data (DR 3 –DR 0 ) are used to set the decay time from when the sound reaches the maximum volume until it falls into the sustain level. The decay time set by the decay rate setting data may range from 4.47 ms to 73.2 sec. The sustain level setting data (SL 3 –SL 0 ) are used to set a sustain level when the envelope waveform is determined by the envelope waveform type data (EGT) to be sustain sound. In the case of decayed sound, the release rate setting data (RR 3 –RR 0 ) sets the decay time from the sustain level to the timing at which the length of the tone generation is terminated, and after the timing of terminating the duration of the tone generation, it is decayed at a predetermined sharp angle of tilt. In the case of sustained sound, the release rate setting data sets the decay rate from the timing of terminating the tone generation. The decay rate set by the release rate setting data may range from 4.47 ms to 73.2 sec. The waveform selection data (WAV) are set to determine whether the waveform generated by the sine wave generator is a sine wave or a half-wave rectified sine wave. The feedback amount setting data (FL 2 –FL 0 ) are used to set a feedback factor for the feedback FM tone generator shown in FIG. 11 ; they are effective for the carrier operator alone. Therefore, it is desirable to set the data in the carrier so as to generate a string type of tone. The feedback amount setting data may be represented as time ranging from 0 to 4π. The total level data (TL 5 –TL 0 ) are designed to set the total volume. If the tone generator 35 is thus configured as an FM tone generator, for example, timbre data of one tone color can be represented as a pair of 32-bit (32×2 bits) data consisting of 32-bit timbre data for the modulator and 32-bit timbre data for carrier. Since the amount of timbre data for eight tone colors to be stored in the timbre data storage unit (Voice RAM) 34 can be reduced to 8×(32×2) bits, i.e., 64 bytes, the use of the FM tone generator as the tone generator 35 has the advantage of reducing the storage capacity of the timbre data storage unit (Voice RAM) 34 . Further, even if the transfer rate of timbre data to the timbre data storage unit (Voice RAM) 34 is low, since the amount of timbre data for eight tone colors is reduced, the timbre data can be transferred in a very short time. Therefore, even if the processing speed of the CPU 10 is slow, a music piece of several tones can be reproduced with high quality. Furthermore, timbre data can be downloaded from the download center 6 in a short time because of a small amount of timbre data per tone color. The amount of timbre data per tone color may be a few k-bytes for the waveform memory type of tone generator (PCM tone generator). Therefore, it is apparent that the use of an FM tone generator allows the amount of timbre data per tone color to be greatly reduced compared to that for the waveform memory type of tone generator. Although the use of an FM tone generator is described here, the present invention is not limited thereto, and other types of tone generator, such as tone generators of the waveform memory type (PCM tone generator) and of physical model type, can be used as the tone generator 35 in the music piece reproducing apparatus of the present invention. Further, the tone generator may also be composed of either hardware using a DSP or the like or software implementing a tone generator program. Furthermore, the musical score data are formatted as shown in FIG. 4 , but the present invention is not limited to this format. For example, the musical score data may be transferred as a MIDI file with time information or an SMF (standard MIDI file). As described above, according to one aspect of the present invention, timbre data transferred through the interface means are stored into the timbre data storage means, the storage capacity of which is available only for necessary kinds of timbre data, so that the data amount for parameters in the timbre data can be large enough to obtain tones of high quality even if the timbre data storage means has a small storage capacity, thereby reproducing a piece of music with tones of high quality. Further, among the many kinds of timbre data stored in the storage means provided outside the music piece reproducing means, only the timbre data necessary to reproduce a piece of music are transferred to the music piece reproducing means and stored in the timbre data storage means, so that several kinds of timbre data can be selected with which the piece of music is reproduced even though the storage capacity of the timbre data storage means is small. In addition, if the timbre data are downloaded to an external storage means through a communication line, a choice of timbre data can be widened. All the data processing means has to do is to read desired timbre data and to send the same to the music piece reproducing means; it is not required to carry out reproduction of a piece of music. This allows music of high quality to be reproduced even with a low-speed processing unit. In addition, if the tone generator of the music piece reproducing means provided in a telephone terminal device is adopting a frequency modulating method, the amount of timbre data required for the frequency modulation type of tone generator can be extremely reduced as compared to that of a waveform memory type of tone generator (PCM tone generator). Therefore, even if the timbre data is transmitted through a low-speed transmission path, for example, due to low speed of data processing by the data processing unit, the telephone terminal device can reproduce a piece of music with a variety of tones of high quality. Further, since the amount of timbre data is reduced, timbre data enough to reproduce a piece of music with tones of high quality can be stored even in a timbre data storage means, the storage capacity of which is small. Furthermore, timbre data can be downloaded from the download center in a short time because of a small amount of timbre data per tone color. According to another aspect of the present invention, when a vacant area is created in the musical score storing memory, a next portion of the musical score data is subsequently loaded into the memory. By such a construction, a music piece of a high quality requiring a great data volume can be reproduced even though the music score storing memory has a small capacity. A music piece having a long play time can be reproduced without interruption. Further, the CPU is not required to execute the music reproduction process, but simply executes a data transfer process of feeding a next portion of the music score data when a vacant area is yielded in the memory buffering the music score data. Therefore, the CPU of moderate speed may be sufficient to reproduce the high quality of the melody tones.

In a music reproducing apparatus, a timbre data memory has a limited capacity for storing timbre data corresponding to a first number of timbres, which is less than a second number of timbres reserved in a data source. An interface can be operated to transfer the timbre data from the data source to the timbre data memory so that the timbre data memory stores the transferred timbre data. A score data memory stores score data representing a music piece. A tone generator is set with a tone generating parameter derived from the score data stored in the score data memory for generating tones of the music piece. A performance controller interprets the score data to read out timbre data designated by the score data from the timbre data memory for setting the tone generator with the read timbre data so that the tone generator can generate the tones having timbres specified by the score data. Further, a memory monitor detects when a vacant area is created in a limited space of the score data memory upon sequential retrieval of the score data for operating the interface to load another part of the score data into the vacant area, thereby enabling the tone generator to continue the generating of the tones of the music piece.

RELATED APPLICATIONS [0001] This application is related to i) the U.S. patent application entitled “Moldable Footwear Insole” (Attorney Docket No. ZGI.002A) and ii) the U.S. patent application entitled “System and Method for Reproducing Molded Insole” (Attorney Docket No. ZGI.004A) concurrently filed with this application, both of which are incorporated herein by reference. BACKGROUND [0002] 1. Field [0003] The described technology generally relates to a molding device and a method of use thereof to produce a custom molded insole. [0004] 2. Description of the Related Technology [0005] A shoe insole or insole refers to an insert with a cushion layer which is fitted into a shoe. Insoles are widely used to provide support and comfort for a user's foot. To provide optimized comfort to a specific foot, custom-made insoles have been developed that conform to the unique and specific shape of a user's foot. In general, custom insoles can be made by molding insoles using a person's feet. These customized insoles are generally more comfortable than mass produced insoles. SUMMARY [0006] The apparatuses and systems of the present disclosure have several features, no single one of which is solely responsible for its desirable attributes. Without limiting the scope of the described technology as expressed by the claims which follow, its more prominent features will now be discussed briefly. After considering this discussion, and particularly after reading the section entitled “Detailed Description,” one will understand how the features of this disclosure provide several advantages over current insole molding technologies. [0007] In one aspect, a molding device includes a foam layer, a gel layer placed over the foam layer, and a flexible cover configured to enclose the foam layer and the gel layer, wherein the flexible cover includes a movable portion and an intermediate portion placed below the movable portion, wherein the intermediate portion is placed between a portion of the gel layer and a portion of the foam layer, and wherein the flexible cover includes a surface that contacts a top of the gel layer, wherein the gel layer is configured to elastically support the shoe insole via the surface of the flexible cover, and wherein the movable portion is configured to move the portion of the gel layer between a first position where the movable portion contacts the intermediate portion and a second position where the movable portion is separated from the intermediate portion. [0008] Another aspect is a method of custom molding a shoe insole including placing the insole on a molding device, wherein the molding device includes a foam layer, a gel layer, and a flexible cover, first pressing the insole between a user's foot and a surface of the molding device with the molding device in a first position, wherein the surface contacts a top of the gel layer; and second pressing the insole between the user's foot and the surface of the molding device with the molding device in a second position different from the first position. In some aspects the method further includes heating the insole to a temperature in the range of approximately 120° C. and approximately 140° C. for between about three minutes and about five minutes; [0009] Another aspect is a shoe insole molded by the above method. [0010] Another aspect is a molding device for molding a shoe insole including a gel layer and a flexible cover configured to enclose the gel layer, wherein the flexible cover includes a surface that contacts a top of the gel layer, wherein the gel layer is configured to elastically support the shoe insole via the surface of the flexible cover. BRIEF DESCRIPTION OF THE DRAWINGS [0011] The above mentioned and other features of this disclosure will now be described with reference to the drawings of several embodiments of the present molding device and method of use thereof. The illustrated embodiments of the apparatuses and methods are intended to illustrate but not to limit the disclosure Like reference numerals refer to like elements throughout the detailed description. The drawings contain the following figures: [0012] FIG. 1 is a conceptual drawing that illustrates a method for custom molding an insole using a molding device according to one embodiment. [0013] FIGS. 2A and 2B show top and bottom views, respectively, of a pair of example insoles that can be molded to conform to the specific shape of a user's foot with example molding devices and methods described herein according to one embodiment. [0014] FIGS. 3A and 3B show perspective views of an example molding device including a moveable portion in a first position and a second position, respectively, according to one embodiment. [0015] FIGS. 3C and 3D show side views of the molding device of FIGS. 3A and 3B with the movable portion in the first position and the second position, respectively. [0016] FIG. 3E shows a top view of the molding device of FIGS. 3A and 3B with a movable portion shown in the first position. [0017] FIG. 4 depicts example interior layers of the molding device according to one embodiment. [0018] FIG. 5 is a side view of the molding device that illustrates the placement of each of the internal layers within the cover according to one embodiment. [0019] FIG. 6A shows an example molding stand including two molding devices, according to one embodiment. [0020] FIG. 6B is a cross-sectional view of the molding stand of FIG. 6A and illustrates the placement of the molding devices within the molding stand. [0021] FIG. 7 is a flowchart depicting an example method of using a molding device as described herein to custom mold a moldable insole according to one embodiment. [0022] FIGS. 8A through 8C illustrate comparison of a user's foot to a selected insole to determine whether a properly sized insole has been selected. [0023] FIG. 9 illustrates an example heater configured to heat the insoles according to one embodiment. [0024] FIGS. 10A through 10C illustrate proper and improper insertion of moldable insoles into the heater according to one embodiment. [0025] FIG. 11 illustrates an example of the relative positioning of a user, a heated moldable insole, and a molding device in preparation for molding the moldable insole according to one embodiment. [0026] FIG. 12 provides a detailed view of the alignment of a heated moldable insole on a molding device according to one embodiment. [0027] FIGS. 13A and 13B illustrate the use of an example heel alignment guide on the moldable insole to properly align the user's foot relative to the moldable insole during the molding process according to on embodiment. [0028] FIG. 14 illustrates an example positioning of a user with weight shifted to his or her heels during some portions of the molding process according to one embodiment. [0029] FIG. 15 illustrates an example positioning of a user and the molding device with a movable portion in the second position during some portions of the molding process according to one embodiment. [0030] FIGS. 16A and 16B illustrate the use of an example quality control tool to check that the heel portion of a molded insole is properly aligned and level according to one embodiment. DETAILED DESCRIPTION [0031] Embodiments will be described with respect to the accompanying drawings. Like reference numerals refer to like elements throughout the detailed description. In this disclosure, the term “substantially” includes the meanings of completely, almost completely or to any significant degree under some applications as understood by those skilled in the art. [0032] FIG. 1 is a conceptual drawing that illustrates a method 10 for molding a non-molded insole 100 (hereinafter to be interchangeably used with non-molded insoles 100 ) to produce a custom molded insole 100 ′ using a molding device 300 according to one embodiment. The method 10 the uses non-molded insoles 100 , a heater 200 , and the molding device 300 to mold the non-molded insoles 100 to conform to the unique shape of a user's foot 5 . [0033] The method 10 begins at step 15 with selection of a pair of non-molded insoles 100 , one for each of a user's feet 5 . Each of the insoles 100 may include at least one rigid layer that becomes pliable upon heating. At step 15 , the selected non-molded insole 100 is inserted into the heater 200 and heated until the at least one rigid layer becomes pliable. [0034] At step 20 , the heated insole 100 is removed from the heater 200 and placed on a top surface of the molding device 300 . The user's foot 5 is then placed on top of the heated insole 100 . As the foot 5 presses the heated insole 100 into the molding device 300 , the heated insole 100 substantially conforms to the specific musculoskeletal shape of the foot 5 . As shown in step 20 , the molding device 300 includes a moveable portion 310 resting on top of a fixed portion 320 . This position of the movable portion 310 of the molding device 300 is referred to as the first position throughout this application. The molding device 300 can mold at least the rearfoot and/or midfoot portion of the insole 100 in the first position. In some embodiments, the user leans back, placing his or her weight on her heels to mold a portion of the insole 100 with the movable portion 310 of the molding device 300 in the first position. [0035] At step 25 , the movable portion 310 of the molding device 300 is moved into a second position as shown. When the movable portion 310 is in the second position, the moveable portion 310 can be pulled up away from the fixed portion 320 and toward a user's shin. The molding device 300 includes a handle 350 attached to a distal end of the moveable portion 310 that can be gripped to move the moveable portion 310 into the second position as described. The molding device 300 can mold at least a forefoot and/or midfoot portion of the insole 100 with the movable portion 310 in the second position. [0036] Step 25 can be performed substantially close in time to step 20 , either before or after. In some embodiments, step 25 follows immediately after or precedes immediately before step 20 such that the heated insole 100 remains substantially pliable during step 20 and step 25 . Moreover, in some embodiments, the foot 5 is not repositioned on the heated insole 100 or molding device 300 between step 20 and 25 (other than the movement of the insole 100 and foot 5 as the movable portion 310 of the molding device 300 is moved from the first position to the second position, or vice versa). [0037] Method 10 concludes at step 30 , where the now molded insole 100 ′ is removed from between the user's foot 5 and the molding device 300 and allowed to cool. As the rigid layer of the molded insole 100 ′ cools, it returns to its substantially rigid state and holds its newly molded shape. Accordingly, method 10 allows a user to mold a non-molded insole 100 , with a general shape, into a molded insole 100 ′ with a specific shape that conforms substantially to the unique shape of the user's foot 5 . [0038] In some embodiments, the method 10 is repeated for each of a user's feet 5 . A single insole 100 (for example, for the right foot) can be heated, molded to the user's foot 5 with the movable portion 310 of the molding device 300 in the first position and in the second position, and allowed to cool, and then the process can be repeated again for the other insole 100 (for example, for the left foot). In some embodiments, both insoles 100 (left and right) are heated together and molded separately. For example, both insoles 100 can be heated at the same time, one insole 100 can be molded using the molding device 300 with the movable portion 310 in the first and second positions, and then the other insole 100 can be molded using the molding device 300 in the first and second positions. In some embodiments, the insoles 100 are heated and molded together, for example, using a single molding device 300 wide enough to simultaneously accommodate both of a user's feet 5 , or two narrower molding devices 300 placed side by side. The specific details and devices of method 10 will now be discussed in greater detail below. [0039] FIGS. 2A and 2B show top and bottom views, respectively, of a pair of example insoles 100 that can be molded to conform to the specific shape of a user's foot 5 with embodiments of the molding devices 300 and methods described herein according to one embodiment. The following description of FIGS. 2A and 2B is applicable to insoles 100 in both a molded or non-molded state. [0040] Each pair of insoles 100 includes a right and a left insole 100 , each shaped generally with a profile configured to substantially follow the shape of a user's left and right foot, respectively. Each insole 100 includes a rearfoot or heel area 101 , midfoot or arch area 103 , and a forefoot or toe area 105 as shown. In some embodiments, the insoles 100 are made from one or more layers. For example, as shown in FIGS. 2A and 2B , the insoles 100 are made from four layers. Each of the insoles 100 includes a cover layer 110 placed on top of a foam layer 120 , a rigid layer 130 , formed of a heat-moldable material, placed below the foam layer 120 , and a base layer 140 covering the rigid layer 130 . In some embodiments, the cover layer 110 and the foam layer 120 extend under the entirety of the user's foot 5 , for example, from the rearfoot area 101 to the forefoot area 105 . In some embodiments, the rigid layer 130 and the base layer 140 extend only under the rearfoot area 101 and at least a portion of the midfoot area 103 (or, in other words, in some embodiments, the rigid layer 130 and base layer 140 do not extend under the toe area 105 of the insole 100 ). [0041] The rigid layer 130 of the insole 100 can be made from a heat-formable or thermoplastic material, such as a glycol-modified polycyclohexylenedimethylene terephthalate copolymer (PCTG), ABS, PVC, A-PET, PETG, or another suitable material that is (1) substantially rigid throughout a range of temperatures at which the insole 100 will be used, for example, the range of temperatures typical within a user's shoe, and (2) substantially pliable or moldable throughout a range of temperatures that will be used during the molding process, for example, temperatures in the range of about 120 to about 140° C. In some embodiments, the material of the rigid layer 130 is pliable at temperatures which allow the heated insole 100 to be pressed against a user's foot 5 while still in a pliable state without burning or injuring the user. In some embodiments, the foam layer 120 and the cover layer 130 provide sufficient insulation to protect a user's foot 5 during molding. [0042] In some embodiments, as shown in FIG. 2A , the cover layer 110 also includes one or more heel alignment guides 111 , configured to aid a user in correctly locating his or her heel relative to the insole 100 during molding. Moreover, additional alignment guides 113 are present on the cover layer 111 which may be used to help align the insole 100 relative to the molding device 300 during the molding process. However, some or all of the elements 111 and 113 can be omitted. [0043] A detailed description of an example moldable insole that can be used with the devices and methods described herein is provided in the U.S. patent application entitled “Moldable Footwear Insole” (Attorney Docket No. ZGI.002A) that is concurrently filed herewith and is incorporated herein by reference. It should be noted, however, that the molding devices and methods described herein may be usable with other types of moldable insoles. [0044] FIGS. 3A through 3E show various views of an example molding device 300 according to one embodiment. Specifically, FIGS. 3A and 3B show perspective views of the molding device 300 including a moveable portion 310 in a first position and a second position, respectively. FIGS. 3C and 3D show side views of the molding device 300 shown with the movable portion 310 in the first position and the second position, respectively. FIG. 3E shows a top view of the molding device 300 with a movable portion 310 shown in the first position. Depending on the specific embodiments, certain elements may be removed from or additional elements may be added to the molding device 300 illustrated in FIGS. 3A through 3E . Furthermore, two or more elements may be combined into a single element, or a single element may be realized as multiple elements. [0045] The molding device 300 shown in FIGS. 3A and 3B includes a body 301 shaped as a rectangular prism, although other shapes may be used without departing from the scope of this disclosure. The body 301 is configured to support the insole 100 and the foot 5 during the molding process. The insole 100 can be placed on a top surface 305 of molding device 300 and the foot 5 is placed on top of the insole 100 . [0046] The body 301 of the molding device 300 may include one or more internal layers of gel and one or more internal layers of foam, as will be described below, placed within a flexible cover 360 . Accordingly, as a user steps onto the top surface 305 of the molding device 300 , the user's foot presses into the body 301 of the molding device 300 , and the top surface 305 of the molding device 300 conforms substantially to the specific shape of the bottom surface of the user's foot 5 . The insole 100 , pressed between the foot 5 and the molding device 300 , is therefore molded to conform to the shape of the foot 5 . [0047] A front or distal portion 302 of the body 301 of the molding device 300 is divided between a moveable portion 310 and a fixed portion 320 separated by a gap 315 . The movable portion 310 can be configured as a flap and attached to the rest of body 301 at a proximal end of the movable portion 310 at a hinge region 313 . A handle 350 can be provided at a distal end of the movable portion 310 and configured such that a user can grip the handle 350 and pull the movable portion 310 up away from the fixed portion 320 , thereby increasing the size of gap 315 . In some embodiments, the movable portion 310 connects to the fixed portion 320 at approximately the location where the ball of a foot is placed during molding. In some embodiments, the length of the moveable portion 310 is approximately one-third the total length of the molding device 300 . [0048] FIGS. 3A and 3C show the molding device 300 with the movable portion 310 in the first position. In the first position, the moveable portion 310 rests substantially on top of and is supported by the fixed portion 320 , and the gap 315 is substantially small. In some embodiments, a lower surface of the movable portion 310 rests directly on top of a top surface of the fixed portion 320 such that the gap 315 is substantially closed. With the movable portion 310 in the first position, the top surface 305 of the molding device 300 has a substantially horizontal planar shape. Accordingly, in this position, the molding device 300 provides a flat molding surface. [0049] FIGS. 3B and 3D show the molding device 300 with the movable portion 310 in the second position. In the second position, the moveable portion 310 is pulled up and away from the fixed portion 320 and the gap 315 is substantially open. Because the moveable portion 310 is attached to the body 301 at the hinge region 313 , in the second position, the moveable portion 310 is substantially positioned at an angle relative to the plane of the top surface 305 in the first position. In some embodiments, the moveable portion 310 curves up and away from the body 301 . The molding device 300 , with the movable portion 310 in the second position, provides a molding surface configured to conform to the shape of a user's foot 5 with the toes in extension. [0050] As shown in FIG. 3C , the molding device 300 may have an overall thickness T. In some embodiments, the overall thickness T is between approximately 30 mm and approximately 200 mm. In some embodiments, the overall thickness T is approximately 100 mm. For a front or distal portion 302 of the molding device 300 , the overall thickness T is divided between the thickness of the moveable portion 310 , T m , and the thickness of the fixed portion 320 , T f . In some embodiments, the thickness T m is substantially half or less than half the thickness of T f . For example, in some embodiments, T m is approximately 30 mm and T f is approximately 70 mm. However, the described technology is not limited to the above ranges and other thicknesses for T, T m , and T f are possible. As will be explained below, the thicknesses of T m and T f may correspond to the thicknesses of the individual layers that make up the internal structure of the molding device 300 . [0051] The molding device 300 has an overall length L and an overall width W as shown in FIG. 3E . The length L and width W define the overall shape of the molding device 300 . As shown, the molding device 300 may be substantially rectangular, although other shapes are possible as long as the shape provides adequate space for an insole 100 and user's foot 5 to be received thereon. In some rectangular embodiments, each of the length L and the width W may be in the range of approximately 150 mm and approximately 400 mm. However, other lengths and widths are possible, for example, as long as the length L and width W are sufficient to accommodate the entire length of a user's foot 5 and provide some clearance space (for example, at least 10 mm) around the foot 5 . The width W can be configured such that the molding device 300 is suitable for use with only a single foot 5 at a time. The width W can further be configured such that the molding device 300 is suitable for use with both feet 5 at the same time. [0052] In some embodiments, as shown in FIG. 3E , the top surface 305 of the molding device 300 includes one or more alignment guides 307 that aid a user in placing the insole 100 correctly on the molding device 300 . The alignment guides 307 may be markings corresponding to other alignment guides (for example, front alignment guides 113 as seen in FIG. 2A ) on the cover layer 130 of the insole 100 . For example, in some embodiments, the user may be instructed to align front alignment guides 113 on the cover layer 110 with the alignment guides 307 on the top surface 305 of the molding device 300 . This may help ensure that the insole 100 is correctly aligned on the molding device 300 so as to correctly be molded when the movable portion 310 of the molding device 300 is in the second position. [0053] In some embodiments, as shown in FIG. 3E , the handle 350 of the molding device 300 includes one or more holes 351 extending through the handle 350 . The holes 351 can be configured to make the handle 350 easier to grip. [0054] In some embodiments, as seen in FIGS. 3A and 3B , the molding device 300 includes a cover 360 configured to surround the internal components of the molding device 300 . The cover 360 can be made from any typical flexible fabric, such as flexible cloth. In some embodiments, the cover 360 is made from a thin, elastic cloth, for example Spandex. The particular shape of the cover 360 will become apparent as the internal components of the molding device 300 are described below. [0055] The cover 360 may be configured to be removable. As seen in FIG. 3A , in some embodiments, the cover 360 includes a zipper 365 extending around a back surface of the molding device 300 . The cover 360 may use other closure mechanisms. For example, the cover 360 may include one or more openings that use Velcro, buttons, snaps, toggles, magnets, zippers, or any other suitable closure mechanism. In some embodiments, the cover 360 includes openings that do not use any closure mechanism. For example, the cover 360 may include an opening that includes overlapping flaps. In some embodiments, the cover 360 does not include any opening and may not be removable. In some embodiments, no cover is used. [0056] FIG. 4 depicts example interior layers of the molding device 300 according to one embodiment. In the embodiment shown, the molding device 300 includes two layers: a gel layer 370 and a foam layer 380 . [0057] The gel layer 370 is placed directly below the top surface 305 of the molding device 300 . Accordingly, the gel layer 370 is the structure within the molding device 300 that allows the molding device 300 to accurately mold the insoles 100 to the specific shape of a user's foot 5 . In some embodiments, the gel layer 370 provides a liquid pressure effect against the bottom and sides of the foot during molding. That is, in some embodiments, the gel layer 370 provides a substantially or significantly uniform pressure around the sides of the foot, as well as on the bottom of the foot. The gel layer 370 may allow a more accurate molding of a heel cup region of the insole 100 by providing uniform molding pressure around the heel as high as 2 cm to about 4 cm above the bottom of the insole 100 . Similarly, the gel layer 370 may allow for a higher formed arch and a more generally contoured molded insole 100 . The gel layer 370 may be made from a gel or foam material with a density and/or hardness comparable to the hardness of muscle tissue. For example, in some embodiments, the gel layer 370 is formed from a silicon rubber or other suitable material with a Shore hardness of in the range of about 00-40 and about 00-05. In some embodiments, the gel layer is formed from Ecoflex® Supersoft 0010, Ecoflex® Supersoft 0020, or Ecoflex® Supersoft 0030 available from Smooth-On, Inc., of Macungie, Pa. [0058] The foam layer 380 is placed below the gel layer 370 . The foam layer 380 supports the gel layer 370 , for example, by providing a sturdy, compressible base for the molding device 300 . The foam layer 380 can be made from a stiff, deformable viscoelastic foam, such as memory foam. In some embodiments, the foam layer 380 is made at least partially from a polyurethane material that has viscoelastic property. Preferably, in some embodiments, the foam layer 380 should be just pliable to enough to allow the gel layer 370 to contour to the bottom of the user's foot 5 when the user stands on the molding device 300 . Preferably, in some embodiments, the foam layer 380 is as stiff as possible while still allowing deformation sufficient to allow the gel layer 370 to contour to the entire bottom surface of a user's foot 5 and at least a portion of the side surface of the foot. In some embodiments, the foam layer 380 may deform in the range of between about 0.1 inches to about 1.0 inch when a user stands on the molding device 300 . In some embodiments, the combined deformation of the gel layer 370 and the foam layer 380 is sufficient to allow the top surface 305 to conform to the shape of the arch of the foot 5 when the user stands on the molding device 300 . In some embodiments, each of the gel layer 370 and/or the foam layer 380 includes one or more layers. [0059] Each of the gel layer 370 and the foam layer 380 can be configured in size and shape to fit within the cover 360 . Accordingly, the gel layer 370 and the foam layer 380 may each have a length and a width that correspond to the overall length L and width W of the molding device 300 described above in reference to FIG. 3E . Moreover, the thicknesses of gel layer 370 and the foam layer 380 may correspond to the thicknesses of the moveable portion 310 , T m , and the fixed portion 320 , T f , respectively. [0060] FIG. 5 is a side view of the molding device 300 that illustrates the placement of each of the internal layers 370 , 380 within the cover 360 according to one embodiment. As shown, the cover 360 is configured to substantially surround the gel layer 370 and the foam layer 380 . At the distal end 302 , the molding device 300 is divided into the moveable portion 310 and the fixed portion 320 as described above. The cover 360 includes a movable pocket 361 and a fixed pocket 363 as shown. The foam layer 380 may be inserted into the bottom portion of the cover 360 and a distal end of the foam layer 380 may be placed within the fixed pocket 363 , forming the fixed portion 310 . Similarly, the gel layer 370 may be inserted into the top portion of the cover 360 above the foam layer 370 . A distal end of the gel layer 370 may be placed within the moveable pocket 361 of the cover 360 , forming the movable portion 310 . Accordingly, a top portion of the fixed pocket 363 and a bottom portion of the moveable pocket 361 are located between the distal ends of the foam layer 380 and the gel layer 370 . The proximal ends of the foam layer 380 and the gel layer 370 , in some embodiments, are placed directly on top of each other. [0061] A portion of the gel layer 370 may be placed within the fixed pocket 363 . For example, the distal end of the gel layer 370 is split with a top portion placed within the moveable pocket 361 and a bottom portion placed within the fixed pocket 363 . Or, for example, the gel layer 370 includes two or more layers, with a top layer placed within the moveable pocket 361 and a bottom layer placed within the fixed pocket 363 . Similarly, a portion of the foam layer 380 may be placed within the movable pocket 361 . For example, the distal end of the foam layer 380 is split with a top portion with a top portion placed within the moveable pocket 361 and a bottom portion placed within the fixed pocket 363 . Or, for example, the foam layer 380 includes two or more layers, with a top layer placed within the moveable pocket 361 and a bottom layer placed within the fixed pocket 363 . [0062] The layers placed within the movable pocket 361 , that accordingly include the movable portion 310 of the molding device 300 , are sufficiently pliable to allow movement of the movable portion 310 of the molding device 300 between the first and second positions as described above. The movable portion 310 allows the molding device 300 to more accurately mold the forefoot and/or midfoot portions of the insole 100 . [0063] FIG. 6A shows an example molding stand 400 including two molding devices 300 according to one embodiment. The molding stand 400 includes a base 405 configured to rest on the ground and support one or more molding devices 300 therein. In some embodiments, the base 405 includes one or more recesses 410 formed in a top surface of the base 405 . The base 405 can include a single recess 410 configured to hold a single molding device 300 or two (or more) molding devices 300 side by side. The base 405 may include more than one recess 410 , each recess configured to hold a single molding device 300 . The base 405 may support one or more molding devices 300 above the ground such that a user may easily step up and onto the molding devices 300 in the base 405 of the molding stand 400 . [0064] A vertical support 415 can extend upward from the base 405 and provide a handle 420 that users can use to support and balance themselves during the molding process. In some embodiments, the vertical support 415 extends up and away from an outer edge of the base 405 such that the handle 420 is positioned substantially in front of a user standing on the molding stand 400 . The handle 420 can be positioned between three and four feet above the base 405 . In some embodiments, the vertical support 415 is adjustable, such that the height of the handle 420 can be adjusted to accommodate users of different heights. [0065] FIG. 6B is a cross-sectional view of the molding stand 400 of FIG. 6A and illustrates the placement of the molding devices 300 within the molding stand 400 . As shown, the molding device 300 rests within the recess 410 of the base 405 . In some embodiments, the movable portion 310 is placed substantially above the top surface of the base 405 . This may facilitate use of the molding device 300 . For example, it may make it easier to grab the handle 350 and move the movable portion 310 of the molding device 300 from the first position to the second position. In some embodiments, however, the top surface 305 of the molding device 300 may be level with (or even below) the top surface of the base 300 . [0066] FIG. 7 is a flowchart depicting an example method 700 of using a molding device 300 as described herein to custom mold an insole 100 according to one embodiment. Method 700 describes in detail the molding method 10 discussed at a conceptual level above in reference to FIG. 1 . Depending on the specific embodiment, additional steps may be added, others removed, or the order of the steps changed in the method 700 . The method 700 will now be described in detail with reference to FIG. 7 as well as the specific examples and embodiments illustrated in FIGS. 8A-16B . [0067] The method 700 may be performed in a retail establishment, for example, a sporting goods store, runner specific athletic store, or other shoe store. Accordingly, in some embodiments, the user may be customer visiting a retail establishment to obtain a pair of custom molded insoles 100 . An employee or clerk of the retail establishment may assist the user in custom molding a pair of insoles 100 using the method 700 described herein. In another embodiment, a medical professional, for example a doctor or physical therapist, may assist the user in custom molding a pair of insoles 100 . [0068] At block 704 , a non-molded insole 100 is selected to be custom molded to conform to the specific shape of the user's foot 5 . In some embodiments, selection of the insole 100 involves consideration of several factors. For example, the selection can be made based on the size of the user's foot 5 , the weight of the user, or the anticipated use of the insole 100 . [0069] FIGS. 8A through 8C illustrate comparison of a user's foot 5 to a selected insole 100 to determine whether a properly sized insole 100 has been selected. FIG. 8A illustrates an example of a properly sized insole 100 as compared to the user's foot 5 . FIG. 8B provides an example of an insole 100 that is too small when compared to the user's foot 5 . The toes of the user's foot 5 fall on top of, over, or across the outline of the toe edge of the insole 100 . When comparison of the insole 100 and the foot 5 indicates that the selected insole 100 is too small, a larger sized insole 100 should be chosen. FIG. 8C illustrates an example of an insole 100 that is too large as compared to the user's foot 5 . For example, as shown in FIG. 8C , if there is more than one half-inch space between the end of the user's toes and the toe edge of the insole 100 , the selected insole 100 is too large and a smaller sized insole 100 should be selected. [0070] Returning to FIG. 7 , the selection of the insole 100 performed at block 704 may be made, in part, based upon a user's weight. For example, a thicker, or more rigid, insole 100 may be selected to accommodate a heavier user. In some embodiments, the selection of the insole 100 also may consider, in part, the intended use of the insole 100 . For example, one type of insole 100 may be provided for distance runners, another type of insole 100 may be provided for general athletes, and another type of insole 100 may be provided for general non-athletic use. [0071] At block 706 , the selected insole 100 is heated. The insole 100 can be heated to a temperature in the range of about 120° C. to about 140° C. (for example, about 127° C.) for a range of about three to five minutes (for example, about four minutes). In some embodiments, the insole 100 is heated in a heater 200 . [0072] FIG. 9 illustrates an example of a heater 200 configured to heat the insoles 100 according to one embodiment. The heater 200 includes a slot 203 into which the insoles 100 can be inserted into an interior region of the heater 200 . The heater 200 includes a heating element (not shown) within the interior region of the heater 200 . In some embodiments, the heating element is a resistive wire heater. In some embodiments, the heating element is similar to that used in a traditional oven. The heating element may be positioned above and/or below the insoles 100 . In some embodiments, the heating element includes a heated plate that is pressed against the insoles 100 . A single heated plate may be positioned above and/or below the insoles 100 . In some embodiments, the heated plate is positioned below the insoles 100 and a pillow positioned above the insoles 100 presses the insoles 100 into the heated plate. The heater 200 may also include an on/off switch 205 , one or more heater controls 210 , and a display 215 . The one or more heater controls 210 may allow a user to select between one or more preset heating cycles, or to adjust the heating temperature and/or heating time manually. The display 215 can be configured to display the desired heating temperature, the current internal temperature of the heater 200 , and/or the heating duration. It will be appreciated that the heater 200 shown in FIG. 9 is merely one embodiment that can be used with the method 700 . A person skilled in the art will understand that other types of heaters or methods for heating the insole 100 may be used with method 700 without departing from the scope of this disclosure. [0073] FIGS. 10A through 10C illustrate proper and improper insertion of the insoles 100 into the heater 200 according to one embodiment. In some embodiments, proper heating of the insoles 100 involves heating only the portion of the insole 100 that includes the heat moldable rigid layer 130 . For example, only the rearfoot area 101 and the midfoot area 103 of the insole 100 are inserted into the heater 200 . FIG. 10A illustrates an example where the insoles 100 are inserted into the heater 200 only as far as necessary. As shown, the forefoot area 101 and a very small portion of the midfoot area 103 are positioned outside of the heater 200 . The remainder of the midfoot area 103 and the rearfoot area 101 are inserted into the heater 200 . Accordingly, only the portions of the insole 100 that include the heat moldable rigid layer 130 are heated. FIG. 10B illustrates an example where the insole 100 is not sufficiently inserted into the heater 200 . As shown, a large portion of the midfoot area 103 , including a portion of the rigid layer 130 , is not inserted into the heater 200 . When this occurs, a portion of the rigid layer 130 is not heated and thus cannot be properly molded to the user's foot 5 . FIG. 10C illustrates an example where too much of the insole 100 is inserted into the heater 200 . As shown, only a small portion of the forefoot area 105 of the insole 100 is extending out of the heater 200 . This may be problematic because the heater 200 is heating portions of the insole 100 that do not require heating. [0074] Returning to FIG. 7 , at block 708 , the heated insole 100 is positioned on the top surface 305 of the molding device 300 in preparation for molding. FIG. 11 illustrates an example of the relative positioning of the user, the user's foot 5 , the heated insole 100 , and the molding device 300 in preparation for molding. As shown, two molding devices 300 (one for each foot) are placed in a molding stand 400 . The user stands with his or her left foot 5 on the left molding device 300 and his or her right foot 5 lifted above the top surface 305 of the right molding device 300 . The right heated insole 100 is placed on the top surface 305 of the right molding device 300 below the user's foot 5 . Although FIG. 11 illustrates an example where a user is preparing to mold a right-footed insole 100 , it will be understood that the example can be reversed and applied to the positioning for molding a left-footed insole 100 . [0075] FIG. 12 provides a detailed view of the alignment of the heated insole 100 on top of a molding device 300 and below the user's foot 5 . Front alignment guides 113 on the cover layer 110 of the insole 100 (also shown in FIG. 2A ) are aligned with the alignment guides 307 (also shown in FIG. 3E ) on the top surface 305 of the molding device 300 . In some embodiments, this ensures that the heated insole 100 is positioned correctly on the molding device 300 so as to properly be molded when the movable portion 310 of the molding device 300 is in both the first and second positions. The heel alignment guide 111 on the top surface of the insole 100 is positioned below the heel. [0076] Once the heated insole 100 and user have been properly positioned relative to the molding device 300 , the user's foot 5 , is placed into contact and aligned with the insole 100 . At block 710 , the user's foot 5 can be correctly positioned by aligning the heel of the user's foot 5 with the heel alignment guides 111 on the insole 100 , and then ensuring that the user's foot 5 is centered along the width of the insole 100 . [0077] FIGS. 13A and 13B illustrate the use of an example heel alignment guide 111 on the moldable insole 100 to properly align the user's foot 5 relative to the moldable insole 100 during the molding process 700 according to on embodiment. As shown in FIG. 13A , an employee or other person assisting the user, may place the thumb of one hand at the bottom of the circles of the heel alignment guide 111 . The thumb may provide a backstop against which the user's foot 5 will be positioned. As shown in FIG. 13B , the employee or other person assisting the user uses his or her other hand to guide the placement of the user's foot 5 onto the heated insole 100 . The user's heel is placed against the employee's thumb, and the employee ensures that foot 5 is centered on the insole 100 across the insole's width. [0078] Returning again to block 710 of the method 700 illustrated in FIG. 7 , once the user's foot 5 is aligned and placed onto the heated insole 100 with the user's weight applying downward pressure, the heated insole 100 begins to conform to the unique shape of the user's foot 5 . In some embodiments, after the foot 5 is properly placed and aligned on the insole 100 , the user stands with weight distributed evenly on both feet 5 , looking straight ahead, for example, for approximately ten seconds to allow time for the insole 100 to mold to the user's foot 5 . In some embodiments, during this step the user may stand with weight evenly distributed between each foot 5 , looking straight ahead, for example, for between about five and about thirty seconds. [0079] At block 712 , the molding device 300 is used with the movable portion 310 in the first position to mold a portion of the insole 100 . In some embodiments, with the movable portion 310 in the first position, the user shifts his or her weight to his or her heels and distributes the weight equally between each foot 5 . That position may be held, for example, for approximately ten seconds, while continuing to look straight ahead. In some embodiments, this is accomplished by having the user grip the handle 420 of the molding stand 400 and lean backward, placing weight onto his or her heels, for example as shown in FIG. 14 . After shifting weight to the heels for, for example, ten seconds, the user is directed to return to an upright position with weight distributed equally. In some embodiments the user may shift weight to the heels, for example, for between about five and about thirty seconds before returning to an upright position. [0080] At block 714 , the movable portion 310 of the molding device 300 is adjusted to the second position to mold a portion of the insole 100 . FIG. 15 illustrates an example positioning of a user and the molding device 300 with the movable portion 310 in the second position. As shown, an employee or other person assisting the user, uses one hand to grab the handle 350 on the distal end of the moveable portion 310 and pulls the moveable portion 310 straight back towards the user's shin, pulling the toes of the user's foot 5 back and up. With his or her other hand, the employee or other person assisting the user can hold the user's ankle or lower leg to ensure that the user's ankle and foot alignment remains neutral throughout the molding process. This positioning is held for, for example, approximately ten seconds to allow the insole 100 to conform to the shape of a user's foot 5 . In some embodiments, this position is held for, for example, between about five and about thirty seconds. After the designated time, the movable portion 310 of the molding device 300 is returned to the first position by lowering the handle 350 until the movable portion 310 rests on top of the fixed portion 320 . This allows the user's toes to come back down to a normal standing position. At this point, the user lifts his or her foot off the insole 100 and the insole 100 is removed and allowed to cool. As the insole 100 cools, the rigid layer 130 hardens and retains the newly molded shape. [0081] At block 716 , the now molded insole 100 is checked for quality. In some embodiments, this involves visually inspecting the molded insole 100 , placing the insole 100 in a user's shoe to check for comfort, and/or checking the molded insole against a quality control tool. [0082] FIGS. 16A and 16B illustrate the use of an example quality control tool 800 to check that the heel portion 101 of a molded insole 100 is properly aligned and level according to one embodiment. The quality control tool 800 includes a semicircular body 801 with one or more parallel lines 805 inscribed on an inside wall of the body 801 . Each of the interior lines 805 may be a different color to allow a user to easily follow each single interior line 805 . The heel area 101 of the molded insole 10 can be inserted into the interior region of the body 801 and the compared against the plurality of lines 805 to determine whether the heel area 101 is properly aligned and level. In some embodiments, as shown in FIG. 16A , the edge of a properly aligned and level heel area 101 of the molded insole 100 generally follows the interior lines 805 of the quality control tool 800 . This indicates that the heel cup is level. FIG. 16B shows an improperly molded insole 100 compared against the quality control tool 800 . When the edge of the heel area 101 crosses through several of the interior lines 805 of the quality control tool 800 , this indicates that the insole 100 has not been properly molded. [0083] If the quality of the molded insole 100 is determined to be insufficient, the molded insole 100 may discarded and the method 700 may begin again with a new non-molded insole 100 . If the quality of the molded insole 100 is determined to be sufficient, method 700 ends. [0084] The toe edge of the molded insole 100 may be trimmed before use. This may be done by placing the molded insole 100 on top of or below the insole from the user's shoe. The user or employee assisting the user can then trim the toe edge of the molded insole with scissors using the insole from the user's shoe as a template. It may not be necessary to trim the heel edge of the molded insole 100 . The molded insole 100 is then ready for insertion into a user's shoe and is ready for use. [0085] According to at least one of the disclosed embodiments, an insole 100 can be efficiently and accurately molded by a molding device 300 . The molding device 300 include a movable portion 310 that is movable between a first position, useful for molding at least a rearfoot and/or midfoot portion of the insole 100 , and a second position, useful for molding at least a forefoot and/or midfoot portion of the insole 100 . [0086] While the above description has pointed out features of various embodiments, the skilled person will understand that various omissions, substitutions, and changes in the form and details of the device or process illustrated may be made without departing from the scope of the appended claims.

A molding device is disclosed. In one aspect, the molding device includes a foam layer, a gel layer placed over the foam layer, and a flexible cover configured to enclose the foam layer and the gel layer, wherein the flexible cover comprises a movable portion and an intermediate portion placed below the movable portion, wherein the intermediate portion is placed between a portion of the gel layer and a portion of the foam layer, and wherein the flexible cover includes a surface that contacts a top of the gel layer, wherein the gel layer is configured to elastically support the shoe insole via the surface of the flexible cover, and wherein the movable portion is configured to move the portion of the gel layer between a first position where the movable portion contacts the intermediate portion and a second position where the movable portion is separated from the intermediate portion.

FIELD OF THE INVENTION [0001] The present invention relates generally to a routing method in wireless communication systems, and more particularly, to a routing method during communication process and a mobile terminal to perform the method. BACKGROUND OF THE INVENTION [0002] Wireless networks have become increasingly popular in current social life, for their provision of ubiquitous computing capability and information access regardless of the location. [0003] Currently, there are two variations of mobile wireless networks—infrastructure-based mobile wireless network such as cellular networks and WLANs (Wireless Local Area Network), and wireless networks without infrastructure such as mobile ad hoc networks. Generally, in infrastructure-based wireless networks, the coverage range of a base station or AP (access point) determines the size of a cell and the mobile nodes (mobile terminals) camping within the cell connect to and communicate directly with the nearest bridge (base station or access point). While in mobile ad hoc networks, the mobile nodes are self-organizing. Two communicating mobile nodes can still maintain communication with each other when they are out of the radio range provided that they can reach each other via intermediate mobile nodes acting routers that forward packets from source to destination. In infrastructure-based wireless networks, mobile nodes are directly connected to the base station or AP, so infrastructure-based wireless networks are considered as one-hop network. While in mobile ad hoc networks, there usually is no direct link between two mobile nodes and they have to communicate through relaying of other mobile nodes, so mobile ad hoc networks are also called as multi-hop network. [0004] Due to the potential ease of deployment, mobile ad hoc networks are spreading madly to many practical applications, including PAN, HAN, military environments, search-and-rescue operations and so on. Due to the fact that the theoretical total transmission power will be reduced when breaking the direct one-hop link between the mobile node and the base station into multi-hop link with other mobile nodes working as interim relayers, ad hoc networking, especially the relaying communication mechanism is becoming an interesting approach for cellular networks to extend coverage and increase system capacity. FIG. 1 shows an example for the application of ad hoc and multi-hop concepts in cellular communication system. Furthermore, mobile ad hoc networks can also be applied to high speed WLANs to solve the capacity problem. [0005] The wide range of potential application has led to a recent rise of research and development activities around the world in the area of mobile ad hoc networking. However, the benefits from mobile ad hoc networks are at the expense of some additional networking complexity, especially when adopting wireless routing algorithms to support dynamic topology structure. For at least a decade, wireless routing has been an active research topic in mobile and wireless area. As mobile and wireless technologies proliferate, this area is gaining more and more attention, and there are more enterprises and standards involved, such as IETF's MANET group, ATM Forum's Mobile ATM and a number of efforts in 3G wireless standards and so forth. In spite of such great emphasis in ad hoc routing protocols, there is no one protocol that can be suitable for all applications yet. Wireless routing is still a challenging research topic due to the mobility of mobile nodes in ad hoc networks. [0006] The routing issue in mobile ad hoc networks is more challenging than that in traditional networks. First, in traditional solutions such as that of infrastructure-based cellular networks, it's assumed that the network topology structure is relatively steady, while the topology of ad hoc networks (infrastructure-based systems with multi-hop and ad hoc functions enabled and those without fixed infrastructure) is varying constantly. Second, traditional routing solutions are dependent on the distributed routing database stored in some network nodes or specified management nodes, but for mobile ad hoc networks, routing information is unlikely to be stored permanently in some nodes, and furthermore the information stored in the nodes is not always real and reliable. Therefore, in traditional infrastructure-based cellular networks, route computation is usually centralized and can be easily implemented, while in mobile ad hoc networks, route computation must be distributed because centralized routing in a dynamic network is impossible even for a fairly small network. [0007] In general, the distributed routing is realized by the Bellman-Ford algorithm in mobile ad hoc network, where a mobile node tells other nodes its route cost to the destination node and then other nodes will calculate the total route cost to the destination node by combining the route cost indicated in the received response message from the mobile node and the route cost of each other node to the mobile node, and the source node will choose to relay over the node through which the total route cost to the destination node is the lowest. Most of the present routing protocols and algorithms are variations based on Bellman-Ford, only with different cost focus, such as system overhead, packet latency, battery consumption, transmission power, memory storage, system stability and so on. [0008] The basic idea of Bellman-Ford algorithm can be illustrated as FIG. 2 , wherein the circle indicates the mobile node, the connecting line between circles indicates an existing wireless link and the data on the line indicates the hop cost for forwarding packets from one node to another node involved in the radio connectivity. The hop cost can be one or a group of performance parameters for the hop or node, such as system overhead, packet latency, battery consumption, transmission power, memory storage, node mobility and so on. Costs for different performances are normalized to measure unit with the same weight. [0009] In the following, as an example for finding the route from node A to node T, we will describe how the above Bellman-Ford algorithm works. [0010] First of all, before describing the routing method, let's assume that the network system satisfies the following three conditions: [0011] (1) Route probing signals from node A can reach nodes with different range at different transmission power. [0012] (2) Node A may or may not have direct reachable link with node T. When the cost value exceeds a certain set value, the link can be taken as practically unreachable. [0013] (3) When the cost on the link between node X 1 to node X 2 is low, the transmission power of the transmitting node can be reduced so as to reduce the system interference. [0014] With the above three assumed conditions, the process to find the best route (lowest cost) from node A to node T, comprises: [0015] (1) Node A sends route probing signals at a certain transmission power, and the node which received the route probing signals will send back response message to node A if it has routes to node T, and forward the route probing signals if it has no route list to node T. In FIG. 2 , node B and node G received the route probing signals from node A respectively. [0016] (2) Node B or Node G will check its own route list. If there is a route to node T in the route list, the related route list will be sent to node A; if there is no available route to node T in the route list, the route probing signals will be forwarded. In FIG. 2 , node C and H received the forwarded route probing signals from node B and node G respectively. [0017] (3) Node C has two routes to node T as C-D-T (8+8) and C-T (20) respectively. Node C compares the cost of the two routes and will respond to node B with its lowest cost route to node T as C-D-T (16). Of course, it can also respond to node B with the two routes to node T with cost indication. [0018] (4) Node B will respond to node A with its best route to node T as B-C-D-T (10+16). Of course, node B can also respond to node A with its entire routes to node T as B-T (40), B-C-D-T (26) and B-C-T (32). [0019] (5) Similar to node B, node G will respond to node A with its best route to node T as G-H-I-J-T (27) or its entire routes to node T as G-T (42), G-H-K (32) and G-H-I-J-T (27). [0020] (6) Node A obtains its route to node T through the above probing procedure. If the node that received the route probing signals responds to the involved forwarding node only with the lowest cost route, node A will obtain its three routes to node T as A-G-H-I-J-T (35), A-B-C-D-T (46) and A-T (120). If the node that received the route probing signals responds to the involved forwarding node with all possible routes, node A will receive seven routes as shown in Table. 1. [0021] (7) According to the lowest cost rule, node A will select A-G-H-I-J-T (35) as its current route to node T no matter how many hops the route has. [0022] The route cost calculation can be expressed as: [0000] f cost_dbf = ∑ n = 1 N   C  ( n ) ( 1 ) [0023] Where n=1, 2, . . . , N is the hop sequence on the route and N is the total number of hops on the route, C(n) is the cost corresponding to the nth hop, such as transmission power, node latency and so on. [0024] Table 1 summarizes the route calculation and selection from mobile node A to mobile node T based on Bellman-Ford algorithm. The first column lists all possible routes from source node A to destination node T, the second column to the sixth column are the hop cost between the involved nodes on the route list, the seventh column is the number of hops for the related route, and the last column is the computation results of total cost of all hops on the route based on Bellman-Ford Algorithm. According to the lowest cost rule, the best route should be A-G-H-I-J-T, which takes only cost of 35 units while others are more than 35 units. Routes with the same total cost units are regarded as having the same quality no matter how many hops are included on each route. [0000] TABLE 1 Route list and computation based on Bellman - Ford's Algorithm Number Of Total Route node list Hop1 Hop2 Hop3 Hop4 Hop5 hops Cost A-T 120 1 120 A-B-T 20 40 2 60 A-G-T 8 60 2 68 A-B-C-T 20 10 22 3 52 A-B-C-D-T 20 10 8 8 4 46 A-G-H-K-T 8 6 20 6 4 40 A-G-H-I-J-T 8 6 5 8 8 5 35 [0025] Bellman-Ford algorithm and its variations provide a really good solution to hop-by-hop optimal route computation to select the lowest cost route. However, because the cost is determined hop-by-hop and the cost determination on the hop only involves the related nodes and the radio link between them, and therefore the cost concept herein fails to consider the impact on the system performance when a new hop is introduced. Additionally, these algorithms are impliedly assumed that the relationship between the total cost and all one-hop link cost is linear, but the assumption cannot always stand true. For example, the cost such as transmission power (dB) or packet latency on node is linear for all nodes on the route, but there are some exceptions for other performance parameters due to the following reasons: [0026] (1) When the route contains several mobile nodes, the connectivity possibility of the whole route should be a product of the connectivity probability of every single hop. That means the relationship of connectivity probability of each single hop is multiplicative when all related links are combined to an integrated route. When the selected best route is broken due to the changing topology introduced by mobility, more effort is needed to find a new route. More hops on route mean that the connectivity probability is lower and effort needed for maintaining the route is more. [0027] (2) When a new node is introduced to the route, it will forward data or respond to the node of its last step with neighbor list. This behavior seems to be proliferation of node tree, and meanwhile the resource overhead for route discovery and maintenance increases nonlinearly. [0028] (3) When the data packet is forwarded from the source node to the destination node, the resource needed for the service depends on the number of hops on current existing route. The increase of resource overhead is also dependent on current system load and the number of hops on current existing route. [0029] As described above, radio route cost involves not only the radio link cost of each hop, but also the number of hops contained in the link, so current Bellman-Ford algorithm has its shortcoming when being adopted to select the optimal route. SUMMARY OF THE INVENTION [0030] The present invention proposes a new routing method and a mobile terminal to execute the method. The routing method weights the route cost with the number of hops on the route to address the problems introduced by hop-by-hop optimization. [0031] A routing method is proposed, executed by a mobile terminal in wireless communication systems in accordance with the present invention, comprising: (i) receiving route probing signals to the destination mobile terminal from another mobile terminal; (ii) calculating the route cost to the destination mobile terminal via said mobile terminal according to the route probing signals and system performance parameters; (iii) sending response messages to said another mobile terminal according to the calculated route cost. BRIEF DESCRIPTION OF THE DRAWING [0032] FIG. 1 is a block diagram illustrating the application of multi-hop concept in cellular communication systems; [0033] FIG. 2 is a schematic diagram illustrating the route selection based upon Bellman-Ford algorithm; [0034] FIG. 3 is a schematic diagram illustrating the route selection in accordance with the present invention. DETAILED DESCRIPTION OF THE INVENTION [0035] The new routing method proposed in the present invention is still based on distributed Bellman-Ford routing algorithm, but it introduces weighting with the number of hops for route cost computation. The main idea of the new routing method is to classify the route cost into hop-by-hop cost and hop-in-all cost according the different characteristics of cost performance parameters. This can be expressed as: [0000] f cost_new = f 1  ( N ) + f 2  ( N ) · ∑ n = 1 N   C  ( n ) ( 2 ) [0036] Where n=1, 2, . . . , N is the hop sequence on the route and N is the number of hops on the route, C(n) is the cost corresponding to the nth hop, and the cost may take several parameters into consideration such as transmission power, node latency, and etc. f 1 (N) is cost compensation function for system performance such as compensation for system resource overhead, and f 2 (N) is cost adjusting function for link performance such as adjusting function for link connectivity or potential interference. Both f 1 (N) and f 2 (N) are functions which can be determined experimentally or by current system parameters. When f 1 (N)=0 and f 2 (N)=1, the new routing scheme will converge to the distributed Bellman-Ford algorithm. Taking all performance parameters into consideration, C(n) can be expressed as follows: [0000] C ( n )=w p f p ( P 1 )+w d f d (Delay)+w b f b (Battery)+w c f pc (Proc_capability)+w m f m (memory)+w mb f mb (mobility)  (3) [0037] In above equation (3), w x represents the weight of each performance parameter, f x is the function of the mapping relationship between performance parameters and the measurement we consider in route selection. Where w p is the weight of transmission power, w d is the weight of transmission delay, f b is the weight of the battery of the node, w c is the weight of the processing capability of the node, w m is the weight of the memory of the node, and w mb is the weight of the mobility of the node. Other performance parameters can also be added into this equation. P 1 is the transmission power of the nth hop, Delay is the transmission delay of the nth link, Battery is the battery volume the nth node as the relayer, Proc_capability is the processing capability of the nth node, memory is the memory space of the nth node, and mobility is the mobility of the nth node which can be measured with moving velocity. [0038] All the above weights w x and mapping functions including f 1 and f 2 can be determined through experiment and the state of the network. We will demonstrate a simple example to illustrate the routing scheme in the present invention. In this embodiment, we only take three factors into consideration: total transmission power, total delay and system overhead, and it's assumed that all mapping functions satisfy the following condition: [0000] f p  ( P t ) = P t P b ( 4 ) [0039] Where P b is the basic power we set and P t is the transmission power of the node. [0000] f d  ( Delay ) = Delay Delay b ( 5 ) [0040] Where Delay is the link's transmission delay and Delay b is the set basic transmission delay. [0041] We also assume all weights as follows: [0042] w p =0.6, w d =0.4, w b =0.0, w c =0.0, w m =0.0, w mb =0.0 [0043] If each direct link can be expressed as X→Y(a,b,c,d,e,f), wherein a represents f p between node X and node Y, b represents f d between node X and node Y, c represents f b of node Y, d represents f pc of Y, e represents f m of Y, f represents f mb of node Y relative to node X. If node Y is the destination node, f b , f pc , f m are all set to 0. But in the embodiment of the present invention, we only take total transmission power and total delay into consideration, so we can express each direct link as X→Y(a,b). [0044] In order to clarify the routing scheme of the present invention, f 1 (N)and f 2 (N) can be simply assumed as: [0000] f 1 (N)=2 N−1   (6) [0000] f 2 (N)=1  (7) [0045] So, equation (2) can be simplified as: [0000] f cost_new = f 1  ( N ) + f 2  ( N ) · ∑ n = 1 N   C  ( n ) = 2 N - 1 + ∑ n = 1 N   C  ( n ) ( 8 ) [0046] f 1 (N) can be explained as the system resource overhead introduced by a new hop, and it increases exponentially with the increasing of the total hops. C(n) can be explained as the transmission power cost to overcome the path loss between two nodes and f 2 (N)=1 means no hop-by-hop weighting is assumed. [0047] In the following, FIG. 3 is also taken as an example for describing how to find the route from node A to node T with the method proposed in the present invention. [0048] We assume all nodes in FIG. 3 have the same processing capability and their channel environments are the same (for example, each node is in free space), thus each node in the figure can be expressed as: [0000] A -> G  ( 5 , 30 ) ∑ C  ( n ) = 0.6 *  5 + 0.4 *  30 = 15 G -> H  ( 11 , 10 ) ∑ C  ( n ) = 0.6 *  11 + 0.4 *  10 = 10.6 H -> K  ( 91 , 30 ) ∑ C  ( n ) = 0.6 *  91 + 0.4 *  30 = 66.6 K -> T  ( 26 , 20 ) ∑ C  ( n ) = 0.6 *  26 + 0.4 *  20 = 23.6 H -> I  ( 20 , 20 ) ∑ C  ( n ) = 0.6 *  20 + 0.4 *  20 = 20 I -> J  ( 14 , 30 ) ∑ C  ( n ) = 0.6 *  14 + 0.4 *  30 = 20.4 J -> T  ( 13 , 10 ) ∑ C  ( n ) = 0.6 *  13 + 0.4 *  10 = 11.8 G -> T  ( 270 , 50 ) ∑ C  ( n ) = 0.6 *  270 + 0.4 *  50 = 182 A -> T  ( 393 , 70 ) ∑ C  ( n ) = 0.6 *  393 + 0.4 *  70 = 263.8 B -> T  ( 249 , 50 ) ∑ C  ( n ) = 0.6 *  249 + 0.4 *  50 = 169.4 B -> C  ( 27 , 20 ) ∑ C  ( n ) = 0.6 *  27 + 0.4 *  20 = 24.2 C -> E  ( 5 , 20 ) ∑ C  ( n ) = 0.6 *  5 + 0.4 *  20 = 11 C -> D  ( 13 , 20 ) ∑ C  ( n ) = 0.6 *  13 + 0.4 *  20 = 15.8 C -> T  ( 41 , 40 ) ∑ C  ( n ) = 0.6 *  41 + 0.4 *  40 = 40.6 D -> F  ( 11 , 20 ) ∑ C  ( n ) = 0.6 *  11 + 0.4 *  20 = 14.6 E -> F  ( 44 , 40 ) ∑ C  ( n ) = 0.6 *  44 + 0.4 *  40 = 42.4 A -> B  ( 14 , 30 ) ∑ C  ( n ) = 0.6 *  14 + 0.4 *  30 = 20.4 D -> T  ( 58 , 40 ) ∑ C  ( n ) = 0.6 *  58 + 0.4 *  40 = 50.8 [0049] With the above assumption, the process to find the best route from source node A to destination node T is as follows: [0050] (1) Node A sends route probing signals at certain transmission power and the node that received the route probing signals will send back response message to node A if it has routes to node T, otherwise it will forward the route probing signals. In FIG. 3 , node B and node G received the route probing signals from node A respectively. [0051] (2) Node B or Node G will check its own route list and respond to node A with the relevant route list if it has route to node T on its route list or forward the route probing signals if it has no available route to node T on its route list. In FIG. 3 , node C and node H received the forwarded route probing signals from node B and node G respectively. [0052] (3) Node C has two routes to node T as C-D-T and C-T respectively. When node C compares the cost of the two routes, it not only sums up the link cost on its route to C as A-B-C but also combines the knowledge about the route probing signals forwards route (cost and number of hops). If only the lowest cost route will be returned to the route probing signals forwarding node (node B), the route cost computation will take place at node C. If all reachable routes will be returned to the route probing signals forwarding node (node B) and therefore to the source node (node A), the route cost computation will take place at node A. When in the former situation (the route cost is computed at node C), the route probing signals received by node C should include probing forwarding route information (cost of each hop and hops). While in the latter situation (the route cost is computed at node A), such information is optional. The calculation rule in both situations should conform to equation (2). That means the cost calculation is for the entire route which contains two parts: the route from source node A to current node C and that from current node C to destination node T. [0000] For   route   A - B - C - D - T ,  N = 4 , ∑ n = 1 N   C  ( n ) = 20.4 + 24.2 + 15.8 + 50.8 = 111.2   f cost_new = 2 4 - 1 + 111.2 = 119.2 ( i ) For   A - B - C - T   N = 3 , ∑ n = 1 N   C  ( n ) = 20.4 + 24.2 + 40.6 = 85.2   f cost_new = 2 3 - 1 + 85.2 = 89.2 ( ii ) [0053] According to the lowest route cost rule, node C will respond to node B with the route A-B-C-D-T as the lowest cost route via node B. Of course, node C can also return the link cost and hops of the two routes C-T and C-D-T to node T, thus the route costs of A-B-C-T (89.2) and A-B-C-D-T (119.2) can be computed respectively at node A through node B. [0054] (4) Similar to node C, node B will calculate the cost for all its reachable routes according to equation (8). In fact, the cost calculation results for route via node C are available and included in node C's response message to node B. So node B need only calculate the related cost for the route A-B-T: [0000] for   the   route   A - B - T ,  N = 2 , ∑ n = 1 N   C  ( n ) = 20.4 + 169.4 = 189.8 f cost_new = 2 2 - 1 + 189.8 = 191.8 [0055] Compared with the cost of route A-B-C-T, the route to destination node T via node B is the route via node C, which means route A-B-C-D-T is returned to source node A as the lowest cost route via node B. [0056] If the cost of each possible route is computed at source node A, node B can also respond to node A with the link overhead and hops of each route (A-B-T, A-B-C-T, A-B-C-D-T) via node B, so that the route cost of each possible route can be computed at node A. [0057] (5) Similar to node B, node G will also calculate the cost for all its reachable routes according to equation (8). Node G will forward the route probing signals to node H. If node H has route lists to destination node T, the cost calculation for route by node H will contains two parts: the information of probing forwarding route (cost and hops) from source node A to current node H (A-G-H) and the information of potential route (cost and hops) from current node H to destination node T (H-K-T and H-I-J-T). [0000] for   the   route   A - G - H - I - J - T    N = 5 , ∑ n = 1 N   C  ( n ) = 15 + 10.6 + 20 + 20.4 + 11.8 = 77.8   f cost_new = 2 5 - 1 + 77.8 = 93.8 ( i ) for   the   route   A - G - H - K - T   N = 4 , ∑ n = 1 N   C  ( n ) = 15 + 10.6 + 66.6 + 23.6 = 115.8   f cost_new = 2 4 - 1 + 115.8 = 123.8 ( ii ) [0058] A-G-H-I-J-T has more hops than A-G-H-K-T, but the total hop-by-hop cost of A-G-H-I-J-T is lower than that of A-G-H-K-T, so route A-G-H-I-J-T will be responded to node A as the lowest cost route via node G according to the lowest route cost rule. [0059] If the cost of each possible route is not computed at each forwarding node, but at source node A, similar to node B, node G will respond to node A with the link cost and hops of each possible route via node G (A-G-T, A-G-H-I-J-T, A-G-H-K-T), so that each route cost can be computed at node A. [0060] (6) Both node B and node G will respond to node A with its lowest cost route. Node A will compare all the costs and select the lowest cost route as the best route to node T. In this embodiment, route A-B-C-T is selected as the best route. [0061] If each route cost is computed at source node A, the cost and hops of all potential routes to the destination node will be responded to the source node A via each forwarding node, then the cost calculation can be done at source node A to select the lowest cost route as the best route to node T. [0062] Table 2 summarized all potential routes from source node A to destination node T. It shows that the best route selection depends on not only the total hop-by-hop cost but also the hop-in-all cost complementation, which is directly related with the number of hops on the route. [0000] TABLE 2 Route list and computation based on new route selection algorithm Hop- Hop- Route by- Num in- node Hop Of All Total list H1 H2 H3 H4 H5 cost Hops cost Cost A-T 263.8 263.8 1 1 264.8 A-B-T 28.2 169.4 197.6 2 2 199.6 A-G-T 15 182 197 2 2 199 A-B- 28.4 24.2 40.6 85.8 3 4 89.8 C-T A-B-C- 28.4 24.2 15.8 50.8 119.2 4 8 127.2 D-T A-G-H- 15 10.6 66.6 19 115.8 4 8 123.8 K-T A-G-H- 15 10.6 20 20.4 11.8 77.8 5 16 93.8 I-J-T [0063] Although the physical characteristic and function definition for f 1 (N), f 2 (N) and C(n) in above embodiment is determined with assumption, they can be explained as different system parameters in different way depending on practical applications and system performance features. For example, f 1 (N) can be explained as the average system overhead for route discovery and maintenance, and f 2 (N) can be explained as the total delay on the route. [0064] The above routing scheme proposed in the present invention can be implemented in computer software in mobile terminals, or computer software, or in combination of both software and hardware. BENEFICIAL RESULTS OF THE INVENTION [0065] As described above, with regard to the wireless routing method as provided in the present invention, the effect of hops on route cost is introduced. This means, route cost is weighted through functions that can reflect the system performance parameters. The routing selection priority rule can be adjusted by adjusting f 1 (N) and f 2 (N)according to different performance parameters emphasis. Moreover, the routing scheme can limit the number of hops on the route by adjusting f 1 (N) and f 2 (N) to avoid probing flooding and help route converge, and therefore make the route discovery easier. [0066] Although the distributed routing scheme has been shown and described with respect to exemplary embodiments of mobile ad hoc networks, it should be understood by those skilled in the art that the scheme is not limited to ad hoc networks, but also applicable to cellular mobile communication systems and WLANs with ad hoc or multi-hop functions enabled. [0067] Although the present invention has been shown and described with respect to specific embodiment, it is to be understood by those skilled in the art that various changes, omissions and additions may be therein and thereto, without departing from the spirit and scope of the invention as defined by the appended claims.

The present invention proposes a routing method performed by a mobile terminal in wireless communication systems, comprising: (i) receiving route probing signals to the destination mobile terminal from another mobile terminal; (ii) calculating the route cost to the destination mobile terminal via said mobile terminal according to said route probing signals and system performance parameters; (iii) sending response messages to said another mobile terminal according to the calculated route cost. This method weights the route cost with the number of hops on the route, to address problems introduced by hop-by-hop

The present invention relates to an improved process for electrolytically producing sulfur-containing nickel. As is well known the presence of a small amount of sulfur, e.g., 50-250 parts per million (ppm) in a nickel anode is highly beneficial to ensure activation of the anode and hence uniform corrosion when it is used for electroplating. Such sulfur-containing nickel anodes were initially produced by melting techniques using electrolytically pure nickel and adding sulfur thereto. A major step forward consisted in the formulation of processes for electrodepositing sulfur-containing nickel. Such processes are described for example, in U.S. Pat. Nos. 2,392,708 (issued to H. E. Tschop) and 2,453,757 and 2,623,848 (both issued to L. S. Renzoni). Generally such processes involve electrorefining an impure nickel anode in an electrolyte containing a sulfur-bearing agent such as sulfur dioxide, or a sulfite, bisulfite or thiosulfate of an alkali metal. More recent improvements in the art of nickel electrodeposition have led to development of various electrowinning processes in which insoluble anodes are used. Unlike electrorefining operations where the overall reaction is the dissolution of an impure nickel anode and deposition of a pure nickel cathode, in electrowinning processes the nickel concentration in the electrolyte is merely depleted by the cathodic electrodeposition and typically it is replenished by recycling the spent electrolyte to a leaching or a solvent extraction operation. The so called "all chloride" electrowinning process, wherein all of the nickel in the electrolyte is in the form of nickel chloride is particularly attractive in that it offers considerable savings in both capital and operating costs over sulfate or mixed sulfate-chloride electrowinning processes. However, for the purpose of depositing sulfur-containing nickel it has not been possible heretofore to resort to electrowinning from chloride-containing electrolytes. The reason for this is that when chloride ions are present in the electrolyte, chlorine is liberated at the insoluble anode, and the presence of chlorine in the electrolyte tends to inhibit sulfur deposition. Thus even though a diaphragm is used to separate the catholyte from the anolyte when carrying out electrowinning, chlorine generated at the anode tends to diffuse to the catholyte. It is an object of the present invention to provide an electrowinning process for depositing sulfur-containing nickel from a chloride-containing electrolyte, and in particular from an "all-chloride" electrolyte. Generally speaking the present invention provides a process whereby sulfur-containing nickel is electrowon from a chloride-containing nickel electrolyte which has dissolved therein a small but effective amount of sulfur dioxide, thiourea, toluene sulfonamide or a sulfite, bisulfite, thiosulfate or tetrathionate of an alkali or alkaline earth metal. The electrowinning is conducted in a cell including one or more electrode assemblies, each assembly comprising a substantially insoluble anode, a cathode, anolyte diaphragm-means for enveloping the anode and a volume of electrolyte adjacent thereto, and catholyte diaphragm-means for enveloping the cathode and a volume of electrolyte adjacent thereto. In this way the diaphragm-means define catholyte and anolyte compartments which are separated from one another by two porous diaphragms with electrolyte therebetween. In operation a hydrostatic head of pressure is maintained in the catholyte compartment by introducing fresh electrolyte only into this compartment and withdrawing spent electrolyte only from the exterior of the catholyte compartment. It is preferable to withdraw electrolyte from the anolyte compartment, thereby establishing a flow of electrolyte within the cell, through both of the diaphragms, from catholyte to anolyte compartments via the remainder of the cell volume which can be termed for convenience `the intermediate compartment.` Such a flow pattern aids in preventing the undesired diffusion to the catholyte of chlorine generated at the anode. However withdrawal of electrolyte from the anolyte compartment is in no way essential and withdrawal from the intermediate compartment has been found satisfactory. The diaphragm-means referred to herein may be any diaphragm-containing assembly which is adapted to house part of the electrolyte in the cell so that communication between the housed electrolyte and the bulk electrolyte in the intermediate compartment can take place only via the porous diaphragm. This can be achieved by resorting to a rigid assembly, i.e an electrode box, wherein at least one side of the assembly consists of a porous diaphragm. Alternatively the assembly may consist entirely of the porous diaphragm, i.e. it may comprise an electrode bag which envelops at least the immersed portion of the electrode. The invention is in no way restricted to any particular type of diaphragm assembly and, for example, in the specific tests referred to below use was made of a cell which incorporated both the above-mentioned types of assembly. In order to ensure the efficient removal, from the vicinity of the anode, of chlorine evolved during the electrowinning, it is preferred that the cell used in carrying out the process of the invention incorporate anode cover-means in the form of an anode hood which is suitably shaped and positioned to seal off the space above the anolyte surface. Where the anode is boxed, the hood may conveniently be adapted to engage mechanically with the anode box. Where use is made of an anode bag, it will be convenient to use a hood which is so dimensioned and positioned that its lower edge, in operation, is immersed below the electrolyte level and encircles the anode bag. The use of both anolyte and catholyte diaphragms is essential to the success of the process of the invention, in that a single diaphragm, whether it be around the anode or around the cathode, has proved incapable of effectively preventing the diffusion of chlorine to the catholyte where it inhibits sulfur deposition. Attempts at overcoming this problem by suitable selection of the porosity of the membrane used as diaphragm are frustrated by the fact that any excessive decrease in the permeability of the membrane will unduly impede the desired ionic flow through the diaphragm. By resorting to the double diaphragm cell referred to above, the problem of chlorine diffusion is overcome without critical requirements on the degree of permeability of the membranes used. Indeed many materials, such as various synthetic fabrics, which have in the past been advocated for use as porous membranes in chloride electrolytes, may constitute the diaphragms in the cell used for carrying out the process of the invention. A double-diaphragm cell has been advocated in the art only as a means for maintaining different ionic species in the anolyte and catholyte compartments. Thus in U.S. Pat. No. 2,578,839 (issued to L. S. Renzoni) a double-diaphragm cell is used to maintain a sulfate anolyte and a chloride catholyte. Such a cell has never been used, so far as we are aware, with the same ionic species being present in anolyte and catholyte compartments as described herein for depositing sulfur bearing nickel from a chloride electrolyte. Thus whereas the process described in the above-mentioned U.S. Pat. No. 2,578,839 involves the prevention of chlorine liberation at the anode, the present invention is based on the simpler procedure of preventing anodically liberated chlorine from impeding sulfur deposition at the cathode. The anode of the electrowinning cell must be substantially inert under the cell operating conditions. Typical materials suitable for use as insoluble anodes include for example graphite, or titanium having a platinum-group metal coating thereon. The cathode may consist of a nickel starter sheet or a reusable inert electrode such as titanium. The composition of the electrolyte used in carrying out the process of the invention is not critical, but it is advantageous to use "all-chloride" electrolytes. Inasmuch as the electrowinning of sulfur-free nickel from chloride-containing electrolytes is known in the art, the interrelation of cell voltage and current density with the electrolyte composition, temperature, pH and flow rate are not discussed in detail herein. The electrolytes used in the process of the invention differ of course from such prior electrowinning electrolytes by virtue of the presence in the former of the sulfur-bearing compounds. However, it has been found that the presence of these compounds does not materially affect the electrowinning operation parameters applicable. A particular reason for favoring "all-chloride" electrolytes lies in the ability to achieve efficiently a high nickel bite when such electrolytes are used, i.e. a large difference between the nickel contents of the fresh and spent electrolytes. For this purpose, a preferred combination of electrowinning conditions comprises using an aqueous solution containing about 150 to 255 grams per liter of nickel as nickel chloride, up to about 20 grams per liter of boric acid and about 50 to 160 milligrams per liter of thiosulfate ions in the form of sodium thiosulfate. The pH of the solution is adjusted to between about -1.5 and 4.0, measured at room temperature, prior to feeding it into the cell which is maintained at about 50°-100° C. The flow rates of the electrolyte into and out of the cell are controlled to give a nickel bite of the order of at least 70 grams per liter and more preferably at least 150 grams per liter. Some examples of the production of sulfur-containing nickel in accordance with the process of the invention will now be described with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 illustrates an electrowinning cell used for the tests described below; FIG. 2 illustrates an electrowinning cell of alternative design more suitable for carrying out the process of the invention on a commercial scale; and FIG. 3 represents a section through the line 3--3 of FIG. 2. DETAILED DESCRIPTION EXAMPLES A series of tests were performed in the apparatus shown in FIG. 1. This consisted of a 22 liter cell 10 which was divided into four compartments consisting of a catholyte compartment 11, two anolyte compartments 12 and 13, while the fourth compartment 14 comprised the remainder of the cell volume, i.e. an intermediate compartment containing the bulk electrolyte. The electrodes consisted of a single cathode 15 in the form of a sandblasted sheet of titanium measuring: 38 cm × 7 cm, and a pair of graphite anodes 16 and 17 located one on either side of the cathode 15 and spaced by 6.5 centimeters from the surface thereof. The anodes were enclosed in synthetic bags 18 and 19 and covered by fiber-glass hoods 20 and 21 the lower edges of which were immersed below the level of the bulk electrolyte in the compartment 14. The anode hoods were provided with inlets conduits 22 and 23 for admitting air to the space above the anolyte and thus aiding the purging of chlorine away from the anodes through outlets 24 and 25. The titanium cathode of the cell was contained in a cathode box consisting of a fiber-glass framework 26 and synthetic fabric membranes 27. The electrolyte was introduced into the catholyte compartment at a pH of about 3.5, measured at room temperature, and spent electrolyte was withdrawn from the bulk electrolyte compartment, the flow rates being controlled to achieve a nickel bite of 160 ± 20 grams per liter. During the electrowinning the electrolyte within the cell was maintained at 70° C. A cell voltage of 2.8 volts provided a current density of 400 amperes per square meter of cathode (amp/m 2 ), and the operational pH was monitored, at the operating temperature, in both the catholyte and bulk electrolyte. The electrolytes used were "all-chloride" electrolytes differing from one another essentially only in the concentration of sulfur-bearing agent present therein. In each of Tests Nos. 1-3 the electrolyte comprised an aqueous solution containing 240 grams per liter of nickel as nickel chloride, 10 grams per liter of boric acid and between 50 and 160 milligrams per liter of thiosulfate ions as sodium thiosulfate. After electrodeposition the nickel on both faces of the cathode was assayed for sulfur and each of the sulfur contents shown in Table 1 below represents the average from both cathode faces. TABLE 1______________________________________S.sub.2 O.sub.3 -Thiosulfate pH (at 70° C) S in DepositTest No (mg/l) Bulk Catholyte (ppm)______________________________________1 160 1.9 2.2 2202 100 1.6 2.0 1433 50 1.4 1.6 59______________________________________ A comparative test was carried out in an apparatus including only a single diaphragm between anolyte and catholyte. An electrolyte of a similar composition to that described above was used, containing in this case 200 mg/l of thiosulfate ions, and the electrodeposition parameters were similar to those described above, the bulk pH being 1.8 at the operating temperature of 70° C. It was found that the deposited nickel contained only 3 ppm of sulfur. The results of Tests Nos. 1-3 show that the double-diaphragm procedure effectively prevented the sulfur deposition from being inhibited by the anodically evolved chlorine. Chlorine assays of the electrolyte in the tests according to the invention showed amounts between 0.2 and 0.8 grams per liter of free chlorine in the spent electrolyte withdrawn from the bulk compartment, whereas no chlorine at all was detected in the catholyte. These assays suggest that when only a single diaphragm separates catholyte from anolyte, the catholyte would be expected to contain up to about 0.8 grams per liter of free chlorine. Such a level of free chlorine in the catholyte has been found to inhibit sulfur deposition. Further tests were carried out using different sulfur-bearing agents. The apparatus used for these tests was a bench-scale version of that used for Tests Nos. 1-3. Apart from the sulfur-bearing agents, the electrolytes contained about 200 g/l of nickel as nickel chloride and about 10 g/l of boric acid. Electrodeposition was carried out at about 70° C with a cathodic current density of about 600 amp/m 2 and nickel bite of about 85 g/l. The results obtained are shown in Table 2 below. TABLE 2______________________________________ mg/l S in DepositTest No S-bearing Additive of Additive (ppm)______________________________________4 Sodium Bisulfite 100 455 Sodium Tetrathionate 100 1906 Thiourea 100 235______________________________________ Thus it will be seen that various sulfur-bearing additives can be used successfully in practising the process of the invention. Referring now to FIGS. 2 and 3, these show a preferred apparatus suitable for practising the process of the invention on a commercial scale. Essentially this apparatus differs from that of FIG. 1 in that: a. a source of reduced pressure is used instead of air purging to remove the anodically liberated chlorine; and b. a cell cover is provided to enclose essentially the space above the bulk electrolyte compartment. No detailed description will be given of components of this preferred apparatus which are identical to components of the apparatus of FIG. 1. Such like components are designated by the same reference numerals as used in FIG. 1. The anodes are covered by hoods 30 and 31 respectively, and the whole of the cell is covered by a lid 34. As is seen from FIG. 3, the anode hood 30 is provided with a port 32 through which the space above the anolyte can be evacuated by means of a source of reduced pressure (not shown). The cell lid 34 serves to enclose the header space 38 above the bulk electrolyte compartment 14. The lid is provided with an aperture through which the cathode can be inserted into and withdrawn from the catholyte compartment, and with a vent 35 through which air enters the header space 38 when the latter is continuously evacuated by means not illustrated. The sweeping of the header space with air in this manner serves to remove electrolyte fumes and also removes any chlorine which may leak into that space from the anolyte compartment. While the present invention has been described with reference to preferred embodiments thereof, it will be understood that various modifications may be made in terms of the electrolyte composition, the design as well as operating conditions of the cell without departing from the scope of the invention which is defined by the appended claims.

Sulfur-containing nickel is electrodeposited from a chloride electrolyte in a cell wherein each cathode is separated from any adjacent anode by a pair of diaphragms.

BACKGROUND OF THE INVENTION The invention relates to a device for monitoring a predetermined level of a liquid in a container comprising an ultrasonic sensor fitted on the outer surface of the container wall at a measurement point situated at the height of the level to be monitored and containing an ultrasonic transducer having a diaphragm in contact with the container wall. In assemblies of this kind it is necessary to attach the ultrasonic sensor to containers of differing shape and/or differing materials. It is known, for example, from the PCT publication WO 95/12804 to secure an ultrasonic sensor to the container by means of a clamping strap, collet or adhesive tapes, the ultrasonic sensor being specially configured for each of these types of fastening. Apart from this, these types of fastening are specially devised for small containers, particularly for medical applications and which are not suitable for fastening to large containers under rough conditions, especially in industrial environments. SUMMARY OF THE INVENTION The object of the invention is to provide a device of the aforementioned kind in which the ultrasonic sensor may be secured to containers of differing shape and size as well as of differing materials by means which are an optimum in each case without necessitating any modifications in design of the ultrasonic sensor. For achieving this object the assembly according to the invention includes an adapter which is configured so that it can be secured to containers of differing shape and/or differing materials in any way required, and a sensor block which contains the components of the ultrasonic sensor including those of the ultrasonic transducer and is releasably connected to the adapter secured to the container wall. In the arrangement according to the invention the adapter is first secured to the desired location on the container wall without the sensor block. This may be done in several, different ways, of which the one most favorable for the shape and material of the container concerned is selected in each case. The adapter is configured so that it can be applied to both a flat and a curved container wall. It is not until the adapter is secured to the container that the sensor block is connected to the adapter. Accordingly, the sensor block may be always configured the same irrespective of the shape, size and material of the container and irrespective of the selected way in which it is to be secured. Even in a special instance, should the same adapter not be suitable for a certain container, merely the adapter needs to be modified in design, which is possible by simple means and at little expense, whilst the sensor block can always remain unchanged. An advantageous embodiment of the invention consists of the adapter comprising a frame adapted to the contour of the sensor block, which frame is provided on the side facing the container wall with a seal running around the periphery. The seal protects the place of contact between the diaphragm of the ultrasonic transducer and the container wall from water splash and other influences. Advantageous embodiments and further aspects of the invention are characterized in the sub-claims. BRIEF DESCRIPTION OF THE DRAWING Further features and advantages of the invention are evident from the following description of an example embodiment with reference to the drawings in which: FIG. 1 is a schematic illustration for explaining the monitoring of predetermined levels of a liquid in a container, FIG. 2 is a perspective view of an embodiment of the ultrasonic sensor used in the invention, FIG. 3 is a longitudinal section through the ultrasonic sensor of FIG. 2 when attached to a flat container wall, FIG. 4(a) is a cross-section through the ultrasonic sensor of FIG. 2 when attached to a cylindrical container wall showing an embodiment of the attachment, FIG. 4(b) is a cross-section through the ultrasonic sensor of FIG. 2 when attached to a cylindrical container wall showing another embodiment of the attachment, FIG. 5 is a section view of the ultrasonic transducer used in the ultrasonic sensor of FIGS. 2 to 4, FIG. 6 is a plan view of a mounting sleeve used in the ultrasonic transducer of FIG. 5, FIG. 7 is a section view of the mounting sleeve of FIG. 6, FIG. 8 is a perspective view of the mounting sleeve of FIGS. 6 and 7, FIG. 9 shows a preferred embodiment of the adapter which is attached to a cylindrical container wall and FIG. 10 shows the adapter of FIG. 9 when attached to a flat container wall. DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows a container 10 which is filled up to a level H with a liquid 11. The level H at which the surface of the liquid 11 is located above the bottom of the container 10, is the momentary level in the container. The level is required not to exceed a maximum level H max and not to drop below a minimum level H min . Each of these limit values of the level is also termed "limit level". Attached to the outer surface of the container wall 12 for monitoring the upper limit level H max is a level sensor 13 which is connected to an excitation and evaluation circuitry 14. Attached to the outer surface of the container wall 12 for monitoring the lower limit level H min is a level sensor 15 which is connected to an excitation and evaluation circuitry 16. Each of the two sensors 13 and 15 is configured so that with the aid thereof it can be defined through the container wall 12 whether the liquid 11 in the container 10 is at the level of the sensor 13 and 15, respectively, or not. For this purpose each of the two sensors 13 and 15 is configured as an ultrasonic sensor which is able, when excited by an electrical alternating voltage pulse furnished by the corresponding excitation and evaluation circuitry 14 and 16, respectively, to send an ultrasonic pulse to the container wall 12 and to convert received ultrasonic signals into electrical alternating voltage signals which are transferred to the circuitry 14 and 16, respectively. The circuitry 14 and 16, respectively, evaluates the received signals and provides at the output a signal which indicates whether the level in the container 10 lies above or below the limit level to be monitored. To establish this it is thus not necessary to provide an opening in the container wall 12 or to introduce the sensor into the interior of the container 10. It is for this reason that the sensors 13 and 15 are also not in direct contact with the liquid 11. The two sensors 13 and 15 as well as the associated electronic circuitries 14 and 16, respectively, are configured absolutely identical. Accordingly, in the following the description relates merely to the sensor 13 and the circuitry 14, this description applying just the same to the sensor 15 and the circuitry 16. FIG. 2 shows a perspective view of the sensor 13, and the FIGS. 3 and 4 show section views of the sensor 13 secured to the container wall 12. FIG. 3 shows a longitudinal section of the sensor 13 for the case that the container wall is flat, and FIG. 4 shows a transverse section through the sensor for the case that the container wall is cylindrical. The excitation and evaluation circuitry 14, which in FIG. 1 is illustrated separately from the the sensor 13 for the sake of clarity, is assembled together with the sensor 13 in the embodiment illustrated in FIGS. 2 to 4. The sensor shown in FIG. 2 consists of a sensor block 20, containing all components of the ultrasonic sensor and the excitation and evaluation circuitry, and of an adapter 21 which serves to secure the sensor block 20 to containers of differing shape and size as well as of differing materials. The sensor block 20 has a sensor housing 22 which is closed off by a cover 23 secured to the sensor housing 22 by means of screws 24. The sensor block 20 is secured to the adapter 21 by means of screws 26 which pass through holes in the protuberances 27 on the narrow sides of the sensor housing 22 and are screwed into tappings in corresponding protuberances 28 on the adapter 21. After having released the two screws 26 the complete sensor block can be removed from the adapter 21 secured to the container wall 12. Vice-versa for fitting a sensor, the adapter 21 is secured without the sensor block 20 to the desired location of a container wall by suitable means and subsequently the sensor block 20 with the ultrasonic sensor assembled ready for operation is mounted on the adapter 21 and secured by means of the screws 26. A terminal block 29 projecting from one side of the sensor housing 22 permits connecting the circuitry accommodated in the sensor housing 22 to outer connecting leads. The adapter 21 is a plastics moulding substantially comprising a plate 30, the contour of which corresponds to the contour of the sensor housing 22, i.e. in the example shown, rectangular. Molded around the plate 30 is a frame 31 which is provided on the side facing the container wall with a groove 32 into which a seal 33 is inserted. On the longitudinal sides of the adapter 21, which in the case of a cylindrical container 10 rest on the container wall 12 along the generatrices, the frame 31 has a consistent height. On the transverse sides which in the case of a cylindrical container 10 rest on the container wall 12 along the periphery, the frame 31 includes a recess 34 in the shape of a circular arc as is evident in FIG. 2 on the front transverse side thereof. The radius of curvature of the recess 34 corresponds to the radius of the container wall 12 of a container 10 having the smallest diameter at which the adapter 21 is to be attached. When the ultrasonic sensor 13 is intended for containers, the nominal width (diameter) of which amounts to at least 200 mm, the radius of curvature of the recess 34 is thus 100 mm. The seal 33 is configured so that its sealing surface intended for contact with the container wall lies in a plane when the adapter 21 is not yet applied to the container wall 12 and thus the seal 33 is still to change shape. So that this requirement is satisfied the seal 33 has a consistent height along the longitudinal sides of the frame 31, while its height in the region of each transverse side increases in keeping with the shape of the recess 34 in the shape of a circular arc towards the center. As evident from the FIGS. 3, 4(a) and 4(b) the seal 33 is preferably configured with two sealing lips 35, between which a notched recess 36 exists. The sealing lips 35 are relatively low along the longitudinal sides of the frame 31 (FIGS. 4(a) and 4(b)) and the depth of the notched recess 36 is at this location correspondingly small, whereas along the transverse sides of the frame 31 the height of the sealing lips 35 and the depth of the notched recess 36 increase to the same extent as the height of the seal 33. Since the section plane of the sectioned view of FIG. 3 passes through the locations at which the recesses 34 are deepest, the sealing lips 35 have in this section view a maximum height and the notched recesses 36 a maximum depth. When the adapter 21 is secured to a flat container wall 12 (FIG. 3) the sealing lips 35 are pressed together in the region of the recesses 34 to the same extent as in the region of the straight longitudinal sides of the frame 31, i.e. relatively slightly, whereas when the adapter 21 is secured to a cylindrical container wall 12 (FIGS. 4(a) and 4(b)), the sealing lips change shape more in the region of the recesses 34 than in the region of the straight longitudinal sides of the frame 31, i.e. all the more, the smaller the radius of curvature of the container wall is. This more pronounced change in shape is made possible by the greater height of the sealing lips 35 and the greater depth of the notched recess 36 in this region. In all cases, however, the sealing lips 35 are in sealing contact with the container wall along the entire periphery of the adapter 21. The section view of FIG. 3 shows a first possibility of securing the adapter 21 to the container wall 12: welded to the container wall 12 are stud bolts 37 which protrude through the openings of bus hes 38 formed integrally with the plate 30 of the adapter 21. Screwed onto the ends of the stud bolts 37 protruding from the bushes 38 are nuts 39 which tension the plate 30 while pressing the seal 31 together against the container wall 12. If required, spacers protruding downwards to the container wall 12 may be formed on the plate 30 which determine a defined spacing of the plate 30 from the container wall 12 and thus a defined position of the adapter 21 as regards the container wall 12. In FIG. 4(a) another way of securing the adapter 21 to the container wall 12 is illustrated. For this purpose one leg of an angular bracket 41 formed of heavy gauge sheet metal is inserted in a side slot 40 provided in the middle of each longitudinal side of the adapter 21 and secured therein by a screw 42. The other leg of the angular bracket 41, which is upswept at a right angle, is bent hook-shaped at the end. This hook-shaped bent end clasps a rail 43 which is welded to the container wall 12 and it is clamped firmly in place to the rail 43 by means of at least one screw 44. This kind of fastening permits defining the position at which the sensor 13 is to be applied to the container 10 by simple means and, where necessary, to subsequently change the position by shifting the adapter 21 along the rail 43. It is shown in FIG. 4(b) that it is also possible to secure the adapter 21 by means of a clamping strap 49 placed around the container. For this purpose an angular bracket 41 is inserted in each of the slots 40 on both sides of the adapter 21 and hook-shaped brackets are hooked onto the bent upper end of the upswept legs of the two angular brackets 41, these brackets being provided at the ends of the clamping strap 49 placed around the container. Such a clamping strap fastening provides an even greater freedom of choice in selecting the location to apply the sensor 13 to the container 10 and has additionally the advantage that no intervention needs to be undertaken on the container itself. Hooking the clamping strap 49 into place at the two upper ends of the upswept legs of the angular bracket 41 results in the points at which the force exerted by the clamping strap 49 is applied lie relatively high on the adapter 21. This is of advantage because particularly in the case of containers having a large radius of curvature the components of the force pressing against the container significantly increase with the height of the point of application. The stud bolts 37 or the rails 43 may be secured to the container wall 12 instead of by welding also by adhesive bonding, this type of securement of the adapter 21 also being suitable for containers of a plastics material. The sensor housing 22 is divided into two spaces 46 and 47 by a transverse wall 45. In the outer space 46 facing away from the container wall 12 the excitation and evaluation circuitry 14 is accommodated which in the usual way is made up of electronic components which are mounted on a circuit board 48. In the inner space 47 facing the container wall 12 and the adapter 21 the components of the ultrasonic sensor 13 are fitted, to which in particular an electroacoustical transducer 50 belongs which serves to convert an alternating voltage pulse furnished by the excitation and evaluation circuitry into an ultrasonic pulse which is transferred to the container wall 12, and to convert ultrasonic vibrations which it receives from the container wall 12 into an electrical alternating voltage which is transferred to the excitation and evaluation circuitry. The electroacoustical transducer 50 is illustrated in more detail in FIG. 5. It contains as the active component a piezoelectric element 51 which in the known way is a slice of a piezoelectric crystal on both sides of which metallizations are applied which serves as electrodes. When an alternating voltage is applied to the electrodes, the piezoelectric crystal is excited to produce physical vibrations at the frequency of the alternating voltage, and when physical vibrations are transferred to the piezoelectric crystal it produces between the electrodes an alternating voltage having t he frequency of the physical vibrations. In FIG. 5 the electrodes are not illustrated since due to the minute thickness of the metallization as compared to the thickness of the piezoelectric crystal they are not visible. The piezoelectric element 51 is arranged in the interior of a pot-shaped transducer housing 52 and is in contact with the bottom 53 of the transducer housing 52 which simultaneously forms the diaphragm of the ultrasonic transducer 50. The transducer housing 52 is made of a plastics material. On the side of the piezoelectric element 51 facing away from the diaphragm 53 a circuit board 54 is arranged which carries the components of a circuit serving to couple the piezoelectric element 51 to the excitation and evaluation circuitry 14. The circuit board 54 is located spaced away from the piezoelectric element 51, and the space between the circuit board 54 and the piezoelectric element 51 is filled with a potting compound 55 which is filled in fluid condition and then solidifies. The side of the piezoelectric element 51 facing away from the diaphragm 53 is covered by a disk 56 of a closed-pore foamed material which prevents the potting compound 55 from coming into direct contact with the piezoelectric element 51. Also the space above the circuit board 54 is filled up to such a level with the potting compound 55 that all circuit components mounted on the circuit board 54 are embedded in the potting compound 55. The potting compound 55 is prescribed for reasons of explosion-protection, it in addition effecting dampening of ultrasonic waves emitted to the side opposite the diaphragm 53. To facilitate installing the piezoelectric element 51 and the circuit board 54, as well as encapsulating these parts, a mounting sleeve 60 is provided which is illustrated in more detail in the FIGS. 6, 7 and 8. The mounting sleeve 60 is a molding of a plastics material which is shown in FIG. 6 in the plan view, in FIG. 7 in longitudinal section along the broken line A--A of FIG. 6 and in FIG. 8 in a perspective view. The mounting sleeve 60 has a widened cylindrical section 61, a narrowed cylindrical section 62 of smaller diameter and a conical section 63 between the two cylindrical sections 61 and 62. The outer diameter of the widened cylindrical section 61 corresponds to the inner diameter of the pot-shaped transducer housing 52, and the inner diameter of the narrower cylindrical section 62 corresponds to the diameter of the piezoelectric element 51. The narrower cylindrical section 62 and the conical transition section 63 are divided into six segments 64 by cutouts. At each segment 64, a paw 65 protruding radially inward is formed at the transition between the cylindrical section 61 and the conical section 63. Below each paw 65 an abutment nose 66 is formed which extends downwards only over a part of the height of the cylindrical section 62 and protrudes only slightly downwards radially. At the transition between the conical section 63 and the widened cylindrical section 61 a shoulder 67 is formed. In the wall of the widened cylindrical section 61 at each of two positions diametrally opposed to each other by cutouts a flexible latch 68 is formed, the free end of which protrudes slightly inwards and is located a distance away from the shoulder 67 which corresponds to the thickness of the circuit board 54. A rib 69 formed on the periphery of the widened cylindrical section 61 engages a corresponding groove in the transducer housing 52, as a result of which the mounting sleeve 60 is prevented from turning in the transducer housing 52. The described configuration of the mounting sleeve 60 permits simple, speedy and precise assembly of the components of the ultrasonic transducer 50 outside of the transducer housing 52. The piezoelectric element 51 with the disk 56 of a closed-pore foamed material placed thereon is introduced into the narrowed cylindrical section 62 from underneath until the piezoelectric element 51 comes up against the ends of the abutment noses 66, thus precisely defining the radial and axial position of the piezoelectric element 51 in the mounting sleeve 60. The diameter of the foamed material disk 56 is somewhat smaller than the diameter of the piezoelectric element 51 and corresponds to the spacing between two abutment noses 66 located diametrally opposed to each other, and the thickness of the foamed material disk 56 corresponds to the height of the abutment noses 66. Accordingly, the paws 65 locate on the upper side of the foamed material disk 56 when the piezoelectric element 51 is introduced to abutment in the mounting sleeve 60, and the abutment noses 66 locate on the periphery of the foamed material disk 56. As a result of this the radial and axial position of the foamed material disk 56 is precisely defined in the mounting sleeve 60, and the foamed material disk 56 is maintained by the paws 65 in close contact with the upper side of the piezoelectric element 51. The circuit board 54 is circular and has a diameter corresponding to the inner diameter of the widened cylindrical section 61 of the mounting sleeve 60. It is introduced from above into the widened cylindrical section 61 until it rests on the shoulder 67. During insertion the latches 68 are forced outwards by the peripheral edge of the circuit board 54 until the peripheral edge of the circuit board 54 has passed the ends of the latches 68. Then, due to their elasticity, the latches 68 snap back inwards so that they clasp the upper side of the circuit board 54 and hold the latter firmly on the shoulder 67, as a result of which the position of the circuit board 54 is fixed in the axial and radial direction in the mounting sleeve 60. The mounting sleeve 60 is then ready for being installed in the transducer housing 52. For this purpose a drop of a hot-curable adhesive is first applied to the bottom 53 of the transducer housing 52, and subsequently the mounting sleeve 60 is inserted into the transducer housing 52 until the piezoelectric element 51 comes into contact with the bottom 53, the adhesive thereby being distributed in a thin layer between the surfaces of the piezoelectric element 51 and the bottom 53 facing each other. The adhesive is then hardened by being heated, the mounting sleeve 60 being weighted down by a weight so that a defined layer of adhesive is attained. The layer of adhesive ensures the contact between the piezoelectric element 51 and diaphragm of the ultrasonic transducer 50 formed by the bottom 53 and it prevents the formation of a layer of air between these parts. The potting compound 55 is then filled into the mounting sleeve 60 from above. This potting compound flows through openings provided therefor in the circuit board 54 also into the space between the circuit board 54 and the foamed material disk 56. The foamed material disk 56 prevents the potting compound 55 from coming into contact with the upper side of the piezoelectric element 51. The paws 65 which force the edge of the foamed material disk 56 onto the upper side of the piezoelectric element 51 prevent the potting compound 55 from creeping between the foamed material disk 56 and the piezoelectric element 51. Serving installation of the pot-shaped transducer housing 52 in the sensor housing 22 is a mounting part 70 having a flange 71 on which a guide bush 72 is formed. The transducer housing 52 is pushed into the guide bush 72, the inner diameter of which corresponds to the outer diameter of the transducer housing 52 so that the transducer housing 52 is a sliding fit in the guide bush 72. The collar 57 on the transducer housing 52 prevents the transducer housing 52 from emerging from the guide bush 72. In the open end of the transducer housing 52 a spring cup 73 is inserted which in turn features a collar 74 supported by the end of the transducer housing 52. The spring cup 73 receives the one end of a coil compression spring 75. Running around the edge of the flange 71 is a collar 76, the inner diameter of which corresponds to the outer diameter of a carrier tube 77 formed on the transverse wall 45. Prior to attaching the mounting part 70 to the carrier tube 77 a connecting lead 78, which is soldered to the circuit board 54 and is intended to connect the ultrasonic transducer 50 to the excitation and evaluation circuitry 14, is inserted through a tube socket 79 standing off from the transverse wall 45 to the opposing side. On the flange 71 a sealing ring 80 is placed to which the outer edge of an annular cuff 81 is secured, the inner edge of which is connected to an elastic ring 82 placed around the transducer housing 52. Then, the collar 76 is placed over the carrier tube 77 and the flange 71 is secured by means of screws 83 which are screwed into the thickened wall sections of the carrier tube 77 and of which one is to be seen in FIG. 4. The coil compression spring 75 is dimensioned so that it is compressed between the spring cup 73 and the transverse wall 45 to achieve a desired pretension when the mounting part 70 is secured to the carrier tube 77. Following this, the connecting lead 78 can be soldered to the terminals provided on the circuit board 48, and the outer space 46 can be filled with a potting compound practically up to the level of the tube socket 79. The tube socket 79 prevents potting compound from flowing into the inner space 47. The sensor block 20 is now fitted ready for operation and it can be secured to the adapter 21. For this purpose the guide bush 72 is inserted through an opening in the plate 30 of the adapter 21 so that the bottom of the transducer housing 52, i.e. the diaphragm 53 of the ultrasonic transducer 50, is in contact with the outer surface of the container wall 12. When the sensor block 20 is moved in the direction of the adapter 21, the transducer housing 52 is firmly held by the container wall 12 so that it is shifted into the guide bush 72, as a result of which the spring 75 is further compressed. Once, in conclusion, the sensor block 20 has been secured to the adapter 21 by means of the screw 26, the diaphragm 53 is urged against the container wall 12 by the force defined by the spring 75. It will be appreciated from comparing the FIGS. 3, 4(a) and (b) that in applying the sensor 13 to a flat container wall 12 (FIG. 3) the ultrasonic transducer 50 protrudes further from the guide bush 72 than in the case of a curved container wall 12 (FIGS. 4(a) and (b)), the contact of the diaphragm 53 with the container wall 12 being assured in each case by the force defined by the spring 75. In all ways of securing the adapter 21 it needs to be assured that the diaphragm, following fitting of the sensor block, is oriented parallel in the case of a flat container wall 12 and tangential and symmetrical in the case of a cylindrical container wall 12. This can only be achieved when the adapter is already correctly oriented on being fitted. In the FIGS. 9 and 10 a preferred embodiment of the adapter 21 is illustrated which satisfies this requirement. In this embodiment spacers 85 are applied to the adapter 21 which dictate the spacing of the plate 30 away from the container wall 12 along two lines oriented parallel to the longitudinal sides of the adapter. The spacers 85 may be pins applied to the four corners of the plate 30, or also strips extending along the longitudinal sides of the frame 31. The spacers 85 ensure that the adapter 21 has a position which is defined with respect to the container wall 12 even when, in the case of the clamping strap attachment, the force acting on the one side is greater than the force acting on the other side, or when, in the case of attachment by threaded studs, the studs are not oriented straight or the forces exerted by the nuts are unequal. It will be appreciated from the transducer housing 52 depicted schematically to the container wall 12 in FIGS. 9 and 10 that due to the spacers 85 the diaphragm is oriented precisely tangential and symmetrical in the case of a cylindrical container wall 12 and, in the case of a flat container wall 12, it is in parallel contact with the container wall 12.

For monitoring a predetermined level of a liquid in a container an ultrasonic sensor is fitted on the outer surface of the container wall at a measurement point situated at the height of the level to be monitored, said sensor containing an ultrasonic transducer having a diaphragm in contact with the container wall. The components of the ultrasonic sensor including those of the ultrasonic transducer are grouped together in a sensor block which is releasably connected to an adapter secured to the container wall, this adapter being configured so that it can be secured in any way required to containers of differing shape and/or material.

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. provisional No. 61/495,060, and the priority of German number 10 2011 106 111.1, filed Jun. 9, 2011, hereby incorporated by reference. BACKGROUND OF THE INVENTION 1. Field of Invention The invention relates to a method and a device for determining at least operating parameter of a device for extracorporeal blood treatment as a function of the absolute pressure. For the sake of simplicity, the term blood treatment device is used hereinafter for all devices for extracorporeal treatment of blood. 2. Description of the Prior Art Various types of blood treatment devices are known. The known blood treatment devices include, for example, devices for hemodialysis, hemofiltration and hemodiaflltration. During extracorporeal blood treatment, the blood flows through a blood treatment unit in an extracorporeal blood circulation. Of the devices for hemodialysis, hemofiltration and hemodiafiltration, the blood treatment unit is a dialyzer or filter which is separated by a semipermeable membrane into a blood chamber and a dialysis fluid chamber, when considered schematically. During the blood treatment by means of hemodialysis or hemodiafiltration, blood flows through the blood chamber while a dialysis fluid flows through the dialysis fluid chamber. Fresh dialysis fluid may be supplied through a dialysis fluid system which is integrated into the device for extracorporeal blood treatment. Clean water, e.g., from reverse osmosis may be supplied to the dialysis fluid system after first being degassed and then mixed with liquid concentrates to prepare fresh dialysis fluid. Mixing may be accomplished, for example, by adding liquid concentrates to the clean water line at separate addition points and then mixing them thoroughly in a mixing chamber or by adding the liquid concentrates through separate feed points directly to a mixing chamber. The fresh dialysis fluid flows first through a balancing system and is then directed through the dialysis chamber of the dialyzer. The fresh dialysis fluid is then loaded with water and ingredients from the blood and thereby becomes spent dialysis fluid. After leaving the dialyzer, the spent dialysis fluid passes through the balancing system, where any difference between the volume of the fresh dialysis fluid and the spent dialysis fluid is determined. The mixing chamber has incoming fluid lines and outgoing fluid lines. The mixing chamber may receive incompletely premixed mixture from degassed clean water and fluid concentrates. The complete mixing takes place in the mixing chamber. Fresh dialysis fluid is removed from the mixing chamber through a dialysis fluid line. Clean water, liquid concentrates and dialysis fluid are delivered in the lines by pumps. The clean water is degassed by creating a vacuum by means of a degassing pump in the clean water line upstream from the mixing chamber. The liquid concentrates are delivered by metering pumps upstream from the mixing chamber. The dialysis fluid is delivered through a dialysis fluid pump in the dialysis fluid line. With the dialysis fluid line upstream from dialyzer and with the dialysis fluid line downstream from the dialyzer, additional pumps may be in fluid connection, such as, for example, a flow pump in the dialysis fluid line and an ultrafiltration pump. With the generic devices for extracorporeal blood treatment, inexpensive relative pressure sensors are usually used to measure the pressures. The pressures inside the dialysis fluid system are therefore usually set at ambient pressure. The generic devices for extracorporeal blood treatment therefore usually do not have an integrated absolute pressure gauge. The operating parameters may be set as a function of the absolute pressure on known devices for extracorporeal blood treatment, which may be done either by a service technician using an external absolute pressure gauge or by storing approximate values in the central control unit. The operating parameters are set by a service technician, who may carry an absolute pressure gauge with him for this purpose, as a function of the absolute pressure in setting up a blood treatment device in a selected geographic region, for example. For example, according to the state of the art in setting up a blood treatment device, the elevation of the setup site is set through the choice of the value ranges and average values for the operating parameters which depend on the absolute pressure are preselected for each value range. For example, average values of the operating parameters depending on the absolute pressure are preselected for the following value ranges as a function of the elevation of the setup site above sea level: setup height less than 800 meters above sea level (N.N.=normal zero of sea level), setup height between 800 meters above sea level and 1400 meters above sea level, setup height 1400 meters above sea level to 2000 meters above sea level, setup height 2000 meters above sea level. The elevation of the setup site can usually be estimated roughly without any additional assistance. The operating parameters predetermined for the value range are set according to the selection of a value range. The known methods for setting operating parameters depending on the absolute pressure on blood treatment devices are associated with disadvantages because they are either complex and difficult to automate or they are inaccurate and also depend on the reliability of a user input that is susceptible to errors. Examples of such operating parameters, which depend on the absolute pressure include the degassing pressure and the boiling point. The absolute pressure may also itself be an operating parameter of a device for extracorporeal treatment of blood. The local ambient pressure may be between 700 hPa and 1060 hPa, for example, depending on the geographic location and the weather situation. An automatic adjustment in the operating parameters depending on the absolute pressure would also be desirable in the case of weather-related changes in the absolute pressure. The degassing pressure must be set for a safe and reliable degassing of the clean water. The dissolving behavior of gases in liquids depends on the absolute pressure. The saturation concentration decreases with a decline in the absolute pressure. In generic blood treatment devices an absolute degassing pressure of approximately 150 hPa based on the vacuum is the goal. The degassing pressure is generated by a degassing pump and a throttle in the clean water line of the dialysis fluid system. Without an absolute pressure measurement, the degassing pressure can only be determined approximately. For a safe and reliable degassing, the most accurate possible setting of the degassing pressure is desirable. The boiling point is needed to prevent steam from forming in hot cleaning of the dialysis fluid system because when steam forms it changes the flow properties in the dialysis fluid system and the steam can escape from the dialysis fluid system and enter the interior of the housing of the blood treatment device, where the steam can condense and lead to damage. The boiling point drops with a drop in pressure. The change in the boiling point with the absolute pressure is known as a qualitative measure and can be obtained from the professional literature, for example, from tables for water and stored in the central control unit of the blood treatment device. In heat disinfection of the dialysate system, the entire dialysis fluid system must be heated to more than 80° C. in a known device. The entire dialysis fluid system is especially advantageously purified by rinsing with hot water at approximately 85° C. In hot purification, the entire dialysis fluid system is rinsed with heated clean water at a predetermined flow rate. The clean water is heated with an electric heating rod. To keep the heating time of the clean water as short as possible, the clean water temperature on the heating rod should be as high as possible. The clean water temperature on the heating rod in the dialysis fluid system is always regulated at a temperature below the boiling point. The absolute pressure may be appropriate for determining additional operating parameters. For example, in another patent application by the present applicant with the title “Method and Device for Testing the Delivery Power of at Least One Delivery Agent of a Device for Extracorporeal Blood Treatment”: (internal application Ser. No. 10/57-d01 DE) with the same filing date as the present application, a method and a device for which knowledge of the absolute pressure is advantageous are described. Reference is thus herewith made to the full extent to the aforementioned other patent application. For determining and providing many operating parameters, however, the existence of a current measured value of the absolute ambient pressure, also referred to simply as absolute pressure, would be advantageous. If there is a measured value for the absolute pressure, such operating parameters can be determined and adjusted with a particularly high precision. SUMMARY OF THE INVENTION One object of the invention is to further improve a generic blood treatment device without its own absolute pressure gauge such that at least one operating parameter which depends on the absolute pressure can be set automatically and without requiring an absolute pressure sensor or the use of a qualified service technician or a user. Another object of the present invention is to determine at least one operating parameter depending on the absolute pressure with a high precision without requiring an absolute pressure gauge for this purpose. Another object of the present invention is to automatically adjust at least one operating parameter, which depends on the absolute pressure when the absolute pressure in the surroundings changes significantly. Another object of the present invention is to improve the user friendliness so that the user, for example, the treating physician or the dialysis nurse is not burdened with setting the operating parameters, which depend on the absolute pressure and therefore there are also no downtimes of the blood treatment machine for service by a qualified service technician. Another object of the present invention is to increase the reliability of the blood treatment device. The more accurately the operating parameters which depend on the absolute pressure can be set, the more reliable the dialysis fluid system and thus the blood treatment device can operate reliably. Another object of the present invention is to increase the safety of the blood treatment device. The more accurately the operating parameters which depend on the absolute pressure can be set, the more reliably the dialysis fluid system can operate. These objects are achieved according to the invention with the features described herein. Advantageous embodiments of the invention are also described herein. According to the teaching of the present invention, these objects are achieved by first setting the absolute ambient pressure in a closed container, which is filled at least partially with air and has an essentially constant container volume, and to do so through equalization of pressure with respect to the surroundings, and then this pressure is kept constant by cutting off the container from the surroundings and next a predetermined sequence of at least two delivery strokes of a fluid is delivered into the container using a delivery means and after each delivery stroke the increased relative pressure in the container is measured and after each delivery stroke the total volume delivered and the relative pressure are assigned to a value pair and the absolute pressure and/or the initial air volume is/are calculated using the value pairs for the at least two delivery strokes executed. The calculation may be performed on the basis of the Boyle-Mariotte law. According to the teaching of the invention these objects are additionally achieved by calculating the operating parameters which depend on the absolute pressure in an additional step. The adjustment of the at least one operating parameter may in many embodiments include calculation and/or storage in a data memory in a control and computation unit. In many embodiments the adjustment of the at least one operating parameter may include execution of a control intervention on a function unit of the device for extracorporeal blood treatment. An example of a function unit is a pump with a controllable pump drive. All the advantages that can be achieved with the method according to the invention can also be achieved in certain inventive embodiments in undiminished form with the device according to the invention and/or with the device for extracorporeal blood treatment. In some inventive embodiments this is also true of the inventive computer program product and the inventive computer program. The method according to the invention may run automatically without requiring user intervention. The method according to the invention may be executed by a control and computation unit, which may be part of the device according to the invention. The method according to the invention may be started automatically by the control and computation unit at regular intervals, for example. A message that there is an automatic update of the operating parameters, which depend on the absolute pressure, may be displayed on the display screen of the blood treatment device while the method is being performed. During the update, the start of the blood treatment may be suppressed by the control and computation unit. The control and computation unit may provide a means for limiting the relative pressure to a maximum level, so that unacceptably high pressures cannot occur. There may be an error message on the display of the blood treatment device indicating a failure of the update of the operating parameters which depend on the absolute pressure. On reaching an inadmissibly high relative pressure, the method according to the invention is terminated and may be restarted at a later point in time. According to the teaching of the invention, these objects are further achieved by setting at least one calculated operating parameter on the blood treatment machine. The absolute pressure is calculated merely on the basis of the measured values of the relative pressure in the closed container. The at least one operating parameter which depends on the absolute pressure may be calculated by the central control and computation unit of the blood treatment device and stored in a data memory and/or adjusted by control and/or regulating interventions. It is not necessary to use an absolute pressure gauge to do so. The device according to the invention provides a closed container with an essential constant internal volume. An essentially constant container volume is understood to mean that the internal volume changes only negligibly or not at all with an increase in the internal pressure in the relevant pressure range. Closed is to be understood here to mean that there is no free opening with the surroundings while performing the method according to the invention and any inlet lines or outlet lines opening into the container but not needed for performing the method are cut off. Inlet lines or outlet lines may include, for example, tubing or pipelines. The inlet lines or outlet lines may be closed by valves. The inlet lines or outlet lines may be closed by pumps that are shut down. The inlet lines or outlet lines not needed for performing the method according to the invention are cut off by intervention measures by the control and computation unit before performing the method according to the invention. In a preferred embodiment, the container is a mixing chamber in a dialysis fluid system of a blood treatment device for preparing fresh dialysis fluid. The device according to the invention has means for measuring the relative pressure in the container. The means for measuring the relative pressure may be a pressure sensor in the container. In particular the means may be a pressure sensor in the air volume in the interior of the container but it may also be a pressure sensor which is functionally connected to the interior of the container for measuring the pressure. The pressure sensor provides an electrical pressure signal as a function of the relative pressure in the container, this signal being relayed over a data line to the control and computation unit. However, it is also possible for the pressure sensor to transmit the pressure signal wirelessly to the control and computation unit. The pressure sensor may be an RFID sensor. The means for measuring the relative pressure may be a relative pressure sensor which is present anyway in the mixing chamber of a dialysis fluid system. The device according to the invention provides means for setting the absolute pressure (absolute ambient pressure) in the container. The absolute pressure level is initially unknown but is being sought. The means for initial setting of the absolute pressure may be a cutoff valve with which an opening in the otherwise closed container with respect to the surroundings can be opened or cut off for performing the additional steps of the method according to the invention. The mixing chamber may have as an opening a line to the surroundings, the end of which is open to the surroundings. The line has a cutoff valve, with which the line can be closed in an airtight manner. The ambient pressure can be adjusted in the container easily by briefly opening the cutoff valve to the surroundings, so the pressure is equalized with the surroundings, and the absolute ambient pressure is automatically established in the container. After the pressure equalization, the cutoff valve is closed. The pressure thereby set remains upheld when the cutoff valve in the container is closed. The cutoff valve always remains closed to the surroundings during the following steps of the method according to the invention, so there cannot be a renewed equalization of pressure with respect to the surroundings. Only after the method according to the invention has been performed completely is a renewed pressure equalization with the surroundings ordered to depressurize the excess pressure that has been built up. The valve may be automatically operable or operated. The valve can be opened and closed by the control and computation unit of the device according to the invention. However, the valve may also be operated by a manual control intervention by the user. For example, it may be a solenoid valve which is controllable electrically. However, it may also be a pneumatically controllable valve. After setting the ambient pressure, an air volume which is referred to below as the initial air volume, is established in the container. The initial air volume fills the container at least partially. The remaining container volume may be filled with an initial liquid volume, which forms a liquid level. It is also possible for the complete internal volume of the container to be filled with air and to form the initial air volume. Then there is no liquid in the container. Means for measuring the liquid volume may be present in the container. The means for measuring the liquid volume may be a filling level measurement by means of a filling level sensor. The filling level sensor delivers an electric filling level sensor as a function of the filling level in the container and this signal is forwarded over a data line to the control line computation unit. The liquid volume can be calculated by the control and computation unit from the measured filling level and the known geometry of the container. The initial air volume can be calculated as the difference between the container volume and the initial fluid volume. For performing the method according to the invention, means for measuring the liquid volume are not necessary because the initial air volume can be calculated by the method according to the invention but a filling level measurement may still be provided in the mixing chamber of a dialysis fluid system, so that it can advantageously be used for a plausibility check of the results of the calculation of the initial air volume. It is of course also possible to determine the initial air volume only by means of a filling level measurement. It is also possible to analyze a measured filling level change as a criterion for a pressure change in the container by means of a filling level measurement in the container with known initial conditions of the pressure and air volume in the container as an alternative to the method according to the invention and from this to conclude the absolute pressure. At least one liquid line having a fluid-carrying connection to a liquid source opens into the container; at least one delivery means for delivering the fluid in a first direction of delivery into the container is arranged in this liquid line. The delivery means is characterized in that there is no return flow through the delivery means in the opposite direction to the first direction of delivery when the delivery means is at a standstill. The delivery means functions like a non-return valve. The delivery performance of the delivery means, in particular the delivery rate of the delivery means per delivery stroke and/or per unit of time is known and is stored in the control and computation unit. In a preferred embodiment, the delivery stroke may be a pump stroke. The liquid is incompressible or is assumed to be incompressible. The at least one delivery means may be controlled by the control and computation unit for starting and stopping and/or for executing at least one delivery stroke. The at least one delivery means may be controlled by the control and computation unit for executing a sequence of delivery strokes. The delivery strokes may each have the same stroke volume but it is not necessary for the implementation of the invention for all the delivery strokes to have the same stroke volume. In a preferred embodiment, all the delivery strokes have the same stroke volume. In a preferred embodiment, the liquid source is from the group of supplying clean water, supplying sodium bicarbonate concentrate and supplying acid concentrate from the dialysis liquid system of a blood treatment device. In a preferred embodiment, the delivery stroke is the pump stroke of a diaphragm pump. The delivery behavior of a diaphragm pump is discontinuous from one delivery stroke to the next. The delivery volume of a complete pump stroke of a diaphragm pump depends only on the geometry of the diaphragm pump. With each complete pump stroke, the same volume of liquid can always be delivered. Another preferred embodiment concerns the pump stroke of a piston pump. The delivery performance of a piston pump is discontinuous from one delivery stroke to the next. The pump stroke of a piston pump depends only on the geometry of the piston pump. The same volume of liquid can always be delivered with each complete pump stroke. In another preferred embodiment, the pump stroke involves a predetermined delivery time of a delivery means having a continuous delivery performance. The delivery means may be, for example, a gear pump or a hose pump. In a preferred embodiment, the delivery means may be a metering pump. The metering pump may be a high precision pump. The metering pump may be a diaphragm pump. In an especially preferred embodiment, the pump stroke may be predefined by specifying a number of steps or a step angle on a stepping motor, which drives the delivery means. The stepping motor may be electrically operated. The step angle and/or the number of steps can be predetermined by electrical pulses of a control and computation unit. The pressure in the container after adjusting the ambient pressure should change only through the supply of fluid through the pump strokes of the delivery means in the method according to the invention. The delivery means can be controlled by a control and computation unit. The control and computation unit may be configured to induce a sequence of delivery strokes of the delivery means. The sequence of delivery strokes has a predetermined number of delivery strokes. The control and computation unit may be configured to detect and/or save a measured pressure value in the container after each delivery stroke is completed. The control and computation unit may additionally be configured to calculate the total liquid volume delivered after each delivery stroke is performed. The total liquid volume delivered is understood to be the sum of the liquid volumes of all delivery strokes already performed while performing the method according to the invention. In a preferred embodiment, the volume of each delivery stroke always has the same amount, namely a constant stroke volume. In this embodiment, the total liquid volume delivered is calculated especially easily as the product of the amount of the stroke volume and the number of delivery strokes performed. The control and computation unit may additionally be configured to assign the amounts of the total liquid volume delivered and the relative pressure in the container to a value pair after each delivery stroke is made and to store them. The control and computation unit may additionally be configured to automatically start the calculation of the absolute pressure and/or of the initial air volume on the basis of all value pairs as the next step after the conclusion and analysis of the last delivery stroke of a predetermined sequence of delivery strokes. The control and computation unit may additionally be configured to calculate the absolute pressure and initial air volume parameters that are sought by way of a fitted calculation on the basis of all value pairs using the following approach, which is obtained by applying the Boyle-Mariotte law to the changes in state in the container such that a best possible approximation of the function described by this approach to the measured values of the relative pressure is obtained as follows: P i = P abs , amb · i · V pump V vessel , air , 0 - i · V pump ; i = 1 , … ⁢ , n In equation (1), P abs,amb denotes the absolute pressure being sought in the surroundings, V vessel,air,0 is the initial air volume being sought in the mixing chamber, V pump is the stroke volume of the diaphragm pump used here, n denotes the total number of delivery strokes of the diaphragm pump, i is the running index for the number of pump strokes and P is the relative pressure in the mixing chamber after performing a pump stroke. The control and computation unit may additionally be configured to calculate the at least one operating parameter as a function of the absolute pressure. The control and computation unit may additionally be configured to adjust the at least one calculated operating parameter in the blood treatment device as a function of the absolute pressure by means of control interventions. The at least one operating parameter can be adjusted through control intervention measures and/or regulating intervention measures on a control and computation unit. The control and computation unit may additionally be configured to regulate the heating of clean water, which can be performed by means of an electric heater, so that the temperature of the clean water is always kept below a temperature limit which is below the boiling point. To this end, the control and computation unit can regulate the heating power and/or the on time of the electric heater. The electric heating may also be a heating rod. The control and computation unit may additionally be configured to adjust the desired degassing pressure as a vacuum with respect to the absolute pressure by means of a control intervention on the degassing pump of the dialysis fluid system. The degassing pressure may be adjusted as a pressure drop on a degassing throttle in the clean water line by means of the rpm-regulated degassing pump. The degassing throttle may be a throttle valve, for example. The device according to the invention may form an independent unit but may also be part of a blood treatment device. It may be a device for retrofitting a blood treatment device which does not have its own inventive container. An especially preferred embodiment provides that the device according to the invention is part of the blood treatment device because the known blood treatment devices already have components which can be utilized by the device according to the invention. In another particularly preferred embodiment, equipping a blood treatment device with the device according to the invention may be limited to updating the software of the control and computation unit because all the required components are present in the blood treatment device through the software. For such embodiments and other embodiments, an inventive computer program with program code and an inventive computer program product with a program code stored on a machine-readable carrier are made available. The device and the method according to the invention may be used with the known blood treatment devices without requiring any great renovation measures. A mixing chamber in a dialysis fluid system is present anyway with the known blood treatment devices. The means for measuring the relative pressure are present anyway on the known blood treatment devices. Retrofitting of a suitable chamber is possible without any great effort on blood treatment devices which do not have a mixing chamber in the dialysis fluid system. Suitable delivery means for delivering a fluid are always present in the dialysis fluid system of the known blood treatment devices. BRIEF DESCRIPTION OF THE DRAWINGS An exemplary embodiment of the invention is explained in greater detail below with reference to the figures. On the basis of the exemplary embodiment shown in the figures, additional details and advantages of the invention will be described in greater detail. The method and the device according to the invention are described on the example of a blood treatment device designed as a hemodialysis device. However, the method according to the invention may also be used in the same way with other blood treatment devices, for example, a hemodiafiltration device. FIG. 1 shows a flow chart of the dialysis system of a blood treatment device having a mixing chamber, designed as a hemodialysis device; FIG. 2 shows a graphic plot of the pressure conditions of the relative pressure in the mixing chamber of the dialysis fluid system from FIG. 1 in performing the method according to the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. FIG. 1 shows in a simplified schematic diagram the essential components of the dialysis fluid system 1 of a blood treatment device designed as a hemodialysis device. In the present exemplary embodiment the blood treatment device which is designed as a hemodialysis device is referred to further in simplified terms as a “blood treatment device” having a dialyzer 2 which is separated schematically by a semipermeable membrane 3 into a blood chamber 4 and a dialysis fluid chamber 5 . The blood chamber is part of the extracorporeal blood circulation (not shown) and the dialysis fluid chamber 5 is part of the dialysis fluid system 1 . The central control and computation unit 100 operates and monitors the blood treatment device and the dialysis fluid system. The control and computation unit 110 of the device according to the invention is part of the central control and computation unit 100 of the blood treatment device in the exemplary embodiment. However, the control and computation unit 110 may also be separate from the central control and computation unit 100 and connected to the latter by data lines. The dialysis fluid system has a mixing chamber 6 for mixing fresh dialysis fluid of clean water and liquid concentrates. The dialysis fluid system has a line 7 for delivering clean water to which a passive membrane 8 ′ is connected, forming a delivery means having a metering function only in cooperation with a gear pump 19 (degassing pump), which is situated upstream and which is referred to hereinafter as delivery means 8 . The line 7 opens into the mixing chamber 6 . The delivery means 8 comprise delivery means for clean water. A line 9 opens into the line 7 downstream from the delivery means for clean water 8 . A delivery means 10 is connected to the line 9 . The delivery means 10 in the exemplary embodiment is a metering pump for sodium bicarbonate concentrate. The metering pump 10 is embodied as a diaphragm pump. Another line 11 also opens downstream from the delivery means for clean water 8 into the first line 7 . Delivery means 12 is connected to the line 11 . In this exemplary embodiment, the delivery means 11 is a metering pump for acid concentrate. The metering pump 12 is designed as a diaphragm pump. A line 21 leads downstream from the mixing chamber 6 to the dialysis fluid chamber 5 of the dialyzer 2 . One delivery means 22 is connected to line 21 . In this exemplary embodiment, this delivery means is a gear pump 22 , which is part of a balancing device 25 . A bypass line 23 having a bypass valve 24 is provided in the parallel connection to the line 21 . The bypass valve 21 is closed during operation of the gear pump 22 . In principle in the exemplary embodiment, each of the delivery means 8 , 10 , 12 or 22 may be selected for delivering a fluid into the container 6 or for delivering the fluid out of the container 6 for performing the method according to the invention. For delivering fluid into the container 6 the delivery means 8 , 10 and 12 must be operated in the normal direction of delivery, while the delivery means 22 would have to be operated in the opposite direction of delivery. For delivering fluid out of the container 6 , the delivery means 8 , 10 and 12 would have to be operated in the reverse direction of delivery, while the delivery means 22 would have to be operated in the normal direction of delivery. In the present exemplary embodiment, the performance of the method according to the invention is explained as an example using the delivery means 10 with which fluid is delivered into the container 6 in the normal direction of delivery. The control and computation unit 110 may have means for selecting one of the delivery means ( 8 , 10 , 12 , and 22 ) for performing the method according to the invention. The choice may also be set fixedly in the control and computation unit 110 or may be made by the user through user intervention, for example, via the touchscreen of the blood treatment device (not shown in FIG. 1 ). In the exemplary embodiment the diaphragm pump 10 for liquid concentrate is selected by the control and computation unit 110 as the delivery means. A delivery stroke of the diaphragm pump 10 in the present example corresponds exactly to the stroke volume which is delivered in the case of a complete pump stroke. This stroke volume of a complete pump stroke is known and constant for the selected pump. However, as an alternative the delivery stroke could also include part of a complete pump stroke, for example, if the pump drive is a stepping motor. The control and computation unit 110 has means for ordering a predetermined number of delivery strokes. The delivery strokes are ordered by control intervention measures 10 a. The device according to the invention has a pressure sensor 13 which measures the relative pressure in the mixing chamber 6 . The measured values of the pressure sensor 13 are transmitted to the control and computation unit 110 where they are stored in the data memory 120 for analysis. In addition, the control and computation unit 110 has means for assigning the delivery volume delivered after each delivery stroke to the measured relative pressure in the mixing chamber as a value pair for the completed delivery stroke. The value pairs of all delivery strokes are stored in the control and computation unit 110 . In addition, the control and computation unit 110 has means for calculating the absolute ambient pressure and/or the initial air volume using the stored value pairs for all delivery strokes. The calculations of the parameters that are sought are performed with the help of a computer program using program code to order the machine steps of the method and to analyze the measurement results. The computation equations are implemented in the program code. The program code is stored in the control and computation unit 110 . The computer program is stored as computer program product with the program code stored on a machine-readable carrier for ordering the machine steps of the method. The computer program runs in the control and computation unit 110 . The control and computation unit 110 has a data memory 120 . The computer program with program code for ordering the machine steps of the method and for analyzing the measurement results starts the calculations as soon as the entire predetermined number of delivery strokes is concluded. The total internal volume of the mixing chamber 6 is known and amounts to 350 mL in this exemplary embodiment. The initial liquid volume 16 in the mixing chamber 6 is calculated from the measured value of the filling level measurement device 15 . The initial air volume 14 in the mixing chamber is calculated by the control and computation unit 110 as the difference in the total internal volume and the liquid volume and amounts to 242 mL in the exemplary embodiment. The temperature in the mixing chamber is 37° C. and is assumed to be constant while the method according to the invention is being performed. The number of delivery strokes to be performed is advantageously more than 50 and especially advantageously up to 120. However, more than 120 delivery strokes are not necessary in the exemplary embodiment and do not yield a more accurate result. The number n of the delivery strokes to be performed is predefined as n=110, for example, in the central control of the blood treatment device in t his exemplary embodiment. The stroke volume of the diaphragm pump 10 in the exemplary embodiment is 1.0 mL (one milliliter) and corresponds to the delivery volume of a single delivery stroke in the diaphragm pump 10 . The control and computation unit 110 starts and stops the delivery strokes of the diaphragm pump through control intervention measures 10 a . With each delivery stroke one milliliter of liquid is pumped into the mixing chamber. There is no return flow of fluid through the diaphragm pump 10 . The pressure in the mixing chamber increases with each delivery stroke in accordance with the Boyle-Mariotte law because with each delivery stroke the liquid volume increases by the amount of one delivery stroke, and on the other hand, the air volume decreases with each delivery stroke to the same extent by the amount of the delivery stroke. The air is therefore compressed by the same amount with each delivery stroke. This relationship is described by equation (1). The thermodynamic basis of equation (1) is the Boyle-Mariotte law applied to the changes in state of the air volume in the mixing chamber caused by the delivery strokes: P abs,amb ·V vessel,air,0 =( P abs,amb +P i )·( V vessel,air,0 −i·V pump ); i= 1, . . . , n   (1) In equation (1), P abs,amb denotes the absolute ambient pressure being sought in the surroundings, V vessel,air,0 denotes the initial air volume being sought in the mixing chamber, V pump denotes the stroke volume of the diaphragm pump, n denotes the total number of delivery strokes of the diaphragm pump, i denotes the running index for the number of pump strokes and P i denotes the relative pressure in the mixing chamber after the i-th pump stroke. Equation (2) is obtained by rearranging equation (1) and is used in the program code for a fitting calculation to calculate the parameters P abs,amb and V vessel,air,0 being sought, wherein no filling level sensor is needed: P i = P abs , amb · i · V pump V vessel , air , 0 - i · V pump ; i = 1 , … ⁢ , n ( 2 ) The calculation is performed under the assumption of a constant absolute pressure during the performance of the method according to the invention. With the substitutions x i =i·V pump and y i =P i the following equation is stored in the program code: f ⁡ ( x i ) = P abs , amb · x i V vessel , air , 0 - x i ( 3 ) where n pump strokes are performed and n value pairs (x i , y i ), where i=1, . . . , n are determined. In these equations i=1, . . . , n denotes the running index for the sequence of pump strokes beginning with the first delivery stroke (i=1), the second delivery stroke (i=2) up to the last delivery stroke (i=n), so that a total of n delivery strokes are executed. The value pairs are stored in data memory 120 . Using the known fitting equation of “minimization of the sum of the distance squared,” also known by the English term “method of least squares” applied to equation (2) together with equation (3), the parameters being sought are calculated on the basis of equation (4). S = ∑ i = 1 n ⁢ ( y i - f ⁡ ( x i ) ) 2 = ∑ i = 1 n ⁢ ( y i - P abs , amb · x i V vessel , air , 0 - x i ) 2 ( 4 ) The parameters P abs,amb and V vessel,air,0 which are being sought are calculated according to the method of least squares so that the error total S in equation (4) assumes a minimum. The first of two necessary conditions for this is obtained from equation (5): ∂ S ∂ P abs , amb = ∂ ∂ P abs , amb ⁢ ∑ i = 1 n ⁢ ( y i - P abs , amb · x i V vessel , air , 0 - x i ) 2 = 2 · ∑ i = 1 n ⁢ ( y i - P abs , amb · x i V vessel , air , 0 - x i ) · ( - x i V vessel , air , 0 - x i ) = 0 ( 5 ) It follows from equation (5) by rearranging: ∑ i = 1 n ⁢ ( y i · x i V vessel , air , 0 - x i ) - P abs , amb · ∑ i = 1 n ⁢ ( x i V vessel , air , 0 - x i ) 2 = 0 ( 6 ) From equation (6) we obtain by rearranging a first determination equation for the two parameters being sought. The determination equation (7) is implemented in the program code. P abs , amb = ∑ i = 1 n ⁢ ( y i · x i V vessel , air , 0 - x i ) ∑ i = 1 n ⁢ ( x i V vessel , air , 0 - x i ) 2 ( 7 ) The first of two required terms is obtained according to equation (8): ∂ S ∂ V vessel , air , 0 = ∂ ∂ V vessel , air , 0 ⁢ ∑ i = 1 n ⁢ ( y i - P abs , amb · x i V vessel , air , 0 - x i ) 2 = 2 · ∑ i = 1 n ⁢ ( y i - P abs , amb · x i V vessel , air , 0 - x i ) · ( + P abs , amb · x i ( V vessel , air , 0 - x i ) 2 ) = 0 ( 8 ) Equation (8) yields a second determination equation (9) for the two parameters being sought. ∑ i = 1 n ⁢ ( y i · x i ( V vessel , air , 0 - x i ) 2 ) - P abs , amb · ∑ i = 1 n ⁢ x i 2 ( V vessel , air , 0 - x i ) 3 = 0 ( 9 ) Inserting the equation for the absolute pressure being sought according to equation (7) into equation (9) yields an implicit determination equation (10) for the parameter V vessel,air,0 being sought. The determination equation (10) is implemented in the program code and is solved by a numerical problem-solving method in the known manner. The known numerical problem-solving method, selected, for example, from the bisection method (e.g., interval halving method) or regula falsi [the false position method] or the Newton-Raphson method is implemented in the program code. ∑ i = 1 n ⁢ ( y i · x i ( V vessel , air , 0 - x i ) 2 ) · ∑ i = 1 n ⁢ ( x i V vessel , air , 0 - x i ) 2 - ∑ i = 1 n ⁢ ( y i · x i V vessel , air , 0 - x i ) · ∑ i = 1 n ⁢ x i 2 ( V vessel , air , 0 - x i ) 3 = 0 ( 10 ) By inserting the calculated parameter V vessel,air,0 , equation (7) yields the second parameter P abs,amb . It would of course also be possible to determine P abs,amb first and then V vessel,air,0 in the opposite order. The absolute pressure being sought is calculated as being 978 hPa in the exemplary embodiment and the initial air volume is calculated as 242 mL. It has surprisingly been found that the accuracy and reproducibility of the absolute pressure determined comply very well with the requirements of accuracy and reproducibility of the calculation of the operating parameters so that no direct measurement of the absolute pressure with an absolute pressure gauge is required. FIG. 2 shows a graphic plot of the pressure conditions of the relative pressure in the mixing chamber of the dialysis fluid system from FIG. 1 in performing the method according to the invention. The number of 110 pump strokes performed is plotted on the abscissa. The relative pressure in the mixing chamber measured after each delivery stroke is plotted on the ordinate in FIG. 2 as a function of the number of pump strokes. The individual value pairs of the measured values of the relative pressure are represented by triangles in FIG. 2 . The absolute pressure parameter 978 hPa and the initial air volume 242 mL in the mixing chamber 6 , which were calculated in performing the fitting calculation, are inserted into equation (2) yielding the fitted curve shown as a solid-line curve in FIG. 2 . In other words the parameters of absolute pressure and initial air volume that are being sought are determined by the control and computation unit 110 by using the fitting equation and using all value pairs, so that the fitted curve according to equation (2) describes the dependence of the measured relative pressure on the number of delivery strokes in the best possible way. To avoid misunderstanding, it is pointed out that the absolute pressure cannot of course be read directly from the curve in FIG. 2 . The control and computation unit 110 calculates the at least one operating parameter, which depends on the absolute pressure after the absolute pressure has been determined in another step. In the present exemplary embodiment the control and calculation unit 110 calculates the boiling point being sought on the basis of the data stored in the control and computation unit for the vapor pressure table for water or on the basis of an approximation equation stored in the control and computation unit. The clean water temperature on the heating rod in the dialysis fluid system is regulated in such a way that it is below the boiling point. The clean water temperature during heat disinfection is especially advantageously always regulated at approximately 1.2° C. below the boiling point. The control and computation unit 110 regulates the heating process of the clean water on the heating rod 17 through regulating intervention measures 17 a in such a way that the temperature of the clean water measured by means of the temperature sensor 18 after passing through the heating rod 17 differs from the calculated boiling point by 1.2° C. and therefore a buildup of steam is reliably prevented. No user intervention is required for this. An absolute pressure gauge is not needed according to the invention. The temperature of the clean water is regulated with a very high precision. The safety and reliability of the dialysis fluid system are thereby improved. To set the desired degassing pressure, the control and computation unit 110 causes regulating intervention measures 19 a on the degassing pump 19 based on the measured value of the absolute pressure of 150 hPa, such that the degassing pressure required as an example is reached. The degassing pressure is therefore set as the pressure drop on the degassing throttle 20 by means of the rpm-regulated degassing pump 19 . The pressure drop on the degassing throttle 20 is measured (pressure measurement points not shown in FIG. 1 ) and transmitted to the control and computation unit 110 . The pressure difference between the calculated absolute pressure and the desired degassing pressure (i.e., 978 hPa minus 150 hPa) is calculated by the control and computation unit 110 and preselected as the setpoint value for the regulation. The pressure drop on the degassing throttle 20 is measured with two relative pressure sensors (not shown in FIG. 1 ) upstream and downstream from the degassing throttle 20 and compared with the setpoint value of the pressure difference. The rotational speed of the degassing pump 19 is regulated by the regulating intervention measures 19 a so that the required pressure difference of 828 hPa at the degassing throttle 20 drops and the desired degassing pressure is reached. No user intervention measure is necessary for this. An absolute pressure gauge is not required according to the invention. The degassing pressure is set very accurately. The safety and reliability of the dialysis fluid system are thereby improved. The control and computation unit 110 stores all the results in the memory 120 . The memory content of the data memory 120 can be displayed on a display screen of the blood treatment device (not shown in FIG. 1 ) or can be read out of the memory via a data interface for documentation purposes. The absolute pressure cannot be displayed visibly for the user, for example, the absolute pressure may be displayed as a numerical value on the display screen of the blood treatment device. According to the invention the objects of the present invention are solved with the exemplary embodiment presented here. However, the present invention is not limited to this exemplary embodiment. The invention being thus described, it will be apparent that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all, such modifications as would be recognized by one skilled in the art are intended to be included within the scope of the following claims. List of reference numerals Reference numeral Explanation  1 dialysis fluid system  2 dialyzer  3 semipermeable membrane  4 blood chamber  5 dialysis fluid chamber  6 mixing chamber  7 first line  8 first delivery means, metering chamber/ diaphragm pump  8a control intervention  9 second line 10 second delivery means, metering pump/diaphragm pump  10a control intervention 11 third line 12 third delivery means, metering pump/ diaphragm pump  12a control intervention 13 pressure sensor 14 initial air volume 15 filling level measurement device 16 initial filling volume 17 heating rod  17a regulating measure 18 temperature sensor 19 degassing pump  19a control intervention 20 degassing throttle 21 Line 22 gear pump  22a control intervention 23 bypass line 24 cutoff valve 25 balancing device 100  central control and computation unit 110  control and computation unit 120  data memory

A method and a device for determining an operating parameter of a device for extracorporeal blood treatment as a function of absolute pressure include setting the absolute ambient pressure in a closed container filled partially with air and having an essentially constant container volume by equalization of pressure with respect to the surroundings, and the pressure is maintained by isolating the container. With delivery means, a predetermined sequence of strokes of a liquid is delivered into or out of the container, and the change in the relative container pressure is measured after each delivery stroke. The total volume delivered and the relative pressure are assigned to a value pair, and the absolute pressure and the initial air volume is determined based on the Boyle-Mariotte law by using the value pairs for at least two delivery strokes. The operating parameter is calculated and adjusted as a function of the absolute pressure.

BACKGROUND OF INVENTION [0001] The present invention relates to complementary metal oxide semiconductor (CMOS) devices, and more particularly to a process and structure for forming a metal oxide semiconductor field effect transistor (MOSFET) implementing thin sidewall spacer geometries. [0002] FIGS. 1 ( a )- 1 ( e ) depict cross-section views of a portion of a semiconductor device manufactured in accordance with conventional processing techniques. As shown in FIG. 1 ( a ), a semiconductor device 10 is formed on a wafer. The device includes a substrate 12 and a patterned gate stack 15 formed thereon. Each patterned gate stack 15 may be formed of a gate material such as polycrystalline silicon, for example, and as conventionally known, the gate 15 is formed on a thin gate dielectric layer 20 previously formed on top of the substrate 12 . Prior to the formation of low resistivity cobalt, titanium, or nickel silicide contacts with active device regions 16 , 18 and gate 15 of the semiconductor device 10 , thin nitride spacers are first formed on each gate sidewall. Typically, as shown in FIG. 1 ( a ), a dielectric etch stop layer 25 , ranging from about 10 Å-300 Å in thickness, but preferably 50 Å-150 Å, is first deposited on the thin gate oxide layer 20 over the substrate surfaces and the patterned gate stack 15 . While this dielectric etch stop prevents recessing of the substrate during reactive ion etching (RIE) of the spacer, it has the disadvantage of being susceptible to removal or undercut during the extensive preclean that must be utilized prior to silicide formation. [0003] Then, as shown in FIG. 1 ( b ), an additional dielectric layer 30 is deposited on the patterned gate stack and active device regions. This additional dielectric layer is typically formed of a nitride material. [0004] While this dielectric etch stop prevents recessing of the substrate during spacer RIE, it has the disadvantage of being susceptible to removal or undercut during the extensive pre-clean that must be utilized prior to silicide formation. [0005] As shown in FIG. 1 ( c ), a RIE process is performed, resulting in the formation of vertical nitride spacers 35 a , 35 b on each gate wall. Prior to metal deposition, which may be titanium, cobalt or nickel, a lengthy oxide strip process is performed to prepare the surface for the silicide formation. This oxide strip is crucial to achieving a defect free silicide. However, as illustrated in FIG. 1 ( d ), the problem with this lengthy oxide strip is that the dielectric etch stop beneath the spacers 25 becomes severely undercut at regions 40 a , 40 b . The resultant oxide loss or undercut gives rise to the following problems: 1) the barrier nitride layer 50 that is ultimately deposited, as shown in FIG. 1 ( e ), will be in contact with the gate dielectric edge 17 , thus degrading gate dielectric reliability; 2) the silicide in the source/drain regions 60 a,b (not shown) may come into contact with the gate dielectric at the gate conductor edge, which would create a diffusion to gate short); and, 3) the degree of undercut will vary significantly from lot to lot. These aforementioned problems are particularly acute for transistors with the thin spacer geometries required for (which becoming continued CMOS scaling. [0006] Thin sidewall spacer geometries are becoming increasingly important aspects of high performance MOSFET design. Thin spacers allow the suicide to come into close proximity to the extension edge near the channel, thereby decreasing MOSFET series resistance and enhancing drive current. The implementation of a spacer etch process (specifically RIE) benefits substantially from an underlying dielectric layer (typically oxide) beneath the nitride spacer film. This dielectric serves as an etch stop for the nitride spacer RIE. Without this etch stop in place, the spacer RIE would create a recess in the underlying substrate, degrading the MOSFET series resistance, and in the case of thin SOI substrates, reducing the amount of silicon available for the silicide process. [0007] In order to avoid the problems associated with thin spacer geometries on thin SOI, it would be extremely desirable to provide a method for avoiding the oxide undercut when performing the oxide removal step during the pre-silicide clean. SUMMARY OF INVENTION [0008] It is thus an object of the present invention to provide a method for avoiding the dielectric, e.g., oxide, undercut when performing the clean step prior to silicide formation, particularly for thin spacer MOSFETS. [0009] In accordance with this objective, it has been found that the formation of a thin nitride plug encapsulating and sealing a segment of the dielectric etch stop layer underlying the vertical spacer elements will avoid the aforementioned undercut and associated problems. [0010] A preferred aspect of the present invention thus relates to a method for forming a CMOS device comprising the steps of: (a) providing a patterned gate stack region on the surface of a semiconductor substrate, the patterned gate stack including gate dielectric and exposed vertical sidewalls; (b) forming a dielectric etch stop layer over the gate region, exposed vertical sidewalls, and substrate surfaces; (c) forming a spacer element at each vertical sidewall, the spacer comprising of a nitride layer; (d) removing the dielectric (oxide) etch stop layer using an etch process such that a portion of the dielectric layer underlying each spacer remains; (e) forming a thin nitride layer over the gate region, the spacer elements at each vertical sidewall, and substrate surfaces; (f) etching said nitride plug layer such that a nitride plug layer remains to encapsulate and seal at least a portion of the dielectric that exists beneath the spacer; (g) performing a pre-silicide clean process for removing any material remaining from the substrate and gate conductor surfaces that may hinder suicide form ation, wherein dielectric undercut is prevented by the provision of said nitride plug layer that forms an etch barrier to protect the dielectric layer beneath the spacer elements. [0011] There are two variations to step (d) above which will be further defined here. [0012] In the first variation of the invention, the dielectric layer removal (step (d)) includes implementing a dry etch process. For example, a RIE process may be used for the dry oxide etch. This RIE process would be selective and anisotropic such that the vertical edge of the said dielectric layer underlying the spacer that is perpendicular to the wafer surface is aligned with the vertical edge of the vertical nitride spacer element furthest from the gate. Another example of a dry process that may be used for the oxide removal is chemical downstream etching (CDE). reactive ion etching OCDE is not necessarily anisotropic, so the edge of the dielectric layer after CDE may or may not be vertical, and may be aligned with the vertical edge of the vertical nitride spacer element furthest from the gate or may be slightly recessed closer to the gate. [0013] In a second variation of the invention, the dielectric layer removal (step (d)) includes implementing a wet etch process, selective such that the dielectric layer underlying the spacer is pulled back toward the gate and out of alignment with the far edge of the vertical nitride spacer element. [0014] In either variation, the nitride plug effectively seals the portion of the dielectric (oxide) layer underlying the spacer elements to prevent the oxide removal and undercut caused by the pre-silicide cleaning process. [0015] Also, for either variation (wet or dry removal of the oxide), the subsequent processing is similar. [0016] There are two variations to step (f) above which are now defined. In the first variation, the nitride etch described in step (f) above is performed with a dry etch, such as RIE or CDE. Nitride is selectively removed from the source/drain regions and the top of the gate, but at least a portion of the nitride plug layer remains beside the edge of the dielectric layer. This nitride etch variation is compatible with both the oxide etch variations described above. [0017] In the second variation, the nitride etch described in step (f) is performed with a wet or liquid phase etch. The wet nitride etch removes nitride from the source/drain regions and atop the gate, while retaining at least a portion of the nitride plug adjacent to the dielectric etch stop to block lateral oxide etching during the silicide preclean. This nitride etch variation is compatible both with CDE in the first variation of step (d) above and the wet oxide etch described in the second variation of step (d) above. BRIEF DESCRIPTION OF DRAWINGS [0018] Further features, aspects and advantages of the apparatus and methods of the present invention will become better understood with regard to the following description, appended claims, and the accompanying drawings where: [0019] FIGS. 1 ( a )- 1 ( e ) are cross-sectional views showing the CMOS processing steps according to a prior art method. [0020] FIGS. 2 ( a )- 2 ( h ) are cross-sectional views showing the basic processing steps according to a first embodiment of the present invention; and, [0021] FIGS. 3 ( a )- 3 ( h ) are cross-sectional views showing the basic processing steps according to a second embodiment of the present invention. DETAILED DESCRIPTION [0022] FIGS. 2 ( a )- 2 ( h ) depict the methodology for avoiding oxide undercut when performing a pre-silicide clean step to remove residual material from the silicon surfaces (either source/drain or gate regions). This methodology enables the formation of transistors with thin spacer geometries for improving FET series resistance. [0023] The various processing steps and materials used in fabricating the CMOS device of the present invention, together with various embodiments thereof, will now be described in greater detail by the discussion that follows. [0024] FIG. 2 ( a ) illustrates an initial structure that is employed in the present invention. Specifically, the initial structure shown in FIG. 2 ( a ) comprises a semiconductor substrate 12 having a patterned gate stack 15 formed on portions of the semiconductor substrate. In accordance with the present invention, each patterned gate stack includes a gate dielectric 20 , gate conductor 15 formed atop the gate dielectric, and an additional dielectric etch stop material atop the gate conductor and substrate regions. [0025] The structure shown in FIG. 2 ( a ) is comprised of conventional materials well known in the art, and it is fabricated utilizing processing steps that are also well known in the art. For example, semiconductor substrate 12 may comprise any semiconducting material including, but not limited to: Si, Ge, SiGe, GaAs, InAs, InP, and all other III/V semiconductor compounds. Semiconductor substrate 12 may also include a layered substrate comprising the same or different semiconducting material, e.g., Si/Si or Si/SiGe, silicon-on-insulator (SOI), strained silicon, or strained silicon on insulator. The substrate may be of n- or p-type (or a combination thereof) depending on the desired devices to be fabricated. [0026] Additionally, semiconductor substrate 12 may contain active device regions, wiring regions, isolation regions or other like regions that are typically present in CMOS devices. For clarity, these regions are not shown in the drawings, but are nevertheless meant to be included within region 12 . In two highly preferred embodiments of the present invention, semiconductor substrate 12 is comprised of Si or SOI. With an SOI substrate, the CMOS device of the present invention is fabricated on the thin Si layer that is present above a buried oxide (BOX) region. [0027] A layer of gate dielectric material 20 , such as an oxide, nitride, oxynitride, high-K material, or any combination and multilayer thereof, is then formed on a surface of semiconductor substrate 12 utilizing conventional processes well known in the art. For example, the gate dielectric layer may be formed by a thermal growing process such as oxidation, nitridation, plasma-assisted nitridation, or oxynitridation, or alternatively by utilizing a deposition process such as chemical vapor deposition (CVD), plasma-assisted CVD, evaporation or chemical solution deposition. [0028] After forming gate dielectric 20 on the semiconductor substrate 12 , a gate conductor 15 is formed on top of the gate dielectric. The term “gate conductor” as used herein denotes a conductive material, a material that can be made conductive via a subsequent process such as ion implantation or silicidation, or any combination thereof. The gate is then patterned utilizing conventional lithography and etching processes well known in the art. Next, a dielectric etch stop layer 25 is formed on top of the patterned gate conductor. The dielectric etch stop or capping layer 25 is deposited atop the substrate 12 and gate stack 15 . In a preferred embodiment, the capping layer 25 is an oxide, ranging from about 10 Å-300 Å in thickness, and formed utilizing a conventional deposition process such as, though not limited to, CVD, plasma-assisted CVD (PECVD), or ozone-assisted CVD. Alternatively, a conventional thermal growing process such as oxidation may be used in forming the dielectric capping layer 25 . [0029] Next, and as illustrated in FIGS. 2 ( b ) and 2 ( c ), spacer elements 35 a , 35 b are formed on the gate sidewalls. Spacer formation begins with the deposition of a nitride film 30 over the dielectric etch stop layer on the patterned gate stack, the gate sidewalls, and the substrate surfaces. The nitride thickness is 700 Å or less, and in the case of this invention is further preferred to be 500 Å or less. It is understood that these thickness values are exemplary and that other thickness regimes are also contemplated in the present invention. The composition of the nitride layer can represent any suitable stoichiometry or combination of nitrogen and silicon. The deposition process can include any of the numerous methods known in the art, such as, though not restricted to, PECVD, rapid thermal CVD (RTCVD), or low pressure CVD (LPCVD). After depositing the nitride layer 30 (via chemical vapor deposition or a similar conformal deposition process) on the structure shown in FIG. 2 ( a ), the vertical gate wall spacers 35 a , 35 b are then formed using a highly directional, anisotropic spacer etch, such as RIE. The nitride layer is etched, selective to the underlying dielectric etch stop layer 25 , to leave the vertical nitride spacers layer 35 a , 35 b. [0030] The key elements of the process are now shown in FIG. 2 ( d ) 2 ( f ) whereby after spacer formation, the dielectric etch stop layer 25 remaining on the substrate 12 is first removed by an oxide etch process. This etch can be either dry (RIE or CDE) or wet, as conventionally known. In FIG. 2 ( d ), there is depicted the RIE example for removing the remaining dielectric etch stop layer 25 save for a small portion of cap dielectric underlying the vertical nitride spacers. Once the dielectric RIE is complete, as shown in FIG. 2 ( d ), the edges of the dielectric etch stop edges 38 a , 38 b under the vertical spacers, i.e., edges 38 a , 38 b , will be flush with the vertical edge of the spacer. Next, as shown in FIG. 2 ( e ), a thin nitride “plug” layer 40 is deposited over the remaining structure including the exposed gate and substrate surfaces. Preferably the thin nitride plug is 100 Å or less in thickness and may include, though not limited to, Si 3 N 4 , Si x N y , carbon-containing Si x N y , an oxynitride, or a carbon-containing oxynitride. After deposition, the nitride “plug” layer 40 is etched using an anisotropic dry etch which removes the plug layer from the substrate surfaces and the top of the gate, as shown in FIG. 2 ( f ). As a result of this process, thin vertical nitride portions 45 a , 45 b remain that function to seal the respective underlying dielectric etch stop edges 38 a , 38 b . If CDE is used instead of RIE to etch the dielectric etch stop layer, the edge of the etch stop may be slightly recessed with respect to the vertical spacer edge. In this case, a wet etch may be used to remove the nitride “plug” layer from the substrate surfaces and the top of the gate, leaving behind a nitride “plug” to block the dielectric etch stop from subsequent lateral etching. Once the dielectric edges are sealed, a lengthy oxide strip may be performed as depicted in FIG. 2 ( g ) as part of the subsequent silicide preclean without the creation of an oxide undercut in the etch stop layer. [0031] That is, prior to the metal deposition for silicide formation, a series of wet cleans, dry cleans, or other physical cleaning techniques, may be implemented to remove contaminants such as: resist residuals, any remaining oxides formed during plasma cleans/strips, implant residuals, metals, and particles from the surface of the silicon wafer. [0032] All three of the above-mentioned problems highlighted in the prior art process depicted in FIGS. 1 ( a )- 1 ( d ) for the conventional CMOS process are solved. [0033] As shown in FIG. 2 ( h ), with spacers and nitride plug layers in place, it is understood that source/drain regions (not shown) may be formed by conventional techniques, e.g., ion implantation into the surface of semiconductor substrate 12 utilizing a conventional ion implantation process well known in the art. It is understood, however, that at any point during the process source/drain regions may be formed. Further, it is noted that at this point of the present invention, it is also possible to implant dopants within the gate material. Various ion implantation conditions may be used in forming the deep source/drain regions within the substrate. In one embodiment, the source/drain regions may be activated at this point of the present invention utilizing conventional activation annealing conditions well known to those skilled in the art. However, it is highly preferred to delay the activation of the source/drain regions until after shallow junction regions have been formed in the substrate. [0034] Finally, silicide contacts 60 a , 60 b may be formed on portions of the semiconductor substrate 12 for contact with the respective source/drain regions. Specifically, the silicide contacts may be formed utilizing a conventional silicidation process which includes the steps of depositing a layer of refractory metal, such as Ti, Ni, Co, or metal alloy on the exposed surfaces of the semiconductor substrate, annealing the layer of refractory metal under conditions that are capable of converting said refractory metal layer into a refractory metal silicide layer, and, if needed, removing any un-reacted refractory metal from the structure that was not converted into a silicide layer. Typical annealing temperatures used in forming the silicide contacts are known to skilled artisans. Note that because of the nitride spacers and nitride plug, the silicide contacts may be self-aligned to any deep junction vertical edge present in the underlying substrate. [0035] Note that in the preferred embodiment of the present invention, as depicted in FIG. 2 ( h ), a silicide region 70 is also formed atop the patterned gate stack region. [0036] Finally, a contact etch stop (or barrier) layer 80 is deposited as a precursor to further CMOS processing, as shown in FIG. 2 ( h ). [0037] As mentioned hereinabove with respect to FIG. 2 ( d ), the oxide cap layer 25 remaining on the substrate 12 is removed by an oxide etch process which may be either dry (RIE or CDE) as shown in FIG. 2 ( d ) or wet, as now described with respect to FIGS. 3 ( d )- 3 ( h ). With respect to the second variation of the present invention, steps depicted in FIGS. 3 ( a )- 3 ( c ) are the same as explained herein with respect to FIGS. 2 ( a )- 2 ( c ). A variation of the “plug” approach however, begins with the wet etch step depicted in FIG. 3 ( d ) wherein, instead of the dry approach, a wet etch is utilized to remove the remaining oxide dielectric layer 25 . As known in the art, a conventional wet etch process is isotropic, and for removing the oxide layer 25 , may comprise aqueous hydrofluoric acid or hydrofluoric acid in a nonaqueous solvent that may include an ammonium fluoride buffer and/or surfactants, or other soluble etchants. As a result of the wet etch process depicted in FIG. 3 ( d ), there is a resultant “pullback” of the oxide 25 remaining underneath the formed vertical nitride spacers 35 a , 35 b . The wet etch oxide pullback, shown as 39 a , 39 b , formed beneath the nitride spacers 35 a , 35 b may be highly controlled, and the pulled-back region can be “plugged” effectively during the subsequent nitride deposition/etch processing. As shown in FIG. 3 ( e ), a thin nitride “plug” layer 40 is deposited over the remaining structure including the exposed gate and substrate surfaces. Preferably the thin nitride plug is 100 Å or less, in thickness, and may include, though not limited to, Si 3 N 4 , Si x N y , carbon-containing Si x N y , an oxynitride, or a carbon-containing oxynitride. [0038] After deposition, the nitride “plug” layer 40 is etched using a dry etch (e.g., RIE or CDE) which removes the layer on top of the gate and substrate surfaces, as shown in FIG. 3 ( f ). However, as a result of this process, thin nitride “plugs” 45 a , 45 b remain that function to encapsulate and seal the underlying oxide dielectric portions 39 a , 39 b. [0039] Once the dielectric portions are sealed, the lengthy strip may be performed during the subsequent silicide preclean ( FIG. 3 ( g )) without the creation of an oxide undercut. [0040] In another embodiment of the invention, the thin nitride plug layer can be etched using wet chemistry (with hot phosphoric acid, hydrofluoric acid in ethylene glycol, or other well know nitride etches) such that the nitride is removed everywhere except in the regions that serves to seal and encapsulate the underlying dielectric (i.e. the “plug” region). [0041] Finally, as depicted in FIG. 3 ( h ), the silicide contacts 60 a , 60 b are formed at each source/drain diffusion region utilizing a conventional silicidation process, as mentioned hereinabove. Optionally, a silicide contact 70 may be formed at top of gate stack 15 . Then the contact etch stop (or barrier) film 80 is deposited as shown in FIG. 3 ( h ). [0042] Advantageously, all three of the above-mentioned problems highlighted in the prior art process depicted in FIGS. 1 ( a )- 1 ( d ) for the conventional CMOS process are solved. [0043] While the invention has been particularly shown and described with respect to illustrative and preformed embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention which should be limited only by the scope of the appended claims.

A method for forming a CMOS device in a manner so as to avoid dielectric layer undercut during a pre-silicide cleaning step is described. During formation of CMOS device comprising a gate stack on a semiconductor substrate surface, the patterned gate stack including gate dielectric below a conductor with vertical sidewalls, a dielectric layer is formed thereover and over the substrate surfaces. Respective nitride spacer elements overlying the dielectric layer are formed at each vertical sidewall. The dielectric layer on the substrate surface is removed using an etch process such that a portion of the dielectric layer underlying each spacer remains. Then, a nitride layer is deposited over the entire sample (the gate stack, the spacer elements at each gate sidewall, and substrate surfaces) and subsequently removed by an etch process such that only a portion of said nitride film (the “plug”) remains. The plug seals and encapsulates the dielectric layer underlying each said spacer, thus preventing the dielectric material from being undercut during the subsequent pre-silicide clean process. By preventing undercut, this invention also prevents the etch-stop film (deposited prior to contact formation) from coming into contact with the gate oxide. Thus, the integration of thin-spacer transistor geometries, which are required for improving transistor drive current, is enabled.

FIELD OF THE INVENTION [0001] The present invention relates to the control of notification modes applied by a telephone device. In particular, the present invention relates to referencing a scheduling application in connection with determining an appropriate notification mode. BACKGROUND OF THE INVENTION [0002] With proliferation of cell phones, pagers, and other wireless devices, such as personal digital assistants (PDAs), there has been an increase in undesirable disruptions. The ability for a user of a communication device to select loud and/or distinctive rings so that the user can more easily identify their own “ring signature” only adds to the problem of such disruptions. A related aspect of the problem also exists for users that wish to set ring preferences for home or office phones. For example, setting one's office phone to suppress the audible ring at times when the user is in a meeting is desirable without having to mute the ring manually. [0003] The prior art solution to disruptive rings or other notification modes relies on manual activation by the user of a silent ring mode. For example, cellular telephones may provide a vibrate mode that can be used instead of a ringer. As another alternative, a device can be switched off, or a selection can be made to have all incoming calls routed immediately to messaging. However, many users forget or don't bother to select such alternate notification modes before entering situations in which normal notification modes would be disruptive. As a result, audible rings that are disruptive to the user and/or others in the immediate area are common in restaurants, meetings, seminars, theaters, etc. Furthermore, the likelihood and problem of such disruptions increases as the size of the group that is attending an event or in a common area increases. In particular, because conventional devices rely on individual users to remember to activate less disruptive notification modes, the probability that an incoming message will be received by a device on which a normal notification mode has not been disabled increases. [0004] It would be desirable for ring selection to be automatically made, without requiring direct user intervention. It also would be desirable to allow notification modes to be selected intelligently, such that user time and effort managing notification modes was reduced, and such that audible disruptions were limited. SUMMARY OF THE INVENTION [0005] The present invention is directed to solving these and other problems and disadvantages of the prior art. According to embodiments of the present invention, an overlay application or notification mode engine allows a determination of notification mode to be made with reference to a user scheduling application. Access to a user scheduling application allows the scheduled status of a user to be determined. Based on the determined status, an appropriate notification mode can be selected from a notification table. The selected notification mode may then be applied to alert the user to the incoming communication. [0006] In accordance with embodiments of the present invention, the user scheduling application may comprise an electronic calendar maintained by or on behalf of the user. Such an electronic calendar may run on a communication device itself, or on another platform that can accessed by the communication device and/or the platform running the notification mode engine, if different from the communication device. Similarly, the notification condition table that relates the user's scheduled status to a proper notification mode can be maintained as part of or in connection with the notification mode engine, on the platform or device on which the notification mode engine is running, or on some other platform or device. The notification mode engine, after determining a proper notification mode, then controls the communication device, either directly or through an appropriate signal, to apply the determined notification mode. [0007] In accordance with embodiments of the present invention, a user makes entries into a scheduling application, such as an electronic calendar. Such entries may relate to one time events scheduled for a particular date and time, or to recurring events. Furthermore, such entries may relate to a scheduled status for a particular date and time, or to a status that is to be applied at certain times during work days, weekends, certain days of the week, holidays, etc. When an entry comprises a scheduled event, a scheduled status corresponding to that event can be determined by key words used to describe the event. Alternatively or in addition, particular words may be used or selections made with respect to a scheduled status, whether or not such scheduled status is associated with a described event. [0008] When an incoming communication is detected, the scheduling application may be checked to determine the scheduled status of the user. The scheduled status is then associated with an appropriate notification mode. In accordance with embodiments of the present invention, the appropriate notification mode is determined by looking up in a notification condition table the notification mode associated with the scheduled status of the user. The notification engine then controls the communication device such that the determined notification mode is applied. [0009] Additional features and advantages of the present invention will become more readily apparent from the following description, particularly when taken together with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0010] FIG. 1 is a block diagram depicting a communication system in accordance with embodiments of the present invention; [0011] FIG. 2 is a block diagram depicting a communication system in accordance with other embodiments of the present invention; [0012] FIG. 3 is a block diagram depicting a communication device in accordance with embodiments of the present invention; [0013] FIG. 4 is a flowchart depicting aspects of the operation of a communication system in accordance with embodiments of the present invention; and [0014] FIG. 5 illustrates an example notification condition table in accordance with embodiments of the present invention. DETAILED DESCRIPTION [0015] With reference now to FIG. 1 , a communication system 100 in accordance with embodiments of the present invention is illustrated. In general, the communication system 100 includes a first communication device 104 interconnected to a second communication device 108 through a communication network 112 . In addition, the communication system 100 includes a user scheduling application 116 associated with or accessible to the first communication device 104 either directly, or through a communication network 112 . A communication device 104 or 108 is generally any device capable of operating as a communication endpoint. Accordingly, examples of communication devices 104 , 108 include telephony devices, such as telephones, wireless telephones, soft telephones, and video telephones. Additional examples of communication devices 104 , 108 include personal digital assistants (PDAs) having communication capabilities, pagers, and general purpose computing devices. Furthermore, as can be appreciated by one of skill in the art from the description provided herein, a communication device 104 , 108 can be part of a device providing additional functions, for example an integrated PDA and cellular telephone. [0016] As shown in FIG. 1 , at least the first communication device 104 includes a notification mode engine 120 and a notification condition table 124 . The notification mode engine 120 may comprise an application executed by the same first communication device 104 that operates to select an appropriate notification mode in response to a scheduled user status, as indicated by the user scheduling application 116 , and a notification mode associated with that status, as indicated by the notification condition table 124 , as will be described in greater detail elsewhere herein. The notification condition table 124 may be maintained in memory associated with the communication device 104 and may associate a selected notification mode with a scheduled status. [0017] The communication network 112 may comprise one or more networks of one or more types. For example, the communications network 112 may comprise a switched circuit network, such as the public switched telephone network (PSTN), and/or a packet data network, such as the Internet, intranet, or a combination of one or more intranets and the Internet. As additional examples, the communication network 112 may comprise wireless voice and/or data networks, such as cellular telephone networks. As illustrated in FIG. 1 , the communication network 112 may serve to place a first communication device 104 in communication with a second communication device 108 to enable a transfer of voice communications and/or data between the communication devices 104 , 108 . In addition, in accordance with embodiments of the present invention, a communication device 104 may access a user scheduling application 116 through the communication network 112 . According to such embodiments, the particular communication network 112 used to transfer data between the user scheduling application 116 and the first communication device 104 may be different from the communication network 112 used for communications between the first communication device 104 and the second communication device 108 . In accordance with still other embodiments of the present invention, the first communication device 104 may be interconnected to the user scheduling application 116 directly, or the user scheduling application 116 may be implemented as part of and/or as an application running on the first communication device 104 . [0018] With reference now to FIG. 2 , a communication system 200 in accordance with other embodiments of the present invention is illustrated. In particular, the system 200 illustrated in FIG. 2 provides a communication manager 204 for running the notification mode engine 120 and maintaining the notification condition table 124 . In accordance with embodiments of the present invention, the communication manager 204 may comprise an application running on a general purpose computer or other programmable device. Furthermore, although the user scheduling application 116 is shown as separate from the communication manager 204 , in accordance with embodiments of the present invention, the user scheduling application 116 may be integrated with the communication manager 204 . The various applications and/or devices 104 , 116 and 204 associated with a first user may be in communication with one another directly, as shown by the dotted lines in FIG. 2 . Alternatively or in addition, the various components 104 , 116 , 204 may be in communication with one another through a communication network 112 . A communication network 112 used for communications between devices or applications associated with the first user can be different from a communication network 112 used for communications between the first communication device 104 and the second communication device 108 . [0019] With reference now to FIG. 3 , components of a communication device 104 or communication manager 204 in accordance with embodiments of the present invention are depicted. The components may include a processor 304 capable of executing program instructions. Accordingly, the processor 304 may include any general purpose programmable processor or controller for executing application programming. Alternatively, the processor 304 may comprise a specially configured application specific integrated circuit (ASIC). The processor 304 generally functions to run programming code implementing various other functions performed by the communication device 104 or communication manager 204 , including telephony or other communication functions, scheduling, notification condition engine or other applications as described herein. [0020] A communication device 104 or a communication manager 204 may additionally include memory 308 for use in connection with the execution of programming by the processor 304 , and for the temporary or long term storage of data or program instructions. For example, the memory 308 may be used to maintain a notification condition table 124 . The memory 308 may comprise sold state memory resident, removable or remote in nature, such as DRAM and SDRAM. Where the processor 304 comprises a controller, the memory 308 may be integral to the processor 304 . [0021] In addition, various user input devices 312 and user output devices 316 may be provided. Examples of input devices 312 include a microphone, keyboard, numeric keypad, and pointing device combined with a screen or other position encoder. Examples of user output devices 316 include a speaker, alphanumeric display, ringer, printer port, IrDA port and vibrator. [0022] A communication device 104 or a communication manager 204 may also include data storage 320 for the storage of application programming and/or data. For example, operating system software 324 may be stored in the data storage 320 . Examples of applications that may be stored in data storage 320 include user scheduling application software 328 , notification condition engine software 332 , notification condition table data 336 , and/or a communication application 340 . As can be appreciated by one of skill in the art, a communication application 340 may comprise program instructions for implementing a soft telephone, for example where the first communication device 104 comprises a general purpose computer. Furthermore, the communication application 340 may comprise instructions controlling the operation of various functions of a first communication device 104 comprising a cellular telephone, the telephony facilities of an integrated telephone and PDA, or other device. The data storage 320 may comprise a magnetic storage device, a solid state storage device, an optical storage device, a logic circuit, or any combination of such devices. It should further be appreciated that the programs and data that may be maintained in the data storage 320 can comprise software, firmware or hardware logic, depending on the particular implementation of the data storage 320 . [0023] A communication device 104 or communication manager 204 may also include one or more communication network interfaces 344 . For example, a communication device 104 may include a communication network interface 344 comprising a cellular telephone network interface. In addition, a communication device 104 in accordance with embodiments of the present invention that operates in connection with a user scheduling application 116 and/or a separate communication manager 204 may include a communication network interface 344 comprising, for example, a wireless data network connection. Such wireless data network connection 344 may be in addition to and separate from the communication network interface 344 for interconnecting to a telephony network, or the provided communication network interface 344 may be capable of supporting both data and telephone communications. With respect to a communication device 204 , the communication network interface 344 may comprise a data network connection. Examples of a communication network interface 344 for supporting voice communications include CDMA, TDM, GSM, PSM, satellite, wireless Ethernet (including various IEEE 802.11 (WiFi) interfaces), ultra wide band, satellite telephony, IrDA or other wireless or wireline interfaces. [0024] With reference now to FIG. 4 , the operation of a communication system 100 , 200 in accordance with embodiments of the present invention is illustrated. Initially, at step 400 , an incoming communication is detected. For example, a telephone call directed to the first communication device 104 placed by the second communication device 108 may be detected by a notification mode engine 120 running on the first communication device 104 or on a communication manager 204 associated with the first communication device 104 . The notification mode engine 120 then contacts the user scheduling application 116 to obtain the current scheduled status for the user associated with the first communication device 104 (step 404 ). [0025] At step 408 , a determination is made as to whether a current specific status entry is available from the user scheduling application 116 . That is, a determination is made as to whether the user has entered a scheduled activity or a desired status at a date and time corresponding to the date and time at which the incoming communication is detected. An example of a specific status entry would be an entry in the user scheduling application 116 indicating that the user is scheduled to be in a meeting at the date and time that the incoming communication is detected. If a specific status entry is not available, a determination is then made as to whether a current general status entry is available in the user scheduling application 116 (step 412 ). An example of a current general status entry would be a selection by the user to have an unavailable status every night after 10:00 pm. If there is no specific or general status entry, the current status is set equal to a default status (step 416 ). The default status may correspond to, for example, a normal audible ring. If a current specific status is found to be available at step 408 , the current status is set equal to that specific entered status at step 420 . If a current specific status entry is not available, but a general status entry is available, then that general status is set as the current status at step 420 . [0026] A status entry may be selected or made by a user or administrator in various ways. For example, according to embodiments of the present invention, a user may make a selection from a menu or a list of available statuses for association with a block of time in the user's scheduling application 116 . The different status selections that may be included in a menu or list may be in the form of a qualitative notification mode or method, such as no real-time notification, no audible notification, normal audible notification, loud audible notification, and combined audible and vibrating notification modes. Alternatively or in addition, the scheduled status can be determined by detecting key words associated with a block of time designated in the user's scheduling application 116 . For example, words such as meeting, game or theater can comprise or be associated with a user status. [0027] After setting the current status at steps 416 or 420 , a look-up of the notification mode for the current status from the notification condition table 124 is performed (step 424 ). At step 428 , a determination is made as to whether a notification mode for the current status is defined in the notification condition table 124 . If a notification mode is defined for the current status, a notification mode is set equal to that defined mode (step 432 ). If a notification mode is not defined for the current status, then the notification mode is set equal to a default mode (step 436 ). [0028] After setting the notification mode at steps 432 or 436 , a determination is made as to whether a notification mode override has been set manually at the communication device 104 (step 440 ). For example, a user may manually disable an audible ringer by making such a selection directly using the communication device 104 , such as when a need to avoid disruptions is realized by the user in real-time. If the user has manually overridden the notification mode, the manually set mode is used to notify the user of the incoming communication (step 444 ). If the user has not overridden the notification mode, then the notification mode that was set at step 432 or 436 is used to alert the user to the incoming communication (step 448 ). As can be appreciated by one of skill in the art, a notification mode engine 120 may operate to directly control the notification mode applied by a communication device 104 where the notification mode engine 124 is running on the communication device 104 . Where notification mode engine 120 is running on a separate platform, such as on a communication manager 204 that is separate from the communication device 104 , the notification mode engine 120 may send a signal to the communication device indicating the notification mode that should be used. Also, it should be appreciated that the notification mode engine 120 need not be aware of a manual override of the notification mode entered by the user in the communication device 104 . [0029] With reference now to FIG. 5 , an example of the contents of a notification condition table 124 in accordance with embodiments of the present invention is illustrated. In particular, as shown in FIG. 5 , a notification condition table 124 may include entries for a number of different user statuses 504 . In addition, the notification condition table 124 may associate a notification mode 508 with each different user status 504 . Examples of such parings include a notification mode comprising routing an incoming communication to voice mail if the user status is unavailable, a vibrate only notification mode corresponding to a meeting (Type 1) user status, a soft audible ring corresponding to a meeting (Type 2) user status; vibrate only notification mode corresponding to a keyword indicating that the user is in a movie; a soft audible ring and vibrate notification mode associated with a keyword indicating that the user is in a restaurant; a loud audible ring and vibrate notification mode associated with a keyword indicating that user is at a game; a loud audible ring in connection with a commute time user status; and a normal audible ring as a default or undefined user status. [0030] As can be appreciated by one of skill in the art, embodiments of the present invention may be applied in connection with portable communication devices, to avoid or limit disruptions caused by incoming communications, according to the scheduled status of the user associated with the communication device. However, the present invention is not so limited. For instance, embodiments of the present invention may be applied to home or office telephones, to avoid disrupting scheduled activities at those locations. Furthermore, it should be appreciated that numerous communication devices associated with a user may have access to a scheduling application 116 associated with that user. For instance, a user scheduling application 116 maintained on a user's office computer may permit access by one or more notification mode engines 120 associated with various communication devices of that user, to provide appropriate notification of incoming communications. As a further example, a central communication manager 204 which may maintain a user's scheduling application 116 , may control the notification mode applied by a number of communication devices associated with the user. In addition, embodiments of the present invention may be applied to coordinate between multiple communications devices 104 . For example, if a scheduling application 116 indicates that a user is not in the office, calls to the user's office telephone can be routed to the user's cellular telephone. As a further example, if a user's scheduling application 116 , in cooperation with the user's notification condition table 124 , indicates that a vibrate mode of notification should be used, an incoming communication addressed to a communications device 104 that is not capable of providing such a notification mode can be rerouted to another of the user's communications devices that is capable of providing that mode of notification. [0031] The foregoing discussion of the invention has been presented for purposes of illustration and description. Further, the description is not intended to limit the invention to the form disclosed herein. Consequently, variations and modifications commensurate with the above teachings, within the skill and knowledge of the relevant art, are within the scope of the present invention. The embodiments described hereinabove are further intended to explain the best mode presently known of practicing the invention and to enable others skilled in the art to utilize the invention in such or in other embodiments and with various modifications required by their particular application or use of the invention. It is intended that the appended claims be construed to include the alternative embodiments to the extent permitted by the prior art.

A system for selecting a notification mode for notifying a user of an incoming communication that makes reference to a user scheduling application is provided. The system allows a notification mode that is appropriate to a scheduled user status to be applied. Accordingly, a user is not required to manually select an appropriate notification mode as the user moves between activities that have been scheduled in the user scheduling application. Therefore, the potential for incoming communications to disrupt user activities is reduced.

FIELD OF THE INVENTION [0001] This invention relates to pyridyl piperazines having affinity for serotonin (5HT) receptors, especially the serotonin IB receptor (5HT 1B ), and to their use in treating diseases or conditions which are caused by disorders of the serotonin system. BACKGROUND OF THE INVENTION [0002] Serotonin, also known as 5-hydroxytryptamine and abbreviated “5HT,” is ubiquitous in plants and animals and is implicated in a great many physiological pathways, both normal and pathological. It is an important neurotransmitter and local hormone both in the periphery, particularly the intestine, and in the central nervous system (CNS). In the periphery, 5HT contracts a number of smooth muscles, induces endothelium-dependent vasodilation through the formation of nitric oxide, mediates peristalsis, and may be involved in platelet aggregation and homeostasis. In the CNS, 5HT is believed to be involved in a wide range of functions, including the control of appetite, mood, anxiety, hallucinations, sleep, vomiting, and pain perception. (Watson, S. and Arkinstall, S. “5-Hydroxytryptamine” in The G Protein - Linked Receptor Factsbook , Academic Press, 1994, pp. 159-180.) [0003] Serotonin plays a role in numerous psychiatric disorders, including anxiety, Alzheimer's disease, depression, nausea and vomiting, eating disorders, and migraine. (Rasmussen et al., “Chapter 1. Recent Progress in Serotonin (5HT), Receptor Modulators,” in Ann. Rep. Med. Chem., 1, 30, pp. 1-9, 1995, Academic Press). Serotonin also plays a role in both the positive and negative symptoms of schizophrenia. (Sharma et al., Psychiatric Ann., 1996, 26 (2), pp. 88-92.) [0004] Several serotonin receptor subtypes have been classified according to their antagonist susceptibilities and their affinities for 5HT. The 5HT 1B receptor was first identified in rats, where it has a distinct pharmacological profile. In humans, however, it shares an almost identical pharmacology with the 5HT 1D receptor. In the CNS, the 5HT 1B receptor is found in the striatum, medulla, hippocampus, frontal cortex and amygdala. In the periphery, it is found in vascular smooth muscle. Therefore, in humans the receptor is often denoted the “5HT 1B /5HT 1D receptor.” The 5HT 1B /5HT 1D receptor may be the therapeutic substrate of the anti-migraine drug, sumatriptan; the 5HT 1B /5HT 1D receptor is also implicated in feeding behavior, anxiety, depression, cardiac function, and movement. (Watson, S. and Arkinstall, S. op. cit.) [0005] The 5HT 1B receptor was the first subtype to have its gene inactivated by classical homologous recombination (Saudou F, et al., Science, 1994, 265, 1875-1878). 5HT 1B receptors are expressed in the basal ganglia, central gray, hippocampus, amygdala, and raphe nuclei. They are located predominantly at presynaptic terminals where they can inhibit release of 5HT and, as heteroceptors, of other neurotransmitters. Selective agonists and antagonists for 5HT 1B receptors have until now been lacking, but indirect pharmacological evidence suggests that 5HT 1B activation influences food intake, sexual activity, locomotion, and aggression. (Ramboz, S., et al., Behav. Brain Res. 1996 73: 305312.) SUMMARY OF THE INVENTION [0006] This invention relates to certain pyridyl piperazines. These compounds are antagonists of the serotonin 5HT 1B receptor. As such, they are effective for the treatment of disorders of the serotonin system, such as depression and related disorders. In particular, the invention is directed to pyridyl piperazine compounds of Formula I: and to pharmaceutically acceptable salts and prodrugs thereof where G is where the dashed line represents an optional double bond; where Ar 1 is phenyl, a 5- or 6-membered heteroaryl ring, or an 8- to 10-membered fused aryl or heteroaryl ring system, said heteroaryl ring, and the heteroaryl moiety of said heteroaryl ring system comprising an aromatic ring made up of carbon and from one to four other elements selected independently from the group consisting of oxygen, nitrogen, and sulfur, which Ar 1 may be singly or multiply substituted with, independently, halogen, hydroxy, nitro, cyano, R 1 , R 2 , R 3 , —OR 4 , —OC(═O)R 5 , —COOR 6 , NHR 7 , NR 8 R 9 , —NHC(═O)R 10 , N(R 11 )(C═O)R 12 , —C(═O)NHR 13 , or Ar 2 ; X is CH 2 , NH, or O; V, W, and Y are, independently, hydrogen, halogen, hydroxy, nitro, cyano or R 7 , where R 1 -R 13 are, independently, C 1 -C 8 alkyl, C 2 -C 8 alkenyl, C 1 -C 8 alkoxy, C 1 -C 8 hydroxyalkyl, C 1 -C 8 alkenoxy, said alkyl, alkenyl, alkoxy, or alkenoxy optionally substituted with one or more halogen atoms or nitro, cyano, or hydroxyl groups, said alkyl or alkenyl groups being straight-chain, branched, or cyclic, wherein an alkoxy-substituted alkyl group may form a cyclic ether, or, in the case of NR 8 R 9 , R 8 and R 9 , may be linked together to form an additional ring; Z is C 1 -C 6 alkyl or C 1 -C 6 alkylcarbonyl; Ar 2 is a 5- or 6-membered aryl or heteroaryl ring or an 8- to 10-membered fused aryl or heteroaryl ring system, which Ar 2 may be singly or multiply substituted with, independently, halogen, hydroxy, nitro, cyano, R 1 , R 2 , R 3 , OR 4 , OC(═O)R 5 , COOR 6 , NHR 7 , NR 8 R 9 , NHC(═O)R 10 , N(R 11 )(C═O)R 12 , C(═O)NHR 13 ; and n is 1 or 2. [0009] The invention is also directed to pharmaceutical compositions comprising the compound of Formula I, or a pharmaceutically acceptable salt or prodrug thereof, and a pharmaceutically effective carrier. [0010] The invention is further directed to a method of treating or preventing a disorder or condition that can be treated by altering serotonin-mediated neurotransmission in a mammal, including a human. [0011] The invention is still further directed to a method of treating, in a mammal, including a human, a disorder selected from the group consisting of anxiety, depression, dysthymia, major depressive disorder, migraine, post-traumatic stress disorder, avoidant personality disorder, borderline personality disorder, and phobias comprising administering to a mammal or human in need thereof a treatment effective amount of the compound of Formula I, or a pharmaceutically acceptable salt or prodrug thereof. [0012] The invention is also directed to any of the foregoing methods wherein the compound of Formula I, or a pharmaceutically acceptable salt thereof, is administered in combination with a serotonin reuptake inhibitor (SRI) (e.g., sertraline, fluoxetine, fenfluramine, or fluvoxamine). The term “administered in combination with,” as used herein, means that the compound of Formula I or pharmaceutically acceptable salt thereof is administered in the form of a pharmaceutical composition that also contains an SRI, or that such compound or salt is administered in a separate pharmaceutical composition from that in which the SRI is administered, but as part of a dosage regimen that calls for the administration of both active agents for treatment of a particular disorder or condition. [0013] The terms “pharmaceutically acceptable salts” and “pharmaceutically acceptable acid salts” of compounds of the Formula I refer to those salts which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of patients without undue toxicity, irritation, allergic response, and the like, as well as zwitterionic forms, where possible of compounds of the invention. The compounds of Formula I are basic in nature and are thus capable of forming a wide variety of salts with various inorganic and organic acids. The acids that can be used to prepare pharmaceutically acceptable acid addition salts of those compounds of Formula I are those that form non-toxic acid addition salts, i.e., salts containing pharmacologically acceptable anions, such as the hydrochloride, hydrobromide, hydroiodide, nitrate, sulfate, bisulfate, phosphate, acid phosphate, isonicotinate, acetate, lactate, salicylate, citrate, acid citrate, tartrate, pantothenate, bitartrate, ascorbate, succinate, maleate, fumarate, gluconate, glucaronate, saccharate, formate, benzoate, glutamate, methanesulfonate, ethanesulfonate, benzenesulfonate, and p-toluenesulfonate. (See, for example, Berge, S. M., et al., “Pharmaceutical Salts,” J. Pharm. Sci . (1977) vol. 66, pp. 1-19, which is incorporated herein by reference.) [0014] The term “one or more substituents,” as used herein, includes from one to the maximum number of substituents possible based on the number of available bonding sites. [0015] The term “disorders of the serotonin system,” as used herein, refers to disorders the treatment of which can be effected or facilitated by altering (i.e., increasing or decreasing) serotonin-mediated neurotransmission. [0016] The term “treating,” as used herein, refers to retarding or reversing the progress of, or alleviating or preventing either the disorder or condition to which the term “treating” applies, or one or more symptoms of such disorder or condition. The term “treatment,” as used herein, refers to the act of treating a disorder or condition, as the term “treating” is defined above. [0017] The term “treatment effective amount,” as used herein, refers to an amount sufficient to detectably treat, ameliorate, prevent or detectably retard the progression of an unwanted condition or symptom associated with disorders of the serotonin system. [0018] The term “serotonin-mediated neurotransmission-altering effective amount,” as used herein, refers to an amount sufficient to increase or decrease neurotransmission in systems controlled by serotonin. [0019] The term “prodrug,” as used herein, refers to a chemical compound that is converted by metabolic processes in vivo to a compound of the above formula. An example of such a metabolic process is hydrolysis in blood. Thorough discussions of prodrugs are provided in T. Higuchi and V. Stella, “Prodrugs as Novel Delivery Systems,” Vol. 14, ACS Symposium Series, and in “Bioreversible Carriers in Drug Design,” ed. Edward Roche, American Pharmaceutical Association and Pergamon Press, 1987, both of which are incorporated herein by reference. [0020] The chemist of ordinary skill will recognize that certain combinations of substituents, included within the scope of formula I, may be chemically unstable. The skilled chemist will either avoid these combinations or protect sensitive groups with well-known protecting groups. [0021] The term “alkyl,” as used herein, unless otherwise indicated, includes saturated monovalent hydrocarbon radicals with 1-12 carbon atoms having straight, branched or cyclic moieties or combinations thereof. The term “lower alkyl” refers to an alkyl group having one to six carbon atoms. Examples include methyl, ethyl, propyl, isopropyl, cyclopropyl, butyl, isobutyl, sec-butyl, t-butyl, pentyl, neopentyl, cyclopentylmethyl, and hexyl. It is preferred that the alkyl group is lower alkyl. The preferred cyclic alkyl groups are cyclobutyl and cyclopentyl. The preferred lower alkyl group contains 1-3 carbon atoms. The most preferred alkyl group is methyl. [0022] The term “alkoxy,” as used herein, unless otherwise indicated, refers to radicals having the formula —O-alkyl, wherein “alkyl” is defined as above. As used herein, the term “lower alkoxy” refers to an alkoxy group having 1-6 carbon atoms. It may be straight-chain or branched or an alkoxy-substituted alkyl group may form a cyclic ether, such as tetrahydropyran or tetrahydrofuran. Examples of acyclic alkoxy groups include methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, pentoxy and the like. It is preferred that alkoxy is lower alkoxy. It is more preferred that alkoxy contains 1:3 carbon atoms. The most preferred alkoxy group is methoxy. The most preferred substituted alkoxy group is trifluoromethoxy. [0023] The halogen atoms contemplated by the present invention are F, Cl, Br, and I. Chlorine and fluorine are preferred. Alkyl groups substituted with one or more halogen atoms include chloromethyl, 2,3-dichloropropyl, and trifluoromethyl. It is preferred that the halo groups are the same. The most preferred halogen-substituted alkyl group is trifluoromethyl. [0024] The term “alkenyl,” as used herein, refers to a hydrocarbon radical with two to eight carbon atoms and at least one double bond. The alkenyl group may be straight-chained, branched, or cyclic, and may be in either the Z or E form. Examples include ethenyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, isopropenyl, isobutenyl, 1-pentenyl, (Z)-2-pentenyl, (E)-2-pentenyl, (Z)-4-methyl-2-pentenyl, (E)-4-methyl-2-pentenyl, 1,3-pentadienyl, 2,4-pentadienyl, 1,3-butadienyl, cyclopentadienyl, and the like. The preferred alkenyl group is ethenyl. [0025] The term “alkynyl, as used herein,” refers to a hydrocarbon radical with two to eight carbon atoms and at least one carbon-carbon triple bond. The alkynyl group may be straight chained or branched. Examples include 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, 1-pentynyl, 2-pentynyl, 3-methyl-1-pentynyl, 3-pentynyl, 1-hexynyl, 2-hexynyl, 3-hexynyl, and the like. The preferred alkynyl group is ethynyl. [0026] The term “aryl,” as used herein, unless otherwise indicated, includes an organic radical derived from a C 6 -C 14 aromatic hydrocarbon by removal of one or more hydrogen(s). Examples include phenyl and naphthyl. The preferred substitution pattern of the phenyl group is para. [0027] The term “heteroaryl,” as used herein, unless otherwise indicated, includes an organic radical derived from an aromatic heterocyclic compound by removal of one or more hydrogen atoms. The term “heterocyclic compound” denotes a ring system made up of 5-14 ring atoms and made up of carbon and at least one other element selected from the group consisting of oxygen, nitrogen, and sulfur. Examples of heteroaryl groups include benzimidazolyl, benzofuranyl, benzofurazanyl, 2H-1-benzopyranyl, benzothiadiazine, benzothiazinyl, benzothiazolyl, benzothiophenyl, benzoxazolyl, furazanyl, furopyridinyl, furyl, imidazolyl, indazolyl, indolinyl, indolizinyl, indolyl, 3H-indolyl, isoindolyl, isoquinolinyl, isothiazolyl, isoxazolyl, naphthyridinyl, oxadiazolyl, oxazolyl, phthalazinyl, pteridinyl, purinyl, pyrazinyl, pyridazinyl, pyridinyl, pyrimidinyl, pyrazolyl, pyrrolyl, quinazolinyl, quinolinyl, quinoxalinyl, tetrazolyl, thiazolyl, thiadiazolyl, thienyl, triazinyl and triazolyl. Preferred heteroaryl groups are oxazolyl and isoxazolyl. [0028] The compounds of Formula I contain one or more chiral centers and therefore exist in different enantiomeric and diasteriomeric forms. Formula I, as defined above, includes—and this invention relates to the use of—all optical isomers and other stereoisomers of compounds of Formula I and mixtures thereof. Where compounds of this invention exist in different tautomeric forms, this invention relates to all tautomers of Formula I. [0029] Preferred compounds of this invention are those wherein V, W, and Y are hydrogen, Z is methyl, and the dashed line in Formula I is a single bond. [0030] Other preferred compounds of this invention are those in which X is CH 2 or O. Most preferred are those in which X is CH 2 . [0031] Other preferred compounds of this invention are those in which G is 4-methyl-piperazin-1-yl. [0032] Specific preferred compounds of formula I are: 1-[4-(3,5-Dimethyl-isoxazol-4-yl)phenyl]-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmethylene]-piperidin-2-one; 2-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethylene]-4-[4-(tetrahydro-pyran-4-yl)-phenyl]-morpholin-3-one; 1-[4-(3,5-Dimethyl-isoxazol-4-yl)phenyl]-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-piperidin-2-one; 2-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-4-[4-(tetrahydro-pyran-4-yl)-phenyl]-morpholin-3-one; 1-[4-(2-Methyl-oxazol-4-yl)-phenyl]-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-piperidin-2-one; 1-[4-(2-tert-Butyl-oxazol-4-yl)phenyl]-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-piperidin-2-one; 1-[4-(2-Isopropyl-oxazol-4-yl)phenyl]-3-[2-(4-methyl-piperazin-1-yl)pyridin-3-ylmethyl]-piperidin-2-one; 1-[4-(2,5-Dimethyl-oxazol-4-yl)-phenyl]-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-piperidin-2-one; 3-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-1-[4-(tetrahydro-pyran-4-yl)-phenyl]-piperidin-2-one; 3-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-1-[4-(tetrahydro-pyran-4-yl)-phenyl]-pyrrolidin-2-one; 3-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-1-(4-oxazol-2-yl-phenyl)-pyrrolidin-2-one; 3-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-1-(4-oxazol-4-yl-phenyl)pyrrolidin-2-one; 3-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-1-(4-oxazol-5-yl-phenyl)-pyrrolidin-2-one; 1-[4-(2-Methyl-oxazol-4-yl)phenyl]-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-pyrrolidin-2-one; 1-[4-(1-Methoxy-cyclobutyl)-phenyl]-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-piperidin-2-one; 3-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-1-(4-trifluoromethyl-phenyl)-pyrrolidin-2-one; 1-[4-(1-Hydroxy-cyclopentyl)phenyl]-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-pyrrolidin-2-one; 1-[4-(1-Hydroxy-1-methyl-ethyl)-phenyl]-3-[2-(4-methyl-piperazin-1-yl)pyridin-3-ylmethyl]-pyrrolidin-2-one; 1-(4-tert-Butyl-phenyl)-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-pyrrolidin-2-one; 1-[4-(1-Hydroxy-cyclopentyl)-phenyl]-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-piperidin-2-one; 1-(4-tert-Butyl-phenyl)-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-piperidin-2-one; 3-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-1-phenyl-piperidin-2-one; 3-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-1-(4-trifluoromethoxy-phenyl)-piperidin-2-one; 1-[4-(1-Hydroxy-1-methyl-ethyl)phenyl]-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-piperidin-2-one; 1-[4-1-Hydroxy-cyclobutyl)-phenyl]-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-piperidin-2-one; 1-(4-tert-Butyl-phenyl)-3-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-pyrrolidin-2-one; 1-(4-tert-Butyl-phenyl)-3-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-piperidin-2-one; 3-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-1-(4-tetrahydropyran-4-yl)-phenyl]-piperidin-2-one; 1-[4-(1-Hydroxy-1-methyl-ethyl)-phenyl]-3-[2-(4-methyl-piperazin-1-yl)pyridin-3-ylmethyl]-piperidin-2-one; and 1-[4-(1-Hydroxy-1-methyl-ethyl)phenyl]-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-pyrrolidin-2-one. [0063] This invention is also directed to an intermediate useful in the synthesis of a compound of Formula I, where the intermediate is selected from 3-[2-(4-Methyl-piperazin-1-yl)pyridin-3-ylmethylene]-pyrrolidin-2-one and 3-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethylene]-piperidin-2-one. [0064] 5HT receptor ligands of the present invention are of clinical use in the treatment of a wide variety of disorders related to serotonin-mediated physiological pathways. Accordingly, this invention is directed to a method of treating a disorder or condition that can be treated by altering (i.e., increasing or decreasing) serotonin-mediated neuro-transmission in a mammal, including a human, comprising administering to said mammal an amount of a compound of the Formula I, as defined above, or a pharmaceutically acceptable salt thereof, that is effective in treating such disorder or condition. [0065] This invention is also directed to a method of treating migraine, headache or cluster headache in a mammal, including a human, comprising administering to said mammal an amount of a compound of the Formula I, as defined above, or a pharmaceutically acceptable salt thereof, that is effective in treating such disorder. [0066] This invention is also directed to a method of treating a disorder selected from, depression (i.e., dysthymia, major depressive disorder, pediatric depression, recurrent depression, single episode depression, post partum depression, depression in Parkinson's patients, cancer patients, and post myocardial infarction patients, and subsyndromal symptomatic depression) generalized anxiety disorder, panic disorder, obsessive-compulsive disorder, post-traumatic stress disorder, avoidant personality disorder, borderline personality disorder and phobias in a mammal, including a human, comprising administering to said mammal an amount of a compound of the formula I, as defined above, or a pharmaceutically acceptable salt thereof, that is effective in treating such disorder. [0067] Formula I above includes compounds identical to those depicted but for the fact that one or more atoms (for example, hydrogen, carbon, or fluorine atoms) are replaced by radioactive isotopes thereof. Such radiolabelled compounds are useful as research and diagnostic tools in, for example, metabolism studies, pharmacokinetic studies and binding assays. [0068] This invention is also directed to a method, such as positron emission tomography (PET), of obtaining images of a mammal, including a human, to which a radiolabelled compound of the Formula I, or pharmaceutically acceptable salt thereof, has been administered. Such imaging methods can be used for any organ or system in which the 5-HT 1B receptor is found, such as those indicated above. The utility of radioactive agents with affinity for 5HT receptors for visualizing organs of the body either directly or indirectly has been documented in the literature. For example, C.-Y. Shiue et al., Synapse, 1997, 25, 147 and S. Houle et al., Can. Nucl. Med. Commun., 1997, 18, 1130, describe the use of 5HT 1A receptor ligands to image 5HT 1A receptors in the human brain using positron emission tomography (PET). The foregoing references are incorporated herein by reference in their entireties. [0069] The compounds of Formula I and their pharmaceutically acceptable salts can be prepared as described below. [0070] Compounds of Formula I in which one or more atoms are radioactive can be prepared by methods known to a person of ordinary skill in the art. For example, compounds of Formula I wherein the radioactive atom is tritium can be prepared by reacting an aryl halide Ar—X, wherein the halogen is chlorine, bromine or iodine, with gaseous 3 H 2 and a noble metal catalyst, such as palladium suspended on carbon, in a suitable solvent such as a lower alcohol, preferably methanol or ethanol. Compounds of Formula I wherein the radioactive atom is 18 F can be prepared by reacting an aryl trialkyl stannane Ar—SnR 3 , wherein R is lower alkyl, preferably methyl or n-butyl, with 18 F-enriched fluorine (F 2 ), OF 2 or CF 3 COOH in a suitably inert solvent (c.f M. Namavari, et al., J. Fluorine Chem., 1995, 74, 113). [0071] Compounds of Formula I wherein the radioactive atom is 14 C can be prepared by reacting an aryl halide Ar—X, wherein X is preferably bromine or iodine, or an aryl trifluoromethane sulfonate (Ar—OSO 2 CF 3 ) with potassium [ 14 C]cyanide or potassium [ 14 C]-cyanide and a noble metal catalyst, preferably tetrakis(triphenylphosphine)palladium, in a reaction inert solvent such water or tetrahydrofuran, and preferably a mixture of water and tetrahydrofuran. (See Y. Andersson, B. Langstrom, J. Chem. Soc. Perkin Trans. 1, 1994, 1395.) [0072] The therapeutic compounds used in the methods of this invention can be administered orally, buccally, transdermally (e.g., through the use of a patch), parenterally or topically. Oral administration is preferred. In general, these compounds are most desirably administered in dosages ranging from about 1 mg to about 1000 mg per day, although variations may occur depending on the weight and condition of the person being treated and the particular route of administration chosen. In some instances, dosage levels below the lower limit of the aforesaid range may be more than adequate, while in other cases still larger doses can be employed without causing any harmful side effects, provided that such larger doses are first divided into several small doses for administration throughout. [0073] The compounds of this invention can be used in combination with a serotonin re-uptake inhibitor (SRI). When used in the same oral, parenteral or buccal pharmaceutical composition as an SRI, the daily dose of the compound of formula I or pharmaceutically acceptable salt thereof will be within the same general range as specified above for the administration of such compound or salt as a single active agent. The daily dose of the SRI in such a composition will generally be within the range of about 1 mg to about 400 mg [0074] The therapeutic compounds used in the methods of this invention can be administered alone or in combination with pharmaceutically acceptable carriers or diluents by either of the two routes previously indicated, and such administration can be carried out in single or multiple doses. More particularly, the therapeutic compounds used in the methods of this invention can be administered in a wide variety of different dosage forms, i.e., they may be combined with various pharmaceutically acceptable inert carriers in the form of tablets, capsules, lozenges, troches, hard candies, powders, sprays, creams, salves, suppositories, jellies, gels, pastes, lotions, ointments, elixirs, syrups, and the like. Such carriers include solid diluents or fillers, sterile aqueous media and various non-toxic organic solvents, for example. Moreover, oral pharmaceutical compositions can be suitably sweetened and/or flavored. [0075] For oral administration, tablets containing various excipients such as microcrystalline cellulose, sodium citrate, calcium carbonate, dicalcium phosphate and glycine can be employed along with various disintegrants such as starch (and preferably corn, potato or tapioca starch), alginic acid and certain complex silicates, together with granulation binders like polyvinyl pyrrolidone, sucrose, gelatin and acacia. Additionally, lubricating agents such as magnesium stearate, sodium lauryl sulfate and talc are often very useful for tabletting purposes. Solid compositions of a similar type can also be employed as fillers in gelatin capsules; preferred materials in this connection also include lactose or milk sugar as well as high molecular weight polyethylene glycols. When aqueous suspensions and/or elixirs are desired for oral administration, the active ingredient can be combined with various sweetening or flavoring agents, coloring matter or dyes, and, if so desired, emulsifying and/or suspending agents as well, together with such diluents as water, ethanol, propylene glycol, glycerin and various like combinations thereof. [0076] For parenteral administration, solutions of a therapeutic compound used in the methods of the present invention in either sesame or peanut oil or in aqueous propylene glycol can be employed. The aqueous solutions should be suitably buffered if necessary and the liquid diluent first rendered isotonic. These aqueous solutions are suitable for intravenous injection purposes. The oily solutions are suitable for intra-articular, intramuscular and subcutaneous injection purposes. The preparation of all these solutions under sterile conditions is readily accomplished by standard pharmaceutical techniques well known to those skilled in the art. Biological Assay [0077] The activity of the compounds of the present invention with respect to 5HT 1B (formerly referred to as 5HT 1D ) binding ability can be determined using standard radioligand binding assays as described in the literature. The 5-HT 1A affinity can be measured using the procedure of Hoyer et al. ( Brain Res., 1986, 376, 85). The 5-HT 1D affinity can be measured using the procedure of Heuring and Peroutka ( J. Neurosci., 1987, 7, 894). [0078] The in vitro activity of the compounds of the present invention at the 5-HT 1D binding site may be determined according to the following procedure. Bovine caudate tissue is homogenized and suspended in 20 volumes of a buffer containing 50 mM TRIS.hydrochloride (tris[hydroxymethyl]aminomethane hydrochloride) at a pH of 7.7. The homogenate is then centrifuged at 45,000 G for 10 minutes. The supernatant is then discarded and the resulting pellet resuspended in approximately 20 volumes of 50 mM TRIS-hydrochloride buffer at pH 7.7. This suspension is then pre-incubated for 15 minutes at 37° C., after which the suspension is centrifuged again at 45,000 G for 10 minutes and the supernatant discarded. The resulting pellet (approximately 1 gram) is resuspended in 150 ml of a buffer of 15 mM TRIS-hydrochloride containing 0.01 percent ascorbic acid with a final pH of 7.7 and also containing 10 μM pargyline and 4 mM calcium chloride (CaCl 2 ). The suspension is kept on ice at least 30 minutes prior to use. [0079] The inhibitor, control or vehicle is then incubated according to the following procedure. To 50 μl of a 20 percent dimethylsulfoxide (DMSO)/80 percent distilled water solution is added 200 μl of tritiated 5-hydroxytryptamine (2 nM) in a buffer of 50 mM TRIS.hydrochloride containing 0.01 percent ascorbic acid at pH 7.7 and also containing 10 μM pargyline and 4 μM calcium chloride, plus 100 nM of 8-hydroxy-DPAT (dipropylaminotetraline) and 100 nM of mesulergine. To this mixture is added 750 μl of bovine caudate tissue, and the resulting suspension is vortexed to ensure a homogenous suspension. The suspension is then incubated in a shaking water bath for 30 minutes at 25° C. After incubation is complete, the suspension is filtered using glass fiber filters (e.g., Whatman GF/B-filters.™.). The pellet is then washed three times with 4 ml of a buffer of 50 mM TRIS.hydrochloride at pH 7.7. The pellet is then placed in a scintillation vial with 5 ml of scintillation fluid (aquasol 2™) and allowed to sit overnight. The percent inhibition can be calculated for each dose of the compound. An IC 50 value can then be calculated from the percent inhibition values. [0080] The activity of the compounds of the present invention for 5-HT 1A binding ability can be determined according to the following procedure. Rat brain cortex tissue is homogenized and divided into samples of 1 gram lots and diluted with 10 volumes of 0.32 M sucrose solution. The suspension is then centrifuged at 900 G for 10 minutes and the supernate separated and recentrifuged at 70,000 G for 15 minutes. The supernate is discarded and the pellet re-suspended in 10 volumes of 15 mM TRIS.hydrochloride at pH 7.5. The suspension is allowed to incubate for 15 minutes at 37° C. After pre-incubation is complete, the suspension is centrifuged at 70,000 G for 15 minutes and the supernate discarded. The resulting tissue pellet is resuspended in a buffer of 50 mM TRIS.hydrochloride at pH 7.7 containing 4 mM of calcium chloride and 0.01 percent ascorbic acid. The tissue is stored at −70° C. until ready for an experiment. The tissue can be thawed immediately prior to use, diluted with 10 μm pargyline and kept on ice. [0081] The tissue is then incubated according to the following procedure. Fifty microliters of control, inhibitor, or vehicle (1 percent DMSO final concentration) is prepared at various dosages. To this solution is added 200 μl of tritiated DPAT at a concentration of 1.5 nM in a buffer of 50 mM TRIS.hydrochloride at pH 7.7 containing 4 mM calcium chloride, 0.01 percent ascorbic acid and pargyline. To this solution is then added 750 μl of tissue and the resulting suspension is vortexed to ensure homogeneity. The suspension is then incubated in a shaking water bath for 30 minutes at 37° C. The solution is then filtered, washed twice with 4 ml of 10 mM TRIS.hydrochloride at pH 7.5 containing 154 mM of sodium chloride. The percent inhibition is calculated for each dose of the compound, control or vehicle. IC 50 values are calculated from the percent inhibition values. [0082] The agonist and antagonist activities of the compounds of the invention at 5-HT 1A and 5-HT 1D receptors can be determined using a single saturating concentration according to the following procedure. Male Hartley guinea pigs are decapitated and 5-HT 1A receptors are dissected out of the hippocampus, while 5-HT receptors are obtained by slicing at 350 mM on a McIlwain tissue chopper and dissecting out the substantia nigra from the appropriate slices. The individual tissues are homogenized in 5 mM HEPES buffer containing 1 mM EGTA (pH 7.5) using a hand-held glass-Teflon® homogenizer and centrifuged at 35,000×g for 10 minutes at 4° C. The pellets are resuspended in 100 mM HEPES buffer containing 1 mM EGTA (pH 7.5) to a final protein concentration of 20 mg (hippocampus) or 5 mg (substantia nigra) of protein per tube. The following agents are added so that the reaction mix in each tube contained 2.0 mM MgCl 2 , 0.5 mM ATP, 1.0 mM cAMP, 0.5 mM IBMX, 10 mM phosphocreatine, 0.31 mg/mL creatine phosphokinase, 100 μM GTP and 0.5-1 microcuries of [ 32 P]-ATP (30 Ci/mmol: NEG-003—New England Nuclear). Incubation is initiated by the addition of tissue to siliconized microfuge tubes (in triplicate) at 30° C. for 15 minutes. Each tube receives 20 μL tissue, 10 μL drug or buffer (at 10× final concentration), 10 μL 32 nM agonist or buffer (at 10× final concentration), 20 μL forskolin (3 μM final concentration) and 40 μL of the preceding reaction mix. Incubation is terminated by the addition of 100 μL 2% SDS, 1.3 mM cAMP, 45 mM ATP solution containing 40,000 dpm [ 3 H]-cAMP (30 Ci/mmol: NET-275—New England Nuclear) to monitor the recovery of CAMP from the columns. The separation of [ 32 P]-ATP and [ 32 P]-cAMP is accomplished using the method of Salomon et al., Analytical Biochemistry, 1974, 58, 541-548. Radioactivity is quantified by liquid scintillation counting. Maximal inhibition is defined by 10 μM (R)-8-OH-DPAT for 5-HT 1A receptors, and 320 nM 5-HT for 5-HT 1D receptors. Percent inhibitions by the test compounds are then calculated in relation to the inhibitory effect of (R)-8-OH-DPAT for 5-HT 1A receptors or 5-HT for 5-HT 1D receptors. The reversal of agonist induced inhibition of forskolin-stimulated adenylate cyclase activity is calculated in relation to the 32 nM agonist effect. [0083] The compounds of the invention can be tested in vivo for antagonism of 5-HT 1D agonist-induced hypothermia in guinea pigs according to the following procedure. [0084] Male Hartley guinea pigs from Charles River, weighing 250-275 grams on arrival and 300-600 grams at testing, serve as subjects in the experiment. The guinea pigs are housed under standard laboratory conditions on a 7 a.m. to 7 p.m. lighting schedule for at least seven days prior to experimentation. Food and water are available ad libitum until the time of testing. [0085] The compounds of the invention can be administered as solutions in a volume of 1 ml/kg. The vehicle used is varied depending on compound solubility. Test compounds are typically administered either sixty minutes orally (p.o.) or 0 minutes subcutaneously (s.c.) prior to a 5-HT 1D agonist, such as [3-(1-methylpyrrolidin-2-ylmethyl)-1H-indol-5-yl]-(3-nitropyridin-3-yl)-amine, which can be prepared as described in PCT Publication WO93/11106, published Jun. 10, 1993, the contents of which are incorporated herein by reference in its entirety, and which is administered at a dose of 5.6 mg/kg, s.c. Before a first temperature reading is taken, each guinea pig is placed in a clear plastic shoe box containing wood chips and a metal grid floor and allowed to acclimate to the surroundings for 30 minutes. Animals are then returned to the same shoe box after each temperature reading. Prior to each temperature measurement, each animal is firmly held with one hand for a 30-second period. A digital thermometer with a small animal probe is used for temperature measurements. The probe is made of semi-flexible nylon with an epoxy tip. The temperature probe is inserted 6 cm. into the rectum and held there for 30 seconds or until a stable recording is obtained. Temperatures are then recorded. [0086] In p.o. screening experiments, a “pre-drug” baseline temperature reading is made at −90 minutes, the test compound is given at −60 minutes and an additional −30 minute reading is taken. The 5-HT 1D agonist is then administered at 0 minutes and temperatures are taken 30, 60, 120 and 240 minutes later. In subcutaneous screening experiments, a pre-drug baseline temperature reading is made at −30 minutes. The test compound and 5-HT 1D agonists are given concurrently and temperatures are taken at 30, 60, 120 and 240 minutes later. [0087] Data are analyzed with two-way analysis of variants with repeated measures in Newman-Keuls post hoc analysis. [0088] The active compounds of the invention can be evaluated as anti-migraine agents by testing the extent to which they mimic sumatriptan in contracting the dog isolated saphenous vein strip (P. P. A. Humphrey et al., Br. J. Pharmacol., 1988, 94, 1128). This effect can be blocked by methiothepin, a known serotonin antagonist. Sumatriptan is known to be useful in the treatment of migraine and produces a selective increase in carotid vascular resistance in the anesthetized dog. The pharmacological basis of sumatriptan efficacy has been discussed in W. Fenwick et al., Br. J. Pharmacol., 1989, 96, 83. [0089] The serotonin 5-HT 1 agonist activity can be determined by the in vitro receptor binding assays, as described for the 5-HT 1A receptor using rat cortex as the receptor source and [ 3 H]-8-OH-DPAT as the radioligand (D. Hoyer et al., Eur. J. Pharm., 1985, 118, 13) and as described for the 5-HT 1D receptor using bovine caudate as the receptor source and [ 3 H]serotonin as the radioligand (R. E. Heuring and S. J. Peroutka, J. Neuroscience, 1987, 7, 894). DETAILED DESCRIPTION OF THE INVENTION [0090] Scheme 1 illustrates general methods suitable for preparing compounds of formula I wherein X is carbon. [0091] Synthesis of aldehyde 2 from 1C involves treatment of 1C with a tertiary amine, preferably N,N′-tetramethyl ethlyenediamine or 1,4-diazabicyclo[2.2.2]-octane, with a lithium alkyl base, preferably butyl lithium, in an ether solvent, preferably diethyl ether, at a temperature from about −100° to −30° C., preferably −78° C. Quenching with dimethylformamide at reaction temperature from about −100° to −30° C., where −78° C. is preferred, affords aldehyde 2. [0092] Pyridyl piperazinyl aldehyde 4 is produced by the reaction of compound 2,2-chloro-pyridine-3-carbaldehyde, with G1* or G2* in the presence of a base such as a trialkyl amine or an alkali metal carbonate (a base that is inert towards 2, G1 or, and the solvent) in a solvent such as water, 1,4-dioxane, n-butanol, N,N-dimethyl-formamide, or dimethyl sulfoxide, at reaction temperature from about 40° to 150° C. The preferred base is potassium carbonate, the preferred solvent is water, and the preferred temperature is from about 90° to about 120° C. [0093] Condensation of 4 and N-substituted lactam 8, in the presence of an amine or metal hydride base affords 5. The N-substituent (R3) can be vinyl or C(═O)R, (wherein R=C 1 -C 8 alkyl-straight chain, branched or (if C 3 -C 8 ) cyclic, or aryl). R=tert-butyl is preferred (Sasaki, H. et al. J. Med. Chem., 1991, 34, 628-633). The base can be sodium hydride or sodium bis(trimethylsilylamide), where sodium bis(trimethylsilylamide) is preferred. The preferred solvent is tetrahydrofuran. The reaction temperature is from about −30° to 100° C., preferably from about −10° to about 30° C. Reduction of the carbon-carbon double bond of 5 to generate 6 can be achieved by placing 5 in a reaction inert solvent such as a lower alcohol, wherein methanol or ethanol are preferred, adding a noble metal catalyst suspended on a solid support, such as platinum or palladium, where 10% palladium on carbon is preferred, then placing the mixture under a hydrogen atmosphere, from about 1 atm to 5 atm, where about 3 to about 4 atm is preferred, at a temperature from about 10° to 100° C., where 40° to 60° C. is preferred, and then shaking the mixture. In the case where R 6 =benzyl or some other group that is labile under hydrogenation conditions, the corresponding NH derivative (R 6 =H) is formed. [0094] The conversion of 6 to 1a, wherein R 3 is an optionally substituted aryl or heteroaryl group, can be accomplished by treating 6, an aryl or heteroaryl chloride, bromide, iodide, or sulfonate, where the bromide is preferred, a base such as potassium phosphate, potassium carbonate, sodium carbonate, thallium carbonate, cesium carbonate, potassium tert-butoxide, lithium tert-butoxide, or sodium tert-butoxide, where potassium carbonate is preferred, a diamine, such as 1,2-ethylenediamine, N,N′-dimethyl ethylenediamine, or cis-1,2-diaminocyclohexane, where N,N′-dimethylethylene-diamine is preferred, a cuprous chloride, bromide or iodide, where cuprous iodide is preferred, a small amount of water, where about 1 to 4 percent is preferred, in a reaction inert solvent such as 1,2-dimethoxyethane, diglyme, t-butyl methyl ether, tetrahydrofuran, benzene, toluene, where toluene is preferred, from about 40° to about 150° C., where about 80° to 120° C. is preferred. Alternatively, the conversion of 6 to 1a, wherein R 3 is an optionally substituted aryl or heteroaryl group, can be accomplished by treating 6 and an aryl or heteroaryl chloride, bromide, iodide, or sulfonate, where the bromide is preferred, with a base such as an alkali metal carbonate, an alkali metal amine base, an alkali metal phosphonate, or an alkali metal alkoxide, where cesium carbonate is preferred, a phosphine ligand, where 9,9-dimethyl-4,5-bis(diphenyl-phosphino)xanthene (XANTPHOS) is preferred, a palladium species, such as palladium (II) acetate or tris(dibenzylidene-acetone)dipalladium (0) or the corresponding chloroform adduct, where tris(dibenzylidene-acetone)dipalladium (0) is preferred, in an inert solvent such as 1,4-dioxane or toluene, where 1,4-dioxane is preferred, at a temperature from about 40° to about 160° C., where 80° to 120° C. is preferred. If R 6 =H, then further functionalization of the secondary amine can be carried out under standard alkylation or reductive amination conditions known to one skilled in the art. [0095] Another route to access compounds of formula 1a and 1b is shown in Scheme 1. The conversion of 5 to 1b, wherein R 3 is Ar 1 , an optionally substituted aryl or heteroaryl group as described above, can be accomplished by treating 5, an aryl or heteroaryl chloride, bromide, iodide, or sulfonate, where the bromide is preferred, a base such as potassium phosphate, potassium carbonate, sodium carbonate, thallium carbonate, cesium carbonate, potassium tert-butoxide, lithium tertbutoxide, or sodium tertbutoxide, where potassium carbonate is preferred, a diamine, such as 1,2-ethylenediamine, N,N′-dimethyl-ethylenediamine, or cis-1,2-diaminocyclohexane, where N,N′-dimethylethylenediamine is preferred, cuprous chloride, bromide or iodide, where cuprous iodide is preferred, a small amount of water, where about 1 to 4 percent is preferred, in a reaction inert solvent such as 1,2-dimethoxyethane, diglyme, t-butyl methyl ether, tetrahydrofuran, benzene, toluene, where toluene is preferred, from about 40° to 150° C., where about 80° to about 120° C. is preferred. Alternatively, the conversion of 5 to 1b, wherein R 3 is an optionally substituted aryl or heteroaryl group, can be accomplished by treating 5 and an aryl or heteroaryl chloride, bromide, iodide, or sulfonate, where the bromide is preferred, with a base such as an alkali metal carbonate, an alkali metal amine base, an alkali metal phosphonate, or an alkali metal alkoxide, where cesium carbonate is preferred, a phosphine ligand, where 9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene (XANTPHOS) is preferred, a palladium species, such as palladium (II) acetate or tris(dibenzylideneacetone)dipalladium (0) or the corresponding chloroform adduct, where tris(dibenzylideneacetone)dipalladium (0) is preferred, in an inert solvent such as 1,4-dioxane or toluene, where 1,4-dioxane is preferred, at a temperature from about 40° to about 160° C., where 80° to 120° C. is preferred. Conversion of 1b to 1a can be achieved by placing 1b in a reaction inert solvent such as a lower alcohol, wherein methanol or ethanol are preferred, adding a noble metal catalyst suspended on a solid support, such as platinum or palladium, where 10% palladium on carbon is preferred, then placing the mixture under a hydrogen atmosphere, from about 1 atm to 5 atm, where about 3 to 4 atm is preferred, at a temperature from about 10° to about 100° C., where 40° to 60° C. is preferred, and then shaking the mixture. In the case where R 6 =benzyl or some other group that is labile towards hydrogenation conditions, the corresponding secondary amine derivative (R 6 =H) is formed. If R 6 =H, further functionalization of the secondary amine can be carried out under standard alkylation or reductive amination conditions known to one skilled in the art. [0096] Another route to 1b is shown in Scheme 1. The conversion of 7 to 8, wherein R 3 is Ar 1 , an optionally substituted aryl or heteroaryl group as described above and in claim 1 , can be accomplished by treating 7, an aryl or heteroaryl chloride, bromide, iodide, or sulfonate, where the bromide is preferred, with a base such as potassium phosphate, potassium carbonate, sodium carbonate, thallium carbonate, cesium carbonate, potassium tert-butoxide, lithium tert-butoxide, or sodium tertbutoxide, where potassium carbonate is preferred, a diamine, such as 1,2-ethylenediamine, N,N′-dimethyl-ethylenediamine, or cis-1,2-diaminocyclohexane, where N,N′-dimethylethylenediamine is preferred, cuprous chloride, bromide or iodide, where cuprous iodide is preferred, and a small amount of water, where about 1-4% is preferred, in a reaction inert solvent such as 1,2-dimethoxyethane, diglyme, t-butyl methyl ether, tetrahydrofuran, benzene, toluene, where toluene is preferred, from about 40° to about 150° C., where about 80° to 120° C. is preferred. Alternatively, the conversion of 7 to 8 can be accomplished by treating 7 and an aryl or heteroaryl chloride, bromide, iodide, or sulfonate, where the bromide is preferred, with a base such as an alkali metal carbonate, an alkali metal amine base, an alkali metal phosphonate, or an alkali metal alkoxide, where cesium carbonate is preferred, a phosphine ligand, where 9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene (XANTPHOS) is preferred, a palladium species, such, as palladium (II) acetate or tris (dibenzylideneacetone)dipalladium (0) or the corresponding chloroform adduct, where tris(dibenzylideneacetone)dipalladium (0) is preferred, in an inert solvent such as 1,4-dioxane or toluene, where 1,4-dioxane is preferred, at a temperature from about 40° to 160° C., where 80° to 120° C. is preferred. [0097] Compound 8 can also be prepared by condensation of R 3 —NH 2 with 8a, in a solvent such as water, acetonitrile, 1,4-dioxane, or tetrahydrofuran, where tetrahydrofuran is preferred, at a temperature from about 100 to 120° C., where 50° to 80° C. is preferred, in the presence or absence of a base, such as triethylamine, diisopropylethyl amine, an alkali metal hydroxide or an alkali metal carbonate, where cesium carbonate is preferred, where the group B of 8a can be F, Cl, Br, I, OC 1 -C 4 alkyl, OH, or an activated carboxylic acid group derived from reaction of the acid with a standard carboxylic acid activating reagent such as, but not limited to, a carbodiimide (dicyclohexyl carbodiimide, commonly abbreviated “DCC,” 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydro-chloride salt) or tripropyl-phosphonic anhydride, where B=Cl is preferred, where the group A of 8a can be F, Cl, Br, I, or an alkyl or aryl sulfonate, where A=Cl is preferred. Synthesis of 1b can be accomplished by reacting 4 and 8 in a solvent such as tetrahydrofuran, tert-butyl methyl ether, or 1,4-dioxane, where tetrahydrofuran is preferred, with an alkali metal amine base, such as sodium bis(trimethylsilylamide), potassium bis(trimethylsilylamide), lithium bis(trimethyl-silylamide), or lithium diisopropylamide, or an alkali metal hydride, such as sodium hydride or potassium hydride, where sodium bis(hexamethylsilylamide) is preferred, followed by the optional addition of diethylchlorophosphonate (in which case lithium diisopropyl amide is the preferred base) from about −30° to about 100° C., preferably from −10° to 30° C. Compound 1b can then be converted to compound 1a as described above. In the case where R 6 =benzyl or some other group that is labile towards hydrogenation conditions, the corresponding NH derivative (R 6 =H) is formed. If R 6 =H, further functionalization of the secondary amine can be carried out under standard alkylation or reductive amination conditions known to one skilled in the art. [0098] Another method to make compounds of formula 1b described in Scheme 1 starts from pyridylaldehyde 2b, where D=chloro or fluoro, where fluoro is preferred. Reacting 2b and 8 in a solvent such as tetrahydrofuran, tert-butylmethyl ether, or 1,4-dioxane, where tetrahydrofuran is preferred, with an alkali metal amine base, such as sodium bis(trimethylsilylamide), potassium bis(trimethylsilylamide), lithium bis-(trimethyl-silylamide), or lithium diisopropylamide, or an alkali metal hydride, such as sodium hydride or potassium hydride, where sodium bis(hexamethylsilylamide) is preferred, followed by the optional addition of diethylchlorophosphonate (in which case lithium diisopropyl amide is the preferred base) from about −30° to 100° C., preferably from −10° to 30° C., affords F. F can then be converted to 1b and 1b can be converted to 1a as described above. [0099] Scheme 2 illustrates general methods suitable for preparing compounds of formula I wherein X is O (Formula 1e below). [0100] Treatment of a mixture of 3-fluoro-pyridine-2-carbaldehyde 2 and G1* or G2* in a solvent such as water, 1,4-dioxane, n-butanol, N,N-dimethylformamide, dimethyl sulfoxide, or acetonitrile, where water is preferred, with a base that is inert toward 2, G1 or G2, and the solvent, such as a trialkyl amine or an alkali metal carbonate, wherein potassium carbonate is preferred, at reaction temperature from about 40° to about 150° C., where 90° to 120° C. is preferred, affords pyridyl piperazinyl aldehyde 4. Addition of 4 and an N-substituted morpholinone 12, where the N-substituent is vinyl or C(═O)R, (wherein R=C 1 -C 8 alkyl, straight chain or branched, C 3 -C 8 cycloalkyl, or aryl), wherein C(═O)R with R=tertbutyl is preferred (Sasaki, H. et al. J. Med. Chem., 1991, 34, 628-633), with an amine or hydride metal base such as sodium hydride or sodium bis(trimethylsilylamide), where sodium bis(trimethylsilylamide) is preferred, in an inert reaction solvent, where tetrahydrofuran is preferred, from about −30° to about 100° C., preferably from about −10° to about 30° C., affords 9. Reduction of the carbon-carbon double bond of 9 to generate 10 can be achieved by placing 9 in a reaction inert solvent such as a lower alcohol, wherein methanol or ethanol are preferred, adding a noble metal catalyst suspended on a solid support, such as platinum or palladium, where 10% palladium on carbon is preferred, then placing the mixture under a hydrogen atmosphere, from about 1 atm to 5 atm, where about 3 to 4 atm is preferred, at a temperature from about 10° to about 100° C., where 40 to 60° C. is preferred, and then shaking the mixture. In the case where R 6 =benzyl or some other group that is labile towards hydrogenation conditions, the corresponding NH derivative (R 6 =H) is formed. [0101] The conversion of 10 to 1e, wherein R 3 is an optionally substituted aryl or heteroaryl group, can be accomplished by treating 10, an aryl or heteroaryl chloride, bromide, iodide, or sulfonate, where the bromide is preferred, a base such as potassium phosphate, potassium carbonate, sodium carbonate, thallium carbonate, cesium carbonate, potassium tert-butoxide, lithium tertbutoxide, or sodium tert-butoxide, where potassium carbonate is preferred, a diamine, such as 1,2-ethylenediamine, N,N′-dimethylethylenediamine, or cis-1,2-diaminocyclo-hexane, where N,N′-dimethylethylenediamine is preferred, a cuprous chloride, bromide or iodide, where cuprous iodide is preferred, a small amount of water, where about 1 to 4 percent is preferred, in a reaction inert solvent such as 1,2-dimethoxyethane, diglyme, t-butyl methyl ether, tetrahydrofuran, benzene, toluene, where toluene is preferred, from about 40° to 150° C., where about 80° to about 120° C. is preferred. Alternatively, the conversion of 10 to 1e, wherein R 3 is an optionally substituted aryl or heteroaryl group, can be accomplished by treating 10 and an aryl or heteroaryl chloride, bromide, iodide, or sulfonate, where the bromide is preferred, with a base such as an alkali metal carbonate, an alkali metal amine base, an alkali metal phosphonate, or an alkali metal alkoxide, where cesium carbonate is preferred, a phosphine ligand, where 9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene (XANTPHOS) is preferred, a palladium species, such as palladium (II) acetate or tris(dibenzylideneacetone)dipalladium (0) or the corresponding chloroform adduct, where tris(dibenzylideneacetone)dipalladium (0) is preferred, in an inert solvent such as 1,4-dioxane or toluene, where 1,4-dioxane is preferred, at a temperature from about 40° to about 160° C., where 80° to 120° C. is preferred. If R 6 =H, then further functionalization of the secondary amine can be carried out under standard alkylation or reductive amination conditions known to one skilled in the art. [0102] Another route to access compounds of formula 1d and 1e is shown in Scheme 2. The conversion of 9 to 1d, wherein R3 is an optionally substituted aryl or heteroaryl group, can be accomplished by treating 9, an aryl or heteroaryl chloride, bromide, iodide, or sulfonate, where the bromide is preferred, a base such as potassium phosphate, potassium carbonate, sodium carbonate, thallium carbonate, cesium carbonate, potassium tert-butoxide, lithium tert-butoxide, or sodium tert-butoxide, where potassium carbonate is preferred, a diamine, such as 1,2-ethylenediamine, N,N′-dimethyl-ethylenediamine, or cis-1,2-diaminocyclohexane, where N,N′-dimethylethylenediamine is preferred, cuprous chloride, bromide or iodide, where cuprous iodide is preferred, a small amount of water, where about 1 to 4 percent is preferred, in a reaction inert solvent such as 1,2-dimethoxyethane, diglyme, t-butyl methyl ether, tetrahydrofuran, benzene, toluene, where toluene is preferred, from about 40° to about 150° C., where about 80° to 120° C. is preferred. Alternatively, the conversion of 9 to 1d, wherein R 3 is an optionally substituted aryl or heteroaryl group, can be accomplished by treating 9 and an aryl or heteroaryl chloride, bromide, iodide, or sulfonate, where the bromide is preferred, with a base such as an alkali metal carbonate, an alkali metal amine base, an alkali metal phosphonate, or an alkali metal alkoxide, where cesium carbonate is preferred, a phosphine ligand, where 9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene (XANTPHOS) is preferred, a palladium species, such as palladium(II)acetate or tris(dibenzylideneacetone) dipalladium(0) or the corresponding chloroform adduct, where tris(dibenzylidene-acetone)dipalladium(0) is preferred, in an inert solvent such as 1,4-dioxane or toluene, where 1,4-dioxane is preferred, at a temperature from about 40° to about 160° C., where 80° to 120° C. is preferred. Conversion of 1d to 1e can be achieved by placing 1d in a reaction inert solvent such as a lower alcohol, wherein methanol or ethanol are preferred, adding a noble metal catalyst suspended on a solid support, such as platinum or palladium, where 10% palladium on carbon is preferred, then placing the mixture under a hydrogen atmosphere, from about 1 atm to 5 atm, where about 3 to 4 atm is preferred, at a temperature from about 10° to about 100° C., where 40° to 60° C. is preferred, and then shaking the mixture. In the case where R 6 =benzyl or some other group that is labile towards hydrogenation conditions, the corresponding secondary amine derivative (R 6 =H) is formed. If R 6 =H, further functionalization of the secondary amine can be carried out under standard alkylation or reductive amination conditions known to one skilled in the art. [0103] Another route that allows for the access to 1d is shown in Scheme 2. The conversion of 13 to 12, wherein R 3 is an optionally substituted aryl or heteroaryl group, can be accomplished by treating 13, an aryl or heteroaryl chloride, bromide, iodide, or sulfonate, where the bromide is preferred, a base such as potassium phosphate, potassium carbonate, sodium carbonate, thallium carbonate, cesium carbonate, potassium tert-butoxide, lithium tertbutoxide, or sodium tert-butoxide, where potassium carbonate is preferred, a diamine, such as 1,2-ethylenediamine, N,N′-dimethyl-ethylenediamine, or cis-1,2-diamino-cyclohexane, where N,N′-dimethylethylenediamine is preferred, cuprous chloride, bromide or iodide, where cuprous iodide is preferred, a small amount of water, where about 1 to 4 percent is preferred, in a reaction inert solvent such as 1,2-dimethoxyethane, diglyme, t-butyl methyl ether, tetrahydrofuran, benzene, toluene, where toluene is preferred, from about 40° to about 150° C., where about 80° to 120° C. is preferred affords 12. Alternatively, the conversion of 13 to 12, wherein R 3 is an optionally substituted aryl or heteroaryl group, can be accomplished by treating 13 and an aryl or heteroaryl chloride, bromide, iodide, or sulfonate, where the bromide is preferred, with a base such as an alkali metal carbonate, an alkali metal amine base, an alkali metal phosphonate, or an alkali metal alkoxide, where cesium carbonate is preferred, a phosphine ligand, where 9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene (XANTPHOS) is preferred, a palladium species, such as palladium(II)acetate or tris(dibenzylideneacetone)dipalladium(0) or the corresponding chloroform adduct, where tris(dibenzylideneacetone)dipalladium(0) is preferred, in an inert solvent such as 1,4-dioxane or toluene, where 1,4-dioxane is preferred, at a temperature from about 40° to about 160° C., where 80° to 120° C. is preferred. In addition, 12 is an N-substituted morpholinone, where the R 3 group may also be defined as an N-substituent defined as vinyl or C(═O)R, (wherein R=C 1 -C 8 alkyl, straight chain or branched, C 3 -C 8 cycloalkyl, or aryl), wherein C(═O)R with R=tert-butyl is preferred is prepared by adding RCOCl (where R is defined above) to morpholinone 13 and a tertiary amine base, wherein triethylamine is preferred, in a chlorinated solvent, wherein methylene chloride is preferred at a temperature from −30° C. to 50° C. wherein 0° C. is preferred to afford morpholinone 12. [0104] In turn, morpholinone 13 was prepared using literature methods (Pfeil, E., et al., Angew. Chem., 1967, 79, 188; Lehn, J.-M., et al., Helv. Chim. Acta, 1976, 59, 1566-1583; Sandmann, G., et al., J. Agric. Food Chem., 2001, 49, 138-141. 13 may also be prepared by condensation of 14 in a solvent such as water, acetonitrile, 1,4-dioxane, or tetrahydrofuran, where tetrahydrofuran is preferred, at a temperature from about 10° to about 120° C., where 50° to 80° C. is preferred, in the presence or absence of a base, such as triethylamine, diisopropylethyl amine, an alkali metal hydroxide or an alkali metal carbonate, where cesium carbonate is preferred, where the group D of 14 can be F, Cl, Br, I, OC1-C4 alkyl, OH, or an activated carboxylic acid group derived from reaction of the acid with a standard carboxylic acid activating reagent such as, but not limited to, a carbodiimide (dicyclohexyl carbodiimide, 1-(3-dimethylaminopropyl) 3 -ethyl-carbo-diimide hydrochloride salt) or tripropylphosphonic anhydride, where D=Cl is preferred. R 9 and/or R 10 can be hydrogen, or an appropriately designed group known in the art which may be removed prior to cyclization such as a carbamate or phthalimide in which the phthalimide is preferred and removed prior to cyclization with hydrazine. Synthesis of 1d can be accomplished by reacting 4 and 12 in a solvent such as tetrahydrofuran, tert-butyl methyl ether, or 1,4-dioxane, where tetrahydrofuran is preferred, with an alkali metal amine base, such as sodium bis(trimethylsilylamide), potassium bis(trimethyl-silylamide), lithium bis(trimethylsilylamide), or lithium diisopropylamide, or an alkali metal hydride, such as sodium hydride or potassium hydride, where sodium bis(hexamethylsilylamide) is preferred, followed by the optional addition of diethylchlorophosphonate (in which case lithium diisopropyl amide is the preferred base) from about −30° to 100° C., preferably from −10° to 30° C. 1d can then be converted to 1e as described above. In the case where R 6 =benzyl or some other group that is labile towards hydrogenation conditions, the corresponding NH derivative (R 6 =H) is formed. If R 6 =H, further functionalization of the secondary amine can be carried out under standard alkylation or reductive amination conditions known to one skilled in the art. [0105] Alternatively, 12 can also be prepared by treatment of 11 with an appropriate oxidation reagent such as potassium permanganate and a quaternary ammonium salt where benzyltrimethylammonium chloride is preferred in a chlorinated solvent such as methylene chloride, dichloroethane, chloroform, where methylene chloride is preferred, at a temperature from about 25° to 160° C., where 30° to 60° C. is preferred. The synthesis of 11 can be accomplished by treating morpholine with an aryl or heteroaryl chloride bromide, iodide, or sulfonate, where the bromide is preferred, a base such as potassium phosphate, potassium carbonate, sodium carbonate, thallium carbonate, cesium carbonate, potassium tert-butoxide, lithium tert-butoxide, or sodium tert-butoxide, where sodium tert-butoxide is preferred, a phosphine ligand, where BINAP or triphenylphosphine is preferred, a palladium species, such as palladium(II)acetate or tris(dibenzylideneacetone)dipalladium(0) or the corresponding chloroform adduct, where tris(dibenzylideneacetone)dipalladium(0) is preferred, in an inert solvent such as 1,4-dioxane or toluene, where 1,4-dioxane is preferred, at a temperature from about 40° to about 160° C., where 80° to 120° C. is preferred. [0106] Another method for synthesizing compounds of formula 1d described in Scheme 2 starts from pyridylaldehyde 2b, where D=chloro or fluoro, where fluoro is preferred. Reacting 2b and 12 in a solvent such as tetrahydrofuran, tert-butyl methyl ether, or 1,4-dioxane, where tetrahydrofuran is preferred, with an alkali metal amine base, such as sodium bis(trimethylsilylamide), potassium bis(trimethylsilylamide), lithium bis (trimethyl-silylamide), or lithium diisopropylamide, or an alkali metal hydride, such as sodium hydride or potassium hydride, where sodium bis(hexamethylsilylamide) is preferred, followed by the optional addition of diethylchlorophosphonate (in which case lithium diisopropyl amide is the preferred base) from about −30° to about 100° C., preferably from −10° to 30° C., affords 1d. 1d can then be converted to 1e as described above. The aryl halides used in the coupling are prepared via the general methods outlined in U.S. Pat. No. 5,612,359 (Preparations 2-9); Guay, D., et al. Biorg. Med. Chem. Lett. 2002, 12,1457-1461; Sall, D. J., et al. J. Med. Chem. 2000, 43, 649-663; Olah, G. A., et al. J. Am. Chem. Soc. 1971, 93, 6877-6887; Brown, H. C. et al. J. Am. Chem. Soc. 1957, 79, 1906-1909; Nenitzescu, C., et al., I. J. Am. Chem. Soc. 1950, 72, 3483-3486; Muci, A. R.; Buchwald, S. L. Top. Curr. Chem .; Springer-Verlag: Berlin Heidelberg, 2002; 219,131-209; DE 19650708; Howard, H. R.; EP 104860; EP 0501579A; Wang, X., et al. Tetrahedron Lett., 2000, 41, pp. 4335-4338. In cases where an alcohol was present on the aryl halide, treatment of the alcohol with an alkali metal hydride or alkali metal hydroxide, such as sodium hydride, potassium hydride, sodium hydroxide, potassium hydroxide, or cesium hydroxide, where sodium hydride is preferred, in a solvent such as tetrahydrofuran, N,N-dimethylformamide, or dimethylsulfoxide, where tetrahydrofuran is preferred, at a temperature from about −20° to about 50° C., followed by addition of an alkyl halide or tosylate, where an alkyl iodide is preferred, affords the corresponding ether. [0107] Examples of specific compounds of Formula 1 are the following: EXAMPLE 1 1-[4-(3,5-Dimethyl-isoxazol-4-yl)-phenyl]-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmeth-ylene]-piperidin-2-one EXAMPLE 2 2-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethylene]-4-[4-(tetrahydro-pyran-4-yl)-phen-yl]-morpholin-3-one EXAMPLE 3 1-[4-(3,5-Dimethyl-isoxazol-4-yl)-phenyl]-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmeth-yl]-piperidin-2-one EXAMPLE 4 2-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-4-[4-(tetrahydro-pyran-4-yl)-phenyl]-morpholin-3-one EXAMPLE 5 1-[4-(2-Methyl-oxazol-4-yl)-phenyl]-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-piperidin-2-one EXAMPLE 6 1-[4-(2-tert-Butyl-oxazol-4-yl)-phenyl]-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-piperidin-2-one EXAMPLE 7 1-[4-(2-Isopropyl-oxazol-4-yl)-phenyl]-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-piperidin-2-one EXAMPLE 8 1-[4-(2,5-Dimethyl-oxazol-4-yl)-phenyl]3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmeth-yl]-piperidin-2-one EXAMPLE 9 3-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-1-[4-(tetrahydro-pyran-4-yl)-phen-yl]-piperidin-2-one EXAMPLE 10 3-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-1-[4-(tetrahydro-pyran-4-yl)-phenyl]-pyrrolidin-2-one EXAMPLE 11 3-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-1-(4-oxazol-2-yl-phenyl)-pyrrolidin-2-one EXAMPLE 12 [2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-1-(4-oxazol-4-yl-phenyl)-pyrrolidin-2-one EXAMPLE 13 3-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-1-(4-oxazol-5-yl-phenyl)-pyrrolidin-2-one EXAMPLE 14 1-[4-(2-Methyl-oxazol-4-yl)-phenyl]-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-pyrrolidin-2-one EXAMPLE 15 1-[4-(1-Methoxy-cyclobutyl)-phenyl]-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-piperidin-2-one EXAMPLE 16 3-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-1-(4-trifluoromethyl-phenyl)-pyrrolidin-2-one EXAMPLE 17 1-[4-(1-Hydroxy-cyclopentyl)phenyl]-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-pyrrolidin-2-one EXAMPLE 18 1-[4-(1-Hydroxy-1-methyl-ethyl)-phenyl]-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-pyrrolidin-2-one EXAMPLE 19 1-(4-tert-Butyl-phenyl)-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-pyrrolidin-2-one EXAMPLE 20 1-[4-(1-Hydroxy-cyclopentyl)-phenyl]-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-piperidin-2-one EXAMPLE 21 1-(4-tert-Butyl-phenyl)-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-piperidin-2-one EXAMPLE 22 3-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-1-phenyl-piperidin-2-one EXAMPLE 23 3-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-1-(4-trifluoromethoxy-phenyl)-piperidin-2-one EXAMPLE 24 11-[4-(1-Hydroxy-1-methyl-ethyl)-phenyl]-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-yl-methyl]-piperidin-2-one EXAMPLE 25 1-[4-(1-Hydroxy-cyclobutyl)-phenyl]-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-piperidin-2-one [0108] Preparation 1 [0109] 2-(4-Methyl-piperazin-1-yl)-pyridine-3-carbaldehyde. A mixture of 1-methylpiperazine (12.8 mL, 120 mmol), potassium carbonate (13.6 g, 99 mmol), and 2-chloro-pyridine-3-carbaldehyde (9.3 g, 66 mmol) in water (75 mL) and 1,4-dioxane (33 mL) was heated at 100° C. for 18 h. The solution was cooled to room temperature, poured into water and extracted with methylene chloride. The combined organic layers were dried (Na 2 SO 4 ) and concentrated to afford 13.2 g of an oil (98% yield). MS (AP/CI) 206.2 (M+1). 13 C NMR (100 MHz, CDCl 3 ) 46.3, 51.2, 55.2, 116.1, 119.6, 140.6, 152.7, 161.8, 190.1. [0110] Preparation 2: General Aldol Procedure [0111] 3-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethylene]-pyrrolidin-2-one. A solution of 10.0 g (49 mmol) of 2-(4-methyl-piperazin-1-yl)-pyridine-3-carbaldehyde and 6.2 g (49 mmol) of N-acetylpyrrolidinone in 100 mL of tetrahydro-furan was slowly added to a 0° C. suspension of 6.45 g (161 mmol, 60% by weight) of sodium hydride in 100 mL of tetrahydrofuran over a 30 minute period. After the addition was complete, the mixture was stirred 10 min at 0° C. and then stirred at room temperature for 18 h. The reaction mixture was quenched into water and extracted with methylene chloride. The organic layer was dried with sodium sulfate and concentrated to provide a yellow solid. Recrystallization from ethyl acetate provided 4.9 g (37% yield) of the title compound as a white solid. MS (AP/CI) 273.3 (M+H). 13 C NMR (100 MHz, CDCl 3 ) 26.3, 39.9, 46.3, 50.4, 55.3, 116.7, 121.7, 127.2, 130.8, 137.0, 147.7, 161.3, 172.6. [0112] Preparation 3 [0113] 3-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethylene]-piperidin-2-one. The title compound was prepared in a procedure analogous to that described in Preparation 2. MS (AP/CI) 287.3 (M+H). 13 C NMR (100 MHz, CDCl 3 ) 23.2, 26.6, 42.5, 46.3, 50.0, 55.4, 116.1, 121.4, 129.0, 133.4, 138.4, 147.6, 161.0, 166.5. [0114] Preparation 4 [0115] 1-[4-(3,5-Dimethyl-isoxazol-4-yl)phenyl]-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmeth-ylene]-piperidin-2-one. The title compound was prepared in a procedure analogous to that described in Preparation 2. MS (AP/CI) 458.2 (M+H). 13 C NMR (100 MHz, CDCl 3 ) 11.0, 11.8, 23.6, 27.1, 46.3, 49.9, 51.5, 55.4, 116.1, 116.3, 121.6, 126.6, 128.8, 129.3, 129.8, 134.0, 138.2, 143.1, 147.6, 158.8, 161.0, 164.9, 165.5. [0116] Preparation 5: General Aldol Procedure for Morpholinones [0117] 2-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethylene]-4-[4-(tetrahydro-pyran-4-yl)-phen-yl]-morpholin-3-one. A solution of of 2-(4-methyl-piperazin-1-yl)pyridine-3-carbaldehyde (196 mg, 0.96 mmol) and 4-[4-(tetrahydro-pyran-4-yl)-phenyl]-morpholin-3-one (300 mg, 1.1 mmol) in 10 ml tetrahydrofuran was added to a suspension of 115 mg of NaH (2.9 mmol, 60% by weight) in 5 ml tetrahydrofuran. The resulting mixture was heated at 65° C. for 18 h. After quenching into water, the mixture was extracted three times with dichloromethane. The combined organic extracts were dried with Na 2 SO 4 and concentrated to an oil. Recrystallization from ether afforded 240 mg of the title compound as a tan solid (56% yield). MS (AP/CI) 449.3 (M+H). 13 C NMR (100 MHz, CDCl 3 ) 34.1, 41.4, 46.3, 49.3, 50.6, 55.5, 64.6, 68.5, 110.1, 117.1, 120.6, 125.3, 127.8, 138.4, 140.1, 144.8, 147.0, 159.8, 161.2. [0118] Preparation 6: General Hydrogenation Procedure [0119] 3-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-pyrrolidin-2-one. To a solution of 4.4 g (16.1 mmol) of 3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmethylene]-pyrrolidin-2-one in 200 mL of ethanol was added 1.1 g of 10% Pd/C. Hydrogenation at 45 psi with heating at 50° C. was complete after 24 h. The reaction was filtered over celite using ethanol and concentrated to 4.4 g (99% yield) of the title compound as an oil. MS (AP/CI) 275.3 (M+H). 13 C NMR (100 MHz, CDCl 3 ) 27.4, 32.3, 40.6, 41.4, 46.4, 50.6, 55.6, 118.8, 127.4, 138.5, 146.2, 162.3, 180.2. [0120] Preparation 7 [0121] 3-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-piperidin-2-one. The title compound was prepared in a procedure analogous to that described in Preparation 6. MS (AP/CI) 289.3 (M+H). 13 C NMR (100 MHz, CDCl 3 ) 21.3, 25.4, 32.8, 41.2, 42.3, 46.1, 50.4, 55.4, 118.8, 127.6, 138.7, 145.9, 162.2, 174.9. [0122] Preparation 8 [0123] 1-[4-(3,5-Dimethyl-isoxazol-4-yl)phenyl]-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmeth-yl]-piperidin-2-one. The title compound was prepared in a procedure analogous to that described in Preparation 6. MS (AP/CI) 460.3 (M+H). 13 C NMR (100 MHz, CDCl 3 ) 11.1, 11.8, 22.3, 26.2, 33.8, 42.2, 46.4, 50.6, 51.7, 55.7, 116.3, 118.8, 126.7, 127.6, 128.9, 129.9, 139.1, 142.9, 146.2, 158.9, 162.3, 165.6, 172.7. [0124] Preparation 9: General Hydrogenation Procedure for Morpholinones [0125] 2-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-4-[4-(tetrahydro-pyran-4-yl)-phenyl]-morpholin-3-one. To a solution of 2-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmethylene]-4-[4-(tetrahydro-pyran-4-yl)-phenyl]-morpholin-3-one (140 mg, 0.31 mmol) in 40 mL of ethanol was added 140 mg of 10% Pd/C. After hydrogenation at 40 psi for 18 h, additional 10% Pd/C (140 mg) was added. Hydrogenation at 40 psi was complete after another 18 h. The mixture was filtered over Celite using ethanol and concentrated to an oil. Purification by silica gel flash column chromatography (88:12, dichloromethane: methanol) afforded 25 mg of the title compound as an oil (18% yield). MS (AP/CI) 451.3 (M+H). 13 C NMR (100 MHz, CDCl 3 ) 33.9, 34.1, 41.4, 46.3, 50.5, 50.6, 55.6, 62.9, 68.5, 77.6, 118.6, 125.9, 126.1, 127.9, 139.2, 140.0, 145.1, 146.4, 162.1, 168.9. [0126] Preparation 10 4-[4-(Tetrahydro-pyran-4-yl)-phenyl]-morpholin-3-one [0127] Step 1: 4-[4-(Tetrahydro-pyran-4-yl)-Phenyl]-morpholine. The title compound was prepared in a procedure analogous to that described in Buchwald et al. MS (APCI) 248.2 (M+H). Diagnostic 13 C NMR (100 MHz, CDCl 3 ) 34.3, 40.8, 49.8, 67.2, 68.7, 116.1, 127.6. [0128] Step 2: 4-[4-(Tetrahydro-pyran-4-yl)-phenyl]-morpholin-3-one. 4-[4-(Tetrahydro-pyran-4-yl)-phenyl]-morpholine (2.37 g, 9.6 mmol), potassium permanganate (4.54 g, 29 mmol) and benzyltriethylammonium chloride (6.59 g, 29 mmol) were combined in dichloromethane (60 ml). After heating 4 h at 45° C., the cooled reaction mixture was quenched with aqueous sodium bisulfite and extracted three times with dichloromethane. The combined organic extracts were dried (Na 2 SO 4 ) and concentrated to an oil. Purification by silica gel chromatography afforded the title compound as a white foam (600 mg, 24% yield). MS (APCI) 262.2 (M+H). 13 C NMR (100 MHz, CDCl 3 ) 34.0, 41.4, 49.9, 64.3, 68.5, 68.8, 125.8, 127.9, 139.7, 145.0, 166.9. [0129] Preparation 11 [0130] 1-[4-(3,5-Dimethyl-isoxazol-4-yl)phenyl]-Piperidin-2-one. 1-(4-Iodo-phenyl)-piperidin-2-one (1.1 g, 3.7 mmol), potassium phosphate (1.57 g, 7.4 mmol), tetrakis (triphenylphosphine)palladium (0) (214 mg, 0.19 mmol) and 3,5-dimethyloxazole-4-boronic acid (780 mg, 5.5 mmol) were combined in 25 mL dioxane. After heating at 90° C. for 18 h, the cooled reaction mixture was poured in aqueous sodium bicarbonate and extracted with dichloromethane. The combined organic extracts were dried (Na 2 SO 4 ) and concentrated to an oil. Purification by silica gel chromatography (4:96, methanol:dichloromethane) afforded 340 mg of the title compound as an oil (34% yield). 1 H NMR (400 MHz, CDCl 3 ) □1.88-1.94 (m, 4H), 2.23 (s, 3H), 2.36 (s, 3H), 2.53 (t, 2H, J=6.2 Hz), 3.62-3.65 (m, 2H), 7.22 (d, 2H, J=8.4 Hz), and 7.29 (d, 2H, J=8.4 Hz). MS (APCI) 271.2 (M+1). [0131] Aryl Halides [0132] In cases where an alcohol was present on the aryl halide, treatment of the alcohol with an alkali metal hydride or alkali metal hydroxide, such as sodium hydride, potassium hydride, sodium hydroxide, potassium hydroxide, or cesium hydroxide, where sodium hydride is preferred, in a solvent such as tetrahydrofuran, N,N-dimethyl-formamide, or dimethylsulfoxide, where tetrahydrofuran is preferred, at a temperature from about −20° to about 50° C., followed by addition of an alkyl halide or tosylate, where an alkyl iodide is preferred, affords the corresponding ether. [0133] Preparation 12 [0134] 2-(4-Bromo-phenyl)-propan-2-ol. A solution of methyl p-bromobenzoate (3 g, 13.2 mmol) in tetrahydrofuran (14 mL) cooled to −30° C. was treated dropwise with methyl magnesium bromide (1 M in diethyl ether, 105.5 mmol, 105.5 mL). Upon completion of addition, the resulting suspension was allowed to warm to room temperature and was stirred for 5 h. Saturated aqueous ammonium chloride (100 mL) was added slowly and the mixture was diluted with ethyl acetate (100 mL). The organic and aqueous layers were separated and the aqueous layer was extracted with ethyl acetate (3×50 mL). The combined organic layers were dried over magnesium sulfate, were filtered, and the solvent was removed in vacuo. Purification by silica gel chromatography (10:1 hexanes—ethyl acetate) gave 2.2 g (79% yield) of 2-(4-bromo-phenyl)-propan-2-ol. 13 C NMR (100 MHz, CDCl 3 ) d 148.4, 131.4, 126.6, 120.8, 72.5, 31.9; MS (AP/CI) 197.1, 199.1 (M+H)+. [0135] Preparation 13 [0136] 2-(5-Bromo-pyridin-2-yl)-propan-2-ol. The title compound was prepared using ethyl-5-bromo-2-carboxypyridine, but otherwise followed the general procedure for Preparation 12. 13 C NMR (100 MHz, CDCl 3 ) d 165.1, 148.9, 139.7, 120.4, 118.9, 72.2, 30.7; MS (AP/CI) 216.0, 218.1 (M+H)+. [0137] Preparation 14 [0138] 1-(4-Bromo-phenyl)-cyclopentanol. The title compound was prepared using the procedure detailed for Preparation 12. 1 H NMR (400 MHz, CDCl 3 ) d 7.44 (d, J=8.3 Hz, 2H), 7.35 (d, J=8.7 Hz, 2H), 1.9 (m, 6H), 1.8 (m, 2H), 1.75 (s, 1H); 13 C NMR (100 MHz, CDCl 3 ) d 146.4, 131.4, 127.2, 120.8, 83.4, 42.2, 24.1. [0139] Preparation 15 [0140] 1-(4-Bromo-phenyl)-cyclobutanol. The title compound was prepared using the procedure detailed for Preparation 12. 13 C NMR (400 MHz, CDCl 3 ) d 145.5, 131.7, 127.1, 121.3, 76.8, 37.2, 13.2; MS (AP/CI) 209.0, 211.0 (M+H−H2O)+. [0141] Preparation 16 [0142] 4-(4-Bromo-phenyl)-tetrahydro-pyran-4-ol. The title compound was prepared using the procedure detailed for Preparation 12. 13 C NMR (100 MHz, CDCl 3 ) d 38.8, 63.9, 70.6, 121.3, 126.6, 131.7, 147.4. [0143] Preparation 17 4-(4-Bromophenyl)-tetrahydropyran [0144] A solution of 4-(4-bromo-phenyl)-tetrahydro-pyran-4-ol (859 mg, 3.3 mmol) and triethylsilane (596 μL, 3.7 mmol) in 12 mL dichloromethane was chilled in an ice bath. Trifluoroacetic acid (2.54 mL, 33 mmol) was added in a dropwise manner over 20 min. After 1 h at 0° C. the reaction mixture was stirred at room temperature for 3 h. 1N aqueous NaOH was added until the aqueous pH remained basic, and the mixture was extracted three times with dichloromethane. The organic extracts were combined, dried (Na 2 SO 4 ) and concentrated to an oily solid. Purification by silica gel chromatography (5:95, ethyl acetate:hexanes) afforded the title compound as a white solid (640 mg, 80% yield). 13 CNMR (100 MHZ, CDCl 3 ) 34.0, 41.3, 68.5, 120.2, 128.7, 131.8, 145.0. [0145] Preparation 18 [0146] 1-Bromo-4-(1-methoxy-1-methylethyl)-benzene. 2-(4-Bromo-phenyl)propan-2-ol (Preparation 17, 1.77 g, 8.2 mmol) and methyl iodide (0.5 mL, 8.2 mmol) in tetrahydrofuran (100 mL) were treated with sodium hydride (60% dispersion in mineral oil, 328 mg, 8.2 mmol). The mixture was stirred for 24 h at room temperature, was poured into 0.5 M aqueous hydrochloric acid, and the mixture was extracted with ethyl acetate. The organic layer was washed with brine, was dried over magnesium sulfate, was filtered, and the solvent was removed in vacuo. The residue was purified by silica gel chromatography (200:1 hexanes-ethyl acetate) to afford 500 mg (27% yield) of the title compound. 13 C NMR (100 MHz, CDCl 3 ) d 145.4, 131.5, 127.9, 121.0, 76.7, 50.9, 28.1; MS (AP/CI) 197.0, 199.0 (M+H−OMe)+. [0147] Preparation 19 [0148] 1-Bromo-4-(1-methoxy-cyclobutyl)-benzene. The title compound was prepared using the procedure detailed for Preparation 17. 13 C NMR (100 MHz, CDCl 3 ) d 142.5, 131.6, 128.4, 121.4, 81.3, 50.8, 33.0, 13.1; MS (AP/CI) 209.1, 211.1 (M+H−OMe)+. [0149] Preparation 20 [0150] 5-Bromo-2-ethoxy-pyridine. A solution of freshly prepared sodium ethoxide (sodium, 4.9 g, 210 mmol; absolute ethanol, 100 mL, room temperature) was treated with 2,5-dibromopyridine (10 g, 42 mmol) and was heated at reflux for 18 h. After cooling to room temperature, the mixture was poured into aqueous saturated sodium bicarbonate solution, was extracted with diethyl ether, and the ether layer was washed with brine, was dried over magnesium sulfate, was concentrated in vacuo. Purification by silica gel chromatography (100:1 hexanes-ethyl acetate) gave 7.5 g (88% yield) of the title compound. 13 C NMR (100 MHz, CDCl 3 ) d 162.9, 147.7, 141.2, 112.9, 111.6, 62.3, 14.7; MS (AP/CI) 202.1, 204.1 (M+H)+. [0151] Preparation 21 [0152] 4-(4-Bromo-phenyl) 4 -methyl-tetrahydro-pyran. The title compound was prepared in a similar fashion as described in EP0501579A1 3 C NMR (100 MHz, CDCl 3 ) 29.2, 35.8, 37.7, 37.8, 64.6, 119.9, 127.7, 127.8, 131.7. [0153] Preparation 22 3-(4-Bromo-phenyl) 3 -methyl-oxetane [0154] Step 1: 2-(4-Bromo-phenyl)-2-methyl-malonic acid diethyl ester [0155] Sodium methoxide (5.96 g, 110.4 mmol) was added to a 0° C. solution of 2-(4-bromo-phenyl)malonic acid diethyl ester (29 g, 92 mmol) in ethanol (200 mL). After 15 min iodomethane (6.9 ml, 110.4 mmol) was added slowly. The reaction mixture was warmed to room temperature and stirred 18 h. Additional portions of iodomethane (1.1 ml, 22 mmol) and sodium methoxide (1.0 g, 22 mmol) were added and the mixture was stirred 66 h. After quenching into water the mixture was extracted three times with ethyl acetate. The combined organic extracts were dried (MgSO 4 ) and concentrated to provide 16.8 g of the title compound as an oil (55% yield). 1 H NMR (400 MHz, CDCl 3 ) 1.23-1.25 (m, 6H), 1.83 (s, 3H), 4.19-4.25 (m, 4H), 7.25 (d, 1H, J=7.4 Hz), 7.46 (d, 1H, J=7.4 Hz). [0156] Step 2: 2-(4-Bromo-phenyl)-2-methyl-propane-1,3-diol [0157] A solution of 2-(4-bromo-phenyl)-2-methyl-malonic acid diethyl ester (10 g, 30.3 mmol) in 100 mL diethyl ether was added in a dropwise fashion to a 0° C. solution of 1.0 M lithium aluminium hydride (45 mL, 45 mmol) in 200 mL diethyl ether. After 30 min the reaction was warmed to 40° C. and heated for 4 h. After cooling to 0° C. and quenching with aqueous saturated sodium sulfate, the reaction mixture was filtered through Celite and concentrated to a thick oil. Purification by silica gel chromatography (1:1, ethyl acetate:hexanes) afforded 3.94 g of the title compound (53% yield). 13 C NMR (100 MHz, CDCl 3 ) 20.9, 44.3, 69.6, 120.8, 126.8, 128.8, 128.9, 131.8, 142.6. [0158] Step 3: 3-(4-Bromo-phenyl) 3 -methyl-oxetane [0159] Triphenylphosphine (3.6 g, 13.8 mmol) was added to a solution of 2-(4-bromo-phenyl)-2-methyl-propane-1,3-diol (1.69 g, 6.89 mmol) in 57 mL toluene. After stirring 5 min, N,N-dimethyldithiacarbonate (3.16 g, 10.34 mmol) and diethyl azodicarboxylate (2.17 mL, 13.79 mmol) were added and the resulting mixture was stirred at room temperature for 18 h. After filtering through Celite the mixture was concentrated to a solid. The crude product was purified by silica gel chromatography (1:19, ethyl acetate:hexanes) to afford 1.26 g of the title compound (81% yield). 13 C NMR (100 MHz, CDCl 3 ) 27.8, 43.3, 83.6, 120.3, 127.1, 131.8, 145.7. [0160] Preparation 23 [0161] General Procedure for the Copper-Mediated Coupling to Afford Compounds 1 of the Invention EXAMPLE 26 1-[4-(2-Methyl-oxazol-4-yl)phenyl]-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-piperidin-2-one [0162] A mixture of 3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-piperidin-2-one (170 mg, 0.59 mmol), 4-(4-bromo-phenyl)-2-methyl-oxazole (281 mg, 1.2 mmol), copper (I) iodide (45 mg, 0.24 mmol), potassium carbonate (166 mg, 1.2 mmol), and N,N′-dimethylthylendiamine (51 μl, 0.48 mmol) in toluene (1.5 mL) was stirred at 100° C. for 24 h. Copper (I) iodide (45 mg, 0.24 mmol) and N,N′-dimethylethylendiamine (51 μl, 0.48 mmol) were added and the reaction mixture was heated at 100° C. for an additional 24 h. The mixture was cooled to room temperature, poured into water and extracted with dichloromethane. The combined organic extracts were dried (sodium sulfate) and concentrated to provide 450 mg crude product. Purification by silica gel chromatography (12:88, methanol:dichloro-ethane) afforded 107 mg (41% yield) of the title compound. MS (AP/CI) 446.3 (M+H). 13 C NMR (100 MHz, CDCl 3 ) 14.2, 22.3, 26.2, 33.7, 42.3, 46.3, 50.5, 51.7, 55.6, 118.8, 126.3, 126.5, 127.8, 129.7, 133.5, 139.1, 140.3, 143.2, 146.1, 162.1, 162.3, 172.5. The enantiomers were separable by HPLC: 65/35 Heptane/Ethanol; Chiralpak AD, 5 cm×50 cm; 85 mL/min). Approximate retention times: t 1 =23 min; t 2 =33 min. [0163] The following compounds were made using the same general procedure as for Example 26. EXAMPLE 27 [0164] 1-[4-(2-tert-Butyl-oxazol-4-yl)-phenyl]-3-[2-(4-methyl-piperazin-1-yl)pyridin-3-ylmethyl]-piperidin-2-one: MS (AP/CI) 488.3 (M+H). 13 C NMR (100 MHz, CDCl 3 ) 22.3, 26.2, 28.8, 33.6, 34.0, 42.3, 46.4, 50.6, 51.7, 55.7, 118.8, 126.5, 127.8, 130.1, 133.1, 139.1, 139.9, 143.1, 146.1, 162.4, 171.8, 172.5. The enantiomers were separable by HPLC: 60/40 Heptane/Ethanol; Chiralpak AD, 5 cm×50 cm; 75 mL/min). Approximate retention times: t 1 =12 min; t 2 =20 min. EXAMPLE 28 [0165] 1-[4-(2-Isopropyl-oxazol-4-yl)-phenyl]-3-[2-(4-methyl-piperazin-1-yl)pyridin-3-ylmethyl]-piperidin-2-one: MS (AP/CI) 474.2 (M+H). 13 C NMR (100 MHz, CDCl 3 ) 20.7, 22.3, 26.1, 28.8, 33.6, 42.3, 46.4, 50.6, 51.7, 55.7, 118.8, 126.4, 126.5, 127.8, 129.9, 133.2, 139.1, 140.0, 143.1, 146.1, 162.3, 169.5, 172.5. EXAMPLE 29 [0166] 1-[4-(2,5-Dimethyl-oxazol-4-yl)-phenyl]-3-[2-(4-methyl-piperazin-1-yl)pyridin-3-ylmeth-yl]-piperidin-2-one: MS (AP/CI) 460.3 (M+H). 13 C NMR (100 MHz, CDCl 3 ) 12.0, 14.1, 22.3, 26.2, 33.7, 42.2, 46.4, 50.6, 51.7, 55.7, 118.8, 126.4, 127.4, 127.8, 131.0, 134.0, 139.1, 142.4, 143.8, 146.1, 159.3, 162.3, 172.5. The enantiomers were separable by HPLC: 60/40 Heptane/Ethanol; Chiralpak AD, 5 cm×50 cm; 75 mL/min). Approximate retention times: t 1 =13 min; t 2 =26 min. EXAMPLE 30 [0167] 3-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-1-[4-(tetrahydro-pyran-4-yl)-phenyl]-piperidin-2-one: MS (AP/CI) 449.5 (M+H). 13 NMR (100 MHz, CDCl 3 ) 22.3, 26.2, 33.7, 34.1, 41.4, 42.2, 46.2, 50.4, 51.9, 55.5, 68.6, 118.8, 126.4, 127.7, 127.8, 139.2, 141.8, 144.5, 146.1, 162.3, 172.5. The enantiomers were separable by HPLC: Methanol; Chiralpak AD, 10 cm×50 cm; 250 mL/min). Approximate retention times: t 1 =25 min; t 2 =44 min. EXAMPLE 31 [0168] 3-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-1-[4-(tetrahydropyran-4-yl)-phenyl]-pyrrolidin-2-one: MS (AP/CI) 435.5 (M+H). 13 C NMR (100 MHz, CDCl 3 ) 24.8, 32.9, 34.1, 41.2, 43.8, 46.4, 46.9, 50.6, 55.6, 68.5, 118.9, 120.1, 127.2, 127.3, 137.9, 138.7, 142.4, 146.3, 162.3, 175.4. EXAMPLE 32 [0169] 3-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-1-(4-oxazol-2-yl-phenyl)-pyrrolidin-2-one: MS (AP/CI) 418.4 (M+H). 13 C NMR (100 MHz, CDCl 3 ) 24.7, 33.0, 43.9, 46.4, 46.7, 50.7, 55.6, 118.9, 119.5, 123.5, 127.1, 127.2, 128.6, 138.7, 141.4, 146.4, 161.8, 162.2, 175.8. EXAMPLE 33 [0170] 3-[2-(4-Methyl-piperazin-1-yl)pyridin-3-ylmethyl]-1-(4-oxazol-4-yl-phenyl)-pyrrolidin-2-one: MS (AP/CI) 418.4 (M+H). 13 C NMR (100 MHz, CDCl 3 ) 24.8, 33.0, 43.9, 46.4, 46.8, 50.7, 55.6, 118.9, 119.9, 126.2, 127.0, 127.2, 133.7, 138.7, 139.5, 140.1, 146.4, 151.5, 162.3, 175.6. EXAMPLE 34 [0171] 3-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-1-(4-oxazol-5-yl-phenyl)-pyrrolidin-2-one: MS (AP/CI) 418.4 (M+H). 13 C NMR (100 MHz, CDCl 3 ) 24.7, 33.0, 43.9, 46.3, 46.7, 50.6, 55.5, 118.9, 119.9, 121.3, 123.9, 125.1, 127.1, 138.7, 139.9, 146.4, 150.5, 151.3, 162.2, 175.7. EXAMPLE 35 [0172] 1-[4-(2-Methyl-oxazol-4-yl)phenyl]-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-pyrrolidin-2-one: 13 C NMR (100 MHz, CDCl 3 ) 14.2, 24.8, 33.1, 43.9, 46.3, 46.8, 50.6, 55.6, 118.9, 119.9, 126.0, 127.2, 127.5, 133.2, 138.7, 139.3, 140.3, 146.4, 162.1, 162.2, 175.5. MS (AP/CI) 432.4 (M+H). EXAMPLE 36 [0173] 1-[4-(1-Methoxy-cyclobutyl)-phenyl]-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-piperidin-2-one: MS (AP/CI) 449.3 (M+H). 13 C NMR (100 MHz, CDCl 3 ) 13.1, 22.3, 26.2, 33.0, 33.1, 33.8, 42.1, 46.4, 50.6, 50.8, 51.8, 55.8, 81.4, 118.7, 126.1, 127.3, 127.7, 139.1, 141.7, 142.6, 146.1, 162.3, 172.6. [0174] Preparation 24 [0175] General Procedure for Palladium Mediated Coupling to Afford Compounds 1 of the Invention EXAMPLE 37 [0176] 3-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-1-(4-trifluoromethyl-phenyl)-pyrrolidin-2-one. 3-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-pyrrolidin-2-one (600 mg, 2.2 mmol), 4-bromobenzotriflouride (369 μL, 2.6 mmol), tris(dibenzylideneacetone)dipalladium (0) (100 mg, 0.11 mmol), 9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene (191 mg, 0.33 mmol) and cesium carbonate (1.08 g, 3.3 mmol) were combined in 4 ml dioxane and heated at 100° C. for 18 h. The cooled reaction mixture was then poured into water and extracted with dichloromethane. The combined organic extracts were dried (Na 2 SO 4 ) and concentrated to an oil. Purification by silica gel chromatography (8:92, methanol: dichloromethane) afforded 500 mg (54% yield) of the title compound as an oil. MS (AP/CI) 419.3 (M+H). 13 C NMR (100 MHz, CDCl 3 ) 24.7, 33.0, 43.8, 46.3, 46.6, 50.7, 55.6, 118.9, 119.2, 126.1, 126.2, 127.0, 138.7, 142.6, 146.5, 162.2, 176.0. [0177] The following compounds were prepared using the same general procedure as Example 37: EXAMPLE 38 [0178] 1-[4-(1-Hydroxy-cyclopentyl)phenyl]-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-pyrrolidin-2-one: MS (AP/CI) 435.3 (M+H). 13 C NMR (100 MHz, CDCl 3 ) 24.0, 24.8, 33.0, 42.0, 43.8, 46.2, 46.9, 50.5, 55.5, 83.4, 118.9, 119.7, 125.9, 127.2, 138.2, 138.7, 143.6, 146.4, 162.2, 175.5. EXAMPLE 39 [0179] 1-[4-(1-Hydroxy-1-methyl-ethyl)-phenyl]-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-pyrrolidin-2-one: MS (AP/CI) 409.3 (M+H). 13 C NMR (100 MHz, CDCl 3 ) 24.8, 32.0, 32.9, 43.8, 46.3, 46.9, 50.5, 55.5, 72.2, 118.9, 119.7, 125.2, 127.2, 138.0, 138.7, 145.9, 146.3, 162.2, 175.5. 50/50 Heptane/Ethanol; Chiralpak AD, 5 cm×50 cm; 75 mL/min). Approximate retention times: t 1 =25 min; t 2 =34 min. EXAMPLE 40 [0180] 1-(4-tert-Butyl-phenyl)-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-pyrrolidin-2-one: MS (AP/CI) 407.4 (M+H). 13 C NMR (100 MHz, CDCl 3 ) 24.8, 31.6, 32.9, 34.6, 43.8, 46.4, 46.9, 50.7, 55.6, 118.8, 119.7, 125.9, 127.3, 137.1, 138.6, 146.3, 147.7, 162.4, 175.3. The enantiomers were separated by HPLC: 75/25 Heptane/Isopropanol; Chiralpak AD, 5 cm×50 cm; 75 mL/min). Approximate retention times: t 1 =24 min; t 2 =32 min. EXAMPLE 41 [0181] 1-[4-(1-Hydroxy-cyclopentyl)-phenyl]-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmeth-yl]-piperidin-2-one: MS (AP/CI) 449.5 (M+H). 13 C NMR (100 MHz, CDCl 3 ) 22.3, 24.0, 26.2, 33.7, 42.1, 42.2, 46.4, 50.6, 51.9, 55.7, 83.5, 118.8, 126.1, 126.2, 127.8, 139.1, 142.3, 145.7, 146.1, 162.3, 172.6. EXAMPLE 42 [0182] 1-(4-tert-Butyl-phenyl)-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-piperidin-2-one: MS (AP/CI) 421.5 (M+H). 13 C NMR (100 MHz, CDCl 3 ) 22.3, 26.2, 31.6, 33.7, 34.7, 42.1, 46.4, 50.6, 51.8, 55.7, 118.7, 125.8, 126.3, 127.8, 139.1, 141.0, 146.1, 149.7, 162.3, 172.5. EXAMPLE 43 [0183] 3-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-1-phenyl-piperidin-2-one: MS (AP/CI) 365.4 (M+H). 13 C NMR (100 MHz, CDCl 3 ) 22.3, 26.2, 33.7, 42.2, 46.3, 50.5, 51.9, 55.6, 118.8, 126.4, 126.9, 127.8, 129.4, 139.1, 143.7, 146.1, 172.5. EXAMPLE 44 [0184] 3-[2-(4-Methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-1-(4-trifluoromethoxy-phenyl)-piperidin-2-one: MS (AP/CI) 449.4 (M+H). 13 C NMR (100 MHz, CDCl 3 ) 22.3, 26.2, 33.7, 42.1, 46.4, 50.7, 51.8, 55.7, 118.8, 121.9, 127.6, 127.8, 139.1, 142.1, 146.2, 162.4, 172.7. EXAMPLE 45 [0185] 1-[4-(1-Hydroxy-1-methyl-ethyl)-phenyl]-3-[2-(4-methyl-piperazin-1-yl)pyridin-3-ylmethyl]-piperidin-2-one: MS (AP/CI) 423.5 (M+H). 13 C NMR (100 MHz, CDCl 3 ) 22.3, 26.1, 31.9, 33.6, 42.2, 46.3, 50.5, 51.9, 55.6, 72.4, 118.9, 125.6, 126.0, 127.9, 139.2, 142.0, 146.1, 148.0, 162.3, 172.6. The enantiomers were separated by HPLC: 70/30 Heptane/Isopropanol/0.1% Trifluoroacetic acid; Chiralpak AD, 5 cm×50 cm; 75 mL/min). Approximate retention times: t 1 =19 min; t 2 =31 min. Additional silica gel chromatography required to remove olefin: 91.5: 8: 0.5, dichloromethane: methanol: ammonium hydroxide. EXAMPLE 46 [0186] 1-[4-(1-Hydroxy-cyclobutyl)-phenyl]-3-[2-(4-methyl-piperazin-1-yl)-pyridin-3-ylmethyl]-piperidin-2-one: MS (AP/CI) 435.5 (M+H). 1 H NMR (400 MHz, CDCl 3 ) □1.42-1.57 (m, 1H), 1.63-1.91 (m, 3H), 1.92-2.03 (m, 2H), 2.15 (br, 1H), 2.36 (s, 3H), 2.30-2.39 (m, 2H), 2.51-2.68 (m, 5H), 2.75 (dd, 1H, J=14.1 and 10.2 Hz), 2.93-3.01 (m, 1H), 3.08-3.25 (m, 4H), 3.50 (dd, 1H, J=14.2 and 3.7 Hz), 3.60-3.70 (m, 2H), 6.91 (dd, 1H, J=7.1 and 4.6 Hz), 7.26 (d, 1H, J=8.2 Hz), 7.49 (dd, 1H, J=7.5 and 1.7 Hz), 7.53 (d, 1H, J=8.3 Hz), and 8.20 (dd, 1H, J=4.9 and 1.6 Hz).

This invention is directed to compounds of Formula I and to pharmaceutical compositions comprising the compound of Formula I. where the dashed line represents an optional double bond; and where n is 1 or 2, and Ar 1 , Ar 2 , . . . and Z are as defined in the specification. The invention is also directed to a method of treating a disorder or condition that can be treated by altering serotonin-mediated neurotransmission, such as migraine, headache, cluster headache, anxiety, depression, etc. This invention is also directed to intermediates useful in the synthesis of compounds of Formula I.

RELATED APPLICATIONS [0001] This application claims priority from provisional application Ser. No. 60/927,164, filed May 1, 2007, which is incorporated by reference as if fully set forth herein. BACKGROUND [0002] Information can be a very valuable, and sometimes difficult to obtain, resource. Many who dwell in underprivileged areas do not have the financial resources to pay for Internet service, or to purchase a personal computer. This is unfortunate, because this is exactly the group that has the most need of accessing the Internet to obtain social services information. Many government offices are open only from 9 AM to 5 PM, potentially putting great stress on the working poor, who may have difficulty obtaining transportation to government facilities and being able to get time off from work to attend to tasks requiring contact with government agencies. Also, the lack of access to information also puts a stress on government agencies. They must spend more employee time on answering telephone calls to field questions that the caller could have found answers to on the Internet, if only the caller had Internet access. [0003] When a disaster strikes, however, even those who normally have Internet access can be deprived of this resource, due to an electric power outage, just at the moment when the need for information regarding the availability of resources may be at its greatest. Although great efforts may be launched to get food, water and shelter to these people, the need for information, for example, on the location and condition of loved ones, could be the greatest perceived need that person has. SUMMARY [0004] In a first separate aspect, the present invention may take the form of an information access kiosk including a computer assembly that provides a wireless internet connection and an energy storage assembly, capable of powering the computer. Also, a protective assembly is adapted to permit the kiosk to withstand attack of earthly elements when placed outside and a computer program, resident on the computer, is adapted to facilitate use of the computer to permit at least one anticipated use by a user. [0005] In a second separate aspect, the present invention may take the form of a method of providing social service information to the public, comprising providing a free-of-charge Internet terminal providing access to a select group of social service websites. BRIEF DESCRIPTION OF THE FIGURES [0006] FIG. 1 is a perspective view of an information access point (IAP) kiosk according to the present invention. [0007] FIG. 2 is a block diagram illustrating the power and electrical systems of the kiosk of FIG. 1 [0008] FIG. 3 is a perspective view of the kiosk of FIG. 1 , with a clam shell panel opened to reveal interior elements. [0009] FIG. 3A is a detail view of a closure element of the kiosk of FIG. 3 , the location of which is indicated by circle 3 A of FIG. 3 . [0010] FIG. 3B is a detail view of the battery tray of the kiosk of FIG. 3 , the location of which is indicated by circle 3 B of FIG. 3 . [0011] FIG. 3C is a detail sectional view of the roof of the kiosk of FIG. 3 , taken along line 3 C- 3 C of FIG. 3 . [0012] FIG. 4 is a perspective view of the kiosk of FIG. 1 , with the electrical cabinet cover removed, revealing interior electrical elements. [0013] FIG. 4A is a downwardly looking sectional view of the kiosk of FIG. 4 , taken along line 4 A- 4 A of FIG. 4 . [0014] FIG. 4B is a detail view of a portion of the kiosk of FIG. 4 , the location of which is indicated by circle 4 B- 4 B of FIG. 4 . [0015] Exemplary embodiments are illustrated in referenced attachments. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than restrictive. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0016] In a preferred embodiment, an Information Access Point (IAP) kiosk 10 includes a main body 12 , containing a power assembly 14 . A middle portion 20 includes an internet terminal computer 22 including a weatherproof keyboard 24 that includes a trackball, and a display monitor 26 , which together with two side display monitors 28 are all held in place by a set of oblique rail pairs 29 . All monitors 26 and 28 are protected by a sheet of transparent protective material, such as Plexiglas. An electrical and control assembly 30 ( FIG. 4 ) is protected by a canister 32 . Oblique rails 29 also support a roof 34 that supports a set of solar panels 36 . [0017] Kiosk 10 may be broken up into component pieces, none of which has a mass of more than 59 Kg (weight of 130 lbs). Accordingly kiosk 10 can be shipped to a destination in a set of boxes (with each packed box having a mass of only about a Kg more than the weight of the packed component), so that it could be handled by a person equipped with a hand truck. Once at the desired location, it can be assembled and put into service by a pair of reasonably strong people in about an hour. Once assembled, it is self powered by a small, lightweight propane powered electrical generator 40 (supplied by a propane tank 41 ), eight batteries comprising a battery pack 42 (on a wheeled tray 43 ), and one solar panel 36 . Accordingly, the only external input is sunlight, used to slow the draining of the propane tank 41 and battery pack 42 . The fact that off-grid operation is possible (indeed generally the preferred mode), greatly expands the possible application of kiosk 10 . This is of particular benefit when kiosk 10 is used to facilitate disaster relief operations, as electrical power is frequently unavailable in an area that has been stricken with a disaster. In a preferred embodiment a power plug is provided to plug kiosk 10 into the electrical grid, where it is available. In an additional preferred embodiment kiosk 10 is always self-powered. [0018] In a preferred embodiment, kiosk 10 meets the National Electrical Manufacturers Association (NEMA) 4× standard for an enclosure that is watertight, dust tight and corrosion-resistant, for indoor and outdoor use. This standard is available on request from NEMA. Because of these design qualities, kiosk 10 may generally be left outside without damage to its internal components. [0019] Referring to FIG. 2 , a solar panel 36 , drives a charge controller 44 that produces a voltage appropriate for charging the battery pack 42 . An inverter 46 converts the power into standard 110 V, 60 Hz AC power, so that standard components can be used. An electrical monitoring unit 48 (in one preferred embodiment the model monitoring unit used is available from Bogart Engineering [www.bogartengineering.com] under the trademark “PentaMetric”) monitors the charge of the batteries and turns the generator on and off as needed, using a generator autostart component 50 . As well as monitoring charge of batteries, the monitoring unit 48 also monitors and reports data on the inverter 46 , the charge controller 44 and a tank level monitor 52 , which monitors the propane fuel tank 41 . A propane leakage monitor 56 prompts computer 22 to send an Email to maintenance personnel so that the kiosk can be serviced. An auditory alarm may sound under these circumstances to ward would-be users away from kiosk 10 . [0020] The resulting information feeds into the computer 22 , which is executing tracking software and which maintains a log of system activity. This enables internal components of kiosk 10 to be controlled and monitored via a remote network connection. Fans 57 located throughout the unit keep the equipment in the unit cool. A climate control device 58 is optional and is warranted if the kiosk 10 is to be placed in a hot location. Lights 70 are controlled by a proximity sensor 72 which recognizes when a person approaches the kiosk 10 and activates the lights in response. Additionally, the kiosk 10 includes a video camera 74 , controlled by the unit interface software and which allows users to create and send pictures or videos to family and friends. [0021] Internet connectivity to the unit is provided through a card 76 that connects to the internet through a cellular telephone system. Such systems are widely available, and in a preferred embodiment an account is prearranged with a cellular telephone provider to provide unlimited access to an Internet service provider 24 hours a day, 7 days a week anywhere within range of a cellular phone tower. In one preferred embodiment the card used for Internet connectivity is available through Sierra Wireless (Internet address www.sierrawireless.com) under the trademark “aircard.” [0022] In a preferred embodiment monitor 26 of computer 22 is used for viewing the Internet and the two side monitors 28 are used to display sponsor banner advertisements. In an alternative preferred embodiment two additional keyboards are provided and all. three monitors 26 and 28 are used for the Internet. [0023] The kiosk 10 user interface is programmed to default to a custom website, which is designed for a specific purpose. For survey taking applications, the website is configured to prompt user responses, whereas for a social services application, the website is configured to make those social services that are anticipated to be in demand in the deployment area readily and easily available. For a disaster relief application, the custom website would include a link to the most likely to be needed part of the Federal Emergency Management Agency (FEMA) and a website designed to match together separated persons. In a preferred embodiment user access is restricted to approved community interest and/or social services information websites, for example the FEMA website or the Social Security website. In an alternative preferred embodiment, the kiosk 10 would serve as a guide to local businesses. In another preferred embodiment the kiosk 10 would provide a listing of local events and sell tickets to these events. [0024] The kiosk 10 is made as secure as possible against vandalism. Towards this end, to gain physical access to the interior of the main body 12 of the kiosk 10 it is necessary to unfasten a number of special threaded fasteners 110 holding a top plate 112 in place. Threaded fasteners 110 can only be unfastened using a proprietary screw driver that is not generally available to the public. Once top plate 112 is removed, an aperture 114 provides access to a deadbolt lock 115 and lock bar 116 (shown removed) that is threaded through a locking hinge 118 , which keeps a pair of clam shell sides 130 of the kiosk main body 12 fastened together. Removing the lock bar 116 permits the clam shell sides 130 to be separated at locking hinge 118 and opened up. The back of the kiosk 10 has a secure door that houses fuel tank 41 . [0025] In an alternative preferred embodiment, a kiosk is provided that does not include the generator 40 and propane tank 41 , but relies entirely on solar panels 36 and batteries 42 for its supply of power. The principal reason for this is that propane is flammable and may not be permitted in unattended form in some areas. Also, there are some restrictions on the shipment of propane as a flammable substance. Accordingly, if it was desired to send a kiosk 10 to a third world country to provide Internet connectivity to a village, the shipment of the propane might present a significant obstacle. The wheels on battery pack 42 provide a substantial advantage in the case where there is no propane generator, as it makes it easier to replace drained batteries. In one preferred embodiment, kiosks 10 are kept in a state of readiness and deployed after a disaster, such as hurricane or earthquake strikes to enable victims to contact social services agencies more easily. In a preferred embodiment a government agency deploys the kiosks 10 , but in another preferred embodiment a nongovernmental organization, such as the Red Cross, deploys the kiosks 10 . In another preferred embodiment a for-profit sponsor would provide the kiosks 10 and use this as an advertising opportunity. In a preferred embodiment the terminals are decorated with advertising imagery and the side monitors are used for advertising display. In an alternative preferred embodiment, the main monitor is used to display the advertising of the IAP sponsor. In another preferred embodiment, the IAP is an internet terminal that is provided in a structure, to protect it from the weather. The IAP may also take the form of a standard personal computer, having a wireless Internet connection and being powered by a transportable generator. In yet another preferred embodiment, a wireless system is deployed in the disaster stricken area, prior to the deployment of the IAPs. [0026] In an additional preferred embodiment, the IAPs are deployed in areas in which many people do not have Internet terminals, to facilitate access to social service agencies, and other websites that would be beneficial to people who do not have Internet access from their homes. In a preferred embodiment, terminals are placed in lower socioeconomic status areas, where the need to make contact with and gain information about social welfare programs is the greatest. These terminals could include television camera surveillance, to prevent vandalism and to safeguard users. The availability of these terminals could also reduce telephone and office meeting time required from social service agencies, as the social service users could gain information over the Internet, rather than by telephoning the social service agency, or traveling to it. [0027] While a number of exemplary aspects and embodiments have been discussed above, those possessed of skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations as are within their true spirit and scope.

An information access kiosk includes a computer assembly, including a wireless internet connection and an energy storage assembly, capable of powering the computer. Also, a protective assembly is adapted to permit the kiosk to withstand the attack of earthly elements when placed outside and a computer program, resident on the computer, is adapted to facilitate use of the computer to permit at least one anticipated use by a user.

This is a continuation of application Ser. No. 07/266,201 filed Oct. 27, 1988 now abandoned, which is a continuation of Ser. No. 913,688, filed Sept. 30, 1986 now abandoned. FIELD OF THE INVENTION This invention relates to a pressure-sensitive adhesive film article. In particular, this invention relates to an article comprising a film of pressure-sensitive adhesive, which article is useful in the moist healing of wounds. BACKGROUND OF THE INVENTION In recent years, the technique of wound repair known as moist healing has become well established. It is an improvement in many cases over the traditional method of letting a wound dry out, forming a scab or crust over the surface, followed by regrowth of tissue underneath the scab. It has been found that, relative to dry healing, moist healing often results in cleaner repair, with less scarring and less pain to the patient than dry healing, especially when the wound is an extensive burn or large abrasion. Dressings for moist healing therapy are frequently made of thin films of synthetic polymers such as polyurethanes as described in U.S. Pat. No. 3,645,835. One of the characteristics of these films is their ability to selectively allow water molecules ("moisture vapor") to pass through them while preventing the passage of liquid water or aqueous solutions and, most importantly, bacteria. By careful selection of film and adhesive, a dressing can be provided which keeps a wound moist and sterile, but which allows excess liquid to evaporate. It also conforms well to the skin, and is unobtrusive in use. Such dressings, however, have several disadvantages when used with certain kinds of wounds. When a wound is seeping copiously the "moisture vapor transmission" (MVT) capability of the film cannot remove excess liquid fast enough. As a result, fluid may accumulate under the dressing which can result in skin maceration. In practice, a film of sufficiently high MVT to be useful as a dressing on highly exudative wounds would have to be too thin to be practical. Even film dressings in commercial use today are so thin and flimsy that they are extremely difficult to apply without special delivery means such as those described in U.S. Pat. Nos. 4,513,739, 4,598,004 and Canadian Patent No. 1,192,825. The problem of handling copiously-seeping wounds was addressed in U.S. Pat. No. 4,499,896 by providing a reservoir dressing with one or more extra layers of thin film, sealed together at their peripheries, to form pouches into which excess liquid can flow temporarily. These pouches or reservoirs have additional surface area through which moisture evaporation can take place. These dressings have found utility, but are clearly more complicated and costly than dressings made from a single film. Another disadvantage of conventional thin film dressings is that they provide very little mechanical cushioning to a wound. Wound protection against bumps and scrapes is not addressed by these thin dressings. Foam backings for wound dressings are known (e.g. Microfoam™ brand surgical tape, 3M Co.) where the foam provides a thicker, more conformable, more cushioning material than would be provided by the same weight of unfoamed backing. The backing of Microfoam™ brand surgical tape is open cell polyvinylchloride which is not a barrier for micro organisims. If the polyvinylchloride was made with closed cells, it would not have a sufficiently high MVT for moist wound healing without skin maceration. U.S. Pat. No. 4,559,938 (Metcalfe) discloses an adhesive dressing comprised of a backing and a conventional pressure-sensitive adhesive. The backing is a film formed from a blend of a continuous matrix of 1,2-polybutadiene and an incompatible polymer which forms a discrete particulate phase within the matrix. This film is stretched to introduce a plurality of small, preferably closed, voids in the film which nominally enhance the moisture vapor permeability of the film. It is believed that the moisture vapor permeability of the dressing (through film and adhesive) is too low to be used in moist wound healing without skin maceration. Thus, there exists a need for a wound dressing which provides controlled transmission and/or absorption of water vapor away from a wound so that the wound remains moist but not excessively so, and which is also thick and flexible enough to alleviate the need for elaborate delivery means and to provide mechanical cushioning of a wound. SUMMARY OF THE INVENTION According to the present invention, there is provided a pressure-sensitive adhesive article for use on skin comprising a continuous film of pressure-sensitive adhesive having dispersed therein a discontinuous gaseous phase contained within voids within said film, which gaseous phase constitutes at least 10 percent of the volume of said pressure-sensitive adhesive. The film has a moisture vapor transmission and absorbency sufficient to permit moist healing of wounded skin without skin maceration, e.g., an MVT of at least about 400 g/m 2 per 24 hours measured at 40° C. and 80% relative humidity differential. The adhesive film of the invention has cellular voids containing a gaseous phase to effect control of adhesive thickness and to provide a multiplicity of microreservoirs or micropouches. The film allows water vapor to pass at a controlled rate by diffusion of water vapor through the adhesive surrounding the voids and collection of water vapor in the voids, but prevents liquid media (e.g., water) and bacteria from traversing the film. This controlled diffusion of water vapor allows for the presence of an optimal amount of moisture at the site of a healing wound covered by the film. The cellular construction of the film also provides mechanical cushioning of the wound. In a preferred embodiment of the adhesive article of the invention, a film of cellular pressure-sensitive adhesive is in contact with one face of a conformable sheet. The conformable sheet preferably has high moisture vapor transmission i.e., at least about 1000 g/m 2 per 24 hrs at 40° C. and 80% humidity differential. Another aspect of this invention relates to a method of preparing a pressure-sensitive adhesive article as described above comprising: (a) forming a hydrophilic polymerizable composition which polymerizes to a pressure-sensitive adhesive state; (b) foaming said composition; (c) coating a carrier with said foamed composition; and (d) polymerizing said coating to a pressure-sensitive adhesive state. The hydrophilicity of the polymerizable composition may be provided by the inclusion of: (1) a hydrophilic, ethylenically unsaturated monomer, e.g., acrylic acid or an acrylate or acrylamide terminated polyether; (2) by a hydrophilic additive, e.g., a polyhydric polyol, or polyether; or (3) both a hydrophilic monomer and a hydrophilic additive. The degree of hydrophilicity required of the polymerizable composition is that degree which is sufficient to provide a pressure-sensitive adhesive having the desired degree of moisture vapor transmission. DETAILED DESCRIPTION The pressure-sensitive adhesive films of this invention must have a sufficiently high moisture vapor transmission and absorbency to permit moist healing of a wound without skin maceration. Moist healing is the retention at a wound of an optimum amount of moisture which (1) prevents the formation of a scab, (2) increases the rate of epithelial cell migration, and (3) does not allow pooling of moisture or wound exudate. Skin maceration is a deleterious effect of pooling of excess liquid, e.g., water or bodily fluid, on the normal skin surrounding a wound. Skin maceration is indicated by whitening and softening of the affected skin. In general, adhesive films of this invention having a moisture vapor transmission of at least about 400 g/m 2 per 24 hrs measured at 40° C. and 80% relative humidity differential are sufficiently absorptive and transmissive to avoid skin maceration and promote moist wound healing. The moisture vapor transmission is preferably at least about 500 g/m 2 per 24 hrs., and most preferably from about 600 to about 2400 g/m 2 per 24 hrs. The adhesive film useful in this invention is cellular, i.e., non-porous, such that it possesses substantially total impermeability to liquid water and bacteria. Moisture vapor transmission as referred to herein and in the claims, except as otherwise noted, refers to moisture vapor permeability determined in accordance with the test described below. Impermeable to liquid water as used herein means impermeable to liquid water as indicated by the dye penetration test described below. The adhesive film is rendered moisture vapor permeable and absorbent by the hydrophilicity of the adhesive composition and the cellular voids in the film. The thickness of the adhesive film, along with the hydrophilicity and the voids, affects the absorption capacity of the adhesive film. The adhesive film is rendered hydrophilic by the addition of hydrophilizing agents to the polymerizable premix from which the adhesive is prepared such as those described below. As used herein, "percent void volume" means that portion of the thickness of the cellular adhesive membrane attributable to cellular voids. Percent void volume is conveniently measured by the equation: ##EQU1## wherein d u is the unfoamed density and d f is the foamed density of the adhesive. Unfoamed density can be determined from the density of the starting materials or by compressing the foamed adhesive. Adhesive films according to the invention should have void volumes of from about 10 to about 85 percent. The higher the void volume of the adhesive film, the greater the MVT, absorbency, conformability, and cushioning ability of the dressing. The adhesive films of this invention possess useful absorbency in addition to their ability to transmit water vapor. When the film is composed of an adhesive having low absorbency, the difference in absorbency between the foamed state and the unfoamed is pronounced (See Examples 1-6). This effect is less pronounced in the case of adhesives which are already highly absorbent, but in both cases the end product has the ability to absorb significant quantities of water. The water is not easily removable from the foam by squeezing. This is a useful distinction from conventional reservoir dressings used on highly exudative wounds, wherein the contents of the reservoirs may leak out when the dressing is manipulated. Also, typical pressure-sensitive adhesive films of the invention have remarkably good flexibility and conformability which are advantageous properties in a wound dressing. The pressure-sensitive adhesive films of the invention are derived from a hydrophilic polymerizable premix into which cellular voids are introduced. The premix is made hydrophilic by the addition of a hydrophilizing agent such as a hydrophilic, ethylenically unsaturated monomer, a hydrophilic additive or both. Preferred hydrophilic additives are polyhydric alcohols, polyethers, or mixtures thereof. The polyhydric alcohol or polyether is present in the premix in an amount sufficient to raise the moisture vapor transmission of the adhesive to the desired level This amount ranges, in general, from about 20 to about 85 parts by weight of the premix, with about 30 to about 70 being preferred. Examples of useful polyhydric alcohols and polyethers include glycerin, propylene glycol, polypropylene oxide glycols, polyethylene oxide glycols, 1,2,4-butanetriol, and sorbitol and mixtures thereof. The dihydric alcohol, ethylene glycol is useful in the present invention, but may cause dermal reactions which limit its utility. The hydrophilizing agent may also have ethylenic unsaturation which will allow it to copolymerize with other free radically polymerizable materials in the premix as described below. For example, a polyether polyol can be terminated with acrylic or methacrylic acid, or a reactive derivative thereof, to yield an acrylate or methacrylate terminated polyether, e.g., poly(oxyethylene)acrylate. Also, an amine terminated polyether can be terminated with acrylic or methacrylic acid, or a reactive derivative thereof, to yield an acrylamide or methacrylamide terminated polyether, e.g, N-poly(oxypropylene)acrylamide. The premix is also comprised of an unsaturated free radically polymerizable material which when polymerized renders the premix pressure-sensitive adhesive, and which is preferably miscible with the hydrophilizing agent. This material may consist of a single monomer or a mixture of comonomers. These monomers or comonomers are present in the premix in amounts of from about 100 to about 10 parts by weight of the premix preferably from about 50 to about 20. Examples of useful monomers or comonomers are alkyl acrylates having an average of 4-12 carbon atoms in their alkyl groups, acrylic acid, methacrylic acid, and salts thereof, acrylamide, methacrylamide, hydroxyalkylacrylates, hydroxyalkylmethacrylates, acrylonitrile, methacrylonitrile, cyanoethylacrylate, maleic anhydride and N-vinyl pyrrolidone. It is preferred that the premix contain a plasticizing component which is conveniently provided by the polyether or polyol hydrophilic additive or the polyether- or polyol-containing monomer. The premix is also preferably comprised of a thickening agent of polymeric material which is preferably soluble in the polymerizable composition. These polymeric materials are present in the premix in amounts of about 0.1 to about 70 parts by weight of the premix. Examples of useful polymeric materials are sodium carboxymethyl cellulose, hydroxyethylcellulose, methoxyethyl cellulose, chitosan, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid, polyvinylethers, copolymers of maleic anhydride and polyvinylethers, starch, hydroxypropyl-cellulose, polyacrylamide, copolymers of alkyl acrylates and acrylic acid or its salts, polyethylenimine, ethylene oxide polymers and propylene oxide polymers. The adhesive film is preferably crosslinked. One means of crosslinking is the inclusion of a multi-ethylenically unsaturated, free radically polymerizable material, generally in an amount of from about 0.1 to about 5 parts by weight per 100 parts of the polymerizable materials in the premix. Examples are triethylene glycol-bis-acrylate, triethylene glycol bis-methacrylate, ethylene glycol-bis-acrylate, ethylene, glycol-bis-methacrylate, and methylene-bis-acrylamide. These multi-ethylenically unsaturated, free radically polymerizable materials crosslink the polymeric material. Other means of crosslinking include crosslinking the polymer with radiation, e.g., E-beam. Polymerization of the premix is carried out using conventional methods, e.g. ultra-violet radiation, heat, E-beam and the like. Polymerization by ultra-violet radiation or heat is facilitated by the presence of a free radical initiator which is soluble in the polymerizable composition. The initiator is generally present in an amount of at least about 0.01 parts by weight per 100 parts of the polymerizable materials in the premix. Examples of useful thermal initiators are benzoyl peroxide, azobisisobutyronitrile, di-t-butyl peroxide, and cumyl peroxide. Examples of useful photoinitiators are disclosed in the article "Photoinitiators--An Overview" by G. Berner et al in the Journal of Radiation Curing (April, 1979) pp. 2 through 9. The preferred photoinitiator is benzildimethylketal. It is often desirable to include a surfactant in the premix, preferably a silicone or fluorochemical surfactant. By doing so, the stability and density of the frothed premix are improved. These surfactants are not always necessary, but when used, are present, as shown in Table III, below, in amounts ranging from 0.5 to 6 parts by weight of the premix. Examples of useful surfactants are described in U.S. Pat. No. 4,415,615. A preferred fluorocarbon surfactant is available under the trade name FC 430, from the 3M Company. Filler materials can also be incorporated in the premix prior to frothing and coating of the premix or during coating of the premix, the amount of filler being dependent upon the type of filler material being used and the properties desired. Useful filler materials include fibrous reinforcing strands, woven and non-woven reinforcing fabrics, glass beads, plastic hollow microspheres or beads, viscosity-adjusting agents, pigments and absorbent particles. These may be used to enhance the internal strength of the adhesive film or to modify the adhesive and absorbent properties as shown in Example 22, below. The pressure-sensitive adhesive films of the invention may be prepared by the methods disclosed in U.S. Pat. No. 4,415,615, the disclosure of which is incorporated herein by reference thereto. In general, the process involves the polymerization of a premix containing voids to a pressure-sensitive adhesive state by conventional means. The cellular voids area preferably formed in the premix before coating the premix onto a carrier. The premix can be coated by any suitable means, which will not destroy the cellular voids in the foamed premix. Absorption capacity, conformability, MVT and cushioning may be controlled by varying the thickness of the adhesive film. Thickness of the adhesive film is determined by the dimensions of the aperture through which the frothed premix passes as it is being coated onto a carrier. Adhesive films having a thickness ranging from about 0.07 to about 1.7 mm are generally suitable. The minimum thickness of the adhesive film is dependent upon the maximum cell size generated in a particular film which is, in turn, determined by the processing conditions and chemical properties of the premix. For example, a surfactant-containing premix would result in an adhesive film with smaller cell diameters and could be coated thinner without the risk of discontinuities than a premix which does not contain surfactant. The maximum thickness is limited by the MVT desired and, as a practical matter, the amount of energy available to effect a complete cure. An adhesive film of the present invention is preferably made by the sequential steps of: (1) foaming a premix, (2) coating the foamed premix onto a carrier, and (3) polymerizing the coated premix in situ to a pressure-sensitive adhesive state. Foaming of the premix is conveniently accomplished by whipping a gas, e.g. air, into the premix as disclosed in U.S. Pat. No. 4,415,615. Foaming of the premix could also be accomplished by including a blowing agent in the premix which can be volatilized to produce cellular voids in the adhesive. Because the viscosity of a mixture of polymerizable monomers tends to be too low to provide a coatable froth or foam, several techniques have been used to thicken the mixtures before frothing or foaming, to provide a composition having a viscosity in the range of 1000 to 40,000 cps. One method is to add thickeners such as those described above to the polymerizable premix. Another method is to thicken the premix with a partially photopolymerized solution or syrup of isooctylacrylate (IOA) and acrylic acid (AA), or IOA and AA in polypropylene glycol. After coating the foamed composition onto a substrate, the polymerization can be initiated by ultraviolet radiation as taught in U.S. Pat. No. 4,181,752. in situ polymerization can also be effected by electron beam. Because air tends to quench photopolymerization, the foaming gas is preferably inert, such as nitrogen or carbon dioxide. When the polymerization is to be effected by ultraviolet radiation, the polymerizable coating is preferably protected from air by polymerization in an inert atmosphere or by the use of a plastic film overlay which is fairly transparent to ultraviolet radiation and has a low-adhesion surface. Biaxially-oriented polyethylene terephthalate film which is about 75% transparent to ultraviolet radiation is very useful as an overlay. If the underlying carrier also has a low-adhesion surface, both the carrier and the overlay can be stripped away so that the self-supporting adhesive film may be obtained. Normally, one does not wish to have an unprotected film of the adhesive at this point in production. In practice, one may either retain the original carrier and overlay or replace one or both (e.g. by lamination) with a liner or backing more suitable for the product. For example, one may wish to use a release liner or a backing bearing a logo, a decorative design, or instructions for use of the product. Ideally, the carrier and the plastic film overlay have sufficiently attractive appearance and properties of low adhesion to the adhesive film that they can be used as protective liners for each face of the adhesive through converting operations and, most preferably, until the final product reaches the hands of the user. For example, when the pressure-sensitive adhesive film is to be used as a means of attaching an ostomy appliance to the skin of a patient, it is desirable to have easy-release liners on each face which are removed sequentially. For example, one might attach the first face of the adhesive to the skin and then an appliance to the second, exposed face of the adhesive. When the adhesive film is used without a backing, it may be desirable to embed a layer of reinforcing material in the film to structurally support the film. This can be accomplished by coating a carrier with a layer of the polymerizable premix, laying down a layer of reinforcing material, e.g. a fabric, on the coating of premix and coating the exposed layer of reinforcing materials with another portion of polymerizable material. It may be necessary to polymerize the first coating of polymerizable premix before laying down and coating the layer of reinforcing material if the energy used to initiate polymerization radiates from a single source which is not sufficient to completely polymerize the premix throughout its entire thickness. When making a wound dressing, one face (the skin-contacting side) of the adhesive film is covered with an easy-release liner, which is removed immediately prior to use, but the other face is usually covered with a backing, i.e., a material which reduces or eliminates the tack of that face of the adhesive and which is permanently attached to the adhesive layer. The backing must not reduce the MVT of the dressing below the required level. A number of materials are suitable for this purpose. For example, a coating of a finely divided inert solid, e.g., talc, or a microporous non-woven fabric or plastic film, e.g., polyethylene, polyvinylchloride, etc. can be used. A very thin continuous film (e.g. ca 25 micrometers) of polyurethane, e.g., Estane™ available from B. F. Goodrich, is preferred as a backing. This polyurethane is a polyoxyethylene polyurethane which contributes to the high MVT. This film has several advantages. It is very soft, and conforms well to body contours. It possesses high moisture vapor transmission (ca 1500 gm/m 2 /hr), allowing absorbed water vapor to escape from the adhesive into the atmosphere. It is also impervious to bacteria. For use, a dressing of this invention is attached to a patient's skin over a wound. In the normal healing process, aqueous fluid-bearing cells, etc. needed for wound repair, will ooze from the damaged tissue. When the wound is of considerable size, excess fluid may be produced. As a result of fluid production a significant pressure will build up in the wound cavity. As described above, the adhesive film already possesses a significant moisture vapor transmission (MVT), so that water vapor from the wound exudate will begin to penetrate the film. As it penetrates, it can encounter one or more of the small voids or reservoirs in the adhesive film. The effective thickness of the dressing as seen by molecules of water vapor passing through the dressing, is controlled by the number of reservoirs the molecules encounter, and by the thickness of the solid zones traversed by the molecules. It will be appreciated that the absorption capacity of the film is dependent upon both the diffusion of water molecules into the solid zones, and the capacity of the reservoirs to contain liquid water which has diffused into them as vapor. A film with only a relatively small number of reservoirs and relatively large solid zones between reservoirs would have a lower MVT than a low density, closed-cell foam adhesive film, in which the solid zones between the reservoirs are very small. A dressing of the latter type will have very high MVT relative to conventional dressings of comparable thickness. As a result, dressings of the present invention can provide optimum MVT previously obtainable only with films that are too thin and flimsy to handle easily. There may be occasions when it would be desirable to include an extra, protective backing or embedded reinforcing layer, e.g., a fibrous and/or fabric filler as discussed above, when, for example, a dressing may be expected to be subjected to mechanical wear-and-tear. Such a backing or reinforcing layer need not be functional from the standpoint of controlling MVT, so long as it doesn't reduce the MVT of the dressing below the desired level. However, backing and reinforcing layers which affect MVT may be utilized to achieve the MVT properties desired in the dressing. EXAMPLES General Procedure For Frothing And Coating Adhesives The uncured adhesive and surfactant solutions were pumped simultaneously using two Zenith QM1416 metering systems, one system at a 20:1 ratio and the other at a 30:1 ratio, (Fenner DC Controllers) and two Zenith gear pumps (BMC 5334 and BPB 5566) through a 99 mm single-stage mixer (SKG Industries) with introduction of nitrogen gas. The resulting frothed premix was coated between two low-adhesion carriers, at least one of which was transparent to UV radiation. The thickness of the coating was controlled by a nip roll or knife. The coating was irradiated through the transparent film(s) with 15 watt fluorescent black lights having a maximum at 350 nm. Conditions for frothing and coating were as follows unless otherwise noted. ______________________________________Uncured adhesive flow rate 96 cc/min.Surfactant flow rate 4 cc/min.N.sub.2 flow rate 100 cc/min.Mixer Speed 300 rpmBack Pressure 211 g/cm.sup.2Adhesive Thickness 0.760 mmExposure 4 × 10.sup.6 ergs______________________________________ Following the curing process, one of the low-adhesion carriers was removed and the adhesive was laminated onto a 0.025 mm thick, polyoxyethylene polyurethane film backing prepared as follows. A one mil, i.e., 25 micron film of Estane™ 58309-021 polyurethane resin (B. F. Goodrich, Cleveland, Ohio) was extruded using a three-quarter inch (1.9 cm) Rheomex Model 252 screw extruder (manufactured by Haake, Saddlebrook, N.J.), a sheeting die and a melt temperature of 190° C. The film was extruded onto the back clay-coated side of a 78 pound (35412 grams) paper which was clay-coated on one side by roll coating (No. 70-05-04-000, Boise Cascade Corporation, International Falls, Minn.). Immediately after extrusion the paper/resin combination was passed through a nip roll at 80 psi (5624 grams per square centimeter). Premix Starting Materials The following materials were used to prepare the adhesives shown in the following examples. Thickeners Thickener A. A solution composed of 30 parts of isooctylacrylate, 30 parts of acrylic acid, 40 parts of polypropylene glycol-425 (PPG-425, Dow Chemical), and 0.04 parts "Irgacure" 651 (2,2-dimethoxy-2-phenylacetophenone, Ciba Geigy) was simultaneously purged with nitrogen gas and irradiated with fluorescent black lights until a temperature of 79° C. was attained. The exposure was then stopped and the reaction was quenched with air. The resulting syrup had a viscosity of 11,000 cps at 25° C. and contained 75% residual acrylate monomer. Thickener B. A solution containing 25 parts of isooctylacrylate, 25 parts of acrylic acid, 50 parts of polypropylene glycol 425 and 0.04 parts of "Irgacure" 651 was simultaneously purged with nitrogen gas and irradiated with fluorescent black lights until a temperature of 77° C. was attained. The irradiation was then stopped and the reaction was quenched with air. The resulting syrup had a viscosity of 6200 cps at 25° C. and contained 71% residual acrylate monomer. Thickener C. A solution containing 80 parts of isooctylacrylate, 20 parts of acrylic acid and 0.04 parts of "Irgacure" 651 was purged with nitrogen and irradiated with fluorescent black lights. The resulting syrup had a viscosity of 11,000 cps at 25° C. and contained 89% residual monomer. Thickener D. A solution containing 60 parts of glycerin and 40 parts of "Goodrite"K722 (a 37% aqueous solution of polyacrylic acid, MW 100,000, B. F. Goodrich) (PAA) was fed through a film extruder available from LUWA Co. at a rate of 100 lbs./hr., 160° F. and 5 mm Hg. The resulting syrup, consisting of 79.8% glycerin, 19.2% polyacrylic acid and 1.0% H 2 O, had a viscosity of 200,000 cps at 25° C. Thickener E. A solution containing 90 parts of isooctylacrylate, 10 parts of acrylic acid and 0.04 parts of "Irgacure" 651 was purged and irradiated as in C, above. The resulting syrup had a viscosity of 4330 cps at 25° C. Thickener F. Sodium carboxymethyl cellulose, Type 7H, Hercules, Inc. Thickener G. Polyvinylpyrrolidone K-90, GAF. Thickener H. Low viscosity chitosan from Protan Laboratories, Inc. Thickener I. A solution containing 80 parts of isooctylacrylate, 20 parts of acrylic acid and 0.04 parts of "Irgacure" 651 was simultaneously purged with nitrogen gas and irradiated with fluorescent black lights until a temperature of 67° C. was attained. The irradiation was then stopped and the reaction was quenched with air. The resulting syrup had a viscosity of 32,000 cps at 25° C. Photoinitiators Photoinitiator A: 2,2-dimethoxy-2-phenylacetophenone available as "Irgacure" 651 from Ciba-Geigy. Photoinitiator B: hydroxycyclohexyl phenyl ketone available as "Irgacure" 184 from Ciba-Geigy. Difunctional Monomers TGBM: Triethylene glycol bis-methacrylate available from Sartomer Company. EGBM: Ethylene glycol bis-methacrylate available from Sartomer Company. Surfactants Surfactant A. A solution of 70 parts of polypropylene glycol having a molecular weight of 425, 40 parts of a fluorosurfactant available as Fluorad™ FC171 from 3M and 60 parts of a fluorosurfactant available as Fluorad™ FC431 from 3M. Surfactant B. A solution of 50 parts of polypropylene glycol 425 and 100 parts of a fluorosurfactant available as Fluorad™ FC431 from 3M. Surfactant C. A solution of 50 parts of polypropylene glycol-425 and 50 parts of a fluorosurfactant available as Fluorad™ FC430 from 3M. Surfactant D. A solution of 50 parts of polypropylene glycol-425 and 50 parts of a fluorosurfactant available as Fluorad™ FC171 from 3M. Surfactant E. To a solution of 60 parts of a fluorosurfactant available as Fluorad™ FC431 from 3M and 40 parts of a fluorosurfactant available as Fluorad™ FC171 from 3M was added 30 parts of carbitol acetate. Under reduced pressure, 30 parts of ethyl acetate were removed by distillation. Test Methods The tests used to evaluate the samples and generate the results shown in Table 4 were accomplished as follows. Moisture Vapor Permeability A modified Payne cup method is used. The method comprises the following steps: (1) A 13/8 inch (35 mm) diameter sample of material to be tested containing no perforations is cut. (2) The sample is entered between the adhesive surfaces of two foil adhesive rings, each having a one inch (2.54 cm) diameter hole. The holes of each ring are carefully aligned. Finger presure is used to form a foil/sample/foil assembly that is flat, wrinkle-free and has no void areas in the exposed sample. (3) A 4 ounce glass jar is filled half full of distilled water. The jar is fitted with a screw on cap having a 1.50 inch diameter hole in the center thereof and with a 1.75 inch diameter rubber washer having a 1.12 inch diameter hole in its center. (4) The rubber washer is placed on the lip of the jar and the foil/sample assembly is placed on the rubber washer. The lid is then screwed loosely on the jar. (5) The assembly is placed in a chamber at 100° F. (38° C.) and 20 percent relative humidity for four hours. (6) The cap is tightened inside the chamber so the sample material is level with the cap (no bulging) and the rubber washer is in proper seating position. (7) The assembly is removed from the chamber and weighed immediately to the nearest 0.01 gram (initial weight -W 1 ). (8) The assembly is returned to the chamber for at least 18 additional hours. (9) The assembly is removed from the chamber and weighed immediately to the nearest 0.01 gram (final weight -W 2 ). (10) The water vapor transmission in grams of water vapor transmitted per square meter of sample area in 24 hours is calculated according to the following formula: ##EQU2## W 1 =initial weight (grams) W 2 =final weight (grams) T 2 =time (hours) When a 1/2 inch sample is tested, the formula is changed to the following: ##EQU3## (11) Three samples of each material should be run and the average taken. Absorbency To determine absorbency, a sample of the cured adhesive was initially weighed and then immersed in deionized water at room temperature for one hour. The sample was then retrieved and weighed again . Absorbency is reported as the difference in weight divided by the initial weight. Optimal absorbency varies greatly depending upon the intended use of the adhesive film. For use on intact skin, low absorbencies are acceptable. Highly exudative wounds require higher absorbency films. Absorption capacity of the film can be controlled by the thickness of the film. In general, an absorbency of at least 50% over 1 hour is preferred. 180° Peel Adhesion One inch (2.54 cm) wide test samples of the cured adhesive are self-adhered to the skin of a human volunteer under the weight of a 2.04-kg hard rubber roller, 2 passes in each direction. After 15 minutes dwell, 180° peel is measured by moving the free end of each tape away from the skin at a rate of about 0.5 cm per second (using a tensile tester). Samples were tested immediately after application (Initial) and at 6 hours after application (Final) and results reported. Preferred adhesives have an initial adhesion of at least about 5 g/cm, more preferably at least 10 g/cm and most preferably at least about 20 g/cm. The final adhesion is preferably less than double the initial adhesion. Density The density of the samples was measured by simply weighing a sheet of each sample and measuring the area and depth of the sheet to calculate volume. EXAMPLES 1-5 and Comparative Example A Examples 1-5 and Comparative Example A, summarized in Table I, below, were prepared by combining the thickener specified with additional isooctylacrylate ("IOA") and acrylic acid monomers ("AA") and polypropylene glycol ("PPG") to give the IOA:AA:PPG ratios (ratio includes copolymerized IOA and AA in thickener) and % solids (IOA-AA copolymer) indicated in Table I. "Irgacure" 651 was added at a level of 0.1% by weight. Triethylene glycol bis-methacrylate (TGBM) was added at the levels indicated and the mixture was mechanically stirred. The resulting solution was frothed in a 96:4 ratio with surfactant E, coated and cured as described in the "General Procedure". TABLE I__________________________________________________________________________Composition of Examples 1-5 and Comparative Example AMonomer-Solvent Thickener Solids TGBMExampleRatio (wt. %) (wt. %) (wt. %) Thickness (mm)__________________________________________________________________________1 IOA-AA-PPG A (69.3) 10.4 2.9 0.7622.5-22.5-552 IOA-AA-PPG A (69.3) 10.4 2.9 0.2522.5-22.5-553 IOA-AA-PPG C (50) 7.3 1.5 0.7640-20-404 IOA-AA-PPG C (44) 6.4 2.0 0.7635-25-405 IOA-AA-PPG C (50) 7.3 2.0 0.7640-20-40A IOA-AA E (100) -- -- 0.7690-10__________________________________________________________________________ EXAMPLES 6-18 Examples 6-18 were prepared by combining thickener D [an 80/20 glycerin-polyacrylic acid ("PAA") solution] with acrylic acid and glycerin to give the AA:glycerin:PAA ratio indicated in Table II. To this was added "Irgacure" 651 at a level of 0.1%, difunctional monomer TGBM or EGBM, and, optionally, lithium hydroxide as indicated, and the mixture was mechanically stirred. The resulting solution was frothed in combination with the surfactant indicated, coated and cured according to the "General Procedure". TABLE II__________________________________________________________________________Composition of Examples 6-18 DifunctionalEx. AA Glycerin PAA Monomer LiOH Surfactant ThicknessNo. (wt. %) (wt. %) (wt. %) (wt. %) (wt. %) (wt. %) (mm)__________________________________________________________________________ 6 25 67.5 7.5 TGBM (0.2) -- E (4) .762 7 25 67.5 7.5 TGBM (0.2) -- E (4) .330 8 25 67.5 7.5 TGBM (0.2) -- E (4) .127 9 30 60 10 TGBM (0.3) -- E (4) .76210 25 67.5 7.5 TGBM (0.2) -- C (4) .76211 25 67.5 7.5 TGBM (0.2) -- C (2) .76212 25 67.5 7.5 TGBM (0.2) -- C (1) .76213 25 67.5 7.5 TGBM (0.2) -- none .76214 25 67.5 7.5 TGBM (0.2) -- D (4) .76215 25 67.5 7.5 TGBM (0.2) -- A (4) .76216 25 67.5 7.5 TGBM (0.2) -- B (4) .76217 19.4 68.4 5.9 TGBM (0.2) 5.9 E (3) .76218 19.4 68.4 5.9 EGBM (0.2) 5.9 E (4) .762__________________________________________________________________________ Examples 11 and 12 were the same as Example 10 with the exception that the level of surfactant was varied. In Example 13, no surfactant was used. The absence of an effect from these variations upon the foamed density is shown in Table III. TABLE III______________________________________Foam Density of Examples 10-13 Surfactant C Foam DensityExample (wt. %) (g/cc)______________________________________10 4 0.5111 2 0.5312 1 0.5113 0 0.53______________________________________ EXAMPLE 19 To 1500 g of the uncured adhesive solution described in Example 6 was added 105 g of glass bubbles (Product #B-22-AS, 3M) with mechanical stirring. The suspension was frothed in 96:4 ratio with surfactant E, coated and cured according to the general procedure. EXAMPLE 20 To 900 g of the uncured adhesive solution described in Example 6 was added 63 g cross-linked polyvinylpyrrolidone (#85,648-7, Aldrich Chemical Company) with mechanical stirring. The resulting suspension was frothed, coated and cured according to the "General Procedure" in a 96:4 ratio with surfactant E. EXAMPLE 21 To a mechanically stirred solution of 875 g of glycerin, 375 g of H 2 O, 500 g of acrylic acid, 120 g of lithium hydroxide, 6.0 g of triethylene glycol bis-methacrylate, 1.0 g of Irgacure 651 and 1.0 g of methyl hydroquinone, an antioxidant hereinafter referred to as MEHQ, was added 50 g of sodium carboxymethyl cellulose (Type 7H, Hercules). The resulting solution having a viscosity of 6500 cps at 25° C. was frothed, coated and cured according to the General Procedure in a 96:4 ratio with surfactant E. EXAMPLE 22 To a mechanically stirred solution of 720 g of glycerin, 720 g of H 2 O, 400 g of acrylic acid, 2.0 g of Irgacure 184, 120 g of lithium hydroxide and 1.0 g of MEHQ was added 60 g of low viscosity chitosan (Protan Laboratories, Inc.). The resulting solution having a viscosity of 2000 cps was frothed, coated and cured according to the "General Procedure" in a 96:4 ratio with surfactant E. EXAMPLE 23 The uncured adhesive solution described in Example 14 was frothed according to the "General Procedure" in a 96:4 ratio with surfactant E and was coated in two 0.015" layers with a spun-bonded nylon fabric (1.0 oz., Cerex) sandwiched between the layers. The resulting multi-layer coating was cured according to the "General Procedure". The properties of the adhesives prepared in Examples 1-23 and Comparative Example A are shown in Table IV, below. TABLE IV__________________________________________________________________________Properties of Dressings with BackingsFoamed Unfoamed 180° Peel Adhesion VoidEx. MVT Absorbency MVT Absorbency Initial Final Density VolumeNo. (g/m.sup.2 - 24 h) (Percent) (g/m.sup.2 - 24 h) (Percent) (g/cm) (g/cm) (g/cc) (Percent)__________________________________________________________________________ 1 477 13.2 316 -- 27.5 36.6 0.915 15 2 411 10.0 283 7.9 34.6 49.2 0.903 17 3 299 17.5 141 4 27.6 21.6 0.946 12 4 266 13 166 9 20.9 19.7 0.952 14 5 291 17 183 5.7 -- -- 0.671 67 A 207 21 102 19 41.3 116 -- 42 6 921 1478 859 788 98.4 70.9 1.007 23.6 7 1198 6977 1059 4323 88.6 74 1.129 7.4 8 1179 9926 1202 6085 35.4 59.1 -- -- 9 1223 1519 1141 734 7.1 17.7 1.129 1310 1339 1023 1226 -- 88.6 82.6 1.025 21.514 1271 1259 1388 -- 72.8 87.4 1.068 18.315 1405 1651 1257 -- 74.8 69.7 1.019 21.716 1315 1191 1285 -- 66.9 71.7 0.995 23.717 1249 1837 1016 3601 88.9 118.7 -- --18 1083 4016 1029 4641 49.4 43.7 -- --19 1264 1937 936 908 54.3 88.6 0.84 15.420 1090 459 1032 427 44.5 61.0 1.03 18.621 1194 6383 1215 5379 0.98 9.06 1.08 14.622 1266 dissolved 1074 dissolved 7.3 12.4 0.616 45.223 1125 312 899 262 70.1 68.9 1.09 15.0__________________________________________________________________________ EXAMPLE 24 A sample was prepared as described in Example 6 with the following modification. During the coating process, the froth was coated directly onto the 0.01 inch thick polyurethane backing film described in the "General Procedure", and covered with a transparent low-adhesion liner. The General Procedure for curing provided a foamed adhesive with a polyurethane backing on a low-release liner. In this case, the additional step of laminating a backing to the cured adhesive was eliminated. EXAMPLE 25 A foamed pressure-sensitive adhesive in which the hydrophilizing component is covalently bonded into the polymer network can be prepared by the following procedure: To a solution of 300 g of Thickener I, 100 g of acrylic acid, 5.0 g of TGBM and 2 g of Irgacure 651, add 600 g of a polyoxyalkyleneacrylate. (A polyoxyalkyleneacrylate can be obtained by adding dropwise, 155 g of 2-isocyanatoethylmethacrylate to a nitrogen purged solution of 4 drops of dibutyltindilaurate and 2170 g of an amine-functional poly(alkylene oxide) having the formula (CH 3 OCH 2 CH 2 O(CH 2 CH 2 O) n (CH 2 (CH 3 )CHO) m CH 2 (CH 3 )CHNH 2 where n/m=2/32, (available as Jeffamine M-2005 from the Texaco Chemical Company), and heating to 35° C. for 2 hours.) The resulting adhesive premix solution is frothed, coated and cured and the resulting film is laminated to a 0.025 mm polyurethane film as described in the General Procedure. EXAMPLES 26-31 In Examples 26-31, earlier examples were repeated with the exception that a different backing or no backing was used when the MVT of the adhesive was tested. EXAMPLE 26 A sample was prepared as described in Example 6 except that the backing lamination step was omitted. The final product consisted of a foamed adhesive layer between two low-adhesion liners. Removal of both liner films at the time of application provided a dressing which was tacky on two sides and was suitable for attachment of additional devices such as an ostomy or exudate collective device. EXAMPLE 27 A sample was prepared as in Example 6, except a rayon non-woven web as described in U.S. Pat. No. 3,121,021 to Copeland, the backing used in Micropore™ brand tape (3M), was substituted for the polyurethane film in the backing lamination step. EXAMPLE 28 A sample was prepared as described in Example 3 except that the backing lamination step was omitted. EXAMPLE 29 A sample was prepared as described in Example 4 except that the backing lamination step was omitted. EXAMPLE 30 A sample was prepared as described in Example 1 except that the backing lamination step was omitted. COMPARATIVE EXAMPLE B A sample was prepared as described in Comparative Example A above, except that the backing lamination step was omitted. TABLE V______________________________________Effect of Backing on MVT MVTExample IOA/AA/PPG Backing* (g/m.sup.2 - 24 hr)______________________________________ 6 -- I 92126 -- none 347627 -- II 3219 3 40/20/40 I 29928 40/20/40 none 447 4 35/25/40 I 26629 35/25/40 none 566 1 22.5/22.5/55 I 47730 22.5/22.5/55 none 531A 90/10/0 I 207B 90/10/0 none 329______________________________________ *Backings: I: 0.025 mm polyurethane film II: nonwoven rayon web The data shown in Table V illustrate the general superiority, in terms of MVT, of the adhesives of this invention as compared with adhesives of the type shown in Comparative Examples A and B. EXAMPLE 31 In order to confirm the impermeability to liquid water, the adhesive described in Example 23 was evaluated by the following procedure. The apparatus used consisted of a pressure loop made of copper tubing, 4.13 cm in diameter One end of the loop was connected to a source of compressed air and was fitted with a pressure regulator. The opposite end of the loop had a flat rigid flange of 7.6 outer diameter and 3.6 cm inner diameter with a rubber O-ring of 4.4 cm diameter embedded in the flange for sealing. A matching top ring was used to clamp the test samples in place. The pressure loop was fitted with a solution of 692 parts deionized water, 7 parts DOWFAX™ 2A1 surfactant available from Dow Chemical Co., and 0.7 parts methylene blue dye. The adhesive sample with both low-adhesion carriers removed, was laminated to a single layer of Whatman 4-Qualitative filter paper. With the filter paper side facing away from the dye solution, the test sample was secured between the two flanges of the apparatus described above, and the apparatus was rotated to exclude air between the sample and the dye solution. Air pressure of 76.2 cm of water was applied for two minutes at which time no evidence of dye solution wetting the paper was observed. The air pressure was increased until the filter paper split due to expansion of the adhesive; still no evidence of wetting of the paper was observed which indicated that the foamed adhesive sample was not permeable to liquid water.

A method is disclosed for treating a wound or attaching a device or article to the skin using a film of pressure sensitive adhesive having dispersed therein a discontinuous gaseous phase contained within voids in the adhesive. The adhesive is formed from the polymerization of a hydrophilic premix and exhibits high moisture vapor transmission and fluid absorbency.

BACKGROUND OF THE INVENTION This invention relates generally to wire guides used to position a catheter or other medical tool at a precise location within a patient. Wire guides are used routinely in various medical procedures. In order to negotiate a tortuous path or avoid obstacles during insertion, wire guides normally include a floppy tip that is often biased in a certain direction. However, it is desirable that the remaining portion of the wire guide be somewhat elastic and resistant to kinking but still able to transmit a torque so that the doctor can change the direction of the biased tip to make a turn or avoid an obstacle while advancing the wire guide into position. It has been found that using a shape memory material, such as a nickel titanium (NiTi) alloy, in the body of the wire guide has significant advantages over conventional steel wire guides in that NiTi's "super elastic" properties can allow doctors to reach much more remote locations within the body. In other words, certain nickel titanium alloys are simply more kink resistant than conventional stainless steel. Unfortunately, however, NiTi alloys are not easily bonded to other materials, making it troublesome to use in manufacturing the distal tip of the wire guide. In order to obtain a desired flexibility at the tip, wire guides are often tapered at their distal end, and often include a coil spring extending over the tapered portion and a smoothly rounded tip attached at the distal end of the mandrel. The smoothly rounded tip must normally be welded to the mandrel. However, because NiTi alloys are generally not easily bonded to other metals, attaching the rounded tip to a NiTi mandrel is a difficult procedure. What is needed is a mandrel for wire guides which is substantially kink resistant over the majority of its length but which also retains the manufacturing advantages and reliability of stainless steel at its distal end. SUMMARY OF THE INVENTION One embodiment of the present invention might include a composite mandrel for a wire guide having a strand of weldable material radially surrounded by and fused with a shape memory material. The strand is preferably coaxial with the shape memory material but could also be off center or eccentric. Also, the strand is preferably formed from stainless steel but could also be formed of some radiopaque material, such as gold or platinum. The shape memory material is preferably a nickel titanium alloy. The shape memory material improves kink resistance over the body of the mandrel, while the strand of weldable material is exposed at the distal tip of the mandrel to facilitate bonding other components, such as a smoothly rounded cap, to the distal end of the mandrel. In another embodiment of the present invention there is provided a wire guide having a composite mandrel of memory shape material and a readily weldable material. The mandrel is machined at its distal end so that only the readily weldable material is exposed. The wire guide includes a flexible coil coaxially surrounding a portion of the distal end of the mandrel, and a smoothly rounded tip is welded to the distal end of the mandrel distally of the flexible coil. Finally, the entire length of the wire guide is coated with a first polymer coating, and the distal 70 to 80% of the wire guide includes a second hydrophilic coating which adds lubricity. In still another embodiment of the present invention there is provided a wire guide having a composite mandrel of memory shape material and a readily weldable material. The distal end of the mandrel is tapered to increase flexibility. The entire length of the wire guide is then coated with a polymer, wherein the coating is made thicker at the distal end to provide the desired flexibility. The distal 70 to 80% of the wire guide is then coated with a hydrophilic coating to increase lubricity. One object of the present invention is to provide an improved wire guide. Another object of the present invention is to provide a wire guide having the advantages of a shape memory material but which retains the advantages of conventional steel wire guides. Related objects and advantages of the present invention will be apparent from the following description. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary longitudinal sectional view of a wire guide according to the preferred embodiment of the present invention. FIG. 2 is a cross section of the wire guide of FIG. 1 along section A--A of FIG. 1 in the direction of the arrows. FIG. 3 is a cross section of a mandrel for a wire guide according to another embodiment of the present invention FIG. 4 is a cross section of a mandrel for a wire guide according to still another embodiment of the present invention. FIG. 5 is a fragmentary longitudinal sectional view of a wire guide according to another embodiment cf the present invention. FIG. 6 is a fragmentary longitudinal sectional view of a wire guide according to another embodiment cf the present invention. FIG. 7 is a fragmentary longitudinal sectional view of a wire guide according to still another embodiment of the present invention. FIG. 8 is a fragmentary longitudinal sectional view of a wire guide according to another embodiment of the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENT For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates. Referring now to FIG. 1, there is shown a wire guide 10 according to the preferred embodiment of the present invention. Wire guide 10 includes a mandrel 11 which is a coaxial composite of shape memory material 12, such as a nickel titanium alloy, and an inner strand of readily weldable material, such as stainless steel. When referring to a "readily weldable material," the applicant means any material which cannot properly be classified as a shape memory material and which can easily be welded to other like materials. In this case, readily weldable material 13 could also be a radiopaque material such as platinum or gold. Wire guide 10 also includes coil spring 17, which is preferably formed of a radiopaque material such as platinum. A radiopaque element near the distal end of the wire guide better enables the physician using the wire guide to determine its exact location via x-rays. Mandrel 11 includes a section 14 having a substantially uniform diameter over the majority of its length and a tapered section 15 that leads to a second uniform diameter section 16. Section 16 consists solely of the readily weldable material 13. Coil 17 is bonded to tapered section 15 at fastening location 18 by some conventional means such as gluing, soldering or possibly by a crimping process. Coil 17 coaxially surrounds the distal end of mandrel 11 but does not extend to any significant distance beyond the tip 20 of mandrel 11. Welded to tip 20 is a smoothly rounded cap 19, which is also preferred to be some readily weldable material, such as stainless steel. One of the advantages of the present invention is a wire guide that includes a kink resistant body and a reliable attachment between the distal tip of the mandrel and the end cap, which serves to reliably secure the coil spring in place and also shields the coils leading edge. Because tip 20 is solely formed of a readily weldable material, instead of an NiTi alloy, there is no need to include a safety wire connection between the end cap and the mandrel to ensure that the cap stays attached to the remainder of the wire guide during the insertion and retrieval process involving a live patient. Finally, the entire wire guide is covered by polymer coating 21, such as polyurethane, which bonds well to the underlying metallic surfaces but also provides good base for hydrophilic coating 22, which provides lubricity to ease insertion of the wire guide. Hydrophilic coating 22 preferably extends along most of the wire guide except for the 20 to 30% of the wire guide near the proximal end to ensure an adequate gripping surface at the proximal end which is free of the hydrophilic coating. Candidates for the hydrophilic coating include but are not limited to polyvinylpyrrolidone or polyethyleneoxide. Wire guides according to the present invention range in length from 20 to 460 centimeters with diameters in the uniform diameter section 14 typically ranging from 0.012 to 0.065 inches. The diameter of the readily weldable material 13 is generally significantly smaller than the overall diameter of the wire guide, as illustrated for instance in FIG. 2. In all the embodiments shown, the mandrel is made up of at least half shape memory material. The combined length of tapered section 15 and uniform diameter section 16 ranges from 1 to 30 centimeters, depending upon the desired flexibility at the distal end, but more typically ranges in length from 10 to 15 centimeters in most applications. Platinum coil 17 typically ranges from 2 to 3 centimeters in length but can vary from 1 to 15 centimeters in length for nontypical applications. Referring now to FIG. 2, there is shown a cross section of the wire guide 10 of FIG. 1 taken along line A--A in the direction of the arrows. Mandrel 11 comprises a coaxial composite of readily weldable material 13 surrounded by a shape memory material 12. Also shown is a cross section of polymer coating 21 and hydrophilic coating 22. FIGS. 3 and 4 show two possible variations of composite mandrels comprising a fusion of readily weldable material and a shape memory material. In the case of FIG. 3, mandrel 30 comprises a side-by-side composite of readily weldable material 32 and shape memory material 31. FIG. 4 shows a mandrel 35 that is an eccentric composite of readily weldable material 37 which is off center with but surrounded by the shape memory material 36. FIG. 5 shows a wire guide 40 according to another embodiment of the present invention. Guide 40 includes a mandrel 41 which is a coaxial composite of readily weldable material 43 surrounded by shape memory material 42. Mandrel 41 includes a first section 44 which is of substantially uniform diameter and extends over a majority of the wire guide s length. Near its distal end, mandrel 41 includes first and second tapered sections 45 and 47 respectively, and second and third uniform diameter sections 46 and 48 respectively, which consist solely of the readily weldable material 43. The lengths and diameters of these various sections can be varied to achieve the desired stiffness and flexibility at the distal end of the wire guide. Attached to tapered section 45 at fastening location 50 is coil spring 49, which is preferably formed from a radiopaque material such as platinum. The distal end of coil spring 49 and mandrel 41 is shielded by smoothly rounded hemispherical tip 51 which is welded to the distal end 52 of mandrel 41. Finally, like the embodiment shown in FIG. 1, the entire length of the wire guide is coated with a polymer coating 53, and a hydrophilic coating 54 covers the portion of the wire guide which will enter the body of the patient during the insertion process. Both coatings can be applied by known methods, such as by spraying or dipping. FIG. 6 shows a wire guide 60 according to another embodiment of the present invention. Guide 60, like the embodiments described earlier, includes a coaxial composite mandrel 61. In this case, mandrel 61 includes a step portion 62 which is immediately proximal to tapered portion 63. Step 62 abuts the proximal end of spring coil 64, which is attached to mandrel 61 at fastening location 65 by crimping, soldering, gluing or some other suitable means. Step 62 permits a smoother transition from the outer surface of coil 64 to the outer surface of mandrel 61. Wire guide 60 also includes a smoothly rounded cap 66 that is welded to the distal tip 67 of mandrel 61. The entire length of wire guide 60 is then coated with a first polymer layer 68, and the distal 70 to 80% of the wire guide is coated with hydrophilic coating 69. FIG. 7 shows a wire guide 70 according to still another embodiment of the present invention. In many respects, the guide is identical to those described above, except guide 70 includes a uniform diameter section 74 which is substantially equal to the inner diameter of coil spring 77. Uniform diameter section 74 results in an improved bonding connection 78 between the mandrel and the coil spring. The bonding connection 78 is better and stronger because it extends for a substantial length unlike the connection 50 of FIG. 5, for example, which mates a taper to a constant diameter. Bonding of connection 78 is accomplished by gluing or soldering. The various tapered and uniform diameter sections of the embodiments shown and described can be formed by grinding methods that are well known in the art. FIG. 8 shows a wire guide 90 according to an embodiment of the present invention that does not include a coil spring at its distal end. Guide 90 includes a mandrel 91 which is a coaxial composite of readily weldable material 93 surrounded by shape memory material 92. Mandrel 91 includes a substantially uniform diameter section 94 over the majority of its length but also includes tapered section 95 and uniform diameter section 96 at the mandrel's distal end. Like the embodiments described above, the entire length of the wire guide is coated with a polymer layer 97. However, in the present embodiment, the polymer coating 97 is thicker at the distal end to give the overall wire guide a substantially uniform diameter, removing the discontinuities along its length that might otherwise exist. The shapes (lengths and diameters) of tapered section 95 and uniform diameter section 96, as well as the thickness of polymer layer 97, can be varied to produce a desired flexibility in the distal end of the wire guide. Guide 90 also includes a hydrophilic coating 98 over the distal 70 to 80% of the wire guide for lubricity. While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.

A wire guide construction for medical procedures that involve accessing specific inner body areas without major surgery. The wire guide comprises a mandrel which is a coaxial composite of a thin stainless steel wire radially surrounded by a shape memory alloy, such as a nickel titanium alloy. The mandrel is of a constant diameter over the majority of its length except it is tapered at its distal end to reveal the inner stainless steel wire. A flexible coil of platinum is attached near the distal end of the mandrel and is secured in place when a smoothly rounded tip is welded to the distal tip of the mandrel. The complete wire guide can be coated with a polymer layer, and 70 to 80% of the distal portion of the wire guide can be coated with a hydrophilic polymer to increase lubricity.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to location systems for providing information services to clients as to the location of mobile user equipment (UE) terminals according to the 3GPP (Third Generation Partnership Program) Technical Specification 23.271 v. 5.3.0, “Functional stage 2 description of LCS”, pages 33-62, June 2002. More specifically, the present invention is concerned with the reuse of last known location information. 2. Description of the Related Art The location information of a mobile UE terminal is usually sensitive to the privacy of the mobile user and often crucial when the user is in a critical situation. To protect mobile users from illegal access to their private location information, the mobile communications network is provided with a sophisticated privacy protection mechanism which imposes various restrictions on location requests according to privacy profiles (time and place) specified by the mobile users. The privacy protection mechanism provides two types of verification on a location request according to decision capability that varies with a point in the network where the location request is being served. The first type of verification is performed on a client terminal when the network receives a location request from this terminal, known as client check. The second type of verification is a permission granted to the location request after location information of a UE terminal has been obtained if the place and time interval specified by the privacy profile of the UE terminal user are satisfied, known as privacy check. Mobile network providers, on the other hand, are required to provide location service in addition to their basic mobile communications service. Specifically, the location service involves several network nodes exchanging special messages with one another for the position calculation of a target UE and exchanging messages with a target UE terminal over wireless link. The 3GPP location information system, as specified in the 3GPP standard, is basically made up of client terminal, GMLC (Gateway Mobile Location Center), SGSN/MSC (Serving General packet radio service Support Node/Mobile Services switching Center), local wireless network known as RAN (Radio Access Network) and UE (User Equipment) terminal connected to the RAN via wireless link. HLR/HSS (Home Location Register/Home Subscriber Server) is connected to the GMLC as a database for holding the identity of the RAN to which UE terminals are connected. Registered client terminals are given exclusive right to access UE terminals. The 3GPP standard provides two modes of operation for requesting location information, i.e., the mobile terminated location request (MT-LR) and the mobile originated location request (MO-LR). In the MT-LR mode, the client terminal can either request the current location of a target UE or the current or last known location of this terminal. The last known location information is used as a location report instead of the current location information when the network has failed in locating the target UE for some reason if the last known location information is usable. More specifically, when the network receives a location request for a target UE, the SGSN/MSC responsible for the management of the target UE is also responsible for the privacy protection of the UE terminal. According to the privacy protection of the MT-LR mode as specified by the 3GPP standard, UE mobile users register their privacy profile (e.g., the identifiers of those clients allowed to request their location) in the SGSN/MSC of their home network. In response to a location request, the SGSN/MSC performs a privacy check by verifying it against the registered privacy profile of the target UE and determines whether or not the location request is granted. If the privacy profile of a UE terminal further specifies that a notification/verification request be sent to the UE terminal, the UE terminal is given a notification that it is being targeted or verifies the location request and returns a verification result to the client terminal. When the location request is acceptable, the SGSN/MSC proceeds with a location estimation process in collaboration with the associated RAN to determine the current location of the target UE. If the SGSN/MSC fails to acquire current location information of a target UE, a copy of the stored last known location information of the target UE is transmitted to the client terminal if this information is currently still usable, or significant. In the MO-LR mode, the mobile UE terminal exclusively requests its own current location from the network. In this mode, a failure in location measurement will result in the transmission of an error report to the requesting mobile UE terminal. Last known location information is not reused at all for transmission instead of the error report. However, a number of shortcomings exist in the prior art location system. First, the flow of traffic through the location network and the amount of location measurement calculations increase in proportion to location requests from client and mobile terminals. Further, part of the location network is shared in common by a mobile communication network. Therefore, when the location network experiences heavy traffic loads, it is likely that mobile communication traffic is adversely affected, which could lead to an extra burden on mobile network providers. Second, in the MT-LR mode of operation, privacy check is performed by the SGSN/MSC. If reusable last known location information of a UE terminal is available in the GMLC, for example, the SGSN/MSC would perform privacy check for the UE terminal. However, no mechanism is provided for the GMLC to request the SGSN/MSC to perform privacy check. As a result, privacy protection of last known location information is only ensured when this private information is maintained in the GMLC. Third, the reusability of last known location information depends exclusively on whether or not an SGSN/MSC is holding the last known location information, and the criteria of usability depends on specific details of an SGSN/MSC which may differ among different SGSN/MSCs. Therefore, it is likely that requesting client terminals may receive worthless last known location information. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a location system that reduces location traffic loads and measurement calculation loads and concomitant elimination of an extra network cost. It is a further object of the present invention to provide a location system capable of utilizing last known location information of a mobile terminal for both MT-LR (mobile terminated location request) and MO-LR (mobile originated location request) modes of operation, regardless of whether an SGSN/MSC has failed in obtaining current location information of a target mobile UE (user equipment) terminal. It is a still further object of the present invention to provide a location system capable of providing privacy protection of target UE terminals when their last known location information are reused. It is a still further object of the present invention to provide a location system capable of establishing reusability criteria for last known location information according to requests from client terminals as well as from UE terminals indicating an age parameter of their last known location information. According to a first aspect of the present invention, there is provided a location system for locating a plurality of mobile terminals. The system comprises a communication terminal for transmitting a location request specifying a target mobile terminal and a type of location information, and a location network. The location network is responsive to the location request from the communication terminal for producing current location information of the target mobile terminal if the type of location information of the received request specifies current location information and transmitting the current location information to the communication terminal and storing the last known location information in a memory as last known location information of the target mobile terminal, and copying stored last known location information of the target mobile terminal from the memory if the type of location information specifies last known location information and transmitting the copied information to the communication terminal. The network performs a reusability test on the stored last known location information and transmits the last known location information if the reusability test indicates a favorable result and transmits the current location information if the reusability test indicates an unfavorable result. According to a second aspect, the present invention provides a location method comprising the steps of transmitting a location request from a communication terminal, the request specifying a target mobile terminal and a type of location information, receiving the location request at a location network, producing current location information of the target mobile terminal and transmitting the current location information from the location network to the communication terminal if the type of location information of the received request specifies current location information, storing the current location information in a memory as last known location information of the target mobile terminal, and copying the stored last known location information of the target mobile terminal from the memory if the type of location information specifies last known location information and transmitting the copied information from the location network to the communication terminal. According to a third aspect, the present invention provides a method of operating a gateway with a location network. The method comprises the steps of receiving a location request from a communication terminal, said request specifying a target mobile terminal and a type of location information, acquiring current location information of the target mobile terminal from said location network and transmitting the current location information to said communication terminal if the type of location information of the received request specifies current location information, storing the current location information in a memory as last known location information of the target mobile terminal, and transmitting a copy of the stored last known location information of the target mobile terminal to said communication terminal if said type of location information specifies last known location information. According to a fourth aspect, the present invention provides a communication terminal which comprises a transmit means for transmitting a location request to a location system in which last known location information of mobile terminals are stored, the location request specifying a target mobile terminal and a type of last known location information, and receive means for receiving from the location system a copy of current location information of the target mobile terminal if the type specifies current location information or a copy of last known location information of the target mobile terminal if the type specifies last known location information. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be described in detail further with reference to the following drawings, in which: FIG. 1 is a block diagram of a location system of the present invention; FIGS. 2A and 2B are block diagrams useful for describing a first network configuration of the present invention; FIG. 3 is a block diagram useful for describing a second network configuration of the present invention; FIG. 4 is a block diagram useful for describing a third network configuration of the present invention; FIG. 5 is a block diagram useful for describing a fourth network configuration of the present invention; FIG. 6 is a block diagram useful for describing a fifth network configuration of the present invention; FIGS. 7A and 7B are block diagrams useful for describing a sixth network configuration of the present invention; FIGS. 8A and 8B are block diagrams useful for describing a seventh network configuration of the present invention; FIGS. 9A and 9B are block diagrams useful for describing an eighth network configuration of the present invention; FIGS. 10A and 10B are block diagrams useful for describing a ninth network configuration of the present invention; FIGS. 11A and 11B are block diagrams useful for describing a tenth network configuration of the present invention; FIGS. 12A to 12E are flowcharts of the operation of a local GMLC which maintains the privacy information of its home UE terminals, and FIG. 12F is a flowchart of a local GMLC which does not maintain the privacy information of its home UE terminals; FIG. 13 is a flowchart of the operation of a SGSN/MSC of the present invention; FIG. 14 is a flowchart of the operation of a mobile terminal of the present invention; FIGS. 15A , 15 B and 15 C are sequence diagrams associated with the first network mode of operation of the present invention; FIG. 16 is a sequence diagram associated with the second network mode of operation; FIG. 17 is a sequence diagram associated with the third network mode of operation; FIG. 18 is a sequence diagram associated with the fourth network mode of operation; FIG. 19 is a sequence diagram associated with the fifth network mode of the present invention; FIG. 20 is a sequence diagram associated with the sixth network mode of the present invention; FIG. 21 is a sequence diagram associated with the seventh network mode of the present invention; FIG. 22 is a sequence diagram associated with the eighth network mode of the present invention; FIG. 23 is a sequence diagram associated with the ninth network mode of the present invention; and FIG. 24 is a sequence diagram associated with the tenth network mode of the present invention. GENERAL DESCRIPTION Referring now to FIG. 1 , there is shown a location system of a mobile multi-network in which the present invention is incorporated. The location system is comprised of a plurality of client terminals 101 , 111 , 121 connected via landline links to a location network and a mobile UE terminal 105 wirelessly connected the location network. The location network is formed by a plurality of GMLCs (Gateway Mobile Location Centers) 102 , 112 , 122 to which client terminals 101 , 111 , 121 are respectively connected to send their location requests to and receive location reports from the associated GMLCs. GMLCs 102 , 112 , 122 are connected to SGSN/MSCs (Serving General packet radio service Support Node/Mobile service Switching Centers) 103 , 113 and 123 , respectively, and mutually connected to one another. SGSN/MSCs 103 , 113 , 123 are respectively connected to RANs (Radio Access Networks) 104 , 114 , 124 . Further associated with the GMLCs 102 , 112 , 122 are HLR/HSSs (Home Location Register/Home Subscriber Server) 106 , 116 and 125 . Privacy profile registers (PPR) 107 , 117 , 127 are also connected to the GMLCs 102 , 112 , 122 , respectively. The network nodes which are directly connected to each other, such as GMLC, HLR/HSS, SGSN/MSC, RAN, PPR, form a group known as a home network for mobile UE (user equipment) terminals. For example, a UE terminal 105 is connected as a home UE terminal via a wireless link to the RAN 104 . As shown in FIG. 1 , the client terminal transmits a location request message 150 having a number of fields containing a message type, a source address (client's identifier), a destination address (phone number of target mobile UE terminal), a location information type and a reusability criteria. The location information type field specifies a type of location information (C=current, L=last known, C/L=current or last known, or L/C=last known or current). The “current or last known” type indicates that the current location information is given priority over the last known location information if both information are available, and the “last known or current” type of location information indicates that the last known location information is given priority over the current location information if both information are available. Current location information may be a default setting. If the requesting user desires a previous location of a target UE terminal, the information-type field of the message is set equal to L. If the requesting user desires a previous location of a target UE terminal, but allows current location information if the previous location is not available nor reusable, the message contains an information-type field set equal to L/C. The information-type field of the message may be set equal to C/L if the user allows last known location information if current location information is not available. The reusability criteria field of the location request message specifies the accuracy of last known location information (allowable distance error) and the allowable age of last known information. The reusability criteria will be used by the location network to make a decision as to whether stored last known location information of a UE terminal can be reused. Each mobile terminal is also capable of transmitting a location request which specifies its own mobile terminal and contains a type of location information. The location network stores last known location information of the mobile terminals. The location network is responsive to a location request from the communication terminal, either from client terminal or mobile terminal, for producing current location information of a target mobile terminal specified by the request and transmitting it to the communication terminal if the type of location information of the received request is current location information, and transmitting a copy of the stored last known location information of the target mobile terminal to the communication terminal if the type of location information is last known location information. The location network is responsive to a location request from the client terminal for performing privacy check on the location request prior to the transmission of said last known location information to the communication terminal. The location network performs reusability check on the stored last known location information according to the privacy profile of the target mobile terminal or client terminal. Identification data of the SGSN/MSCs 103 , 113 , 123 are maintained in the associated HLR/HSSs 106 , 116 , 126 . The privacy profile of UE terminal 105 is stored in the GMLC of the home network, (i.e., GMLC 102 ). Network Configurations The present invention provides a number of network configurations depending on the location of the requesting communication terminal (client or mobile), the location of the target UE terminal 105 as well as the location of network nodes where privacy profiles and location reports are maintained. First Network Configuration The first network configuration is shown in FIGS. 2A and 2B . The client terminal 101 is the requesting terminal, and the target UE 105 is currently establishing its link to home network A. In FIG. 2A , the privacy profile and location information of the target UE are maintained in the home GMLC 102 . The client terminal 101 includes a transmit means 1011 for transmitting a location request to the home GMLC 102 and a receive means 1012 for receiving location information from the GMLC 102 . GMLC 102 includes a memory 1021 for storing the privacy profile and last known location information of UE 105 , and a client/privacy check means 1022 . In response to the location request from the client terminal 101 , the client/privacy check means 1022 performs a client check on the requesting terminal. If the client terminal fails to pass the client check, the client/privacy check means 1022 formulates an error message and sends it from a report transmit means 1026 to the requesting terminal 101 . If the client terminal is verified, the client/privacy check means 1022 proceeds to reference the privacy profile of the target UE stored in the memory 1021 and performs a first privacy check on the location request. If the location request fails to pass the first privacy check, an error message is supplied from the check means 1022 to the report transmit means 1026 and transmitted to the client terminal. If the location request is verified by the first privacy check, the check means 1022 determines which type of location information the request specifies. If the location request specifies type C or C/L, the client/privacy check means 1022 instructs a notification/verification means 1024 to transmit a location request to the SGSN/MSC 103 to perform a location estimation process with the RAN 104 to determine the location of the target UE 105 . A location report is then returned from the SGSN/MSC 103 to a second privacy check means 1025 . In response to the location report, the second privacy check means 1025 proceeds to perform a second privacy check. If the location request specifies type L or L/C, the client/privacy check means 1022 instructs a reusability check means 1023 to make a search through the memory 1021 for last known location information that meets the “age and place” requirements of the client's request. If the requested last known location information of the target UE is not stored in the memory 1021 , the reusability check means 1023 generates an error message and transmits it to the client terminal 101 from the report transmit means 1026 . If the requested last known location information is stored in the memory 1021 , the reusability check means 1023 instructs the notification/verification means 1024 to check the UE's privacy profile to see if notification/verification process must be performed. If this is the case, the notification/verification means 1024 acquires the identity of this SGSN/MSC 103 from the home HLR/HSS 106 of the target UE 105 and transmits a notification/verification message to SGSN/MSC 103 to request it to send a notification to the UE 105 for indicating that a location request is being terminated or a verification message to it to request it to verify the client terminal. In the former case, the SGSN/MSC 103 proceeds to request the second privacy check means to perform a second privacy check on the last known location information. In the latter case, the target UE returns a verification report to the SGSN/MSC 103 , which repeats the report to the second privacy check means 1025 to perform a second privacy check if the location request is verified by the target UE. The second privacy check involves verifying the location request against the privacy profile of the target UE stored in the memory 1021 and determining whether the current or UE's last known location information can be sent to the client terminal. If the location request is not verified by the second privacy check, an error message is sent from the report transmit means 1026 to the client terminal. If the location request is verified by the second privacy check, the report transmit means 1026 transmits the location information contained in the location report from the SGSN/MSC 103 or a copy of the UE's last known location information stored in the memory 1021 . In a MO-LR mode of operation, the mobile UE terminal 105 includes a control unit 1051 for transmitting a location request via a wireless interface 1053 to the RAN 104 for requesting the location information of its own terminal from the SGSN/MSC 103 . The location request is of the same format as used in transmitting a location request from the client terminal. SGSN/MSC 103 formulates and transmits a location report containing current or last known location information of the UE terminal, depending on the type of location information specified by the location request message. The location report is transferred via the RAN 104 to the UE terminal 105 and received and stored in a memory 1052 and then displayed. In FIG. 2B , the privacy profile and location information of the target UE are maintained in the SGSN/MSC 103 . GMLC 102 includes a client check means 1027 and a report transmit means 1026 . Client check means 1027 performs a client check on the location request from the client terminal 101 . If the client check means 1027 does not verify the client terminal 101 , it sends an error message to the client terminal from the report transmit means 1026 . Otherwise, the client check means 1027 acquires the identity of SGSN/MSC 103 from HLR/HSS 106 and sends a privacy check request to the SGSN/MSC 103 . SGSN/MSC 103 includes a first privacy check means 1032 , which receives the privacy check request and performs a first privacy check using the privacy profile of the target UE stored in a memory 1031 . If the location request is verified, the first privacy check means 1032 determines which of the location information type the verified request specifies. If the location request specifies type C or C/L, the first client check means 1032 instructs a notification/verification means 1034 to transmit a location request to the RAN 104 to perform a location estimation process to determine the location of the target UE 105 . A location report is then returned from the RAN 104 to a second privacy check means 1035 . In response to the location report, the second privacy check means 1035 proceeds to perform a second privacy check. If the location request specifies type L or L/C, the first privacy check means 1032 instructs a reusability check means 1033 to make a search through the memory 1031 for last known location information that meets the “age and place” requirements of the client's request. If the requested last known location information of the target UE is not stored in the memory 1031 , the reusability check means 1033 generates an error message and transmits it from the report transmit means 1036 to the client terminal 101 . If the requested last known location information is stored in the memory 1031 , the reusability check means 1033 instructs the notification/verification means 1034 to check the UE's privacy profile to see if notification/verification process must be performed. If this is the case, the notification/verification means 1034 transmits a notification to the UE 105 from the RAN 104 for indicating that a location request is being terminated or a verification message to request it to verify the client terminal. In the former case, the notification/verification means 1034 instructs the second privacy check means 1035 to perform a second privacy check on the last known location information. In the latter case, the second privacy check means 1035 receives a verification report from the target UE and proceeds to perform a second privacy check if the client terminal is verified by the target UE. The second privacy check involves verifying the location request against the privacy profile of the target UE stored in the memory 1031 and determining whether the current or UE's last known location information can be sent to the client terminal. If the location request is verified by the second privacy check, the report transmit means 1036 transmits to the GMLC 102 the location information contained in the location report from the RAN 104 or a copy of the UE's last known location information stored in the memory 1031 . Second Network Configuration According to the second network configuration shown in FIG. 3 , the client terminal 111 is the requesting terminal and the target UE terminal 105 is currently establishing its link to the home network A. The privacy profile and location report of the target UE terminal 105 are maintained in the home GMLC 102 similar to that shown in FIG. 2A . Client terminal 111 includes a transmit means 1111 for transmitting a location request to the home GMLC 112 and a receive means 1112 for receiving a location report from the GMLC 112 . GMLC 112 includes a request transfer means 1121 which identifies the GMLC 102 as a node that maintains the privacy profile and location information of the target UE 105 by acquiring its node identifier from the home HLR/HSS 106 of the target UE. GMLC 112 includes a report transfer means 1122 for repeating a location report from the GMLC 102 to the client terminal 111 . GMLC 102 is of identical configuration to that shown in FIG. 2A . GMLC 102 operates on the location request from the GMLC 112 in a manner identical to its operation on the location request directly received from the client terminal 101 of FIG. 2A . Therefore, the description of GMLC 102 is omitted for simplicity. Third Network Configuration According to the third network configuration shown in FIG. 4 , client terminal 111 is the requesting terminal and the target UE terminal 105 is currently visiting the external network C. The privacy profile and location report of the target UE terminal 105 are maintained in the home GMLC 102 similar to that shown in FIG. 3 . Client terminal 111 sends a location request from transmit means 1111 to the home GMLC 112 and receives a location report by receive means 1112 from the GMLC 112 . Similar to FIG. 3 , the request transfer means 1121 repeats the received location request to the GMLC 102 and the report transfer means 1122 repeats a location report from the GMLC 102 to the client terminal 111 . In the GMLC 102 , memory 1021 maintains the privacy profile and last known location information of the target UE 105 . GMLC 102 is of the same configuration as in FIG. 3 . The operation of GMLC 102 is the same as that of FIG. 3 except that its notification/verification means 1024 sends notification/verification and location request messages to the GMLC 122 of the visited network C and its second privacy check means 1025 receives verification and location reports from the GMLC 122 . GMLC 122 includes a message transfer means 1221 for repeating the message from the GMLC 102 to the SGSN/MSC 123 of the visited network C and a report transfer means 1222 for repeating verification and location reports from the SGSN/MSC 123 to the GMLC 102 . Fourth Network Configuration According to the fourth network configuration shown in FIG. 5 , the client terminal 101 is the requesting terminal and the target UE terminal 105 is currently visiting the external network B. The privacy profile and location report of the target UE 105 are maintained in the home GMLC 102 . The location network of this configuration is similar to that of FIG. 2A with the exception that its notification/verification means 1024 sends notification/verification and location request messages to the GMLC 112 of the visited network B and its second privacy check means 1025 receives verification and location reports from the GMLC 112 . GMLC 112 includes a message transfer means 1121 for repeating the message from the GMLC 102 to the SGSN/MSC 113 of the visited network B and a report transfer means 1122 for repeating verification and location reports from the SGSN/MSC 113 to the GMLC 102 . Fifth Network Configuration According to the fifth network configuration shown in FIG. 6 , the client terminal 111 is the requesting terminal and the target UE terminal 105 is currently visiting the external network B. The privacy profile and location report of the target UE terminal 105 are maintained in the home GMLC 102 . The location network of this configuration is similar to that of FIG. 4 with the exception that the GMLC 112 of the visited network B includes a transfer means 1123 and the notification/verification means 1024 of GMLC 102 sends notification/verification and location request messages to the transfer means 1123 for repeating it to the SGSN/MSC 113 of the visited network B. The second privacy check means 1025 of GMLC 102 receives verification and location reports from the SGSN/MSC 113 via the transfer means 1123 of GMLC 112 . Sixth Network Configuration The sixth network configuration is shown in FIGS. 7A and 7B in which the client terminal 101 is the requesting terminal and the target UE terminal 105 is currently establishing its link to the home network A. In FIG. 7A , the privacy profile and location information of the target UE terminal 105 are both maintained in the PPR 107 . In FIG. 7A , the GMLC 102 includes a client check means 1027 to perform a client check on the location request from the client terminal 101 . If the request is verified, the client check means 1027 transmits an authorization request to the PPR 107 for authorizing it to perform a number of checks including a first privacy check, an information type check and a reusability test. PPR 107 includes a memory 1061 for storing privacy profiles and location information of mobile terminals and a first privacy check means 1072 which receives the authorization request from the GMLC 102 to perform a first privacy check using the privacy profile stored in the memory 1071 . If the request is verified by the first privacy check, the location information type of the request is examined. If the client is requesting current location information, the first privacy check means 1072 instructs the notification/verification means 1024 to determine if notification/verification is required. Notification/verification means 1024 acquires the identifier of SGSN/MSC 103 from the HLR/HSS 106 and sends a location request (and a notification/verification message if required) to the identified SGSN/MSC to obtain location information of the target UE (with or without a verification report). The obtained location information is supplied to a privacy check request means 1028 of the GMLC 102 . In response, the privacy check request means 1028 transmits an authorization request to a second privacy check means 1075 of the PPR to authorize it to perform a second privacy check using the UE's privacy profile stored in the memory 1071 . If the request for the current location information is verified by the second privacy check, the second privacy check means 1075 permits the privacy check request means 1028 of GMLC 102 to transmit the current location information which has been received from the SGSN/MSC 103 to the client terminal 101 via the report transmit means 1026 . If the client terminal 101 is requesting last known location information of the target UE, the privacy check means 1072 of the PPR allows the reusability check means 1073 to perform a reusability test on the “age and place” data of the location request to determine whether the requested last known location information is available in the memory 1071 . If this is the case, the reusability check means 1073 transmits information to the notification/verification means 1024 , indicating whether or not notification/verification is required. If notification/verification is required, the notification/verification means 1024 transmits a notification/verification message to the SGSN/MSC 103 . Privacy check request means 1028 responds to a verification report from the SGSN/MSC 103 by checking it to see if second privacy check should proceed. If so, it sends an authorization request to a second privacy check means 1075 of PPR 107 to authorize it to perform a second privacy check by using the privacy profile of the target UE and returns a privacy check report to the GMLC 102 from report transmit means 1076 . If the second privacy check verifies the request, the report transmit means 1076 transmits a copy of the last known location information of the target UE from the memory 1071 to the GMLC 102 , which is repeated by the report transmit means 1026 to the client terminal 101 . If any of the results of the two privacy checks and the reusability check is unfavorable, an error report will be transmitted from the report transmit means 1076 to the GMLC 102 and repeated by the report transmit means 1026 to the client terminal 101 . In FIG. 7B , the privacy profile and location report of the target UE terminal 105 are respectively maintained by the PPR 107 and the GMLC 102 . Client check means 1027 performs a client check on the received location request. If the request is verified, the client check means 1027 transmits an authorization request to the PPR 107 to authorize it to perform a first privacy check. PPR 107 includes a privacy check means 1077 which references the privacy profile of the UE terminal 105 and performs a privacy check using the referenced privacy profile. If the request is not verified, the privacy check means 1077 transmits an error message to the GMLC 102 from report transmit means 1076 to the client terminal 101 . If the request is verified, the privacy check means 1077 requests the client check means 1027 of the GMLC to examine the type of location information of the location request. If the client is requesting current location information, the client check means 1027 of the GMLC instructs the notification/verification means 1024 to acquire the identifier of the SGSN/MSC 103 from the HLR/HSS 106 and transmits a location request to the SGSN/MSC 103 . Location information obtained by the SGSN/MSC 103 is transmitted to the privacy check request means 1028 . If notification/verification by the UE terminal is required, a notification/verification message is sent with the location request and a verification report will be received by the privacy check request means 1028 . In response to the location information, the privacy check request means 1028 sends an authorization request to the privacy check means 1077 of the PPR to authorize it to perform a second privacy check. If the request is verified by the second privacy check, the privacy check means 1077 allows the privacy check request means to transmit the received current location information to the client terminal 101 via the report transmit means 1026 . If the client terminal 101 is requesting last known location information of the target UE, the client check means 1027 of the GMLC allows the reusability check means 1023 to perform a reusability test on the “age and place” data of the location request to determine whether the requested last known location information is available in the memory 1021 . If this is the case, the reusability check means 1023 instructs the notification/verification means 1024 to check to see notification/verification is required. If notification/verification is required, the notification/verification means 1024 transmits a notification/verification message to the SGSN/MSC 103 to receive a verification report. Privacy check request means 1028 responds to the verification report by checking it to see if second privacy check should proceed. If so, it sends an authorization request to the privacy check means 1077 to authorize it to perform a second privacy check by using the privacy profile of the target UE and returns a privacy check report to the GMLC 102 . If the request is verified by the second privacy check means 1077 , the report transmit means 1026 is directed to transmit a copy of the last known location information of the target UE from the memory 1021 to the GMLC 102 to the client terminal 101 . Seventh Network Configuration The seventh network configuration is shown in FIGS. 8A and 8B in which the client terminal 111 is the requesting terminal and the target UE terminal 105 is currently establishing its link to the home network A. In FIG. 8A , the privacy profile and location information of the target UE terminal 105 are both maintained in the PPR 107 . Client terminal 111 includes a transmit means 1111 for transmitting a location request to the home GMLC 112 and a receive means 1112 for receiving a location report from the GMLC 112 . GMLC 112 includes a request transfer means 1121 which identifies the GMLC 102 as a node that maintains the privacy profile and location information of the target UE 105 by acquiring its node identifier from the home HLR/HSS 106 of the target UE. GMLC 112 includes a report transfer means 1122 for repeating a location report from the GMLC 102 to the client terminal 111 . GMLC 102 and PPR 107 are of identical configuration to that shown in FIG. 7A and hence they operate in the same manner as that of FIG. 7A on the location request repeated by the GMLC 112 . In FIG. 8B , the privacy profile and location information of the target UE terminal 105 are respectively maintained in the GMLC 102 and PPR 107 . Similar to FIG. 8A , the client terminal 111 transmits a location request to the home GMLC 112 and receives a location report from the GMLC 112 . GMLC 102 and PPR 107 are of identical configuration to that shown in FIG. 7B and hence they operate in the same manner as that of FIG. 7B on the location request repeated by the GMLC 112 . Eighth Network Configuration The eighth network configuration is shown in FIGS. 9A and 9B in which the client terminal 111 is the requesting terminal and the target UE terminal 105 is currently visiting the external network C. In FIG. 9A , the privacy profile and location information of the target UE terminal 105 are both maintained in the PPR 107 . Client terminal 111 transmits a location request to the home GMLC 112 and receives a location report from the GMLC 112 . GMLC 112 includes request transfer means 1121 which identifies the GMLC 102 as a node that maintains the privacy profile and location information of the target UE 105 by acquiring its node identifier from the home HLR/HSS 106 of the target UE. GMLC 112 includes report transfer means 1122 for repeating a location report from the GMLC 102 to the client terminal 111 . Since the target UE is visiting the network C, the notification/verification means 1024 acquires the identifiers of GMLC 122 and SGSN/MSC 123 from the HLR/HSS 106 when instructed from the PPR 107 and sends a location request and notification/verification message to the SGSN/MSC 123 via the message transfer means 1221 of GMLC 122 and receives a location report and verification report via the report transfer means 1222 of GMLC 122 . In FIG. 9B , the privacy profile and location information of the target UE terminal 105 are respectively maintained in the GMLC 102 and PPR 107 . The operation of FIG. 9B is similar to FIG. 8B with the exception that location report and verification report are obtained from the SGSN/MSC 123 via the GMLC 122 . Ninth Network Configuration The ninth network configuration is shown in FIGS. 10A and 10B in which the client terminal 101 is the requesting terminal and the target UE terminal 105 is currently visiting the external network B. In FIG. 10A , the privacy profile and location information of the target UE terminal 105 are both maintained in the PPR 107 . Client terminal 101 transmits a location request to the home GMLC 102 and receives a location report from the GMLC 102 . Since the target UE is visiting the network B, the notification/verification means 1024 of GMLC 102 acquires the identifiers of GMLC 112 and SGSN/MSC 113 from the HLR/HSS 106 when instructed from the PPR 107 and sends a location request and notification/verification message to the SGSN/MSC 113 via the message transfer means 1123 of GMLC 112 and receives a location report and verification report via the report transfer means 1124 of GMLC 112 . In FIG. 10B , the privacy profile and location information of the target UE terminal 105 are respectively maintained in the GMLC 102 and PPR 107 . The operation of FIG. 10B is similar to FIG. 8B with the exception that location report and verification report are obtained from the SGSN/MSC 113 via the GMLC 112 . Tenth Network Configuration The ninth network configuration is shown in FIGS. 11A and 11B in which the client terminal 111 is the requesting terminal and the target UE terminal 105 is currently visiting the external network B. In FIG. 11A , the privacy profile and location information of the target UE terminal 105 are both maintained in the PPR 107 . Client terminal 111 transmits a location request to the home GMLC 112 which repeats the request to the GMLC 102 after acquiring its identifier from the HLR/HSS 106 . Client terminal 111 receives a location report from the GMLC 102 via the home GMLC 112 . Since the target UE is visiting the network B, the notification/verification means 1024 of GMLC 102 acquires the identifiers of GMLC 112 and SGSN/MSC 113 from the HLR/HSS 106 when instructed from the PPR 107 and sends a location request and notification/verification message to the SGSN/MSC 113 via the message transfer means 1123 of GMLC 112 and receives a location report and verification report via the report transfer means 1124 of GMLC 112 . In FIG. 11B , the privacy profile and location information of the target UE terminal 105 are respectively maintained in the GMLC 102 and PPR 107 . The operation of FIG. 11B is similar to FIG. 8B with the exception that location report and verification report are obtained from the SGSN/MSC 113 via the GMLC 112 . DESCRIPTION OF PREFERRED EMBODIMENTS The MT-LR operation of a local GMLC proceeds according to flowcharts shown in FIGS. 12A to 12E if the GMLC holds the privacy information of its home UE terminals. In FIG. 12A , when the local GMLC receives a message from a client terminal or from the network, the routine starts with decision step 201 to examine the type and source of the message to determine whether the message is a location request from a client terminal, a location request repeated from other GMLC, or the message contains an SGSN/MSC identifier from an HLR/HSS. If the message is a location request from client terminal, flow proceeds to step 202 to perform a client check to verify the requesting client terminal for agreement with the privacy profile of the target UE maintained in the local GMLC. If the location request is not verified at step 202 , an error message is transmitted to the requesting terminal (step 223 ) and the routine is terminated. If the requesting client is verified (step 202 ) or the received message is a location request from other GMLC (step 201 ), flow proceeds to step 204 to determine whether the local GMLC is the home GMLC of the target UE. If this is the case, flow proceeds to decision step 205 to check to see if a PPR (Privacy Profile Register) is connected to the GMLC. If no PPR is connected to the local GMLC, a first privacy check is performed on the location request for agreement with the privacy profile of the target UE terminal (step 206 ) to determine if the location request is acceptable (step 207 ). The first privacy profile of a UE terminal may include grant/reject indication of whether or not the client terminal is acceptable, or whether or not the requested accuracy of location information is acceptable, or whether or not the requested age of last known location information is acceptable. The first privacy profile may further include an indication of whether the UE terminal user is desirous of notification from the client terminal or verification by the UE terminal as a criteria for the acceptance of a location request. If a UE user desires notification from the requester, the UE user will receive a notification from the network indicating that the UE terminal is being the target of a location request. If a UE user desires verification, the user will receive a verification message from the network indicating whether the current location request should be accepted or not. The UE terminal responds to the verification message with a verification report. If first privacy check step 207 determines that the received location request is not acceptable, flow proceeds to step 223 to transmit an error message to the requesting terminal. If the location request is acceptable, flow proceeds to step 208 to perform a check on the type of location information contained in the received location request to determine which of the parameters (C, L, C/L and L/C) is specified in the request (step 209 ). If the type of location information specifies last known (L) or “last known or current (L/C) location information” (indicating that the client user desires last known location information but satisfies with it if current location information is not available), flow proceeds to step 210 to perform a check on the last known location information for reusability. If the requested “age and place” requirements of the location request meet the privacy profile of the target UE, a further check is made as to whether last known location information that fulfills the requirements is stored in memory (step 211 ). If such last known location information is available, flow proceeds to step 212 to check to see if the privacy profile of the target UE indicates that notification to or verification by the target UE is required. If this is the case, flow proceeds to step 213 to send an enquiry message to an HLR/HSS for requesting the identifier of a SGSN/MSC responsible for the target UE terminal. If no response is received from the HLR/HSS, an error message is sent to the client terminal (step 223 ). When a response message is received from the HLR/HSS (step 214 ), the GMLC proceeds to step 215 to examine its contents and transmits a notification/verification message to the identified SGSN/MSC if the response message contains only SGSN/MSC identifier. If the response message from the HLR/HSS contains the identifier of a GMLC in addition to an SGSN/MSC identifier, the GMLC sends the notification/verification message to the identified GMLC. If the privacy profile of the target UE requires only notification (step 216 ), flow proceeds to step 218 . Otherwise, flow proceeds to step 217 to check to see if a verification report from the UE terminal indicates that the requesting client terminal is verified. If the decision is negative at step 217 , flow proceeds to step 223 to send an error message to the requesting terminal. If the decision at step 217 is affirmative, flow proceeds to step 218 to determine if the GMLC is connected to a PPR. If no PPR is connected to the GMLC (step 218 ), flow proceeds to step 219 to perform a second privacy check on the current or last known location information to determine whether its time of location estimation and its estimated location agree with allowed “time-zone and area” parameters of the UE's privacy profile (step 220 ). If the result of the second privacy check is unfavorable (step 220 ), an error message is transmitted to the client terminal (step 223 ). Otherwise, the location information is processed according to the UE's privacy profile if the accuracy of the location information is higher than the allowed accuracy (step 221 ). At step 222 , the location information (current or last known) is transmitted to the client terminal. If the location information is current and a copy of the current location information is stored in memory as last known location information. If no notification/verification is required by the UE terminal, the decision at step 212 is negative and flow proceeds to step 219 to perform second privacy check, skipping steps 214 through 218 . If current (C or C/L) location information is specified in the received location request (step 209 ) or last known location information is not available (step 211 ), flow proceeds to step 231 ( FIG. 12B ) to transmit an enquiry message to the home HLR/HSS for requesting the identifier of a SGSN/MSC responsible for the target UE terminal. When the requested identifier is received (step 232 ), flow proceeds to step 233 to check to see if the privacy profile of the target UE indicates that notification/verification is required. If not, a location request is sent to the home or external SGSN/MSC depending on the current location of the target UE to obtain its current location information. When the requested current location information is received (step 235 ), flow returns to step 218 . If there is no response, an error message is transmitted to the requesting terminal (step 223 ). If the decision at step 233 is affirmative, flow proceeds to step 236 to transmit a location request and notification/verification request message to the home or external SGSN/MSC depending on the current location of the target UE for receiving a response (step 237 ). If the current location information of the target UE and a verification report is received, flow proceeds from step 237 to step 217 . If no response is received, flow proceeds from step 237 to step 223 to send an error message to the client terminal. If the decision at step 204 indicates that the local GMLC is not the home GMLC of the target UE, flow proceeds to step 241 ( FIG. 12C ) to send an enquiry message to the external HLR/HSS, which is the home HLR/HSS of the external target UE, to obtain the identifier of an appropriate GMLC. When the identifier of the appropriate GMLC is obtained, a location request is transmitted to the identified GMLC to obtain the location information of the target UE. If the location information is received successfully, flow proceeds to step 222 to repeat the received location information to the requesting terminal. If no response is returned, an error message is sent to the requesting terminal (step 223 ). If the decision at step 201 indicates that a message such as notification/verification message, verification report, location request, or location report is received from other GMLC, flow proceeds from step 201 to step 251 ( FIG. 12D ) to repeat the received message to downstream node identified by a SGSN/MSC (or plus GMLC) identifier contained in the message. If a PPR is connected to the local GMLC, the decision at step 205 is affirmative and flow proceeds to step 224 to send an authorization request (for privacy check with or without a location-info-type check) to the PPR to obtain a report. The PPR performs a first privacy check on the location request and additionally an information-type check with an attendant reusability test on stored location information of the target UE if the PPR maintains location information of mobile terminals. At step 225 , the GMLC receives a report from the PPR indicating a result of the first privacy check and a result of the reusability test. Step 225 analyzes the received report. If the result of the first privacy check is favorable and no reusability test is performed (a), flow proceeds to step 208 . Otherwise, flow proceeds to step 223 to send an error message to the requesting terminal. If the results of the first privacy check and reusability test are both favorable (b), flow proceeds to decision step 212 . If the result of the first privacy check is favorable, but the result of the reusability test is unfavorable (c), flow proceeds to step 231 ( FIG. 12B ). If the decision at step 218 is affirmative, flow proceeds to step 261 ( FIG. 12E ) to send a request to the PPR for requesting it to perform a second privacy check. At step 262 , a report indicating a result of the second privacy check is received from the requested PPR and the result is analyzed. If the result indicates a favorable decision, flow proceeds from step 262 to step 222 to transmit the location information of the target UE to the requesting terminal. If the report from the PPR indicates an error at step 262 , flow proceeds to step 223 to send an error message to the requesting terminal or GMLC. If the privacy information of home UE terminals is not maintained in the local GMLC, the MT-LR operation of the GMLC proceeds according to the flowchart of FIG. 12F and the home SGSN/MSC of target UE terminal operates according to the flowchart of FIG. 13 . In FIG. 12F , the routine starts with step 271 to check the type and source of a message when it arrives on the local GMLC. If the message is a location request from a client terminal, flow proceeds to step 272 to perform a client check. If the client terminal is verified (step 273 ), flow proceeds to step 274 to check to see if the local GMLC is the home GMLC of the target UE. If so, flow proceeds to step 231 ( FIG. 12B ). Otherwise, flow proceeds to step 241 ( FIG. 12C ). If the message is a location request from other GMLC, steps 272 , 273 are skipped and step 274 is executed. If the message contains a node identifier, flow proceeds from step 271 to step 251 to repeat the message downstream. The MT-LR operation of the SGSN/MSC of the present invention will be described below with reference to the flowchart of FIG. 13 . The routine of a SGSN/MSC begins with the reception of a message either from a GMLC or a mobile UE terminal (step 300 ). If the location request is transmitted from a GMLC and the SGSN/MSC maintains location reports and private profiles of UE terminals (step 301 ), flow proceeds to step 302 to perform a privacy check for agreement with the first privacy profile of the target UE. If the request is acceptable, flow proceeds to step 304 to check the location information type of the request. If the request is not acceptable (step 303 ), an error message is returned to the requesting GMLC (step 315 ). If the location reports and private profiles of UE terminals are not maintained by the SGSN/MSC, flow proceeds to step 331 to transmit a location request to the RAN and repeats a location report from the RAN to the requesting GMLC (step 332 ). If the decision at step 300 indicates that the location request is transmitted from a UE terminal, flow proceeds to step 304 , skipping steps 302 and 303 . If the location request specifies last known location information of the target UE (step 304 ), a reusability test is provided (steps 306 , 307 ). If the result of the reusability test at step 307 is unfavorable, flow proceeds to step 308 to transmit a location request to the associated RAN to obtain the current location information of the target UE (steps 308 , 309 ). If no response is received, an error message is transmitted to the requesting source (step 315 ). If the decision at step 307 or 309 is affirmative, flow proceeds to step 310 . If the location request has been received from a GMLC, flow proceeds to step 311 to perform a privacy check for agreement with a second privacy profile of the target UE terminal (step 312 ). If the result of the privacy check is unfavorable, an error message is returned to the requesting source (step 315 ). Otherwise, flow advances to step 313 to process the location information according to the privacy profile if the accuracy of the location information (either current or last known) is higher than the allowed accuracy. The processed location information is then transmitted to the requesting source (step 314 ). If the location request has been received from a UE terminal, flow proceeds from step 310 to step 314 to transmit the location information to the requesting UE terminal. If the SGSN/MSC receives a notification/verification message from a GMLC (step 300 ), flow proceeds to step 320 to check to see if notification or verification is requested. If notification is requested, flow proceeds to step 321 to send a notification message to the target UE and terminates the routine. If verification by the target UE is requested, flow proceeds to step 322 to send a verification message to the target UE. In response, the target UE checks the requesting terminal and sends a verification report to the SGSN/MSC. This report is repeated by the SGSN/MSC to the requesting GMLC (step 323 ). The MO-LR operation of the mobile UE terminal of the present invention proceeds according to a flowchart shown in FIG. 14 . The routine of a mobile UE terminal starts with step 401 when the user of the UE enters a request to the terminal for requesting a location information of its own terminal. The entered request data specifies one of the types of location information as described above. At step 402 , the UE terminal checks the entered type of location information and determines which type is specified (step 403 ). If the last known location information is requested, flow proceeds to step 404 to determine whether past location information is stored in the memory 1052 ( FIG. 2A ) of the UE terminal. If the decision is affirmative at step 404 , flow proceeds to step 405 to check the stored last known location information for reusability (step 406 ). If the stored information satisfies the privacy profile of the UE terminal, the stored location information is determined to be reusable and the stored information is read (step 407 ) and displayed on a map (step 411 ). If the decision at step 403 indicates that the entered request specifies current location of the UE terminal or if the decision at step 404 or 406 is negative, flow proceeds to step 408 to transmit a location request to a SGSN/MSC via a RAN. The location request is processed in the SGSN/MSC and location information is transmitted from the SGSN/MSC and received by the UE terminal at step 409 . Depending on the type of location information specified in the transmitted location request message, the location information received from the SGSN/MSC is either last known or current location information of the requesting UE terminal. The memory of the UE terminal is updated with the received location information at step 410 and the received information is displayed (step 411 ). Network Modes of Operation The present invention operates in first to tenth network modes corresponding respectively to the first to tenth network configurations discussed previously. The following is a description of the network modes of operation using the flowcharts just described above. First Network Mode FIG. 15A is a sequence diagram illustrating a location network operating in MT-LR mode in which the client terminal 101 is the requesting terminal and the mobile terminal 105 is the target UE which is currently staying in the home network A. The home GMLC 102 of target UE maintains its privacy profile and location report. Client terminal 101 initially transmits a location request (event 501 ) to the home GMLC 102 . In response, the GMLC 102 performs a client check (event 502 ), a privacy check (event 503 ) and a location information type check (event 504 ) by executing steps 200 through 211 of FIG. 12A . If the location request specifies current location information of the target UE and notification/verification is not required, steps 231 through 235 are executed by sending a location request to the SGSN/MSC 103 using its identifier acquired from HLR/HSS 106 (events 505 , 506 , 507 ). If the location request specifies last known location information of the target UE and the stored information is reusable (step 211 ), and notification/verification is required (step 212 ), steps 213 through 215 are executed by sending a notification/verification request to the SGSN/MSC 103 using its identifier obtained from HLR/HSS 106 (events 505 , 506 , 507 ). SGSN/MSC 103 executes steps 300 , 320 ˜ 323 in response to the notification/verification message (event 507 ) from the GMLC 102 or executes steps 300 , 301 , 331 , 332 in response to the location request from the GMLC 102 (event 508 ) and transmits a location report or a verification report (event 509 ) to the GMLC 102 . If verification report is received, the GMLC 102 checks to see if the target UE has verified the request (step 217 ). If the request is verified, the GMLC 102 performs a second privacy check (event 510 ) on the current or last known location information by executing steps 219 to 221 and transmits location information to the client terminal 101 (event 511 ). FIG. 15B is a sequence diagram illustrating a location network operating in the MT-LR mode in which the client terminal 101 is the requesting terminal, the mobile terminal 105 is the target UE establishing its wireless link to the home network A, and the home SGSN/MSC 103 of target UE maintains its privacy profile and location report. Client terminal 101 transmits a location request (event 601 ) to the home GMLC 102 . In response, the GMLC 102 executes steps 271 ˜ 273 ( FIG. 12F ) to perform a client check (event 602 ). Being the home GMLC of the target UE, the GMLC 102 makes an affirmative decision at step 274 and executes steps 231 , 232 ( FIG. 12B ) to acquire the identifier of SGSN/MSC 103 (events 603 , 604 ) from HLR/HSS 106 and sends a location request to the SGSN/MSC 103 (event 605 ). In response to the location request from GMLC 102 , the SGSN/MSC 103 executes steps 300 ˜ 307 to perform a first privacy check and information type check (events 606 , 607 ) and executes steps 308 , 309 to perform location estimation process (event 608 ) to obtain a location report. Second privacy check is performed (event 609 ) by the SGSN/MSC 103 by executing steps 310 ˜ 313 . The location report is then transmitted (step 314 ) to the GMLC 102 (event 610 ), which receives this location report (step 235 , FIG. 12B ) and repeats it to the client terminal 101 (step 222 , FIG. 12A , event 611 ). In FIG. 15C , the location network operates in MO-LR mode in which the UE terminal 105 transmits a location request to the SGSN/MSC 103 (event 701 ). SGSN/MSC 103 responds to this request by executing steps 300 , 304 and 305 ( FIG. 13 ) to perform an information type check (event 702 ). If the current location is specified in the location request, the SGSN/MSC 103 sends a location request to the RAN 104 (steps 308 , 309 , 310 , 314 ) to provide a location estimation process (event 703 ). If last known location is specified in the location request, the SGSN/MSC 103 performs a reusability test (steps 306 , 307 ) and sends a location report (event 704 ) to the UE terminal (steps 310 , 314 ). Second Network Mode FIG. 16 is a sequence diagram illustrating a location network operating in the MT-LR mode in which the client terminal 111 is the requesting terminal, the mobile terminal 105 is the target UE which is currently staying in its home network A, and the home GMLC 102 of target UE 105 maintains its privacy profile and location report. Client terminal 111 initially transmits a location request (event 801 ) to the home GMLC 112 . In response, the GMLC 112 executes steps 201 ˜ 203 ( FIG. 12A ) to perform a client check (event 802 ). Since the privacy information of the target UE is not available, the GMLC 112 passes through steps 204 , 205 and executes steps 241 and 242 ( FIG. 12C ) to acquire the identifier of GMLC 102 (events 803 , 804 ) from the home HLR/HSS 106 of the target UE 105 and sends a location request to the GMLC 102 (event 805 ). In response to the location request from GMLC 112 , the GMLC 102 passes through steps 201 , 204 and executes steps 206 ˜ 211 to perform a first privacy check and information type check (events 806 , 807 ) and executes steps 212 ˜ 215 to obtain the identifier of SGSN/MSC 103 from HLR/HSS 106 (events 808 , 809 ) and transmit a notification/verification message or a location request (event 810 ) to the SGSN/MSC 103 . SGSN/MSC 103 performs its routine (event 811 ) and returns a location report or a verification report to the GMLC 102 (event 812 ). In response, the GMLC 102 executes steps 216 ˜ 218 and then performs a second privacy check on the received location information (steps 219 , 220 , 221 , event 813 ). The location report is then transmitted (step 222 , event 814 ) to the requesting GMLC 112 , which receives this location report (step 242 , FIG. 12C ) and repeats it to the client terminal 111 (step 222 , FIG. 12A , event 815 ). Third Network Mode FIG. 17 is a sequence diagram illustrating a location network operating in the MT-LR mode in which the client terminal 111 is the requesting terminal, the mobile terminal 105 is the target UE which is currently visiting the external network C, and the home GMLC 102 of target UE 105 maintains its privacy profile and location report. Client terminal 111 initially transmits a location request 901 to the home GMLC 112 . In response, the GMLC 112 executes steps 201 ˜ 203 ( FIG. 12A ) to perform a client check 902 . Since the privacy information of the target UE is not available, the GMLC 112 passes through steps 204 , 205 and executes steps 241 and 242 ( FIG. 12C ) to acquire the identifier of GMLC 102 (events 903 , 904 ) from the home HLR/HSS 106 of the target UE 105 and sends a location request 905 to the GMLC 102 . In response to the location request from GMLC 112 , the GMLC 102 passes through steps 201 , 204 and executes steps 206 ˜ 211 to perform a first privacy check 906 and information type check 907 and executes steps 212 ˜ 215 to obtain the identifiers of SGSN/MSC 123 and GMLC 122 from HLR/HSS 106 (events 908 , 909 ). On receiving these identifiers, the GMLC 102 executes step 215 and transmits a notification/verification request or a location request 910 to the GMLC 122 . Each of these requests contains the identifiers of SGSN/MSC 123 and GMLC 122 . In response to the request message from the GMLC 102 , the GMLC 122 passes through step 201 to step 251 ( FIG. 12D ) to repeat the received request message to the SGSN/MSC 123 . SGSN/MSC 123 performs its routine 911 and returns a location report or a verification report 912 to the GMLC 112 , which repeats it to the GMLC 102 (step 252 , FIG. 12D ). GMLC 102 executes steps 216 ˜ 218 for verification and then performs a second privacy check 913 on the received location information (steps 219 , 220 , 221 ). The location report 914 is then transmitted (step 222 ) to the requesting GMLC 112 , which repeats this location report 915 (steps 242 , 222 ) to the client terminal 111 . Fourth Network Mode FIG. 18 is a sequence diagram illustrating a location network operating in the MT-LR mode in which the client terminal 101 is the requesting terminal, the mobile terminal 105 is the target UE which is currently visiting the external network B, and the home GMLC 102 of target UE 105 maintains its privacy profile and location report. Client terminal 101 initially transmits a location request 1001 to the home GMLC 102 . In response, the GMLC 102 executes steps 200 through 211 ( FIG. 12A ) to perform a client check (event 1002 ), a privacy check 1003 and an information type check 1004 . Since the target UE is visiting the network of SGSN/MSC 113 , the GMLC 102 acquires the identifiers of SGSN/MSC 113 and GMLC 112 (events 1005 , 1006 ) from HLR/HSS 106 when its has executed steps 212 and 213 , and sends a notification/verification or location request message (each containing the acquired node identifiers) to the GMLC 112 (event 1007 ). GMLC 112 executes steps 201 , 251 ( FIG. 12D ) to repeat the received request message to the SGSN/MSC 113 . SGSN/MSC 113 executes steps 300 , 320 ˜ 323 of FIG. 13 in response to the notification/verification message from the GMLC 112 or executes steps 300 , 321 ˜ 332 in response to the location request 1008 from the GMLC 112 and sends a location report or a verification report 1009 to the GMLC 112 . GMLC 112 executes step 252 ( FIG. 12D ) to repeat the received report message to the GMLC 102 . If verification report is received, the GMLC 102 checks to see if the target UE has verified the request (step 217 ). If the request is verified, the GMLC 102 performs a second privacy check 1010 on the current or last known location information by executing steps 219 to 221 and transmits location information 1011 to the client terminal 101 . Fifth Network Mode FIG. 19 is a sequence diagram illustrating a location network operating in the MT-LR mode in which the client terminal 111 is the requesting terminal, the mobile terminal 105 is the target UE which is currently visiting the external network B, and the home GMLC 102 of target UE 105 maintains its privacy profile and location report. Client terminal 111 initially transmits a location request 1101 to the home GMLC 112 . In response, the GMLC 112 executes steps 201 ˜ 203 ( FIG. 12A ) to perform a client check 1102 . Since the privacy information of the target UE is not available, the GMLC 112 passes through steps 204 , 205 and executes steps 241 and 242 ( FIG. 12C ) to acquire the identifier of GMLC 102 (events 1103 , 1104 ) from the home HLR/HSS 106 of the target UE 105 and sends a location request 1105 to the GMLC 102 . In response to the location request from GMLC 112 , the GMLC 102 passes through steps 201 , 204 and executes steps 206 ˜ 211 to perform a first privacy check 1106 and information type check 1107 and executes steps 212 ˜ 215 to obtain the identifiers of SGSN/MSC 113 and GMLC 112 from HLR/HSS 106 (events 1108 , 1109 ). On receiving these identifiers, the GMLC 102 executes step 215 and transmits a notification/verification request or a location request 1110 to the GMLC 112 . Each of these requests contains the identifiers of SGSN/MSC 113 and GMLC 112 . In response to the request message from the GMLC 102 , the GMLC 112 passes through step 201 to step 251 ( FIG. 12D ) to repeat the received request message to the SGSN/MSC 113 . SGSN/MSC 113 performs notification/verification or location estimation routine 1111 and returns a location report or a verification report 1112 to the GMLC 112 , which repeats the report to the GMLC 102 (step 252 , FIG. 12D ). GMLC 102 executes steps 216 ˜ 218 for verification and then performs a second privacy check 1113 on the received location information (steps 219 , 220 , 221 ). If the privacy check result is favorable, the location report 1114 is transmitted from the GMLC 102 (step 222 ) to the requesting GMLC 112 , which repeats this location report 1115 to the client terminal 111 (steps 242 , 222 ). Sixth Network Mode FIG. 20 is a sequence diagram illustrating a location network operating in the MT-LR mode in which the client terminal 101 is the requesting terminal and the mobile terminal 105 is the target UE which is staying in the home network A. The PPR 107 is connected to the GMLC 102 . The privacy profile and location report of target UE 105 are maintained in the PPR 107 . Client terminal 101 initially transmits a location request 1201 to the home GMLC 102 . In response, the GMLC 102 performs a client check 1202 (steps 202 ˜ 203 ) and sends an authorization request 1203 to the PPR 107 (steps 204 , 224 ). PPR 107 performs a first privacy check 1204 and a location information type check 1205 and returns a report message 1206 . Alternatively, information type check 1207 may be provided by the GMLC 102 . GMLC 102 analyzes the received report message 1206 (step 225 ) and executes steps 212 and 213 to send an enquiry message 1208 to HLR/HSS 106 to acquire the identifier 1209 of SGSN/MSC 103 and transmits a notification/verification message or a location request message 1210 to the SGSN/MSC 103 . SGSN/MSC 103 performs a notification/verification process or location estimation process 1211 and returns a location report or verification report message 1212 to the GMLC 102 . In response to the report message, the GMLC 102 sends an authorization request 1213 to the PPR 107 (steps 216 , 217 , 218 , 261 ) to authorize it to perform a second privacy check 1214 and then analyzes a privacy check report 1215 from the PPR 107 , indicating a result of the second privacy check (step 262 ). If the result of the privacy check is favorable, the GMLC 102 repeats the location information 1216 received from the SGSN/MSC 103 to the client terminal 101 . Seventh Network Mode FIG. 21 is a sequence diagram illustrating a location network operating in MT-LR mode in which the client terminal 111 is the requesting terminal and the mobile terminal 105 is the target UE which is located in the home network A. The privacy profile and location report of target UE 105 are maintained in the PPR 107 connected to the GMLC 102 . Client terminal 111 initially transmits a location request 1301 to the home GMLC 112 . In response, the GMLC 112 performs a client check 1302 (steps 202 ˜ 203 ) and transmits an enquiry message 1303 to the HLR/HSS 106 to acquire the identifier 1304 of the home GMLC 102 of the target UE. Using the acquired identifier, the GMLC 112 sends a location request 1305 to the GMLC 102 . GMLC 102 responds to the location request by transmitting an authorization request 1306 to the PPR 107 . PPR 107 performs a first privacy check 1307 and an information type check 1308 and returns a report message 1309 to the GMLC 102 . GMLC 102 analyzes the received report (step 225 ) and executes steps 212 and 213 to acquire the identifier of SGSN/MSC 103 from HLR/HSS 106 (events 1310 , 1311 ) and transmits a notification/verification message or a location request message 1312 to the SGSN/MSC 103 . SGSN/MSC 103 performs a notification/verification process or location estimation process 1313 and returns a location report or verification report message 1314 to the GMLC 102 . In response to the report message 1314 , the GMLC 102 sends an authorization request 1315 to the PPR 107 (steps 216 , 217 , 218 , 261 ) to authorize it to perform a second privacy check 1316 and analyzes a privacy check report 1317 from the PPR 107 (step 262 ). If the result of the privacy check is favorable, the GMLC 102 sends the location information 1319 received from the SGSN/MSC 103 to the client terminal 101 . Eighth Network Mode FIG. 22 is a sequence diagram illustrating a location network operating in the MT-LR mode in which the client terminal 111 is the requesting terminal and the mobile terminal 105 is the target UE which is visiting the external network C. The privacy profile and location report of target UE 105 are maintained in the PPR 107 connected to the GMLC 102 . Client terminal 111 transmits a location request 1401 to the home GMLC 112 . In response, the GMLC 112 performs a client check 1402 and transmits an enquiry message 1403 to the HLR/HSS 106 to acquire the identifier 1404 of the home GMLC 102 of the target UE. Using the acquired identifier, the GMLC 112 sends a location request 1405 to the GMLC 102 . GMLC 102 responds to the location request by transmitting an authorization request 1406 to the PPR 107 . PPR 107 performs a first privacy check 1407 and an information type check 1408 and returns a report message 1409 to the GMLC 102 . GMLC 102 acquires the identifiers of SGSN/MSC 123 and GMLC 122 from HLR/HSS 106 (events 1410 , 1411 ) and transmits a notification/verification message or a location request message 1412 to the SGSN/MSC 123 via the GMLC 122 . SGSN/MSC 123 performs a notification/verification process or location estimation process 1413 and returns a location report or verification report message 1414 to the GMLC 102 via the GMLC 122 . In response to the report message 1414 , the GMLC 102 sends an authorization request 1415 to the PPR 107 to authorize it to perform a second privacy check 1416 and analyzes a privacy check report 1417 from the PPR 107 . If the result of the privacy check is favorable, the GMLC 102 sends the location information 1418 received from the SGSN/MSC 123 to the GMLC 112 , which sends location information 1419 to the client terminal 111 . Ninth Network Mode FIG. 23 is a sequence diagram illustrating a location network operating in the MT-LR mode in which the client terminal 101 is the requesting terminal and the target UE 105 is visiting the external network B. The privacy profile and location report of the target UE are maintained in the PPR 107 connected to the GMLC 102 . Client terminal 101 transmits a location request 1501 to the home GMLC 102 . In response, the GMLC 102 performs a client check 1502 and transmits an authorization request 1503 to the PPR 107 . PPR 107 performs a first privacy check 1504 and an information type check 1505 and returns a report message 1506 to the GMLC 102 . GMLC 102 acquires the identifiers of SGSN/MSC 113 and GMLC 112 from HLR/HSS 106 (events 1507 , 1508 ) and transmits a notification/verification message or a location request message 1509 to the SGSN/MSC 113 via the GMLC 112 . SGSN/MSC 113 performs a notification/verification process or location estimation process 1510 and returns a location report or verification report message 1511 to the GMLC 102 via the GMLC 112 . In response to the report message 1511 , the GMLC 102 sends an authorization request 1512 to the PPR 107 to authorize it to perform a second privacy check 1513 and analyzes a privacy check report 1514 from the PPR 107 . If the result of the privacy check is favorable, the GMLC 102 sends location information 1515 received from the SGSN/MSC 113 to the client terminal 101 . Tenth Network Mode FIG. 24 is a sequence diagram illustrating a location network operating in MT-LR mode in which the client terminal 111 is the requesting terminal and the target UE 105 is visiting the external network B. The privacy profile and location report of target UE 105 are maintained in the PPR 107 connected to the GMLC 102 . Client terminal 111 transmits a location request 1601 to the home GMLC 112 . In response, the GMLC 112 performs a client check 1602 and transmits an enquiry message 1603 to the HLR/HSS 106 to acquire the identifier 1604 of the home GMLC 102 of the target UE. Using the acquired identifier, the GMLC 112 sends a location request 1605 to the GMLC 102 . GMLC 102 responds to the location request by transmitting an authorization request 1606 to the PPR 107 . PPR 107 performs a first privacy check 1607 and an information type check 1608 and returns a report message 1609 to the GMLC 102 . GMLC 102 acquires the identifiers of SGSN/MSC 113 and GMLC 112 from HLR/HSS 106 (events 1610 , 1611 ) and transmits a notification/verification message or a location request message 1612 to the SGSN/MSC 113 via the GMLC 112 . SGSN/MSC 113 performs a notification/verification process or location estimation process 1613 and returns a location report or verification report message 1614 to the GMLC 102 via the GMLC 112 . In response to the report message 1614 , the GMLC 102 sends an authorization request 1615 to the PPR 107 to authorize it to perform a second privacy check 1616 and analyzes a privacy check report 1617 from the PPR 107 . If the result of the privacy check is favorable, the GMLC 102 sends the location report 1618 received from the SGSN/MSC 113 to the GMLC 112 which transmits the location information 1619 to the client terminal 111 .

A location system comprises a communication terminal for transmitting a location request specifying a target mobile terminal and a type of location information, and a location network. In response to the location request, the location network produces current location information of the target mobile terminal if the type of location information of the received request specifies current location information and transmits the current location information to the communication terminal and stores the last known location information in a memory as last known location information of the target mobile terminal. If the type of location information specifies last known location information, stored last known location information of the target mobile terminal is copied from the memory and transmitted to the communication terminal if the location request is verified by a privacy check and if the stored information is reusable.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This Application claims the priority under 35 USC 119 of U.S. Provisional Patent Application No. 60/433,755, filed Dec. 16, 2002. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] This invention relates to electrical stimulation of a cavernous nerve and a device for doing the same. [0004] 2. Description of the Prior Art [0005] Nerve impulses are transmitted in the body by the nervous system which includes the brain, spinal cord, nerves, ganglia and the receptor. Nerves are made up of axons and cell bodies together with their respective protective and supporting structures. The axon is the long extension of the nerve cell that conducts nerve impulses to the next neuron. [0006] The propagation of the nerve impulse along the axon is associated with an electric potential and a flow of cations into and out of the axon. This electric potential is called the action potential. The typical human action potential has an advancing front of depolarization with a peak value of +40 mV. In order to continue to propagate, the action potential must trigger the depolarization of the neural tissue directly at the front of the advancing wave. [0007] In order to produce depolarization, the interior of the axon must be depolarized from its resting potential of −70 mV (a typical resting voltage potential) to a potential of −60 mV. However, once −60 mV is reached, the sodium channels in the axon opens and causes sodium cations (Na+) to flow into the axon, thereby allowing the depolarization to proceed to +40 mV. Other ion channels then open and cause the potassium cations in the axon to flow out of the axon until the interior of the cell repolarizes to −70 mV. [0008] Thus, all that is necessary to propagate the action potential is to have an external potential which can bring the interior of the cell to −60 mV. Since the action potential consists of an advancing wave of +40 mV, under normal conditions the interior of the cell will depolarize to −30 mV (−70 mV+40 Mv), which is more than enough to propagate the action potential. As is known, these potentials are externally induced transmembrane potentials which are measured across the wall of the axon. [0009] Given the fact that the nerve impulse is transmitted along the axon due to an electrical potential (the action potential), there have been a number of studies into the artificial propagation of nerve impulses using various electrical devices. For example, electrodes have been inserted into a nerve and a current passed through the nerve to cause movement of muscles. [0010] Direct application of electric current has also been used to effect neurostimulation. In this technique, electrodes were applied directly to the skin or to underlying structures in a way which created an electric current between the two electrodes in the tissue in which the target neuronal structure was located. This technique employed a constant voltage source and was intended to cause neuronal transmission and thereby produce stimulation both in peripheral nerves and in the brain. [0011] The influence of an external electric field on neuronal tissue has also been studied. One model for this is the effect of a monopolar electrode in the proximity of a neuron. (Rattay F, J Theor. Biol (1987) 125,339-349). The model for electrical conduction in the neuron, which has been widely accepted, is the modified cable equation: ∂ V ∂ t = [ d 4     ρ i  ( ∂ .  V ∂ x 2 + ∂ V e ∂ x 2 ) - i i ] / c m ( eqn     1 ) [0012] where: [0013] V represents voltage, [0014] i i is the total ionic current density, [0015] ρ i =the resistivity of the axoplasm, [0016] c m =capacitance of the membrane, [0017] Ve=externally applied voltage, [0018] the term: ∂ V e ∂ X 2 ( eqn     2 ) [0019] is referred to the activating function by Rattay because it is responsible for activating an axon by external electrodes. [0020] The activating function has two possible effects on an axon. If its magnitude is sufficient there is a superthreshold response. This leads to the generation of an action potential. If this occurs then the cable equation will predict the expected response. In order to calculate the equation however the ionic current term i i must be calculated. [0021] In order to calculate the ionic current, an equation of membrane ionic current, as a function of the externally induced transmembrane potential, is used. For myelinated membranes the Hodgkin-Huxley equation can be used. For unmyelinated membranes the Huxley-Frankenhaeuser equation is used. [0022] There are other equations which account for membrane temperature as well. The other possible effect on the axon is subthreshold stimulation. [0023] If a subthreshold stimulus is applied, then the transmembrane voltage is directly related to the activating function. The voltage changes due the opening of voltage sensitive ionic channels can be ignored. The calculation of transmembrane voltage becomes simplified. It is the subthreshold stimulation of the neuron which is considered in this patent application. SUMMARY OF THE INVENTION [0024] The present invention stimulates a cavernous nerve of a patient by exposing the cavernous nerve of the patient to different spatially and temporally varying electromagnetic fields by means of a magnetic flux generator positioned external to the patient close to the cavernous nerve. More specifically, the invention generates an electric current in the cavernous nerve producing areas of depolarization which lead to the propagation of nerve signals in the cavernous nerve. Thus, this invention provides for an entirely new form of stimulation both sensory stimulation and motor (erectile function) stimulation. [0025] The term cavernous nerve as used herein means one or more nerves which have erectile function in an animal, especially, a human being. [0026] This invention also provides a localizing system. In the prior art of neurostimulation, an electronic device is usually implanted in the patient. However, with implanted electronic devices, complexity and cost increases. The present invention avoids these problems. Broadly, the method of the present invention comprises: [0027] (1) creating a magnetic flux with a magnetic flux generator, said generator being positioned completely external to the patient; and [0028] (2) treating a cavernous nerve of said patient with said magnetic flux to cause an electric current along an axon which leads to a focused propagation of an action potential in said cavernous nerve thereby resulting in an erection. [0029] As is known, a time varying magnetic field, which is a magnetic flux, results in an electric field. The orientation and strength of the magnetic flux and its resulting electric field is such that it depolarizes regions along the axon so as create areas of neurostimulation. Electric current is thus caused to travel in the cavernous nerve. [0030] To accomplish stimulation in accordance with the present invention, a preliminary study is performed wherein the nerve response to specific stimuli is recorded. More specific microelectrodes are used to measure the individual axonal response of a nerve to specific stimuli. The axonal action potentials created by the magnetic flux reproduce the previously measured axonal responses to stimuli thereby causing an erection and sensory stimulation in the brain. [0031] The strength of depolarization is expressed as a voltage and is a measurement of the voltage or electric potential between the inside of the axon and the outside of the axon. This electric potential is sometimes referred to as the externally induced transmembrane potential since it is measured across the cell wall. [0032] For depolarization, the magnetic flux should be of such an orientation and strength so as to create a net externally induced transmembrane potential equal to or greater than −60 mV. More preferably, the electric potential created by the magnetic flux of the present invention should be about −50 mV or greater and, more preferred, about −40 mV or greater. It should be understood that “greater” means more positive. [0033] The orientation of the electric field is such that it has a component parallel to the long axis of the axon. [0034] Preferably, the configuration of magnetic flux generators produces a depolarized region. This ensures propagation of a nerve signal down an axon. [0035] The magnetic flux generator of the present invention is a RLC (resistor, inductor, capacitor) circuit with a coil of wire as the inductor. The magnetic flux generates a depolarized region. The externally induced transmembrane potentials for the depolarized region have a strength and orientation as referred to above, e.g. depolarized equal to or greater than −60 mV. [0036] Suitable, the coil of wire can have various shapes and sized such as round, figure eight, square, torroidal, etc. Most preferably, the magnetic flux generator is an RLC circuit with a round coil of wire. As will be appreciated by one of skill in the art, any high DC voltage pulsed power supply can be employed with the inductive elements. [0037] The round coil of wire is preferably in series with a capacitor and a resistor so as to form a RLC circuit. The capacitor is discharged through the device so as to form a time varying magnetic field which in turn creates an electric field. [0038] Furthermore, a plurality of magnetic flux generators can be used such that no one individual magnetic flux generator produces the necessary electric field but that the combined generators, when oriented towards the cavernous nerve to produce a net electric field. That net electric field is of sufficient magnitude to produce a depolarized region of sufficient externally induced transmembrane potential to produce a unidirectional neural impulse. [0039] The round coil of wire is preferably housed within a housing so as to insulate the round coil of wire from the skin. Examples of a preferred housing is a ring, a patch, or a prophylactic. The housing is adapted to be worn on the outside of the penis so as to maintain the coil in close proximity to the cavernous nerve during movement of the cavernous nerve. [0040] The round coil of wire is designed to be mounted in a plane substantially perpendicular or substantially parallel to a plane of the cavernous nerve. This substantially parallel arrangement would also include a half-wrap around the penis. All of these configurations may be incorporated into a housing as well. [0041] The capacitor and the voltage source are mounted external to the housing that houses the coil. Suitably, they are located in a pouch that is worn by the patient, or in a pouch that is beside the patient. [0042] Broadly, the present invention can be described as follows: [0043] A method for stimulating the cavernous nerve in a patient comprising the steps of: [0044] creating a time varying magnetic field with a device positioned completely external to said patient, said time varying magnetic field resulting in an electric current in said cavernous nerve, for as long as required, said electric current causing the progation of a neural impulse in said neural tissue thereby resulting in an erection. [0045] Preferably, the device comprises a coil of wire which can produce a time varying magnetic field. [0046] More preferably, said coil of wire is housed within a housing so as to insulate said coil of wire. [0047] Suitably, said device comprises a resistor, a capacitor and a coil of wire in series. [0048] More preferably, said capacitor is discharged through said coil of wire so as to form a time varying magnetic field which in turn creates said electric field. [0049] More preferably, said coil of wire is circular in shape and has about 7 to about 10 turns, and said coil of wire has a diameter of about 3 to about 7 cm. [0050] Preferably, a time varying current passes through said device and said time varying current increases from 0 to about 6000 amps in 60 microseconds. [0051] More preferably, said coil of wire has a resistance (R) of about 0.1 to about 0.5 ohms and a inductance (L) of about 10 to about 90 microhenries. [0052] Alternatively, the present Invention can be described as follows: [0053] An electrical device for producing a nerve impulse in the cavernous nerve so as to produce an erection, said device comprising: [0054] a RLC circuit comprising a resistor, a coil of wire, and a capacitor, wherein said coil of wire is positioned so as to situate said coil in close proximity to said cavernous nerve; [0055] a housing for insulating said coil of wire. [0056] Preferably, said housing is a ring, a patch, or a prophylactic; and said housing is adapted to be worn on the outside of a penis. [0057] Suitably, said coil of wire completely encircles a penis. [0058] Preferably, said coil of wire is in a plane substantially perpendicular to a plane of said cavernous nerve. [0059] Suitably, said coil of wire is in a plane substantially parallel to a plane of said cavernous nerve. [0060] Preferably, said coil of wire is half-wrapped around a penis. [0061] Preferably, current produces an electrical field which creates a triphasic potential within the cavernous nerve, said triphasic potential consisting of a virtual cathode surrounded by a virtual anode on either side of said virtual cathode. [0062] Suitably, the RLC circuit creates a time varying magnetic field, said time varying magnetic field resulting in an electric current in said cavernous nerve, for as long as required, said electric current causing the progation of a neural impulse in said neural tissue thereby resulting in an erection. [0063] Suitably, said coil of wire is circular in shape and has about 7 to about 10 turns, and the coil has a diameter of about 3 to about 7 cm. [0064] Preferably, a time varying current passes through said RLC circuit and said time varying current increases from 0 to about 6000 amps in 60 microseconds. [0065] Preferably, said coil of wire has a resistance (R) of about 0.1 to about 0.5 ohms and an inductance (L) of about 10 to about 90 microhenries. BRIEF DESCRIPTION OF THE DRAWINGS [0066] These and other aspects of the present invention may be more fully understood by reference to one or more of the following drawings wherein: [0067] [0067]FIG. 1 is an overall schematic of the present invention illustrating the magnetic flux generator as a round coil in a RLC circuit; [0068] [0068]FIG. 2 illustrates a nerve modeled as a lumped circuit; [0069] [0069]FIG. 3 illustrates a computer program used to calculate externally induced transmembrane potentials; [0070] [0070]FIG. 4 a illustrates the calculated electric field along a length of axon; [0071] [0071]FIG. 4 b illustrates the calculated externally induced transmembrane potential along a length of axon using the computer program; [0072] [0072]FIGS. 4 c - 4 g show the graphs of the externally induced transmembrane potential across different cross sections of the nerve bundle, corresponding to FIG. 4 b; [0073] [0073]FIG. 4 h illustrates the calculated externally induced transmembrane potential along a length of axon using the computer program with a different set electrical circuit parameters than FIG. 4 b; [0074] [0074]FIGS. 4 i - 4 k show the graphs of the externally induced transmembrane potential across different cross sections of the nerve bundle, corresponding to FIG. 4 h; [0075] [0075]FIG. 5 illustrates current versus time for a coil used in accordance with the present invention; [0076] [0076]FIG. 6 illustrates two proximate coils used to maintain the magnetic flux; [0077] [0077]FIGS. 7 a - 7 i illustrate a several arrangements of the coil of the present invention; and [0078] [0078]FIG. 8 illustrates a schematic for a circuit that can deliver high frequency, high voltage DC current. DETAILED DESCRIPTION OF THE INVENTION [0079] [0079]FIG. 1 illustrates magnetic coil 10 overlying axon 12 and the coordinate system used to describe the three dimensional space around these elements. Coil 10 which lies above axon 12 consists of a series of turns of a conduction wire typically copper although other metals or alloys can be used. Coil 10 is the inductive component in the RLC circuit 13 . [0080] RLC circuit 13 is well known to those experienced in the art of electronics. It consists of resistor R, inductive element L, which is coil 10 in the circuit shown in FIG. 1, and capacitor C in series. The behavior of the RLC circuit 13 is well known to those experienced in the field of electronics. Voltage source Vo in conjunction with switch So is used to charge capacitor C when switch S is in position 1 . [0081] Capacitor C is then discharged through resistor R and coil 10 when switch S is moved to position 2 . The total current I(+) and the rate of change of the current when capacitor C is discharged through resistor R and coil 10 can be calculated in a conventional manner. [0082] Axon 12 is parallel to the y-axis; it lies Z o below the coil and X o from its axis. When capacitor C is discharged, the current, I(t) in the coil induces an electric field in the tissue whose gradient in the direction of the nerve axis is the activating function. It determines the local transmembrane current in the axon and is related to the magnetic vector potential, Ao, and its component lying along the axon, Ay. [0083] The externally induced transmembrane potential in axon 12 is calculated using the cable equation. The cable equation is: δ 2  ∂ 2  V ∂ x 2 - V - α     ∂ V ∂ t = δ 2  ∂ E x ∂ x ( eqn     3 ) ∂ E x ∂ x ( eqn     4 ) [0084] where [0085] δ=space constant of the cable equation, [0086] α=the time constant of the cable equation, the term: E = - Δ     ϕ - 1 c  ∂ A ∂ t ( eqn     5 ) [0087] is referred to as the activating function. The activating function determines the transmembrane voltage for subthreshold stimulation. [0088] One of Maxwell's Equations relates the electric field E along the axon to the magnetic potential A created by the coil 10 : where the first term in the equation: −Δφ [0089] represents the contribution to the electric field from fixed charge. In this particular example, there is no fixed charge contributing to the field thus this term can be eliminated and the equation for the electric field becomes: E = - 1 c  ∂ A ∂ t ( eqn     6 ) [0090] For the case of the coil with a time varying current, such as coil 10 in the present invention, the equation for the induced magnetic vector potential has been described (Jackson J D. Classical Electrodynamics. 1962, New York): A c = I  ( t )  ρ c  μ π  ∫ 0 2  π     cos     φ      φ ( ρ     c ) 2 + ρ 2 - 2     ρ     ρ c     sin     θ     cos     φ ( eqn     7 ) [0091] the equation simplifies to: A c = I  ( t )  ρ c  μ π  ( ρ     c ) 2 + ρ 2 - 2     ρ     ρ c     sin     θ     cos     φ ×     ( 2 k 2  ( ( K  ( k ) - E  ( k ) ) - K  ( k ) ) ) ( eqn     8 ) [0092] where k is defined by: k 2 = 4     ρ c  ρ     sin     θ ρ c 2 + ρ 2 - 2  ρ     ρ c  sin     θ ( eqn     9 ) [0093] substituting the expression for the magnetic vector potential into the expression for the component of the electric field along the axon 12 (y component): E =  ( ∂ A ∂ t ) =   ( I  ( t ) )  t  ρ c  μ     cos     ( φ ) π  ( ρ     c ) 2 + ρ 2 - 2     ρ     ρ c     sin     θ     cos     φ ×  ( 2 k 2  ( ( K  ( k ) - E  ( k ) ) - K  ( k ) ) ) ( eqn     10 ) [0094] In order to calculate the value of the preceding equation, the time derivative of the current (dI/dt) must be determined. But to do this an expression for the current in the coil 10 must be obtained. [0095] The circuit for the magnetic coil takes the form of an RLC circuit. There is a resistor R, a capacitor C, and the coil 10 , which is the inductive element (L). The inductance of the coil can be calculated by standard formulas known to those experienced in the art (Smythe W R Static and Dynamic Electricity. New York: McGraw-Hill, 1968): L = μ 0  r c  N 2  ( ln  ( 8     r c r w - 1.75 ) ) ( eqn     11 ) [0096] where [0097] L is the inductance of the coil, [0098] rc is the coil radius, [0099] rw is the wire radius, [0100] N is the number of turns in the coil, and [0101] mu is the magnetic permeability. [0102] The equation for the current in an underdamped RLC circuit is also well known to those experienced in the art of electronics: I  ( t ) = V o w b  L   ( - w a  δ )  t  sin     w b  t ( eqn     12 ) [0103] where [0104] w a =(1/LC) 0.5 [0105] w b =w a (1−delta 2 ) 0.5 [0106] δ=R/2(C/L) 0.5 [0107] Vo=initial voltage across capacitor, [0108] C is the capacitance of the capacitor (in farads), and [0109] R is the resistance of the resistor (in ohms). [0110] The axial electric field gradient is the source term in the modified cable equation (Equation 1) for nerve conduction. The ultimate objective is to calculate the other variable in the equation which is the externally induced transmembrane potential, V in Equation 3. [0111] Equation 3 is a nonlinear second order partial differential equation. Traditionally all equations in this class tend to be difficult to solve analytically. There have been many publications describing the solution of the modified cable equation (Nagarajan S S, Durand D M and Warman E N. Effects of Induced Electric Fields on Finite Neuronal Structures: A Simulation Study. Transactions on Biomedical Engineering 40(11), pgs;1175-1187), 1993). [0112] It has been a common practice to reduce the equation to a series of linear differential equations using a compartmental analysis technique. (Segev I Fleshman W and Burke RE, “Compartmental Models of Complex Neurons” Methods of Neuronal Modelling: From Synapses to Networks, Koch C and Segev I, Eds. Cambridge, Mass.; MIT Press, 1989, pgs:63-97) [0113] In this method the nerve is divided into N compartments. Each compartment is modeled as a lumped circuit. The repeating unit of this compartmental circuit is shown in FIG. 2. In the case of a myelinated nerve the repeating unit can be taken as the portion the nerve bounded by two adjacent nodes. [0114] The axial current in each compartment is secondary to two factors. The first is the voltage gradient along the axon. The second is the extrinsically induced electric field from the externally fluxing magnetic field. The current can be related to these electric potential terms by Ohm's Law in the following fashion: I=G ( V a −V b )− G∫ a b E x dx   (eqn 13) [0115] where a and b are two adjacent nodes, [0116] I net is the axial current, [0117] G is the conductance in the axon, [0118] Ex is the axial component of the magnetically induced electric field, and [0119] Va and Vb are the voltages at the two adjacent nodes. [0120] In order to extend Equation 13 to the entire axon it is necessary to apply the above equation to a node and its two adjacent nodes such that a current balance equation for the central node is created, The equation for the transmembrane current at the middle node is: I net =G ( V c −2 V b +V c )− G (∫ b c ( Ex ) dx−∫ a b ( Ex ) dx )  (eqn 14) [0121] where the naming conventions used in Equation 13 apply and where Vb is the potential in the center node and Va and Vc are the potentials in the two surrounding nodes. The net transmembrane current can be expressed as the sum of channel current and the current due to the capacitative elements in the cell: I t = C   v  t + I t ( eqn     15 ) [0122] where: [0123] C dV/dt is the capacitative current term, and [0124] I ch is the ionic channel term. [0125] This can be substituted into Equation 14 for the net current term Inet. [0126] In the steady state condition the time dependent terms vanish and this equation now becomes: I ch =G ( V c −2 V b +V c )− G (∫ b c ( Ex ) dx−∫ a b ( Ex ) dx )  (eqn 16) [0127] Finally the transmembrane current through the center node in the subthreshold steady state I ch can be expressed as the product of the channel conductance Gm and the externally induced transmembrane potential Vb. V h G M =G a ( V c −2 V b +V c )− G a (∫ b c ( Ex ) dx−∫ a b ( Ex ) dx )  (eqn 17) [0128] rearranging terms: V c - ( ( G m G a + 2 )  V b ) + V a = ∫ b c  ( Ex )   x - ∫ a b  ( Ex )   x ( eqn     18 ) [0129] Finally the equation is applied to all nodes such that each node is successively treated as the center node with the exception of the two terminal nodes: V n - 1 - ( ( G m G a + 2 )  V n ) + V n - 1 = ∫ ( n )   l ( n - 1 )   l  ( Ex )   x - ∫ ( n - 1 )   l ( n )   l  ( Ex )   x ( eqn     19 ) [0130] where: [0131] n=2, 3, 4, . . . L−1, [0132] dl is he internodal distance, and [0133] L is the total number of nodes in the nerve segment of interest. For the two terminal nodes the applicable equations are: for     n = 1     ( ( G m G a + 1 )  V 1 ) - V 2 = ∫ 0 2  dl  ( Ex )   x ( eqn     20 ) for     n = L     V n - ( ( G m G a - 1 )  V n - 1 ) = ∫ ( L - 1 )  dl ( L )  dl  ( Ex )   x ( eqn     21 ) [0134] Thus, there are L equations in L unknowns. The unknowns are the externally induced transmembrane potentials located in the vector V=(V 1 ,V 2 ,V 3 , . . . V 1 ). The known quantities in the equations are the internodal potential differences due to the externally induced electric field: E={E 1 ,E 2 ,E 3 ,E 4 . . . EL}. These are L linear simultaneous equations which can easily be solved by a variety of techniques. [0135] A computer program, shown in FIG. 3, calculates the externally induced transmembrane potentials in the subthreshold condition. In this program the simultaneous equations are expressed as the matrix product of the matrix: A which contains the coefficients for V 1 ,V 2 . . . and the product of the matrix: B which contains the coefficients of E 1 ,E 2 ,E 3 . . . leading to the following equation: A*V=B*E   (eqn 22) [0136] Then V can be solved for: V=A −1 *B*E   (eqn 23) [0137] Using the preceding equations it is possible to calculate the correct coil and circuit parameters to produce a region of depolarization along the nerve. Depolarization leads to a propagating neural impulse. [0138] Thus, a neural impulse can be propagated in a unidirectional fashion. The typical human action potential has an advancing front of depolarization with a peak value of 40 mv. In order to continue to propagate, the action potential must trigger the depolarization of the neural tissue directly at the front of the advancing wave. [0139] In order to produce depolarization the interior of the axon must be depolarized from its resting potential of −70 mv to a potential of −60 mv. Once −60 mv is reached the sodium channels in the cell opens allowing the depolarization to proceed. Other ion channels can then open until the interior of the cell depolarizes to 40 mv. [0140] Thus, all that is necessary to propagate the action potential is to have an external potential which can bring the interior of the cell to −60 mv. Since the action potential consists of an advancing wave of 40 mv, under normal conditions the interior of the cell will be depolarized to −30 mv, which is more than enough to propagate the action potential. [0141] Equations 12, 13, 20, 21, 22, and 23 can be used to calculate the resultant externally induced transmembrane potential induced for a specific set of coil and RLC circuit characteristics. Thus the circuit parameters required to produce +10 mv of depolarization at any one point along an axon can be determined. This is the requirement for producing a unidirectional neural signal. [0142] Equations 12, 13, 20, 21, 22, and 23 were incorporated into the computer program shown in FIG. 3. As described earlier, it calculates the externally induced transmembrane potential when the coil and circuit characteristics are provided. The input (independent variables) are coil radius, resistance capacitance, inductance and initial voltage for the RLC circuit, and the position of the coil with respect to the target axon. [0143] As is understood by those skilled in the art, temperature can change the resting potential of the cell and, hence, can cause a change in the necessary electric field for propagation or blocking of the action potential. Additionally, other metabolic conditions can cause a change in the resting potential and, hence, would require a change in the necessary electric field generated by the magnetic flux in accordance with the present invention. Furthermore, it is known that some nerves have resting potentials which are greater than −70 mv. Again, adjustments are made to the magnitude of the magnetic flux so as to produce the necessary externally induced transmembrane potential. EXAMPLE 1 [0144] This example illustrates stimulation in accordance with the present invention. [0145] Using this computer program it is thus possible to calculate the correct values for the RLC circuit and coil to produce sufficient transmembrane voltage to produce a unidirectional focused neural impulse. There are different possible combinations of circuit and coil parameters which will satisfy the required transmembrane voltage criteria. The following example illustrates one set of conditions which produce the desired effect. One set of values of circuit and coil which yield sufficient externally induced transmembrane potentials are: [0146] Rc=radius of coil=1 cm, [0147] Rw=radius of wire=1 mm, [0148] Resistance R=0.21 ohms, [0149] Capacitance C=0.0072 Farad, [0150] Inductance of coil=L=9e-5 Henry, [0151] Voltage=Vo=700 volts, and [0152] z0=height is coil above axon=3 cm. [0153] [0153]FIGS. 4 a and 4 b show the results of the calculation of induced electric field and externally induced transmembrane potential, respectively, along the length of the axon using the preceding coil and circuit values. Note that this is the externally induced transmembrane potential induced by the coil. The net transmembrane potential would be equal to the induced transmembrane potential plus the resting potential of the neuron (e.g. −70). [0154] The time is 60 microseconds from the application of 100 volts dc across the circuit. FIG. 4 a shows a surface plot of the induced electrical field in neuronal tissue in a plane 3 cm below the coil. The x and y axes represent all points in that plane. The vertical z axis represents the electric field strength in FIG. 4 a and the externally induced transmembrane potential (millivolts) in FIG. 4 b. [0155] From examination of the graph in FIG. 4 a , it can be seen that there is a maxima and a minima in the electric field. Similarly there are multiple maxima and minima in externally induced transmembrane potential as shown in FIG. 4 b . The minima correspond to hyperpolarized points. To block propagation of neural impulses these points have to have an induced transmembrane potential more negative than −30 mv. In that case the net transmembrane potential at these points will be greater than −100 mv and thus cannot be depolarized by an advancing action potential. [0156] Among the maxima in the graph there are points with an induced transmembrane potential of greater than 10 mv. Thus the net transmembrane potential at these points will be greater than −60 mv and thus can initiate depolarization and an axonal impulse. [0157] [0157]FIGS. 4 c - 4 g show the graphs of the externally induced transmembrane potential across a specific cross section of the nerve bundle. These graphs correspond to the coil used for FIGS. 4 a and 4 b . FIGS. 4 c - 4 g would correspond to a specific y value (position along the axon). The vertical axis shows the externally induced transmembrane potential at each point along a cross section of a nerve bundle. The calculation was done for a cross section from x=−4 to +4 cm. [0158] Obviously there are no nerve bundles with such a large diameter. However the graph allows one to see how the externally induced transmembrane potential is affected by the positions of a nerve bundle with respect of the overlying coil. The electrical parameters for the coil circuit are those given in Example 1. The data presented in these graphs is simply a subset of the data shown in FIGS. 4 a and 4 b. [0159] [0159]FIG. 4 c shows the externally induced transmembrane potential at the nerve bundle cross section which is +1.0 cm from the center of the coil. At this point it can be seen that there is a sharply delineated zone where the externally induced transmembrane potential rises to a value of 10.2 mv. This is just above the value necessary to cause depolarization. What is even more important is the singularity of the maxima and the linearity of the data around this point. [0160] These two features provide for the stimulation of only a small zone within a nerve bundle. Ideally, a single axon within the bundle is stimulated. One of the critical objects of this invention is the ability to cause focal axonal stimulation. [0161] That is because different axonal fibers within a nerve bundle correspond to different end organ receptors and thus would be carrying different neural impulses to the brain. In order to accomplish this it is necessary to have a means of creating a focal change in the externally induced transmembrane potential that would not affect adjacent axonal fibers. [0162] Given that the maxima in FIG. 4 c is a single point it is possible to make the zone of stimulation as narrow as desired. This can be proven on the basis of the theory in mathematical analysis called the continuity theory. This states that for a curve for any two chosen points (such as the points where the externally induced transmembrane potential equals 9.5 and top of the curve where it is 10.2 mv), all intermediate values on the curve exist. [0163] In fact, it is possible to make minor changes to the voltage so that the maxima can take on values as close to 10.0 as desired. As the maxima get closer and closer to 10 mv, the range of x values (along the cross section of the nerve) for which the externally induced transmembrane potential is greater than 10 mV., can be made as small as desired. This is a result of the aforementioned continuity theory. Thus, it is literally possible to make the zone of axonal stimulation as narrow as desired. Thus, the present invention has the complete ability to focus the stimulation and stimulate only one axon if desired. [0164] In addition, it will be noted that at all cross sectional segments to the right, (more positive than the current one (x=1.0 cm) have no areas of critical depolarization (>10). This can be seen by observing FIGS. 4 d (x=1.5 cm), 4 e (x=2 cm), 4 f (2.5 cm), and 4 g (3.0 cm). For the purpose of sensory stimulation, the coil will be oriented so that the region to the right of the coil (x>0) is lying on the proximal side of the neuron (closer to the brain than the coil). [0165] Thus, the present invention provides a means of selectively stimulating a tiny (axonal) segment of a nerve bundle and then propagating that signal. Because of the absence of areas of critical depolarization to the right of the signal origin, it will always remain as focused desired. [0166] As noted before, a conventional preliminary study has to be carried out so as to pinpoint which axon to stimulate for a specific sensory perception. Then this axon is stimulated in accordance with the present invention. [0167] Referring back to FIG. 5, it can be seen that this time interval corresponds to the portion of the current versus time curve where there is a rapid rise in current from 0 amps to 5827.6 amps over a 60 microsecond interval. Therefore, in order to maintain the proscribed transmembrane potential, it is necessary to have an electrical circuit which can maintain this rapid rise of current change through the magnetic coil at all times. In order to accomplish this, two components are needed. [0168] The first is a high voltage DC generator which can produce high voltage DC pulses at a rapid rate. This type of circuit is well known to those experienced in the art of electronics. There are many commercial firms which manufacture such high voltage supplies. One such company is Huettinger Electronic, Inc, (111 Hyde Road, Framington, Conn. 06032, USA). Many other circuits can also be used to produce high frequency, high voltage DC pulses. One such circuit is shown in FIG. 8. [0169] As shown in FIG. 8, horizontal drive transformer (T 1 ) was from small B/W monitor, flyback transformer (T 2 ) was from MacIntosh Plus computer monitor, original primary windings were removed, component values are not critical, output may exceed 25,000 V at certain frequencies with 24 V power—could destroy flyback. Sparkgap provides more protection. Input power was current limited to about 5A. Good heat sink is important on Q2 for continuous operation. [0170] Regardless of how fast the high voltage generator can pulse a RLC circuit, there will be a discontinuity in the current gradient and thus the externally induced transmembrane potential. That is because the current flow in the circuit must drop back down to zero so that there can be another steep rise in current, which is necessary to generate the proper externally induced transmembrane potential. [0171] In order to prevent discontinuity in the externally induced transmembrane potential, there can be two separate RLC circuits with identical values for resistance, inductance, capacitance and initial voltage. Both circuits are powered by high frequency high voltage DC pulses. The two coils are proximate to each other so that they produce the same spatial and temporal distribution of electric fields for a given coil current. [0172] [0172]FIG. 6 illustrates such an arrangement. As shown, one coil 10 a is positioned directly on top of the other coil 10 b with insulating material 10 c positioned between the two to prevent direct electrical contact. For the purpose of the rest of this document, the conglomerate of the two proximate coils will be referred to by the number 10 . [0173] In addition to the proximate coils 10 , there is a high speed discharge circuit which will short circuit the capacitor in the RLC circuit 13 a and 13 b and, thus, bring the circuit current down to zero almost instantaneously. The two circuits 13 a and 13 b are timed so that the second circuit is pulsed with a DC discharge 50 microseconds after the first circuit was pulsed. Ten microseconds later, the first circuit is short circuited so that the current in the coil drops to zero. [0174] Fifty microseconds later, the first circuit receives its next DC pulse. Ten microseconds later the second circuit is short-circuited. This cycle is repeated continuously so that there is always one coil with a large enough value of dI/dt to produce the requisite externally induced transmembrane potential in a continuous fashion. [0175] Turning now to FIGS. 7 a - 7 i , several different configurations of the present invention are illustrated. [0176] [0176]FIGS. 7 a and 7 b depict an arrangement of coil 10 of the present invention in which coil 10 completely encircles penis 20 . If desired, coil 10 can be housed within ring 50 , as shown in FIG. 7 a , or coil 10 can be housed within prophylactic 30 , as shown in FIG. 7 b. [0177] [0177]FIG. 7 c is a top view of an arrangement of coil 10 housed within prophylactic 30 and half-wrapped around penis 20 , while FIG. 7 d shows a side view of the FIG. 7 c. [0178] [0178]FIG. 7 e is a side view of an arrangement of coil 10 in which coil 10 is housed within patch 40 , and patch 40 is worn on the outside of penis 20 , while FIG. 7 f shows a top view of FIG. 7 e. [0179] [0179]FIG. 7 g is a side view of an arrangement of coil 10 in which coil 10 is housed within prophylactic 30 and coil 10 is worn on the surface of penis 20 , while FIG. 7 h shows a top view of FIG. 7 g. [0180] [0180]FIG. 7 i depicts an arrangement of the present invention in which coil 10 is mounted within patch 40 and patch 40 is half-wrapped on the outside of penis 20 . [0181] It will be understood that the claims are intended to cover all changes and modifications of the preferred embodiments of the invention herein chosen for the purpose of illustration which do not constitute a departure from the spirit and scope of the invention.

Cavernous nerve stimulation is induced by means of a device which creates a time varying magnetic field which, in turn, creates an electric field in a direction parallel to the nerve and at the nerve so as to cause depolarization leading to an action potential and subsequent sensory stimulation and erection.

BACKGROUND OF THE INVENTION [0001] The present invention relates to antennas, and specifically to feedlines for spiral antennas. [0002] Spiral antennas are well known for being able to transmit and receive signals consistently over a wide range of frequencies. Typically, traditional spiral antennas operate over a 10:1 bandwidth, meaning the upper frequency limit of the antenna is approximately ten times that of the lower frequency limit. In traditional spiral antennas, the upper and lower frequency limits are highly dependent on the inner and outer radii of the spiral, respectively. The circumference or fineness of the spiral center determines the upper frequency limit. [0003] Manufacturing a spiral antenna to operate at millimeter wave frequencies (the frequencies in the range of about 18 GHz to about 60 GHz) becomes increasingly difficult because the upper frequency limit is so dependent upon the fineness of the spiral. The manufacturing tolerances on the spiral surface continue to diminish as cost for manufacturing grows. SUMMARY OF THE INVENTION [0004] The present invention provides a spiral antenna system that is designed to have an increased upper frequency limit. More specifically, the system includes a spiral antenna element having a feed end, and a helical antenna element having a helical portion electrically interconnected with the feed end of the spiral antenna element. In one embodiment, the helical antenna element comprises a coaxial cable having a portion of the outer conductor removed (e.g., tapered). For example, the helical antenna element could comprise a portion of the feedline that follows a substantially helical path. Preferably, the spiral antenna element defines a spiral axis, and the helical antenna element defines a helical axis substantially aligned with the spiral axis. The helical antenna element can be spaced from the helical axis a distance less than or equal to the radial distance of the feed end of the spiral antenna. [0005] Other features and advantages of the invention will become apparent by consideration of the detailed description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0006] [0006]FIG. 1 is a plan view of a spiral antenna embodying the present invention. [0007] [0007]FIG. 2 is a side view of the spiral antenna as shown in FIG. 1. [0008] [0008]FIG. 3 is a perspective view of an alternative feed structure. [0009] [0009]FIG. 4 is a perspective view of a plurality of feedlines included in a feed structure embodying the invention. [0010] [0010]FIG. 5 is a cross-sectional view of the plurality of feedlines shown in FIG. 4, taken along line 5 - 5 . [0011] [0011]FIG. 6 is a graph illustrating the predicted relationship between the upper frequency limit of a spiral antenna to the diameter of the feedline. [0012] [0012]FIG. 7 is a plan view of a broadband antenna system incorporating the spiral antenna as shown in FIG. 1 [0013] [0013]FIG. 8 is a side view of the broadband antenna system as shown in FIG. 7, taken along line 8 - 8 . [0014] [0014]FIG. 9 is a side view of a second embodiment of the present invention. [0015] [0015]FIG. 10 is a side view of a third embodiment of the present invention. [0016] Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. DETAILED DESCRIPTION [0017] A broadband antenna system 20 embodying the invention is illustrated in FIGS. 1 - 7 . The antenna system 20 includes a spiral antenna 24 having a plurality of spiral antenna elements or arms 28 defining a spiral axis 30 . In the embodiment shown, the antenna 24 is a planar equiangular spiral antenna and has four spiral arms 28 . In other embodiments, the antenna 24 can be an Archimedean spiral, a sinuous antenna, a log-periodic antenna or other antennas from the traveling wave or frequency independent antenna class. The antenna 24 can also include more or fewer arms 28 than the embodiment shown in FIGS. 1 - 2 . Each spiral arm 28 has a first or feed end 42 and a second or outside end 46 . The feed end 42 is spaced a radial distance from the spiral axis 30 . In other embodiments, the outside end 46 of each spiral arm is connected to additional electronics or circuitry, or connected to an electrical load. [0018] The antenna system 20 also includes a feed structure 58 having a plurality of helical feedlines 61 - 64 that define a helical axis, which in the illustrated embodiment is aligned with the spiral axis 30 . In other embodiments, the feed structure 58 includes a plurality of feedlines that take the form of a conical helix. The feedlines 61 - 64 electrically connect the plurality of spiral arms 28 to a receiving or transmitting network (not shown). In the present invention, the feed structure 58 includes the same number of feedlines as the number of arms 28 in the spiral antenna 24 . For the spiral antenna 24 illustrated in FIG. 1, the feed structure 58 includes four helical feedlines 61 - 64 . For illustrative purposes, only one feedline 61 is shown in FIG. 2 in solid line. The other three feedlines 62 - 64 are shown in dashed lines and are not labeled. All of the feedlines 61 - 64 are illustrated and labeled in FIG. 5. The feedlines shown in FIG. 2 form a helix having one turn. In other embodiments, the helical feedlines 61 - 64 can include more or fewer turns. [0019] [0019]FIG. 3 illustrates another feed structure having eight feedlines 65 . The feedlines each include a straight portion 66 and a helical portion 67 . In this embodiment, the helical portions each travel about one quarter of a turn. At least part of the helical portions 67 is unshielded so that the feedlines 65 can transmit and/or receive signals. The straight portions 66 can remain shielded. In this manner, the helical portions 67 essentially act as a miniature helical antenna element. The helical portions 67 are spaced from the axis 30 approximately the same distance as the feed ends 42 . [0020] The unshielding of the helical portions of the feedlines is illustrated in FIGS. 4 and 5. The feedlines 61 - 64 are preferably configured from coaxial transmission line. In other embodiments, the feedlines could be configured from microstrip transmission line or a similar transmission line. Referring to FIGS. 4 and 5, each feedline 61 - 64 includes an inner conductor 68 , a dielectric layer 72 and an outer conductor 76 . For ease of explanation, the feedlines 61 - 64 shown in FIGS. 4 and 5 are not arranged in a helix. The dielectric layer 72 surrounds the inner conductor 68 , and the outer conductor 76 surrounds the dielectric layer 72 . Each feedline 61 - 64 further includes a bottom end or input end 80 , a top end or output end 84 , and a transition section 88 found between the input end 80 and the output end 84 . The feedlines 61 - 64 are in a substantially uncoupled state at each of the input ends 80 . At the output ends 84 , the feedlines 61 - 64 are in a highly coupled state. The transition between the uncoupled state to the highly coupled state takes place during the transition section 88 . The outer conductor 76 of each feedline 61 - 64 is tapered in a manner such that the transition from one state to the other is smooth. The outer conductor 76 can be tapered linearly, exponentially or another manner that allows the states to transition smoothly. The illustrated tapering starts on the inside (i.e., the side facing the other feedlines) and moves toward the outside, but could instead be outside to inside or side to side. The dielectric layer 72 can also be tapered in the same fashion as the outer conductor 76 , tapered in a different manner than the outer conductor 76 , or not tapered at all. [0021] Tapering the feedlines 61 - 64 allows each feedline 61 - 64 to transition from a substantially uncoupled state at the input end 80 to a highly coupled state at the output end 84 . Having the feedlines 61 - 64 in a coupled state allows the feed structure 58 to better match the antenna input impedance to the feedline impedance, and can simultaneously match multiple antenna modes having different modal impedances. Also, at the output end or highly coupled end 84 , each feedline 61 - 64 is able to radiate when excited because the feedlines 61 - 64 are unshielded. It is believed that a helical feedline can increase the upper frequency limit of a spiral antenna 24 by a factor of two, allowing the antenna 24 to operate in the millimeter-wave frequency region. [0022] The diameter of the helical feedline and the number of antenna elements or arms both become a factor in determining the upper frequency limit of an antenna. The graph shown in FIG. 6 illustrates the predicted relationship between the upper frequency limit and the diameter of the feedline for various multi-element spiral antennas having a helical feed structure. The feedline diameter is represented on the x-axis 90 and the upper frequency limit is represented on the y-axis 92 . The first solid line 94 illustrates the relationship for a spiral antenna having four antenna elements, the second solid line 96 illustrates the relationship for a spiral antenna having six antenna elements, and the third solid line 98 illustrates the relationship for a spiral antenna having eight elements. [0023] Still referring to FIG. 6, the dashed line 102 , 104 , and 106 illustrates the relationship between the upper frequency limit and the diameter of the feedline for various multi-element spiral antennas not including a helical feed structure. The first dashed line 102 illustrates the relationship for a spiral antenna having four antenna elements, the second dashed line 104 illustrates the relationship for a spiral antenna having six elements, and the third dashed line 106 illustrates the relationship for a spiral antenna having eight elements. The vertical lines 108 represent the diameters of commercially available or standard coaxial cable. As illustrated by the first solid line 94 , a spiral antenna having four antenna elements can include a standard coaxial cable with a large diameter (such as 0.047 inches) for the helical feedline and have an upper frequency limit of approximately 60 GHz. As illustrated by the first dashed line 102 , a spiral antenna having four antenna elements and not having the helical feed structure would have an upper frequency limit of approximately 20 GHz when using standard 0.047 in. coaxial cable for the feedlines. [0024] When the helical feedlines 61 - 64 are excited and start to radiate, the feedlines produce backfire radiation. In other words, the helical feedlines radiate in the opposite direction. As the number of turns in the helix increases, the directivity of the back lobe or rear beam increases and causes the front-to-back ratio (the ratio of the maximum directivity of an antenna to its directivity in a specified rearward direction) to decrease. Therefore, in one embodiment, the helical feedlines have approximately one quarter of a turn and a reflective element 110 (FIG. 8) is positioned beneath the helical feedlines to reflect the backfire radiation. The reflective element 110 is a metallic disc with an opening (not shown) or a series of openings (not shown) for the helical feedlines to pass through. In other embodiments, the reflective element 110 can vary in shape and size and can be configured from other materials with reflective properties. [0025] The antenna system 20 can also include a reflective cavity 112 . When a planar spiral antenna radiates, it typically produces equal radiation above and below the antenna. In order to produce one beam of radiation, the reflective cavity 112 is positioned substantially beneath the spiral antenna 24 . As shown in FIGS. 7 and 8, the reflective cavity 112 substantially surrounds the helical feedlines 61 - 64 and reflective element 110 . The cavity 112 includes a reflective base 114 and sidewall 118 . In other embodiments, the cavity 112 can vary in shape and size and include more or less sidewalls 118 . The cavity 112 can further include a single reflective base 114 of varying shape and size, such as a conical base 120 , shown in FIG. 9, or include a stepped base cavity 124 , shown in FIG. 10, with or without the additional inner side walls 128 . Also, the reflective base 114 can be substantially parallel to the spiral antenna 24 or not. In the embodiment of FIG. 8, a radio frequency absorber 132 is positioned within the reflective cavity 112 to avoid reflections that could degrade the antenna patterns over wide bandwidths. The absorber 132 can included one or more layers of a foam absorber, a honeycomb absorber, and/or a loaded material, as is known in the art. Typically, in the embodiments when the reflective base 114 is shaped, such as shown in FIGS. 9 and 10, the absorber 132 is not used. A layer or multiple layers of unloaded foam or honeycomb (not shown), in some embodiments, may be placed within the reflective cavity 112 to support the spiral antenna 24 and the reflective element 110 . [0026] Various features and advantages of the invention are set forth in the following claims.

A spiral antenna system that is designed to have an increased upper frequency limit. The system includes a spiral antenna element having a feed end, and a helical antenna element having a helical portion electrically interconnected with the feed end of the spiral antenna element. In one embodiment, the helical antenna element comprises a coaxial cable having a portion of the outer conductor removed (e.g., tapered). For example, the helical antenna element could comprise a portion of the feedline that follows a substantially helical path. Preferably, the spiral antenna element defines a spiral axis, and the helical antenna element defines a helical axis substantially aligned with the spiral axis. The helical antenna element can be spaced from the helical axis a distance less than or equal to the radial distance of the feed end of the spiral antenna.

CROSS REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Patent Application No. 61/415,623, entitled Data Integration and Analysis, filed Nov. 19, 2010. The entirety of this application is hereby incorporated by reference herein. BACKGROUND Data is stored at a variety of locations and in a variety of forms. Data can be commercially relevant when it can be used to answer commercial questions (e.g., how is a product or product line performing in the market vs. its competitors, to what extent is a product or product line being adopted by a particular market segment, etc.). In turn, insight into these and other commercial questions can help one make business decisions intelligently. SUMMARY A method disclosed herein includes a computerized method for performing the steps of: identifying a universal data set enumerating a population of consumers within a geographic area; identifying a plurality of ancillary data sources that each provide ancillary data describing commercial behavior of a corresponding subset of consumers at the respective ancillary data source; partitioning the geographic area into a plurality of sectors; enumerating the plurality of sectors; identifying a sample of the plurality of sectors; extracting data from each of the ancillary data sources in an order consistent with an enumerated order of the cells until meeting data thresholds corresponding to each of the respective ancillary data sources; and combining the extracted data with panel data from a panel data source. Implementations may include one or more of the following features. The ancillary data includes point of sale data. The ancillary data includes shipping data. The ancillary data includes media delivery data. The ancillary data includes credit card data. The ancillary data includes clickstream data. Enumerating the plurality of sectors includes identifying coordinates corresponding to each sector and interleaving digits of the coordinates, thereby producing an integer. In general, in another aspect: identifying a data set including: characteristics of a population of consumers within a geographic area partitioned into sectors; ancillary data from at least two sources describing, on a sector-by-sector basis, consumer behaviors within the geographic area, wherein one of the sources is a panel data source; identifying a first propensity of consumers in a first sector to engage in a specified behavior with a first data source, by computing a ratio of a number consumers in the first sector who engage in the specified behavior to a total number of consumers in the first sector; identifying a modeled second propensity of consumers in the first sector to engage in the specified behavior with a second data source, wherein the data set does not include data sufficient to compute an actual second propensity corresponding to the modeled second propensity; using the first propensity and the modeled second propensity, identifying third and forth modeled propensities of consumers in a second sector to engage in the specified behavior with, respectively, the first and second data sources, wherein the data set does not include data sufficient to compute actual third and forth propensities corresponding to the modeled third and fourth propensities. Implementations may include one or more of the following features. Identifying the modeled second propensity includes setting the second propensity equal to the first propensity. Identifying the modeled second propensity includes employing a shrinkage estimator. Identifying the modeled second propensity includes using an elasticity model describing propensity variation across data sources. Identifying the modeled second propensity includes using regression, imputation, projection, or similarity-based techniques. The specified behavior includes buying a particular brand of goods or services. The specified behavior includes consume media from a particular media outlet. The specified behavior includes a purchasing a specified collection of goods or services. The specified behavior includes purchasing at least a specified dollar amount worth of goods or services. The specified behavior includes shopping at a particular store. The specified behavior includes buying goods or services at a discount. Identifying the modeled third and fourth propensity includes regression, imputation, projection, or similarity-based techniques. Identifying the modeled third and fourth propensity scores includes verifying that the scores total to a known value. In another aspect there is disclosed herein a computer program product embodied in a non-transitory computer readable medium that, when executing on one or more computing devices, performs the steps of: receiving a universal data set comprising geographic data for a plurality of customers within a geographic area, the universal data set having an order and the universal data set aggregated at a household level; importing consumer panel data according to the order of the universal data set, the consumer panel data including a number of customer-reported transactions for a first subset of the plurality of customers and the consumer panel data aggregated at an individual customer level; importing retailer data according to the order of the universal data set, until a pre-determined threshold of a retailer for obtaining the retailer data from the retailer is achieved, the retailer data including customer data from the retailer for a second subset of the plurality of customers, wherein the second subset overlaps the first subset, and the retailer data aggregated at a retailer-provided level; and combining the consumer panel data and the retailer data according to the order of the universal data set at a normalized level of aggregation, thereby providing data set representative of the first subset of the plurality of customers and the second subset of the plurality of customers. DESCRIPTION OF DRAWINGS Features and advantages of the invention will be apparent from the following description of particular embodiments thereof, as illustrated in the accompanying drawings, wherein: FIG. 1 is a schematic depiction of disparate data sets. FIG. 2 is a flowchart for integrating and sampling data. FIG. 3 is a schematic depiction of integrated data sets. FIGS. 4 and 5 are flowcharts for data modeling. FIG. 6 is a block diagram for a data integration system. FIG. 7 is a flowchart of a process for combining data sets. DETAILED DESCRIPTION FIG. 1 is a schematic depiction of disparate data sets. As described more fully below, various data sets 10 are often available from many (though not all) market participants 12 . The market participants can include any entity participating in a market (whether on the supply side or demand side), such as retailers, manufacturers, publishers, service providers, etc. Moreover, the term “market participant” includes third-party analysts or aggregators of market data in a particular market, even if they do not participate in that market themselves. For example, in FIG. 1 , the “Panel” market participant denotes an organization that collects data from a group of consumers (e.g., by survey or other mechanism by which consumers self-report their behavior) without necessarily selling to or buying from the consumers. For purposes of illustration, the other market participants in FIG. 1 are MegaMart, Texas Grocers, California Farmers' Markets, and SecretCo. Illustrative aspects of these market participants and their corresponding data is explained in more detail below. Each data set at least partially describes commercially relevant information about a population of consumers. Commercial relevance is a subjective characteristic. For example, a manufacturer of lawn mowers may not consider the average number of museum visits of a particular consumer to be commercially relevant piece of data. However, a magazine publisher who specifically targets museum-goers as potential subscribers may consider the same data to be highly commercially relevant. In general, if a particular piece of data can be used to bear on commercial issues (e.g., whether to develop one product vs. another, whether to advertise a product in a particular way or to a particular target audience, whether to expand retail operations into a particular geographic region or to exit a particular region, etc.) of a particular entity, then it is commercially relevant to that entity. Conversely, if a particular piece of data does not bear on any commercial issue of a particular entity, then it is not commercially relevant to that entity. In what follows, the adjective “commercially relevant” will be assumed to apply to all data sets 10 unless otherwise specified. The commercially relevant information in the data sets 10 can include information about consumer behaviors, characteristics or attitudes. A consumer behavior is any commercially relevant action that a consumer takes. For example, purchasing a particular product or combination of products, shopping at a particular store, shopping with a particular frequency, spending a particular amount of money, consuming media through a particular outlet (e.g., a particular television station, radio station, online media source, etc.), and visiting particular websites are all examples of consumer behaviors. Many other examples are possible. A consumer characteristic is information about a consumer (or group of consumers). For example, a consumer's age, gender, location information (including physical locations such as address, zip code, census block, city, state, etc. and network locations such as an IP address), profession, income, shopping options, shopping location, etc. are all examples of consumer characteristics. An e-mail address, MAC address, or other computer-based characteristics are included in this term. Other characteristics are possible. A consumer attitude is a belief or disposition that the consumer has on an issue. For example, consumer attitudes may be reflected by political affiliations, family values, lifestyle choices, etc. Often, consumer attitudes are determined via a survey, in which one or more questionnaires are presented to consumers to directly establish consumer attitudes. Other consumer attitudes may be inferred by consumer behavior. For example, one may infer that a particular consumer is vegetarian if that consumer purchases no meat at grocery stores or restaurants. Similarly, one may infer certain consumer attitudes based on the consumer's membership in particular organizations, contributions to particular charities, etc. The data sets described above are often structured as a database or equivalent structure. That is, the data sets often have (or are capable of having) a hierarchical structure, in which several different pieces of data are associated with a particular consumer or group of consumers. Thus, e.g., a single record may be associated with the characteristics, behavior, or attitudes of a single consumer or group of consumers. In what follows, reference will be made to various database concepts (e.g., data in a certain record or field, categories or “dimensions” of data, etc.). However, this database-type language is employed for convenience, and the data sets 10 need not bear an explicit database structure. In FIG. 1 , it will be assumed that a universal data set 14 is available. The universal data set contains characteristic information on a relatively large number of consumers throughout a geographic area. In some implementations, the characteristic information includes location information (e.g., address, zip code, etc.) of the consumers. In some implementations, the characteristic information includes one or more of the characteristics listed in Appendix A. In addition to the universal data set 14 , one or more ancillary data sets 16 are also available. Each ancillary data set 16 includes (but is not limited to) information on consumer behaviors, as well as some degree of consumer characteristic information. The consumer characteristic information in the ancillary data sets 16 need not be represented the same level of specificity or granularity as the consumer characteristic information in the universal data set 14 in order to engage in meaningful analysis as described below. For example, if a consumer's location is described as an address in the universal data set 14 , it is permissible to merely describe the consumer's zip code in an ancillary data set 16 . Similarly, if the universal data set 14 describes only households, it is permissible for an ancillary data set 16 to describe a particular individual's (i.e., a household member's) consumer behavior. The ancillary data sets 16 often come from the internal business records of market participants 12 . For example, retail stores often keep records on each transaction made at the store, describing what item or items were purchased, what price was paid for each item, where the item or items were purchased (i.e., which of possibly several stores), etc. Moreover, many retail stores have “frequent shopper” or “loyalty” cards that allow the retailer to track the transaction details of individual consumers. Alternatively or additionally, credit card or debit card information can be used to track transactions. Various other sources of ancillary data exists, such as shipping or receiving records, manufacturing records, usage records of a particular resource, traffic records, including both physical traffic (as measured by, e.g., a counter at an entrance at a retail store) or network traffic (as measured from clickstream data reported, e.g., by a router or web server that provides content to a consumer), etc. Market participants 12 often sell this data (after removing sensitive information of its consumers, such as full credit card numbers, etc) to third parties. However, some market participants 12 only release a relatively small proportion, typically on the order of 5% or 10% of the total data. Moreover, market participants 12 will often allow the third party to request specific transactions (e.g., transactions from a particular geography, transactions involving a certain dollar amount, etc.), subject to the limit on the total data to be released. Some market participants 12 will not sell even a small portion of their data to third parties. In general, ancillary data sets 16 from different market participants may—but need not—overlap. In FIG. 1 , this possibility is illustrated by the vertical placement of the data sets. Specifically, data sets that overlap on a common horizontal line are intended to describe consumer behaviors of the same consumer (or aggregated group of consumers) at the respective market participants. Thus, in the illustrative data of FIG. 1 , at least some shoppers at MegaMart also shop at Texas Grocers, because the line 18 runs through both data sets. Conversely, the data reveals no consumer who shops at both Texas Grocers and California Farmers' Market, because there is no horizontal line between these data sets. Furthermore, note that both Texas Grocers and California Farmers' Market have relatively little data compared to the universal data set 14 . Thus, if the universal data set 14 describes consumer characteristics throughout the United States, the data for Texas Grocers and California Farmers' Market is consistent with those stores doing business only in Texas and California, respectively. Furthermore, the highly fractured nature of the sample panel data is consistent with data gathered by a survey in which only select individuals or groups of individuals were asked to participate or otherwise completed the survey. This is in contrast to the data of MegaMart and SecretCo. Almost all consumers in the universal data sample engage in some consumer behavior at MegaMart and SecretCo. Directly analyzing the entire amount of available data is often challenging or unfeasible. One challenge is that the data sets 10 from different sources are often structured or formatted differently. For example, different market participants may report consumer characteristics at different levels of granularity. Moreover, even if each data set 10 were structured exactly the same, the sheer volume of the data can present challenges. For example, a universal data set 14 may describe as many as 116 million households, such as a list of all or substantially all the people or households in a large geographic area, such as the United States. (Here, the word “substantially” is used to acknowledge the fact that some people or households, in principle, may be unintentionally omitted from such a list, due to limitations in data gathering techniques.) Further still, market participants 12 often regard their data sets 16 as proprietary, and consequently will not make the entire data set available to third parties. FIG. 2 is a flowchart for integrating and sampling data. The process 20 produces, from a variety of data sets 10 , a data sample with desirable characteristics as described more fully below. The data sample produced by process 20 is typically smaller than the total available data, such that performing various analyses on the sample is feasible. Process 20 begins by identifying a universal data set 14 and ancillary data sources (step 22 ). The universal data set describes characteristics of a population of consumers. Each ancillary source is a source of an ancillary data set 16 that describes (at least) one or more consumer behaviors. In some implementations, the ancillary data sources are market participants 12 , and the consumer behaviors include behaviors at that particular market participant. At least two ancillary data sources are identified in step 22 . In principle, there is no upper limit on the number of data sources that may be identified. In step 24 , the population of consumers of the universal data set is partitioned into non-overlapping sectors, according to a partitioning criterion. The partitioning criterion may include any shared characteristic of the consumers. For example, partitioning may performed by geographic area, last name, telephone number, etc. In the case of geographic areas, for example, one may partition the geographic area into households, streets, zip codes, census blocks, towns, states, etc. One may also partition the geographic area into irregular units according to an ad hoc partitioning scheme. In the case of last name, the population can be partitioned by providing alphabetical ranges; e.g., one partition may consist of consumers whose last name begins with the letter “A,” another partition may consist of consumers whose last name begins with the letter “B,” etc. Other partitioning criteria are possible. The partitioning criterion need not involve a single parameter or dimension (such as first letter of last name, etc.), but rather can involve two or more parameters or dimensions. Partitioning the consumer population according to a criterion may have statistical consequences in the resulting data sample. For example, when partitioning by the first letter of the consumers' last name, it may happen that consumers with a particular ethnic background are over-represented or under-represented in partitions that begin with certain letters; e.g., consumers of Russian ethnicity may be under-represented in the partition of last names beginning with “H,” because the letter “H” is rarely used as an initial letter in Russian-to-English transliteration. In some implementations, the choice of a partitioning criterion may involve the subjective judgment of one or more people responsible for partitioning. In some implementations, a partitioning criterion that is relatively stable selected. A criterion is stable if it is unlikely to change for a particular consumer. For example, a consumer's last name is relatively stable, insofar as men's last names typically do not change, and women's last names typically only change after a marriage, which typically occurs only a relatively few number of times in a woman's life. By contrast, a consumer's annual income is less stable, insofar as a consumer's annual income often changes, if only slightly, every year. In step 26 , the sectors are enumerated. Any enumeration of sectors is permissible. In some implementations, the sectors are enumerated by a random assignment of numbers to sectors. For multi-dimensional partitioning criteria or criteria that involve several parameters, in some implementations, the sectors can be enumerated by first enumerating the individual dimensions or parameters, and then interleaving the parameters to produce a one-dimensional list. For example, in some implementations in which the partitioning criterion involves a geographic location, two dimensional coordinates (e.g., latitude/longitude or other coordinate system) can be assigned to each sector, and then the digits of the coordinates can be interleaved. The assignment of coordinates can be performed in any manner; e.g., associating a sector with its geometric center, centroid, barycenter, an extremal point, or some other preferred point in the sector. For example, if the coordinates of a sector are (abc, ABC), where each of a, b, c, A, B, and C are digits of the respective coordinates, then that sector can be enumerated as the number aAbBcC obtained by interleaving the coordinates. In some implementations, the coordinates are expressed in binary. Once the sectors are enumerated, a subset of sectors is identified (step 28 ). The subset may be identified by any method. For example, a subset can be identified by a statistical sampling scheme, such as by selecting sectors according to a probability distribution. Similarly, a subset may be identified by systematic sampling—i.e., selecting sectors at fixed, regular intervals (e.g., including every thousandth sector in the sample), etc. The subset need not be a proper subset—i.e., the subset can include the entire list of sectors. In general, the manner in which the subset of sectors are identified may be decided in light of statistical, logistic, or other consequences, and therefore may involve the subjective judgment of one or more people responsible for performing the sampling. In some implementations, the subset of sectors is chosen to be contained within sectors for which pre-determined data is available. For example, the subset of sectors can be chosen to be contained within sectors for which panel participants are present. Once the sample of sectors is determined, data is imported from the data sources (step 30 ). As mentioned above, some data sources will only release a certain proportion (i.e., 5% or 10%) of their available data. Some data sources will allow this proportion of data to be selected according to customer-specified preferences. In this case, in some implementations, the data is imported on a sector-by-sector basis, in the sectors' enumerated order, until source-imposed threshold (e.g., 5% or 10%) is met. In some implementations, one may have external knowledge (e.g., knowledge from a source other than an ancillary data source 16 ) that particular data is not available from a particular source in a particular sector. For example, in some implementations in which the sectors are geographic sectors, one may have external knowledge that a particular retailer does not do business outside of California. Consequently, no data will be available from that retailer in sectors that lie outside of California. In some implementations, the externally-known data may be used to augment the data sample. Thus, in some implementations, sectors for which external data is available may be omitted in step 30 described above. This may provide an advantage, since externally-obtained data does not count towards the total of data released directly by the data source. In step 32 , one or more key dimensions are identified. A “key dimension” is a type of data that is common among two or more data sets. For example, if two data sets describe consumers' addresses and purchases at two stores, then “address” is a key dimension. Identifying a key dimension may require supplementing one or more data sets. For example, if one data set includes the location of a consumer and another data set includes the consumer's IP address, then apparently there is no available key dimension. However, one may associate an IP address with a location using geolocation techniques. Thus, one may supplement the IP address data with location data, to identify location as a key dimension. Similarly, two data sets may include the same type of information at different levels of specificity or granularity. For example, one data set may describe consumers' locations as an address, while another data set may describe consumers' location as a zip code. When this occurs, one may select the zip code as a key dimension, but aggregate the locations in the first data set from the address level to the zip code level. In any case, the data is aggregated and/or supplemented, if necessary, so that it reflects consumer behaviors, characteristics, or attitudes on a sector-by-sector basis (step 34 ). After supplementing and/or aggregating the data sets if necessary, the data sets may optionally be combined along the key dimension(s) into a single data set (step 36 ). For example, the combination may be (but need not be) implemented using the traditional “join” operation on databases. Another implementation may be to simply include pointers from one data set to the others, indicating the appropriate relationships amongst the data. Other implementations are possible. FIG. 3 shows an exemplary data sample 37 that is produced from process 20 . The sample 37 has the property that the available data from the various ancillary data sets for a particular sector is a non-decreasing function of the sector number. That is, the data is “nested,” in the sense that if the sampled data set contains data from a particular ancillary data source in sector N, then the data sampled data set also contains data from that ancillary data source in sectors M, for all M<N. Moreover, if the sampled data set contains data from a different ancillary data source in sector N′, where N′<N, then the sampled data set also contains data from that ancillary data source in sectors M′, for all M′<N′. Thus, for all sectors up to N′, information is available for both ancillary data sources. For all sectors N′+1 through N, information is available for only the first source, and is known not to be available from the second source. Said another way, the nesting property provides a structure such that that data from the various data sources is simultaneously available for the maximal number of sectors. Having data simultaneously available from numerous data sources for a particular geographic sector allows certain types of inferences to be made. Consider, for example, the geographic sector corresponding to the line 39 in FIG. 3 , in which data is available from both MegaMart and Texas Grocers. If the data from Texas Grocers indicates that a particular consumer has a loyalty card, but MegaMart's data does not reveal a corresponding loyalty card, then it can be inferred that the consumer does not shop at MegaMart. (Such an inference rests on the assumption that those who regularly shop at a store hold a loyalty card at that store.) Similarly, if the data from Texas Grocers indicates that a particular consumer has a loyalty card, and MegaMart's data also reveals a loyalty card belonging to the same shopper, then the extent to which Texas Grocers and MegaMart provide competing or complementary behavior can be assessed. For example, the data could reveal that the chains could fully overlap (i.e., similar consumer behavior in both chains), or large trips made to Texas Grocers and small trips made to MegaMart, or food bought at Texas Grocers and health and beauty aids bought at MegaMart, among many potential possible behaviors. If this behavior were assessed with two random 10% samples from each of MegaMart and Texas Grocers, the sample overlap would typically be 1% of the total sampled data. Using the techniques described herein, however, the overlap will be much higher—in theory 100% if everyone had cards from both retailers and the keying information was completely accurate. Note that this inference could not accurately be made if the data sets did not overlap (or were not known to overlap) on that sector. That is, if a loyalty card for a particular consumer is not included in a particular data set from a retailer, then all one can infer is either that the consumer does not shop at the retailer, or that the consumer is not included in the sampled data. But in the case of nested data sets, if a consumer behavior is described in any single data set (or if the consumer is described in the universal data set), the consumer's absence in other data sets contains information that the consumer actually did not engage in behavior described by the other data sets, not merely that the other data sets are silent as to the consumer's behavior. More generally, several other negative inferences can be made from different data sets that overlap on a sector. A “negative inference” is an inference that a consumer does not engage in a particular behavior, based on a) observing a lack of evidence for the particular behavior, and b) observing evidence to support the inference that, if the consumer had engaged in the particular behavior, there would be evidence of it. In nested data sets, condition b) is satisfied when data sets overlap on a particular sector. In addition to enhancing the opportunity to make negative inferences, the structure of the data sample produced by process 20 has other desirable properties. For example, the data sample is easily updatable in the event two or more data sources merge. For example, if MegaMart merges with Texas Grocers to form a new retailer called BrandNewMart, then creating a data sample for BrandNewMart can be accomplished by combining the MegaMart/Texas Grocers data in relatively straightforward ways—e.g., by adding numerical data such as sale volume, amount, etc., or by aggregating and eliminating redundant non-numerical data such as loyalty card data. In particular, because the data sample is nested, no additional work need be done to account for the possibility that the MegaMart data is potentially based on a different sample than the Texas Grocer data. Similarly, the data sample of process 20 is amenable to changing degrees of aggregation. For example, retailers typically have their own privacy policies through which personally identifying information is removed from data before it is provided to third parties. One common technique for removing personally identifying information is to aggregate information on a geographic or other basis. If a retailer modifies their privacy policy resulting in a change to the level of aggregation of reported data, the then the corresponding sectors of the data sample can be similarly aggregated, resulting in the continued usefulness of the data sample. This data set can be used to gain insight into market-related questions. For example, one class of questions involves ascertaining, predicting, or otherwise modeling the propensity that a consumer or group of consumers will behave in a certain way. For example, one might want to know the propensity of a group of consumers to buy one brand of detergent vs. another brand, or the propensity to buy a high-end version of a product vs. a low-end version, or the propensity to buy a given product at all, or the propensity to spend at least a certain amount of money buying a certain type of product or products. Generally, one may inquire about consumers' propensity to engage in virtually any measurable behavior, which may be quantified as a propensity score or the like indicative of a tendency of a consumer or group of consumers to engage in a specific behavior. Given the data set derived from process 20 , there will often be some consumers for whom a desired propensity can be directly calculated from available data. For example, if point of sale (“POS”) data is available from MegaMart for particular geographic sector, then questions such as those above can be directly calculated using traditional techniques, at least as those propensities relate to MegaMart behaviors. (E.g., one may calculate the propensity of a consumer to engage in a particular behavior at MegaMart.) Similarly, if other data sources are available for the same sector, then propensity scores can be refined by the additional data. This can occur according to several mechanisms. In one instance, merely having more data often results, as a general statistical matter, in increased accuracy in any conclusions made from the data. Additionally, with sufficient data, one may make inferences by process of elimination or other exclusionary inferences. For example, suppose a particular geographic sector has exactly three stores that sell a certain product. If one has point of sale data from two of the stores, and one knows the total amount of money spent on that product, then one may infer the amount of money spent on the product in that sector by subtracting the known amounts from the total. FIG. 4 is a flowchart for analyzing an integrated data set. The analysis process 38 may be carried out on a data set describing a population of consumers in a geographic area, including two or more ancillary data sets describing consumer behavior on a geographic sector-by-sector basis. In some implementations, the analysis process 38 may be carried out on the output of process 20 . In step 40 , such a data set is identified, as is an initial sector in the data set. In step 42 , propensity scores are directly computed for those cells for which data is available. A “cell” is the data in a particular ancillary data set for a particular sector. When data is available, a general formula for computing a propensity score is to compute ratio of consumers in the cell who exhibit the behavior to the total number of consumers in the cell. Other ratios can be computed that yield scores that provide equivalent information; i.e., the ratio of consumers who exhibit a particular behavior to the consumers who do not exhibit the behavior. Similarly, these or other ratios may be scaled (i.e., linearly scaled, logarithmically scaled, geometrically scaled, exponentially scaled, etc.) and still provide the same information. In general, there will be cells for which data is unavailable from any ancillary data source. For example, in FIG. 3 , no data is available from SecretCo, illustrating the scenario in which SecretCo does not release any of its data. For these cells a modeled propensity score can be determined in a variety of ways. One simple way is to set the modeled propensity score equal to a computed propensity score from another cell for which data is available. Similarly, a modeled propensity score can be determined as a combination (e.g., average, weighted average, etc.) of computed propensity scores. More sophisticated techniques, such as regression models, gravity models, projection techniques, etc. may be used. Moreover, in these or other techniques, the availability of making negative inferences is enhanced by the nested configuration of the data sample. In step 44 , propensity scores are propagated from cells in which scores were calculated to cells for which no data was available using these techniques. Thus, after step 44 , all the cells in a particular sector contain propensity information, either directly calculated from other data from the cell, or modeled based on other propensity scores. In step 46 , the propensity data in the sector can be refined. Such refinements can implement global aspects of modeling that were not (or cannot be) implemented in the cell-by-cell modeling. For example, stability enhancing techniques can be applied to the data in step 46 . Stability enhancing techniques include applying a hierarchical weighting scheme, a shrinkage estimator (e.g., inverse Bayesian shrinkage), or the like. The specific stability enhancing techniques are applied and/or tuned on a case by case basis depending on the particular data sets involved. FIG. 5 is a flowchart for analyzing an integrated data set. In process 48 , a data set is identified that describes a population of consumers in a geographic area partitioned into sectors, and a number of ancillary data sources. Moreover, for a given sector, there is either a computed or modeled propensity score for the consumers in at least one sector to engage in a particular behavior at each of the data sources. For example, the process 48 can operate on the output of process 38 . In step 50 , a data set is identified, along with those sectors for which propensity data is available. In step 52 , the propensity data is propagated to those sectors for which no propensity data is available, using traditional mathematical modeling techniques (e.g., regression, similarity, projection, gravity models, etc.) The processes 38 and 48 are illustrative of a larger class of analyses. That is, starting with the data sample produced by process 20 , some analytic item of interest (e.g., propensity scores) can be computed for some cells, and then modeled for those cells for which no data is available. This general approach can be followed to compute, model, or otherwise gain insight into virtually any analytic question about consumer behaviors, including shared wallet estimation, market segmentation, etc. However, following such an approach using a more-nested data sample vs. a less-nested sample allows for a greater number (or higher quality) of negative inferences to be made during some or all of the modeling, ultimately leading to enhanced accuracy. FIG. 6 is a block diagram of a data integration system. The data integration system 54 includes a front end 56 , a data integration engine 58 , a data analysis engine 60 , and a data store 62 . The data integration system 54 is in data communication with one or more users 64 , and in data communication with one or more market participants 12 . The data communication can be implemented in any fashion, including by direct physical connection, wireless communication, or indirect communication through a computer network such as a local area network or a wide area network such as the Internet. The data integration engine 54 is operable to identify various ancillary data sources 16 from the various market participants 12 and integrate them. For example, the integration may include performing process 20 , thus producing a data sample. The data store 62 is operable to store data needed by the data integration system. For example, the data store 62 may store the data sample produced by the data integration system. The data analysis engine is operable to perform various analyses on the data in the data store, such as the analyses of processes 38 and 48 , among others. The front end 56 is operable to interface with one or more users 62 , and to allow the users to conveniently interact with the data integration system 54 . Through the front end, the users may cause the system to perform various analyses, view or manipulate the data sample, or export data or analytic results to external systems. In some implementations, each user 64 is associated with a user profile. The user profile includes information such as a user name, password, permissions, etc. In some implementations, the user profile is stored in the data store 62 . In some implementations, the front end 56 presents options to the user based on the user's permissions or other information in the user's profile. For example, some users 56 have “read only” permissions for certain data, in which case the front end 56 will suppress functionality that involves writing to that data. Similarly, to maintain confidentiality, read permissions associated with individual market participants 12 may be assigned to different users. FIG. 7 is a flowchart of a process 700 for combining data from disparate data sets using the techniques described above. As shown in step 702 , the process 700 may begin with receiving a universal data set comprising geographic data for a plurality of customers within a geographic area, the universal data set having an order and the universal data set aggregated at a household level. This may for example include phone-book type data for a geographic area organized according to residential address, or any other similar data set from any commercial or non-commercial source. The data may be received, e.g., by downloading data from an online commercial provider, or otherwise creating a local copy of the data in the data set from a disk or other computerized or written sources in any suitable manner. As shown in step 704 , the process 700 may include importing consumer panel data according to the order of the universal data set. This may, for example, be obtained from an online commercial source acquires and sells data concerning individual consumer purchasing behavior or the like. The consumer panel data may include a number of customer-reported transactions for a first subset of the plurality of customers and the consumer panel data may be aggregated at an individual customer level. This may, for example, include data concerning individual consumer behavior gathered by a commercial service based upon voluntary consumer participation, or any other data that similarly represents purchasing activity on an individual consumer basis. As shown in step 706 , the process 700 may include importing retailer data according to the order of the universal data set. In general, the retailer data may include customer data from a retailer for a second subset of the plurality of customers that overlaps the first subset of customers from the consumer panel data set. The retailer data may, for example, be aggregated at any retailer-provided level, such as a store, customer, household, credit card, or other level. This may include any data that is gathered by a retailer in the course of doing business. By way of example and not limitation, the retailer data may include point of sale data for stores operated by the retailer. The retailer data may include clickstream data obtained from online purchases. This may include shipping data for products shipped by the retailer to individual customers or the like. This may also or instead include media delivery data, such as where a retailer sells media including movies, music, games, software, and so forth, either online or in stores or some combination of these. This may also or instead include credit card data relating to any/all credit card purchases made with the retailer. More generally, any data from the retailer relating to actual purchases made by specific customers may be included in the retailer data as that term is used herein. The retailer data may be imported until a pre-determined threshold of a retailer for obtaining the retailer data from the retailer is achieved, such as an explicit limit on the quantity of data that the retailer is willing to provide. As shown in step 708 , the method may include combining the consumer panel data and the retailer data according to the order of the universal data set at a normalized level of aggregation, thereby providing a data set representative of the first subset of the plurality of customers and the second subset of the plurality of customers. This operation is described in greater detail above, and when so combined, provides a basis for drawing inferences about characteristics and behavior of the more general population in the universal data set for a geographic area. As shown in step 710 , with the data combined in this manner, consumer propensities may be modeled for customers in the universal data set according to the data set representative of the first subset of the plurality of customers and the second subset of the plurality of customers. This may include consumer propensities for any specific behavior for consumers. By way of example and not limitation, this may include a propensity for buying a particular brand of goods or services, or a propensity for purchasing a specified collection of goods or services. This may also or instead include a propensity for spending a certain dollar amount worth of goods or services, such as at least one hundred dollars, or not more than twenty dollars. This may also include (for media purchases), a propensity for consuming media from a particular media outlet, or of a particular format or type. This may also or instead include a propensity for shopping at a particular retailer, or at a particular store. Other propensities may similarly be measure, such as a propensity for buying goods or services at a discount, or a tendency to respond or not respond to any other types of promotions, coupon sources, and so forth. The above systems, devices, methods, processes, and the like may be realized in hardware, software, or any combination of these suitable for the control, data acquisition, and data processing described herein. This includes realization in one or more microprocessors, microcontrollers, embedded microcontrollers, programmable digital signal processors or other programmable devices or processing circuitry, along with internal and/or external memory. This may also, or instead, include one or more application specific integrated circuits, programmable gate arrays, programmable array logic components, or any other device or devices that may be configured to process electronic signals. It will further be appreciated that a realization of the processes or devices described above may include computer-executable code created using a structured programming language such as C, an object oriented programming language such as C++, or any other high-level or low-level programming language (including assembly languages, hardware description languages, and database programming languages and technologies) that may be stored, compiled or interpreted to run on one of the above devices, as well as heterogeneous combinations of processors, processor architectures, or combinations of different hardware and software. At the same time, processing may be distributed across devices such as the various systems described above, or all of the functionality may be integrated into a dedicated, standalone device. All such permutations and combinations are intended to fall within the scope of the present disclosure. In some embodiments disclosed herein are computer program products comprising computer-executable code or computer-usable code that, when executing on one or more computing devices (such as the devices/systems described above), performs any and/or all of the steps described above. The code may be stored in a non-transitory computer readable medium such as a computer memory, which may be a memory from which the program executes (such as random access memory associated with a processor), or a storage device such as a disk drive, flash memory or any other optical, electromagnetic, magnetic, infrared or other device or combination of devices. In another aspect, any of the processes described above may be embodied in any suitable transmission or propagation medium carrying the computer-executable code described above and/or any inputs or outputs from same. It will be appreciated that the methods and systems described above are set forth by way of example and not of limitation. Numerous variations, additions, omissions, and other modifications will be apparent to one of ordinary skill in the art. In addition, the order or presentation of method steps in the description and drawings above is not intended to require this order of performing the recited steps unless a particular order is expressly required or otherwise clear from the context. The meanings of method steps of the invention(s) described herein are intended to include any suitable method of causing one or more other parties or entities to perform the steps, consistent with the patentability of the following claims, unless a different meaning is expressly provided or otherwise clear from the context. Such parties or entities need not be under the direction or control of any other party or entity, and need not be located within a particular jurisdiction. Thus for example, a description or recitation of “adding a first number to a second number” includes causing one or more parties or entities to add the two numbers together. For example, if person X engages in an arm's length transaction with person Y to add the two numbers, and person Y indeed adds the two numbers, then both persons X and Y perform the step as recited: person Y by virtue of the fact that he actually added the numbers, and person X by virtue of the fact that he caused person Y to add the numbers. Furthermore, if person X is located within the United States and person Y is located outside the United States, then the method is performed in the United States by virtue of person X's participation in causing the step to be performed. While particular embodiments of the present invention have been shown and described, it will be apparent to those skilled in the art that various changes and modifications in form and details may be made therein without departing from the spirit and scope of the invention as defined by the following claims. The claims that follow are intended to include all such variations and modifications that might fall within their scope, and should be interpreted in the broadest sense allowable by law.

Uncorrelated data from a variety of sources, such as consumer panels or retailer points of sale, are combined with maximal coverage of a universal data set for a population in a manner that permits useful inferences about behaviorial propensities for the population at an individual or household level.

FIELD OF THE INVENTION The present invention relates generally to arc welding systems, and particularly to a wire-feed welding system having a welding gun. BACKGROUND OF THE INVENTION Welding is a common manufacturing process used to join, or to separate, metal work pieces. Arc welding is a common type of welding method. An arc welding system typically comprises a power supply coupled to a welding gun or torch housing an electrode. A welding cable may be used to couple the welding gun to the power supply. A conductive cable and a clamp may be used to couple a work piece to the power supply. A circuit between the power supply and work piece is completed when the electrode is placed against, or in proximity to, the work piece, producing an electric arc between the electrode and the work piece. The heat of the electric arc is concentrated on the work piece, or pieces, to be joined. The heat of the arc melts the metal piece, or pieces. A filler material may be added to the molten metal. The molten mass cools and solidifies when the arc is removed, forming the weld. There are many different types of arc welding, such as metal-inert-gas (“MIG”) welding and submerged arc welding. In MIG and submerged arc welding, a metal wire is used as the electrode. Additionally, the electrode wire may act as filler material for the weld. The wire is fed from a wire feeder coupled to the power supply. In MIG welding, the electrode wire is shielded at the point of contact by an inert gas. In submerged arc welding, a powdery flux is used to shield the electrode wire at the point of contact. The inert gas and flux shields the molten metal at the point of contact from outside contaminants and gases that may react with the molten material. Non-inert gases, such as CO 2 , also may be used in MIG welding systems. The wire and gas typically are fed through a welding gun having a welding cable. The welding cable receives the wire from a wire feeder and gas from a gas cylinder. The welding cable also has additional conductors to assist the wire in conducting power from the power source. The welding gun typically has a handle and neck that are used to direct gas or flux and wire towards a work piece. A retaining nut typically is used to secure a neck to a connector coupled to the welding cable. The connector enables electricity to flow from the welding cable to an inner portion of the neck. If the retaining nut loosens, the area of contact between the neck and the connector and/or welding cable will decrease. This increases the electrical resistance between the neck and the welding cable. In some applications, such as with electrical currents above 400 amps, the increase in electrical resistance results in the production of a substantial amount of resistive heating. The heat from the resistive heating produced at the interface may heat up the handle to the point where it cannot be held. Consequently, it may be desirable to wrench tighten the retaining nut so that neck does not come loose. However, hand-tightening the retaining nut to the connector is sufficient in many applications and does not require a tool to perform. There exists then a need for a method of securing a neck to a welding implement that provides an assembler with the option of configuring the welding implement for either wrench-tightening or hand-tightening a securing nut for the neck. SUMMARY OF THE INVENTION The present technique provides a novel technique designed to respond to such needs. According to one aspect of the present technique, a welding system is provided. The welding system comprises a welding implement having a neck adapted to convey electrode wire therethrough. The welding implement comprises an operator securable to a wrench-tightenable retaining nut to enable a user to hand tighten the retaining nut to secure the neck to the welding gun. The hand operator may be an optional attachment adapted to be disposed over the retaining nut. The hand operator may be adapted to secure to the retaining nut when disposed over the retaining nut. In one embodiment of the present technique, the retaining nut is adapted to be wrench-tightened and to enable the hand operator to be attached to the retaining nut. According to another aspect of the present technique, a method of assembling a welding implement is featured. The welding implement comprises a neck secureable to the welding implement by a retaining nut. The retaining nut may be adapted to be wrench-tightened. The method may comprise disposing an operator to a retaining nut to enable a user to hand tighten the retaining nut to secure the neck to the welding implement. BRIEF DESCRIPTION OF THE DRAWINGS The invention will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements, and: FIG. 1 is a diagram of a MIG welding system, according to an exemplary embodiment of the present technique; FIG. 2 is an elevational view of a welding gun having a retaining nut, according to an exemplary embodiment of the present technique; FIG. 3 is an elevational view of a welding gun having a hand operator disposed over a retaining nut, according to an exemplary embodiment of the present technique; FIG. 4 is an elevational view illustrating the attachment of the neck of FIG. 3 to the welding handle, according to an exemplary embodiment of the present technique; FIG. 5 is an elevational view of a welding gun neck and retaining nut, according to an exemplary embodiment of the present technique; and FIG. 6 is a cross-sectional view of the retaining nut and hand operator of FIG. 5 , according to an exemplary embodiment of the present technique. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring generally to FIG. 1 , an exemplary metal inert gas (“MIG”) welding system 20 is illustrated. However, the present technique also is operable with other types of welding systems, such as submerged arc welding systems. The illustrated welding system 20 comprises a combination power source/wire feeder 22 . However, a separate power source and wire feeder also may be used. The illustrated welding system also comprises a gas cylinder 24 containing a gas 26 that is coupled to the power source/wire feeder 22 . A spool 28 of electrode wire 30 also is coupled to the power source/wire feeder 22 . The electrode wire 30 and gas 26 are coupled to a welding gun 32 having a welding cable 34 . However, the present technique is applicable with welding implements other than a welding gun, such as a robotic welder. In the illustrated embodiment, the welding cable 34 is adapted to receive gas 26 and electrode wire 30 . Additionally, in this embodiment, the welding cable 34 has a plurality of conductors that, along with the electrode wire 30 , couple electricity from the power source 22 to the welding gun 32 . The additional conductors prevent the electrode wire from having to carry the entire electrical current load, which could lead to failure of the electrode wire. In addition, the additional conductors reduce resistive heating losses. The work clamp 36 is clamped onto the conductive work piece 40 to be welded. The work clamp 36 and the ground cable 38 electrically couple the power source/wire feeder 22 to the work piece 40 . Additionally, the wire 30 within the welding cable 34 is electrically coupled to the power source/wire feeder 22 . The welding gun 32 is used to direct the gas and wire toward the work piece 40 and to control the supply of gas 26 and wire 30 from the power source/wire feeder 22 . The electrical circuit is completed when the electrode wire 30 contacts, or is brought into proximity with, the work piece 40 . Electricity from the power source 22 flows through the electrode wire 30 and work piece 40 , producing an arc. The electric arc produces heat that melts the work piece 40 in a region surrounding the point of contact between the wire 30 and the work piece 40 . The wire 30 also acts as filler material. The heat of the arc melts the wire 30 along with the work piece 40 . The inert gas 26 forms a shield that prevents harmful chemical reactions from occurring at the weld site. When the arc is removed, the work piece 40 and the filler material solidify, forming the weld. Referring generally to FIGS. 1 and 2 , the welding gun 32 comprises a handle 42 , a trigger 44 , a trigger lock 46 , a neck 48 , a retaining nut 50 , and a nozzle assembly 52 . In this embodiment, the handle 42 comprises two handle pieces secured to each other around the welding cable 34 to form the handle 42 . The welding cable 34 also has an electrical cable (not shown) that is electrically coupleable to the trigger 44 to enable the trigger 44 to control the power source/wire feeder 22 . In this embodiment, a number of events occur when the trigger 44 is operated. One event is that the power source/wire feeder 22 draws in wire 30 from the wire spool 28 and feeds it though the welding cable 34 to the neck 48 of the welding gun 32 . Gas 26 also flows from the gas cylinder 24 flows through the welding cable 34 to the neck 48 of the welding gun 32 . In addition, electricity from the power source/wire feeder 22 is supplied to the conductors in the welding cable 34 and conducted to the neck 48 of the welding gun 32 . Preferably, the neck 48 comprises copper. The nozzle assembly 52 is coupled to the opposite end of the neck 48 and is adapted to direct wire 30 and gas 26 towards the work piece 40 . In addition, the nozzle assembly 52 has a contact tip (not shown) that is adapted to conduct the electricity flowing through the neck 48 to the electrode wire 30 . The nozzle assembly 52 may also have a gas diffuser to provide optimal gas flow properties. The trigger lock 46 is operable to secure the trigger 44 engaged so that a user need not actively hold the trigger 44 engaged during prolonged periods of operation. When the trigger 44 is released, gas 26 , wire 30 , and electrical power are no longer fed to the welding gun 32 . A voltage control 54 and a wire speed control 56 are provided to enable a user to vary the voltage applied to the electrode wire 30 by the power source/wire feeder 22 and the speed that the wire 30 is fed from the power source/wire feeder 22 . In the illustrated embodiment, the neck 48 is secured to the welding handle 42 by threading the retaining nut 50 to a threaded portion 58 of the welding cable 34 . However, the neck 48 may be threaded to another portion of the welding gun. For example, the welding cable 34 and neck 48 may be coupled through a separate threaded connector. The retaining nut 50 is adapted to be wrench-tightened to the threaded portion 58 (see FIG. 4 ) of the welding cable 34 . Preferably, the retaining nut 50 comprises metal. However, other materials may be used. Of the metals, brass is preferred. However, other metals, such as aluminum and steel may be used. A boot (not shown) comprised of an electrically insulating material may be disposed over the retaining nut 50 . Referring generally to FIGS. 3 and 4 , a hand operator 60 , rather than a boot, is disposed over the retaining nut 50 in the illustrated embodiment. The hand operator 60 is adapted to enable a user to hand-tighten, rather than wrench-tighten, the retaining nut 50 onto the threaded portion 58 of the welding cable 34 . Preferably, the hand operator 60 is comprised of an electrically insulating material, such as a polymer. For example, the hand operator 60 may be comprised of a glass-filled nylon or a glass-filled polycarbonate. The hand operator 60 may be secured to the retaining nut 50 by the manufacturer or provided to a customer to enable a customer to elect whether or not to install the hand operator 60 . As illustrated in FIG. 5 , the hand operator 60 is adapted to slide over the neck 48 . The neck assembly 52 may be removed to facilitate the installation of the hand operator 60 . The hand operator 60 has a plurality of indentations 62 disposed around the circumference of the hand operator 60 to enable a user to hand-tighten the retaining nut 50 . In this embodiment, the indentations 62 are curved to receive the digits of a users hand so that a user may rotate the hand operator 60 , as well as the retaining nut 50 , easily when the hand operator 60 is secured to the retaining nut 50 . In addition, the indentations 62 provide leverage to enable a user to provide force to tighten the retaining nut 50 onto the threaded portion 58 of the welding cable 34 . The retaining nut 50 is adapted with a plurality of faces 64 to enable a wrench to be used to tighten the retaining nut 50 onto the threaded portion 58 of the welding cable 34 . The neck 48 has a first end 66 that is adapted to be inserted into a portion of the welding cable 34 . The neck 48 has a second end 68 that is adapted to receive the nozzle assembly 52 . In the illustrated embodiment, to secure the neck 48 to the handle 42 , the first end 66 of the neck 48 is placed within the threaded portion 58 of the welding cable 34 . The retaining nut 50 then is threaded into the threaded portion 58 of the welding cable 34 . As illustrated in FIG. 6 , the neck 48 is adapted with a first groove 70 and the retaining nut 50 is adapted with a corresponding second groove 72 . A retaining ring 74 , such as a snap ring, is disposed within the grooves to secure the retaining nut 50 to the neck 48 . The illustrated retaining ring 74 allows the retaining nut 50 to rotate relative to the neck 48 . The retaining nut 50 also has a threaded portion 76 that is adapted for threaded engagement with the threaded portion 58 of the welding cable 34 . As the retaining nut 50 is threaded with the threaded portion 58 of the welding cable 34 , the retaining nut 50 urges the retaining ring 74 , and thus neck 48 , towards the welding cable 34 , forming a seal between the neck 48 and the welding cable 34 . In the illustrated embodiment, the hand operator 60 is securable to the retaining nut 50 without the use of tools. The hand operator 60 is adapted to slide over and snap-fit onto the retaining nut 50 . The illustrated embodiment of the hand operator 60 is adapted with a plurality of fingers 78 that are adapted to flex as the hand operator 50 is slid over the retaining nut 50 and snap into a securing groove 80 in the retaining nut 50 , securing the hand operator 60 to the retaining nut 50 . In this embodiment, the fingers 78 are adapted with a catch portion 82 adapted to abut a surface 84 of the securing groove 80 . The hand operator 60 also has a rear lip 86 adapted to abut against a rear surface 88 of the retaining nut 50 to urge the retaining nut 50 towards the threaded connector 58 . The hand operator 60 also is adapted to contact the faces 64 of the retaining nut 50 to rotate the retaining nut 50 as the hand operator 60 is rotated. In the illustrated embodiment, the rear surface 88 of the retaining nut is adapted with a curved surface 90 to facilitate flexing the fingers 78 of the hand operator 60 , as the hand operator 60 is slid over the retaining nut 50 . The catch portion 82 is adapted with a corresponding angled surface to further facilitate the flexing the fingers 78 of the hand operator 60 . Referring again to FIG. 4 , the electrode wire and gas are conveyed through the neck 48 to the nozzle assembly 52 . In the illustrated embodiment, within the nozzle assembly 52 is an insulator 92 , a diffuser 94 , and a contact tip 96 . Electricity from the welding cable 34 is coupled through an inner portion of the neck 48 to the contact tip 96 . The contact tip 96 is used to conduct the electrical current from the power source into the electrode wire 30 . The contact tip 96 also is used to guide the electrode wire. The diffuser 94 is used to establish the desired flow characteristics of the gas 26 , e.g., pressure. The diffuser 94 may be connected to the neck 48 and the contact tip 96 secured to the gas diffuser 94 . The insulator 92 is used to prevent electricity in the gas diffuser 94 from flowing to the welding gun 32 through an outer portion of the neck 48 . The nozzle 52 is used to direct the gas 26 and wire 30 to the work piece 40 . It will be understood that the foregoing description is of preferred exemplary embodiments of this invention, and that the invention is not limited to the specific forms shown. For example, the retaining nut and/or hand operator may be formed of different materials than described. These and other modifications may be made in the design and arrangement of the elements without departing from the scope of the invention as expressed in the appended claims.

A welding system having a welding implement. The welding implement having a neck, a handle and a retaining nut for securing the neck to the handle. The neck being operable to convey electrode wire therethrough. The retaining nut being adapted for wrench-tightening to a threaded portion of the welding implement. An optional retaining nut operator. The optional retaining nut operator being adapted to secure to the retaining nut. The optional retaining nut operator being adapted for manual rotation to thread the retaining nut to the threaded portion of the welding implement. The optional retaining nut operator may be adapted to snap-fit onto the retaining nut. The optional retaining nut operator may include an electrically insulating material. The electrically insulating material may include a polymer.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority from U.S. Provisional Patent Application Ser. No. 61/370,487, filed Aug. 4, 2010. FIELD OF THE INVENTION [0002] The present invention is directed to minimally invasive surgery, and more particularly to an acetabular prosthetic cup impactor tool for use in minimally invasive hip replacement surgery. PRIOR ART [0003] Approximately 200,000 hip replacements are performed each year in the United States and the number is expected to continue to grow as the population continues to age. The usual reasons for hip replacement are osteoarthritis, rheumatoid arthritis and traumatic arthritis, all of which can cause pain and stiffness that limit mobility and the ability to perform daily living activities. Hip replacement surgery is usually performed where other measures (e.g. physical therapy, medications, and walking aids) are unable to overcome the chronic pain and disability associated with these conditions. [0004] Obesity is an increasingly common health concern in the United States. According to the Center for Disease Control and Prevention (CDC), about one third of the U.S. population is obese. Studies have suggested that obesity is linked to the development of joint ailments, particularly of the hip and knee. These studies disclosed, for example, that obesity increases the risk for developing osteoarthritis in the hip and the knee, and suggest that obesity plays a role in initiating and accelerating hip and knee osteoarthritis. The development of osteoarthritis occurs either directly by the increased load on a joint or indirectly because obesity is associated with a variety of metabolic disorders. Additionally, the added weight of an obese person contributes to the stresses that are applied to a person's joints thereby increasing joint wear, and in so doing accelerating the need for replacement. Therefore, there is an increasing need to address joint ailments for obese patients as well. [0005] Various techniques are used by orthopedic surgeons to perform hip replacements. These include the following approaches: anterior, antero-lateral, lateral, postero-lateral and posterior. The posterior and postero-lateral approaches account for approximately 60%-70% of hip replacement surgeries. [0006] Traditional hip replacement surgery involves an open surgical procedure and extensive surgical dissection. However, such procedures require a longer recovery period and rehabilitation time for the patient. The average hospital stay for open hip replacement procedures is 4-5 days, followed in most cases by extensive rehabilitation. [0007] More recently, there has been considerable interest and research done in Minimally invasive Surgery (MIS), including the use of MIS procedures in connection with hip replacement surgery. In comparison with the traditional open surgical approach, MIS hip replacement surgeries involve fewer traumas to the muscles surrounding the hip joint. Specifically, fewer muscles that help to stabilize the hip joint are cut in MIS hip replacement surgeries, reducing the risk of dislocation of the hip surgery and speeding recovery. Patients spend less time in the hospital and return to normal life activities more quickly. [0008] MIS approaches use smaller surgical openings, which require specialized instruments to perform hip replacement procedures. As such, these MIS procedures are beneficial since they are less traumatic to the body. However, these MIS procedures are particularly difficult to perform with obese patients. The increased body mass and overall tissue volume of obese patients add additional complications in performing MIS procedures, particularly in accessing the surgical site. [0009] In these cases, the incision is especially deep as there are thicker and deeper masses of soft tissue. Traditional acetabular cup impactors provide some clearance of soft tissue. However, traditional impactors provide inadequate clearance particularly when performing a MIS procedure on an obese patient. Accordingly, there is a need for an improved impactor tool for use in MIS orthopedic procedures (e.g., hip replacement surgery) with obese patients that addresses some of the shortcomings in the existing surgical impactors noted above. SUMMARY OF THE INVENTION [0010] In accordance with one embodiment, an orthopedic cup impactor for use in minimally invasive hip replacement surgical procedures is provided. The impactor comprises a handle, residing at a proximal end portion and a cup engagement sub-assembly located at a distal portion. A shaft resides therebetween. The shaft portion is designed with a large radius of curvature that provides added clearance when inserting the impactor in obese patients. The shaft portion is further designed with a curved underside surface and a planar top surface with beveled side edges. These features aid in the insertion of the impactor and provide surfaces to aid in the leverage of the tissue. [0011] In accordance with another embodiment, the impactor of the present invention features an offset between the handle portion and the distal portion. The offset between the handle portion and the distal end allows for a much deeper insertion of the cup impactor into obese patients than traditional impactors with obese patients. [0012] In accordance with an additional embodiment, the impactor of the present invention features a shaft with a curved cross-section. This feature enables the impactor access into an obese patient with increased efficiency. Furthermore, the shaft's curved cross-section helps to retard tissue necrosis. [0013] In accordance with yet another embodiment, the impactor features a cup engagement subassembly comprising a drive shaft having multiple degrees of freedom. This drive shaft design feature, comprising a series of “U” and “H” joints, provides full rotation at differing bend angles when inserting an orthopedic implant. Furthermore, in yet another embodiment, the drive train may be designed to be removable from the cup impactor. Such a feature allows for efficient and thorough cleaning of the drive train after a surgical procedure. BRIEF DESCRIPTION OF THE DRAWINGS [0014] FIG. 1 is a perspective view of an embodiment of a cup impactor. [0015] FIG. 2 is a side view illustrating alternate orientations of the cup impactor embodiment shown in FIG. 1 . [0016] FIG. 3 illustrates a bottom view of the embodiment of the cup impactor shown in FIG. 1 . [0017] FIG. 4 shows a magnified cross-sectional view of a distal end portion of the cup impactor embodiment shown in FIG. 1 . [0018] FIG. 5 illustrates a side view of an embodiment of a drive train of the present invention. [0019] FIG. 6 shows a magnified side view of the embodiment of the drive train shown in FIG. 5 . [0020] FIG. 7 is a perspective view of the cup impactor with an embodiment of a drive tool. [0021] FIG. 8 shows an end view of the cup impactor embodiment shown in FIG. 1 . [0022] FIG. 8A illustrates an alternate embodiment of the cup impactor shown in FIG. 1 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0023] Now turning to the figures, FIGS. 1 to 8A illustrate embodiments of a cup impactor 10 of the present invention. As illustrated in FIG. I, the cup impactor 10 comprises a handle 12 located at a proximal end portion 14 and an orthopedic cup engagement sub-assembly 16 located at a distal end portion 18 thereof. A shaft 20 resides between the respective handle portion 12 and the distal end portion 18 of the impactor 10 . [0024] The cup impactor 10 has an impactor length 22 and an impactor height 24 ( FIG. 7 ). In a preferred embodiment, the impactor length 22 ranges from about 20 cm to about 100 cm, more preferably, from about 40 cm to about 60 cm. In a further embodiment, the impactor height 24 ranges from about 5 cm to about 20 cm, more preferably, from about 10 cm to about 15 cm. [0025] In an embodiment, the shaft 20 is curved between the handle 12 residing at the proximal end 14 and the distal end 19 of the impactor 10 . Preferably, the shaft 20 is curved similarly to that of an arc 26 with an apex 28 positioned at about its maximum height. In a preferred embodiment, the arc 26 has a radius of curvature 30 that ranges from about 10 cm to about 20 cm as measured with respect to an inner surface 32 thereof. [0026] The shaft 20 preferably has a planar top surface 34 . Beveled top side edges 36 , 38 transition from the top surface 34 to respective left and right sidewalls 40 , 42 of the shaft 20 ( FIG. 8 ). The beveled side edges 36 , 38 further extend longitudinally from the handle portion 12 to the distal end 19 of the impactor 10 . In a preferred embodiment, the top side edges 36 , 38 have a radius of curvature 44 , 46 that ranges from about 0.1 cm to about 2 cm. Furthermore, the left and right sidewalls 40 , 42 may have a surface 48 that is planar. Alternatively, the left or right sidewall 40 , 42 may also have a curved surface 48 . [0027] In a preferred embodiment, the inner surface 32 has curved inner surface side edges 50 , 52 . These side edges 50 , 52 are designed such that they fluidly transition into the left and right sidewalls 40 , 42 of the shaft 20 , as illustrated in FIG. 3 . In a preferred embodiment, the inner surface 32 has an inner surface radius of curvature 54 that ranges from about 1 cm to about 5 cm. [0028] Alternatively, the shaft 20 could be constructed such that it has a curved cross-section and more preferably, a round cross-section. As such, the shaft 20 may have a diameter that ranges from about 1 cm to about 10 cm. The curved cross-section of the shaft 20 is beneficial because it reduces the physical resistance of the cup impactor 10 as it is inserted within the body of a patient. Reduced resistance is especially beneficial when the impactor 10 is inserted within an obese human body of a large mass and volume. The curved surfaces of the impactor 10 allow the user to turn and rotate the instrument more efficiently. Furthermore, the arc design of the shaft 20 provides for improved access to the hip area of the patient. [0029] In a preferred embodiment, the handle 12 is positioned such that it is about coplanar with that of the distal end 19 of the impactor 10 . As illustrated in FIG. 1 , longitudinal axis A-A extends through the center of the handle 12 and through the distal end 19 of the impactor 10 . Alternatively, as shown in FIG. 2 , the handle 12 may be positioned such that it is offset from the plane of the distal end 19 , i.e., deviating from axis A-A. In a further embodiment, a handle offset angle 56 is established between longitudinal axis A-A and handle axis B-B. Axis B-B is herein defined as the axis that extends longitudinally through the center of the handle portion 12 . Handle axis B-B can therefore assume multiple positions depending on the particular handle offset that is desired, as shown in FIG. 2 . The handle offset angle 56 is herein defined as the angle 56 between the intersection of longitudinal axis A-A and handle axis B-B. It is preferred that the handle offset angle 56 range from about 2° to about 40°. [0030] Furthermore, the distal end 19 of the impactor 10 may be constructed such that it is offset from longitudinal axis A-A. In an additional embodiment, a distal end offset angle 58 is established between axis C-C, an axis extending longitudinally through the center of the distal end 19 of the impactor 10 , and imaginary line D-D ( FIG. 2 ). Line D-D is an imaginary line that extends about the middle of a distal portion 57 of the shaft 20 , along sidewall 40 , 42 as shown in FIG. 2 . The distal end offset angle 58 is herein defined as the angle between the intersection of axis C-C and imaginary line D-D. It is further preferred that the distal end offset angle 58 may range from about 40° to about 60°. Additionally, the offset of the distal end 19 from the proximal end 14 may be defined by a distal end offset distance 59 . The distal end offset distance 59 is herein defined as the distance between longitudinal axis A-A and axis CC as shown in FIG. 2 . In a preferred embodiment, the offset distance 59 ranges from about 1 cm to about 10 cm. [0031] It is further contemplated that the cup impactor 10 may or may not have an offset handle angle 56 or a distal end offset angle 58 or a distal end offset distance 59 . Furthermore, the respective offset angles 56 , 58 of the impactor 10 may be offset at angles that are similar or different from each other. [0032] The cup engagement sub-assembly 16 comprises a drive train 60 that extends to a rod end 62 as shown in FIGS. 1 , 4 , and 7 - 8 . The cup engagement sub-assembly 16 preferably resides at the distal end portion 18 of the impactor 10 . In a preferred embodiment, the drive train 60 at least partially resides within a cavity 64 at the distal end portion 18 of the impactor 10 . [0033] The cavity preferably extends from the distal end 19 of the impactor 10 to a region proximate the distal end 19 . The cavity 64 preferably furthermore resides within the top surface 34 of the shaft 20 of the impactor 10 . In a preferred embodiment, the cavity 64 has a cavity depth 66 from about 1 cm to about 4 cm, a cavity length 68 from about 10 cm to about 20 cm and a cavity width 70 from about 1 cm to about 5 cm. Left and right cavity sidewalls 72 , 74 extend along the length 68 of the cavity 64 . The cavity 64 is further positioned such that it extends through the distal end 19 of the impactor 10 creating an opening 76 thereof. The opening 76 is preferably dimensioned such that at least a portion of the distal end of the cup engagement sub-assembly 16 , particularly the rod 62 of the sub-assembly 16 , extends therethrough. In a preferred embodiment, the opening 76 at the distal end 19 may have a diameter that ranges from about 0.5 cm to about 2 cm. In a preferred embodiment, the cavity 64 ends at a position that is distal of the apex 28 of the middle shaft portion and provides for receiving a driver tool 78 for rotating the drive shaft with the threaded rod 62 being at an angle 80 from about 40° to about 60°, preferably at about 55° with respect to a major shaft 82 of the drive train 60 . [0034] Furthermore, the depth 66 of the cavity 64 may be designed such that it gradually increases from the proximal end 18 to the distal end 19 of the impactor 10 . The maximum cavity depth 66 is achieved at the opening 76 of the distal end 19 of the impactor 10 . This design feature of the cavity 64 allows for improved unobstructed motion of the drive train 60 within the cavity 64 and provides an improved means of accessing the drive train 60 within the body of the patient. [0035] The cavity 64 further has a series of slots 84 that extend through each of the cavity sidewalls 72 , 74 and bottom surface 32 of the shaft 20 . These slots 84 are designed to allow for efficient and thorough cleaning of the cavity 64 . Furthermore, the cavity 64 has an additional opening 86 extending through the inner surface 32 of the shaft 20 distal of the slot openings 84 . This additional opening 86 is preferably positioned along a bend 88 where the distal end 19 transitions into the arc 28 of the shaft 20 . The opening 86 provides for easy access to the cup engagement sub-assembly 16 to allow for efficient and through cleaning thereof. [0036] As particularly shown in FIGS. 4-6 , the drive train 60 comprises a major shaft 82 as a cylindrically-shaped member having a proximal portion 90 and a distal end 92 with a length therebetween. Furthermore, the major shaft 82 comprises a bar bell portion 94 at both the proximal 90 and distal ends 92 thereof. The bar bell portion 94 is designed such that a portion of the major shaft 82 is removed to create a recessed region 96 along the shaft 82 . This recessed shaft region 96 is characterized with a shaft diameter that is smaller than that of the major shaft 82 . The recessed shaft region 96 is designed such that it enables a pin or pins 98 to be positioned across the region 96 between the cavity sidewalls 72 , 74 thereby permitting rotational movement of the shaft while preventing the drive shaft 82 from being removed from the cavity 64 of the impactor 10 , as shown in FIGS. 1 and 4 . [0037] The proximal shaft end 90 preferably has a socket 100 therewithin designed to engage the drive tool 78 ( FIG. 6 ). The drive tool 78 is designed to be inserted into the socket 100 of the proximal end 90 of the drive train 60 . The drive tool 78 comprises a hexagonal end or similar type structure that provides flats for detachable connection of the socket 100 at the proximal end 90 . In a preferred embodiment, the drive shaft 60 may be rotated clockwise or counterclockwise when the tool 78 is engaged in the socket 100 . Rotation of the drive shaft 82 in turn rotates the threaded rod 62 at the distal end 19 of the impactor 10 . Alternately, a rotary drive power source (not shown) could also engage the socket 100 of the drive shaft 82 to provide rotation. [0038] As particularly shown in FIGS. 5 and 6 , a first or proximal U-joint 102 is supported at the distal end 92 of the major shaft 82 . The proximal U-joint 102 is comprised of a proximal cylindrical sidewall 104 supporting a pair of yoke plates 106 and 108 having respective openings 110 , 112 . Connection of the U-joint 102 to the shaft 82 may be made by a screw and the like. The screw is received in an opening 114 in the sidewall 104 and seats against a flat 116 at the distal shaft end 92 . In the alternative, the proximal U-joint could be welded or otherwise secured in place or, the U-joint and shaft could be machined from a single piece of material. [0039] The drive train 60 further includes an H-shaped joint 118 comprising a cylindrical intermediate section 120 supporting opposed first and second pairs of yoke plates 122 , 124 and 126 , 128 . Respective openings 130 , 132 and 134 , 136 are provided in the yoke plates. A proximal pivot block 138 ( FIG. 6 ) resides between the yoke plates 106 , 108 of the proximal U-joint 102 and the first pair of yoke plates 122 , 124 of the H-joint 118 . The proximal pivot block 138 comprises two pairs of perpendicularly opposed openings 142 and 144 . [0040] Pin 146 is received in the openings 110 , 112 in the yoke plates 106 and 108 of the U-joint 102 and the opening 142 in the pivot block 138 , and a pin 148 is received in the opening 142 of the pivot block 138 and the openings 110 , 112 of the yoke plates 122 , 124 of the H-plate 118 to thereby pivotably secure the proximal U-joint 102 to the first end of the H-joint 118 . It is noted that only one of the pins 146 or 148 extends completely from one face of the pivot block 138 to the other face. As passage from one face to the other is blocked by the first pin, the other of the two pins 146 or 148 is two “half pins”. [0041] As shown in FIGS. 5 and 6 , the drive train 60 also includes a distal U-joint 150 that comprises a distal cylindrical side wall 152 supporting a pair of yoke plates 154 and 156 having respective openings 158 , 160 . Opposite the yoke plates, the cylindrical sidewall 152 meets a base plate 162 having an enlarged diameter. A cylinder 164 extends outwardly from the base plate 162 . The threaded rod 62 preferably extends outwardly from the cylinder 164 of the distal U-joint 150 . Each of the components of the drive train 60 have their respective axes aligned parallel to each other and co-axial with, but spaced from, a longitudinal axis E-E of the distal U-joint 150 . [0042] A distal pivot block 166 , similar in structure to the proximal pivot block 138 , comprises two pairs of perpendicularly opposed openings 168 and 170 . Pin 174 is received in the openings 158 , 160 in the respective yoke plates 154 , 156 of the distal U-joint 150 and the opening 168 in the pivot block 166 , and a pin 172 is received in the openings 134 , 136 of the respective yoke plates 126 , 128 of the H-joint 118 and opening 168 of the pivot block 166 to thereby pivotably secure the distal U-joint 150 to the second or distal end of the H-joint 118 . As with the pivotable connection between the H-joint 118 and the proximal U-joint 102 , only one of the pins 172 , 174 extends the full width of the pivot block 166 from one face to an opposite face thereof. The other pin is provided as two partial length pins. [0043] In this manner, the drive train 60 comprising the drive shaft 82 , the proximal U-joint 102 , the first pivot block 138 , the H-joint 118 , the second pivot block 166 and the distal U-joint 150 provides for transmission of rotational motion imparted to the proximal end of the shaft 82 to the base plate 162 and its supported rod 62 . [0044] Although the H-joint 118 is preferred, it is contemplated that the drive train 60 may be constructed without the H-joint 118 . In this embodiment, the drive train 60 would comprise the drive shaft 82 , the proximal U-joint 102 , the first pivot block 138 and the distal U-joint 150 . It is further contemplated that the drive train 60 may comprise a flexible shaft design such as wire wound shaft or a shaft that is laser cut. [0045] The threaded rod 62 extends through the distal end 19 of the impactor 10 . The threaded rod 62 preferably engages with an orthopedic implant 176 . Prior to the surgical procedure, a connection between the threaded rod 62 and the orthopedic implant 176 is established. In a preferred embodiment, the threaded rod 62 is mated with corresponding grooves (not shown) of the implant 176 . Once the implant is secured to the distal end 19 of the impactor 10 , the implant 176 is inserted into a patient. Once the implant 176 is correctly positioned within the body, the drive shaft 82 is rotated in a reverse direction with respect to the threads of the rod 62 . Typically, the rod 62 is provided with right hand threads so that counterclockwise rotation disengages the implant 176 from the impactor 10 . [0046] Additionally, a series of slots 178 , as shown in FIG. 7 , may extend around the perimeter of the base plate 162 of the threaded rod 62 . These slots 178 are designed such that they fit with corresponding implant slot grooves (not shown) providing additional support between the threaded rod 62 of the impactor 10 and the implant 176 . [0047] The drive train 60 may be designed without pins 98 such that it is removable from the cavity 64 of the impactor 10 . A removable drive shaft 82 is beneficial in that it provides for more efficient and thorough cleaning of the cup engagement sub-assembly 16 . As shown in an alternate embodiment of FIG. 8A , a sleeve 180 may be positioned over the proximal end portion 90 of the drive shaft 82 . This sleeve 180 provides for a wider perimeter diameter that creates a snug or interference fit when positioned within the cavity 64 . Alternatively the proximal end 90 of the drive shaft 82 may be constructed with an increased diameter that creates an interference fit when positioned between the sidewalls 72 , 74 of the cavity 64 . [0048] Furthermore, it is contemplated that a plurality of pads may be positioned around the perimeter of the major shaft 82 of the drive train 60 and/or positioned along the inside surface of the cavity sidewalls 72 , 74 . These pads are designed to provide an additional interference fit within the cavity 64 such that the drive train 60 remains within the cavity 64 during the surgical procedure. [0049] Of course, the forgoing description is that of certain features, aspects and advantages of the present invention, to which various changes and modifications can be made without departing from the spirit and scope of the present invention. Moreover, the cup impactors need not feature all of the objects, advantages, features and aspects discussed above. Thus, for example, those of skill in the art will recognize that the invention can be embodied or carried out in a manner that achieves or optimizes one advantage or a group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein. In addition, while a number of variations of the invention have been shown and described in detail, other modifications and methods of use, which are within the scope of this invention, will be readily apparent to those of skill in the art based upon this disclosure. It is contemplated that various combinations or sub-combinations of these specific features and aspects of embodiments may be made and still fall within the scope of the invention. Accordingly, it should be understood that various features and aspects of embodiments may be made and still fall within the scope of the invention. Accordingly, it should be understood that various features and aspects of the disclosed embodiments can be combined with or substituted for one another in order to form varying modes of the discussed cup impactor embodiments.

An orthopedic cup impactor for use in minimally invasive hip replacement surgical procedures is described. The impactor comprises a handle, residing at a proximal end portion, and a cup engagement sub-assembly located at a distal portion. A shaft resides therebetween. The shaft portion is designed with a large radius of curvature that provides added clearance when inserting the impactor in obese patients. The cup engagement sub-assembly features a drive train that comprises a series of “U” and “H” joints deigned to provide full rotational motion. The drive train may be designed to be removable from the cup impactor to provide more efficient and thorough cleaning.

FIELD OF THE INVENTION [0001] The invention relates generally to optoelectronic modules, and more particularly to a plug arrangement used in conjunction with an optoelectronic module. One preferred field of application of the invention is low-cost optoelectronic modules which are coupled to POF (Plastic Optical Fiber) optical waveguides. Within this preferred field of application, the invention is particularly suitable for use in multimedia networks, in the in-house area and automotive area. BACKGROUND OF THE INVENTION [0002] DE 199 09 242 A1 discloses an optoelectronic module in which a mount with an optoelectronic transducer is positioned in a module housing and is encapsulated by means of a translucent material which can be shaped. The light is injected or output via an optical fiber, which is coupled to a connecting stub on the module housing. The driver module and the receiving module for the optoelectronic transducer are also located on the mount. [0003] The data rates for POF transmission systems are rising increasingly. So-called RCLEDs (Resonant Cavity LEDs) with data rates of up to 500 Mbit/s are thus being used increasingly. These RCLEDs have the disadvantage that they have a resonant-like behavior in the temperature range from about −40° C. to 85° C. In particular, there is a considerable reduction in power at the upper temperature limit. These reductions in power can be decreased by circuitry measures on the driver module. [0004] In the case of transceiver embodiments in which the driver module is encapsulated in the encapsulation body with the RCLED, it is, however, impossible to implement appropriate circuitry measures. Firstly, it is difficult to additionally accommodate the external circuitry in the encapsulation body and to carry out the wiring. Secondly, a large amount of heat is developed, because the driver stage and the optical transmission source draw more current at high data rates, and because of the additional external circuitry. This heating can lead to clouding or blackening of the encapsulation body, and to destruction of the transducer module. [0005] The only known way until how to reduce undesirable heating has been to restrict the temperature range to 0° C. to about 60° C. External circuitry which reduces the reductions in the power of the transducer module are also dispensed with in the case of transducer modules which are encapsulated in an encapsulation body. Obviously, this is not satisfactory. [0006] U.S. Pat. No. 5,768,456 describes an optoelectronic module having a transmitting and/or receiving element which is arranged on a flexible substrate. The flexible substrate is connected to-a printed circuit board. A holding is provided for holding an optical waveguide which can be coupled to the transmitting and/or receiving element, and the holder-is likewise arranged on the printed circuit board. [0007] U.S. Pat. No. 5,259,052 discloses an optical plug arrangement, in which an optical plug has a protective bracket which can be moved in the longitudinal direction with respect to the optical waveguides. During insertion of the optical plug into a plug housing, the protective bracket is moved relative to the optical waveguides, so that they project beyond the protective bracket. SUMMARY OF THE INVENTION [0008] The present invention is directed to an optoelectronic module which is distinguished by being physically compact. The aim in this case is to prevent undesirable heating caused by electrical circuits. A further aim is to provide a plug arrangement for POF transmission systems, which allows optical fibers to be connected to an optoelectronic module. [0009] Accordingly, provision is made that, in the case of an optoelectronic module, the electrical drive and/or receiving circuit is arranged outside the holding and coupling part for the transmitting and/or receiving element, to be precise on a submount which lies on a plane which runs parallel to the longitudinal axis of the coupling area. The mount for the optoelectronic module on which the transmitting and/or receiving element is arranged in this case runs at right angles to the submount. The separation of the optical transducer (transmitting and/or receiving element) from the electrical circuitry allows each of these components to be optimized individually. In this case, only the transmitting and/or receiving element and, possibly additionally a monitor diode are/is accommodated in the holding and coupling part. The transmitting and/or receiving element is sheathed by an encapsulation material. [0010] This results in a small, transparent encapsulation body, which has a largely homogeneous expansion behavior. Only minor stresses occur in the encapsulation body over the maximum temperature range from −40° C. to +85° C., as is required in automotive applications, thus considerably improving the fatigue life. [0011] The arrangement of the submount parallel to the longitudinal axis or optical axis of the coupling area allows the submount to be arranged directly on a main circuit board. The submount together with the electrical drive and/or receiving circuit in this case represents a unit which can be tested in advance. It should be mentioned that the electrical drive and/or receiving circuit may also have the additional electrical circuitry mentioned initially, in addition to the actual transducer module or receiving module, thus making it possible to reduce the resonant-like behavior of the transducer module, in particular of an RCLED. [0012] In one preferred refinement of the invention, the holding and coupling part forms a cylindrical cutout, one of whose ends contains the transmitting and/or receiving element, and whose other end forms the coupling area for an optical fiber. The holding and coupling part is accordingly essentially a cylinder, at one of whose ends the transmitting and/or receiving element is arranged in the encapsulation material, and whose other end is used to hold an optical fiber. The optical axis of the transmitting and/or receiving element is in this case located on the longitudinal axis of the cylinder or coupling area. The inner wall of the cylinder is used in a simple manner for passive fiber guidance and for fixing the fiber with respect to transverse deflections. [0013] The mount for the transmitting and/or receiving element is preferably a leadframe, which provides the electrical link for the transmitting and/or receiving element (in particular by means of bonding wires between the individual contacts of the leadframe and the transmitting and/or receiving element). The leadframe is in this case electrically connected to the submount, and for this purpose has an area at one of its ends which is bent through 90° and is mounted on the submount. At least in the area of the holding and coupling part, the leadframe preferably runs at right angles to the longitudinal axis of the coupling area or to the plane on which the submount is arranged. [0014] The encapsulation material in the holding and coupling part preferably forms an integrated lens on the side facing the coupling area. For this purpose, a filling closure is inserted into the coupling area before the filling process, on whose end surface the coupling lens is formed in negative form. Once the holding and coupling part has been filled with the encapsulation material and the material has been cured, the filling closure is removed again, with the desired coupling lens being integrated in the encapsulation material. [0015] The integrated form of a lens in the encapsulation body increases the injected transmission power and the received power which is imaged on a receiving element. [0016] A fiber stop ring is furthermore preferably provided in the encapsulation material around the lens in order to prevent the end surface of an optical fiber which is inserted into the coupling area being able to touch the lens apex of the lens. The fiber stop ring also leads to positioning in the longitudinal direction of the coupling area, thus resulting in fiber guidance on all three spatial axes. [0017] In one preferred refinement of the invention, the optoelectronic module is mechanically coupled to a plug holder. The coupling is in this case provided via the outer wall of the holding and coupling part. Self-coupling structures may be provided in this case, allowing simple and automatic coupling between the holding and coupling parts and the plug housing. During insertion of a plug into the plug holder, the corresponding optical fiber is inserted into the coupling area of the holding and coupling part. [0018] It is also possible to provide for the module to be mechanically coupled to a naked fiber adaptor. The optical fiber is in this case, for example, firmly clamped by means of clamp in an area of the naked fiber adaptor which is in the form of a trough. It is also possible to provide for the naked fiber adaptor to be formed integrally with the holding and coupling part, and to be formed by an extension of the cylindrical coupling area of the holding and coupling part. The arrangement of a naked fiber adaptor represents a physically simple and low-cost variant for coupling the optical fiber to the optoelectronic module. [0019] In a further preferred refinement of the invention, the submount can be mounted on a main circuit board, in particular by SMD mounting. The main circuit board is in this case preferably used as a heat sink for the submount and for the electrical modules arranged on it. For this purpose, the submount preferably has plated holes which, in addition to electrical connection, also provide heat conduction between the electrical components on the submount and the main circuit board. Solder pad contacts are provided in particular on the lower face of the submount, via which the submount is mounted by SMD mounting on the main circuit board. [0020] Lithographic circuit wiring techniques allow the electrical submount to be very compact, so that the entire transceiver structure has a width of less than 13.5 mm and thus satisfies the industry criterion of a “small form factor”. The submount and the holding and coupling part are arranged alongside one another or else one above the other on the main circuit board, with the holding and coupling part possibly being held by further structures such as a plug housing. [0021] The holding and coupling part and/or the submount preferably have/has self-coupling structures which allow automatic adjustment between these parts and/or with respect to a main circuit board. Corresponding structures may also be provided on a-plug housing or on a naked fiber adaptor. [0022] The electrical contacts on the lower face of the submount are preferably designed such that they are as far apart from one another as possible, for example being offset. This makes it possible to design a plug housing or a naked fiber adaptor, to which the holding and coupling part is connected, with clamping structures on the lower face such that the module is fixed by the optoelectronic module being latched in on a main circuit board such that the solder connections between the submount and the main circuit board are already pre-adjusted. The module is finally fixed on the main circuit board in a subsequent soldering process. [0023] The lower face of the submount and of the plug housing and/or of a naked fiber adaptor are thus designed such that plugging the module onto a main circuit board leads to precise initial adjustment, and the module can be fixed in a subsequent soldering process without any bad electrical contacts occurring. [0024] In one preferred refinement, a housing cover is provided, which surrounds the submount and/or one end of the holding and coupling part. For electromagnetic shielding, the holding and coupling part and/or the abovementioned housing cover are/is provided with an electrically conductive layer. Alternatively, the holding and coupling part and/or the housing cover are/is composed of an electrically conductive plastic material which, by way of example, is produced by adding small electrically conductive balls to the plastic, and which is known per se. [0025] The housing cover of the holding and coupling part as well as the ground layer on the submount form a cage, which prevents or greatly reduces incident interference radiation. [0026] In a further refinement of the invention, the holding and coupling part is in the form of a double chamber, which has a transmitting element and a receiving element in parallel, separate areas. Each of these parallel areas in turn has its own coupling area, via which an optical fiber is connected. In this refinement, two submounts are preferably provided, one submount in each case for the transmitting element and one submount for the receiving element. A common housing cover, which is provided with an electrically conductive layer, in this case preferably separates the two submounts, thus preventing electrical crosstalk. [0027] A second aspect of the invention provides a plug arrangement with a plug housing and a housing associated with the plug. The plug arrangement is particularly suitable in conjunction with the optoelectronic module as claimed in claim 1 , with the external contour of the holding and coupling part being coupled to the plug holder. [0028] On the basis of the solution according to the invention, the plug has a protective bracket which can move relative to the housing of the plug, and which has at least one opening for an optical fiber in the plug. When it is not inserted, the protective bracket is arranged as protection in front of the optical fiber which projects out of the plug housing. [0029] The plug housing which can be coupled to the plug has three steps, in that it has three areas whose internal diameters differ, between which a first and a second step stop are formed, with the first step stop on the plug housing acting as a stop for the protective bracket, so that the protective bracket is moved from the locking position to the first step stop during insertion of the plug into the plug housing, and is moved in the direction of the housing, with the at least one optical fiber projecting out of the corresponding opening in the protective bracket. The second step stop is used as a stop for the end face of the housing of the plug. [0030] The arrangement of a protective bracket allows “blind” insertion, as is frequently required in automotive designs, and which in the process protects the fiber end surface against dirt. [0031] The so-called “Kuchiri” criterion is known for this purpose: the fiber is protected in a type of “scabbard” (Japanese: Kuchiri) such that the fiber cannot project out of the protective environment until the plug has been introduced into the plug housing, so that it is positioned in front of the appropriate transducer without becoming dirty. [0032] The plug preferably has two optical fibers, whose center axes are separated by 5 mm. The plug in this case preferably has a width of 13.5 mm, so that it satisfies the industry “small form factor” standard. [0033] The protective bracket is preferably attached to the plug housing by means of attachment arms, with the attachment arms being mounted on the plug housing such that they are sprung and can be moved. By way of example, two such attachment arms are provided and project at right angles from that surface of the protective bracket which is arranged in front of the ends of the optical fibers. [0034] In this case, the latching arms may have latching elements, via which the plug can be latched in the plug housing. BRIEF DESCRIPTION OF THE FIGURES [0035] The invention will be explained in more detail in the following text using a number of exemplary embodiments and with reference to the figures of the drawing, in which: [0036] FIG. 1 shows a first exemplary embodiment of an optoelectronic module, in the form of a section illustration; [0037] FIG. 2 shows the exemplary embodiment shown in FIG. 1 , with the module being coupled to a plug housing; [0038] FIG. 3 shows a second exemplary embodiment of an optoelectronic module which is coupled to a plug housing; [0039] FIG. 4A shows a third exemplary embodiment of an optoelectronic module, in which the module is coupled to a naked fiber adaptor; [0040] FIG. 4B shows a cross section through the module shown in FIG. 4A ; [0041] FIG. 5 shows a fourth exemplary embodiment of an optoelectronic module, with the module forming a naked fiber adaptor; [0042] FIG. 6A shows a perspective view of the plug of a plug arrangement for POF transmission systems; [0043] FIG. 6B shows a section view of the plug shown in FIG. 6A ; [0044] FIG. 6C shows a plan view of the locking apparatus between the plug and plug housing shown in FIG. 6B ; [0045] FIG. 7 shows a section view of a plug housing of a plug arrangement for a POF transmission system; [0046] FIG. 8 shows the connection between a plug as shown in FIGS. 6A, 6B and a plug housing as shown in FIG. 7 in a position in which the plug has not yet been completely inserted into the plug housing; [0047] FIG. 9 shows a plug arrangement as shown in FIG. 8 , with the plug having been completely inserted into the plug housing; [0048] FIG. 10 shows an optoelectronic module as shown in FIG. 1 , connected to a plug arrangement as shown in FIGS. 6 to 9 , and [0049] FIG. 11 shows an optoelectronic module as shown in FIG. 3 , connected to a plug arrangement as shown in FIGS. 6 to 9 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0050] FIG. 1 shows an optoelectronic module 1 whose main components are a holding and coupling part 2 , which is also referred to as a CAI (Cavity AS Interface) housing, and a submount 3 with electrical components. The arrangement of the CAI housing 2 and submount 3 is covered by a housing cover 4 . The housing cover is connected to the CAI housing 2 in an interlocking manner via a projection 41 . [0051] The CAI housing 2 is used firstly for holding and for insertion of a mount (lead structure) 5 with a transmitting and/or receiving element, which is in this case an optoelectronic transducer 6 , and secondly for forming a coupling area 27 for holding an optical fiber. For this purpose, at one of its ends, the CAI housing has an encapsulation body 21 composed of transparent encapsulation material, which sheaths (secures) the mount 5 together with the optoelectronic transducer 6 , which may be in the form of a transmitting element or a receiving element. [0052] On the one hand, a lens 22 is integrated in one piece in the transparent encapsulation body 21 in order to increase the light transmission power which can be injected into an optical fiber by means of a transmitting element or to increase the received light power imaged onto to a photodiode. [0053] Furthermore, the encapsulation body 21 forms a fiber stop ring or protective ring 23 , which protects the integrated lens 22 against being adversely mechanically affected by touching the fiber. [0054] The CAI housing 2 is essentially in the form of a cylinder 24 , which surrounds a cylindrical cutout (opening) 25 . The encapsulation body 21 is located at one end of the cylindrical cutout. The area 27 of the cylindrical cutout which is adjacent to it is used together with the inner wall 28 of the cylinder 24 for passive guidance and for fixing with respect to transverse deflections of an optical fiber which can be inserted into the cylindrical cutout 25 . [0055] The transmitting and/or receiving element 6 is in this case centered with respect to (i.e., intersects) the optical axis 29 of the CAI housing. [0056] The mount 5 is in the form of a leadframe which is aligned at right angles to the optical axis 29 and is soldered at its lower end 51 (which is bent through 90°) by means of an SMD contact to the submount 3 . [0057] Self-adjustment markings 61 , 62 are furthermore provided on the CAI housing and on the submount and are used for self-adjustment and coupling of the CAI housing 2 to the submount 3 and, respectively, to a plug housing which is coupled to the outer wall of the CAI housing 2 (see FIG. 2 ). [0058] The submount 3 is a printed circuit board which has at least two layers and contains external circuitry 31 as well as an IC driver module or a receiving module (control circuit) 32 . The external circuitry 31 is used for power optimization, and is used in particular when RCLEDs are used as transmitting elements. [0059] The submount 3 has two or more plated holes 33 to solder pad contacts 34 on the lower face of the submount, via which the submount can be arranged on a main circuit board (see FIG. 2 ). Very good heat dissipation takes place by means of the plated holes 33 from the transmitting module or receiving module 32 to a main circuit mount, which is used as heat sink that is coupled to the submount 3 . [0060] All of the pad contacts 34 are formed on the lower face of the submount. There is an offset between the contacts 34 , so that they are very compact with respect to one another while at the same time being as far away from one another as possible. Additional adjustment pins, advantageously at ground potential, may optionally be provided, and ensure that the submount fits precisely into a main circuit mount. [0061] The submount 3 runs on a plane which is arranged parallel to the optical axis 29 of the CAI housing. [0062] The CAI housing 2 and the housing cover 4 have a metallically conductive surface which, together with the ground layer on the submount, provides EMC shielding. [0063] For this purpose, it is feasible for the CAI housing 2 and the housing cover 4 to be formed from an electrically conductive plastic material. [0064] FIG. 2 shows the optoelectronic module from FIG. 1 in conjunction with an SMI plug arrangement for plastic fiber transmission paths. SMI is short for “small multimedia interface” and is a conventional standard in the in-house field. [0065] However, in principle, other plug systems may also be used in conjunction with the optoelectronic module 1 , in particular the plug system which is explained in the following text with reference to FIGS. 6 to 9 . [0066] The SMI plug housing 71 is plugged onto the cylinder 24 on the CAI housing 2 . The figure shows a plan view of the inserted plug 72 . As can be seen, a fiber 73 , which is guided in the plug 72 , is inserted into the cylindrical holding opening 25 in the CAI housing 2 , and its end surface makes mechanical contact with the fiber stop ring 23 on the encapsulation body 21 . [0067] It should be mentioned that the plug housing 71 is arranged on a main circuit mount 8 on which the submount 3 is also located. The plug housing 71 in this case latches into the main circuit mount 8 via latching elements 71 a. [0068] As can also be seen, the self-adjustment marking 61 is used for connection and passive adjustment between the CAI housing 2 and the plug housing 71 . [0069] In this context, it should be mentioned that the CAI housing 2 has a side opening 2 a , through which the mount 5 can be inserted together with the transmitting and/or receiving element 6 into the CAI housing 2 . [0070] The CAI housing is also filled with encapsulation material via this opening 2 a . While the CAI housing 2 is being filled with encapsulation material, a filling closure is inserted into the holding opening 25 , and is removed again once the encapsulation material has cured. This filling closure is a negative of the shape of the lens 22 which is associated with the transmitting and/or receiving element 6 . [0071] The exemplary embodiment in FIG. 3 shows an alternative refinement of an optoelectronic module 1 ′ connected to a plug housing 71 ′. In this refinement, the submount 3 is placed underneath the CAI housing 2 , and on the lower face of the plug housing 71 ′. [0072] In order to create sufficient space on the lower face, the height of the plug housing 71 in this case had to be adapted, that is to say the distance between the optical axis 29 and the main circuit mount 8 is somewhat enlarged. However, in comparison to the exemplary embodiment shown in FIGS. 1 and 2 , the overall physical length of the optoelectronic module 1 ′ is considerably reduced. [0073] The lower face 71 a ′ of the plug housing 71 ′ is metalized, so as to provide EMC shielding for the electronic components 32 and 31 . [0074] It should be mentioned that the lower end 51 of the mount 5 is bent up in the other direction in this refinement. [0075] The CAI housing 2 is fixed on the plug housing 71 ′ by means, for example, of a clamp 71 b ′ on the plug housing 71 ′, which clasps one edge of the CAI housing 2 in an interlocking manner. [0076] FIGS. 4A and 4B show one embodiment of an optoelectronic module, in which the plug housing in FIGS. 2 and 3 is replaced by a naked fiber adaptor 9 . [0077] FIG. 4A shows a schematic longitudinal section, corresponding to the illustration shown in FIGS. 1 to 3 . FIG. 4B shows a cross section along the line IVb-IVb in FIG. 4A . [0078] The CAI housing 2 is in this case pushed into the naked fiber adaptor 9 . In principle, the CAI housing 2 and the naked fiber adaptor 9 may also be integral. An optical fiber 12 is inserted into the CAI housing 2 , and is firmly clamped by means of a clamp 11 in an area 91 of the naked fiber adaptor 9 which is in the form of a trough. [0079] The inner face of the clamping apparatus 11 , the configuration of the trough shape and the fixing of the clamping apparatus in the naked fiber adaptor 9 are designed so as to prevent the fiber 12 from being pulled back. [0080] Provision is advantageously made for the clamp 11 to cover the open end of the cylindrical CAI housing 2 , thus preventing it from becoming dirty. [0081] Instead of fixing in the adaptor area, a clamping apparatus (cutting clamp) can alternatively be provided in the area of the fiber coupling in the CAI housing itself. [0082] FIG. 5 shows a further embodiment variant with a naked fiber connection, with the CAI housing and the naked fiber adaptor forming an integral molding 13 . The molding 13 is coated with a metallically conductive layer, thus providing EMC shielding for the transmitting and/or receiving element. The optical waveguide 12 is fixed by means of a clamping apparatus 14 , which clasps the casing of the inserted optical waveguide 12 . [0083] The molding 13 is firmly connected to the main circuit board 8 by means of clamping elements 13 a . The lower face 13 b is once again metalized, for electromagnetic shielding. [0084] It should be mentioned that the illustrated embodiment of the CAI housing may also be combined with a naked fiber connection in the case of an embodiment in which the submount 3 is arranged alongside the CAI housing rather than underneath it, as is illustrated in FIGS. 1 and 2 . [0085] FIGS. 6A, 6B show a novel plug for a plug arrangement which is preferably connected to the CAI transceiver 2 in the optoelectronic module in FIGS. 1 to 5 . [0086] The plug 15 has a housing 151 with two plastic optical fibers 152 , which are separated from one another by 5 mm, and a protective bracket 153 . [0087] When the plug 15 is not inserted, the protective bracket 153 is positioned in front of the end surfaces of the optical fibers 152 , so that the optical fiber ends which project out of the housing 151 are protected by the protective bracket 153 . The protective bracket has a cutout 153 a in the area of each of the optical fibers 152 . [0088] Furthermore, the protective bracket 153 has three attachment arms 153 b , by means of which it is attached to the housing 151 of the plug such that it can move. The attachment arms 153 b are in this case guide in the corresponding grooves or holders in the housing 151 , sprung by means of their geometric configuration. [0089] As can be seen from the side view in FIG. 6B , the plug 15 has a locking part 154 for detachably locking the attachment arms 153 b . An unlocking part 165 , which, for example, is in the form a web on the plug housing 71 , 71 ′, 16 , allows the lock to be released by lifting the attachment arms 153 b. [0090] FIG. 6 c shows a plan view of the locking apparatus shown in FIG. 6 b along the direction in which the unlocking part 165 extends, illustrated separately. As can be seen, the attachment bracket 153 b which is associated with the unlocking part 165 has a latching tab 153 c which engages over the unlocking part 165 . The latching tab 153 c interacts with the locking part 154 in order to unlock the plug 15 and plug housing 16 . [0091] FIG. 7 shows a plug housing 16 associated with the plug 15 shown in FIGS. 6A and 6B . [0092] The plug housing 16 has three steps. A first step 161 is used to accommodate and hold a CAI housing 2 as shown in FIGS. 1 to 5 . [0093] A second step 162 is used to guide the protective bracket 153 of the plug 15 . The stop 163 which is formed between the first and second steps represents a stop for the protective bracket 153 of the plug 15 . The third step 164 is used to guide the actual plug 15 and the housing 151 of the plug 15 . [0094] The first step is in the form of a circular opening, whose diameter corresponds to the external diameter of the cylinder 24 of the CAI housing 2 . The second step is rectangular, corresponding to the external shape of the protective bracket 153 . The third step is likewise rectangular, corresponding to the cuboid shape of the housing 151 associated with the plug 15 . [0095] FIG. 8 shows the CAI housing 2 as shown in FIGS. 1 to 5 , mounted in the plug housing 16 . The plug 15 has at this stage been inserted sufficiently into the plug housing 16 that the protective bracket 153 is resting on the protective bracket stop 163 . [0096] FIGS. 7 and 8 likewise show an unlocking part 165 for unlocking the protective bracket 153 , illustrating, likewise schematically, a plug lock 156 by means of which the completely inserted plug 15 is latched to the plug housing 16 . The plug 156 may, of course, also be used for unlocking. [0097] FIG. 9 shows the plug 15 after it has been completely inserted into the plug housing 16 . As can be seen from the figure, the protective bracket 153 has been inserted further into the housing 151 of the plug 15 from the position shown in FIG. 8 . The end surface of the optical waveguide 152 accordingly projects out of the opening 153 a in the protective bracket 153 , and rests directly on the encapsulation part 21 of the CAI housing 2 . This satisfies the “Kuchiri” criterion. [0098] The invention therefore provides for the protective bracket 153 to be pulled back into the housing 151 of the plug 15 as soon as it reaches the step stop 163 on the plug housing 16 . The movement distance is designed precisely such that the fiber 152 is placed in front of the integrated lens 22 in the encapsulation body 21 , and the plug 15 is latched in at the same time. The unlocking mechanism must then be released before the plug 15 can be removed from the plug housing 16 again. [0099] The shapes and additional structures of the lower attachment arm 153 b and of the unlocking part 165 can be designed such that the lower attachment arm 153 b is forced out of the plug housing 16 while the plug 15 is being pulled out. The protective bracket 153 is thus pulled out of the housing 151 of the plug 15 until the lower attachment 153 b is once again locked on the locking device 154 (see FIG. 6B ). This may be achieved with spring assistance or by mechanical parts engaging in one another, with these mechanical parts also being moved by the mechanical pulling movement of the lower attachment arm 153 b. [0100] FIGS. 10 and 11 show the novel plug arrangement, as described above, in conjunction with an optoelectronic module 1 as illustrated in FIGS. 1 and 3 , respectively. The figures each show the final position, with the plug 15 completely inserted into the plug housing 16 . [0101] In this case, with regard to the exemplary embodiment shown in FIG. 10 , it should also be noted that the external dimensions of the plug housing 16 are such that the plug housing 16 comes to rest on the main circuit board 8 . It should also be mentioned that the transparent encapsulation body 21 in this exemplary embodiment represents a side wall for the cylindrical CAI housing 2 . In this case, the CAI housing 2 is a cylinder which is open at both ends, with one end of the cylinder being closed by the encapsulation body 21 . The mount 5 is in this case bent into an S shape, so that it is completely surrounded by the encapsulation body 21 . [0102] With regard to the exemplary embodiment shown in FIG. 11 , it should be noted that a preferably metalized protective cap 17 is additionally connected in an interlocking manner firstly to the plug housing 16 and secondly to the main circuit board 8 . In this exemplary embodiment, the mount 5 is straight. [0103] Because the mount 5 is straight, it is possible to use a version of the CAI housing 2 in which one end of the cylindrical CAI housing 2 is closed by a housing cover 4 , 2 b , as is illustrated in FIGS. 1 to 5 , 10 and 11 .

A compact optoelectronic module that prevents undesirable heating by locating the electrical drive and/or receiving (control) circuit outside of the housing containing the optoelectronic transducer. The control circuit is mounted on a submount (PCB). The housing is mounted on the submount adjacent to the control circuit, and the optoelectronic transducer is coupled to the control circuit via a mount (leadframe) that extends substantially perpendicular to the submount plane and is surface mounted on the submount. The housing includes an opening, and a lens is provided between the optoelectronic transducer and the opening and defines an optical axis that is parallel to the submount plane. An encapsulating body is used to secure the optoelectronic transducer and mount inside the housing, and a portion of the encapsulating material is used to form the lens.

TECHNICAL FIELD OF THE INVENTION [0001] The technical field of this invention is digital data processing and more specifically digital data error detection and correction. BACKGROUND OF THE INVENTION [0002] Memories and registers are exposed to radiation that can introduce soft errors in both the memory bit cells and the flip flops. This causes the content of the memory or the flip flops to be corrupted, which often causes device failure. The probability of such a soft error corruption in flip flop increases with increased integration and smaller manufacturing technologies. The percentage of FIT rate (Failure in Time over billion seconds) that is directly related to such soft error corruption in the flip flops is on the rise. [0003] Conventional solutions to this problem include adding ECC (Error Correction Code) to the memory bit cells. This requires extra hardware logic to detects and correct errors on every read to the memory. This logic adds to the latency of memory accesses causing an overall degradation in performance. Conventional solutions for errors in discrete registers includes using specially designed and radiation hardened flip flops or using flip flops with ECC or parity built into them. Each of these conventional solutions adds gates to the flip flop and has a negative impact on the area and speed of the design. SUMMARY OF THE INVENTION [0004] This invention is data processing apparatus and method. Data is generally protecting from corruption using an error correction code. This includes generating an error correction code corresponding to the data. The data and the corresponding error correction code are stored in corresponding data registers. The data and the corresponding error correction code are transferred to another set of registers without regenerating the error correction code or using the error correction code for error detection or correction. Only upon reaching a subsequent register set are error correction detection and correction actions taken. The differing data/error correction code registers may be in differing pipeline phases in the data processing apparatus. [0005] Existing solutions apply the detection and correction logic only at the point when the data is read. The error correction code is not carried forward with the data and is lost. This provides no protection for that data from that point until the error correction code is recomputed. This invention forwards the error correction code with the data through the entire datapath that carries the data. [0006] This invention does not need any special cells for the registers. This invention does not need multiple detection and correction or syndrome generation hardware. Registers throughout the datapath get soft error protection. This protection is of the same quality as the protection of memories. This has a very positive impact on the soft error protection of the device. The cycles spent in detection and correction at every level are avoided. This avoids any area or performance impact of adding ECC protection at every level. BRIEF DESCRIPTION OF THE DRAWINGS [0007] These and other aspects of this invention are illustrated in the drawings, in which: [0008] FIG. 1 illustrates a single core scalar processor according to one embodiment of this invention; [0009] FIG. 2 illustrates a dual core scalar processor according to another embodiment of this invention; [0010] FIG. 3 illustrates a single core vector processor according to a further embodiment of this invention; [0011] FIG. 4 illustrates a dual core vector processor according to a further embodiment of this invention; [0012] FIG. 5 illustrates construction of one embodiment of the CPU of this invention; [0013] FIG. 6 illustrates the global scalar register file; [0014] FIG. 7 illustrates global vector register file; [0015] FIG. 8 illustrates the local vector register file shared by the multiply and correlation functional units; [0016] FIG. 9 illustrates local register file of the load/store unit; [0017] FIG. 10 illustrates the predicate register file; [0018] FIG. 11 illustrates the pipeline phases of the central processing unit according to a preferred embodiment of this invention; [0019] FIG. 12 illustrates sixteen instructions of a single fetch packet; [0020] FIG. 13 illustrates an example of the instruction coding of instructions used by this invention; [0021] FIG. 14 illustrates the carry control for SIMD operations according to this invention; [0022] FIG. 15 illustrates another view of dual core vector processor emphasizing the cache controllers; [0023] FIG. 16 illustrates the error detection and correction of this invention; and [0024] FIG. 17 illustrates the use of the error detection and correction of this invention in a pipelined system. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS [0025] FIG. 1 illustrates a single core scalar processor according to one embodiment of this invention. Single core processor 100 includes a scalar central processing unit (CPU) 110 coupled to separate level one instruction cache (L1I) 111 and level one data cache (L1D) 112 . Central processing unit core 110 could be constructed as known in the art and would typically include a register file, an integer arithmetic logic unit, an integer multiplier and program flow control units. Single core processor 100 includes a level two combined instruction/data cache (L2) 113 that holds both instructions and data. In the preferred embodiment scalar central processing unit (CPU) 110 , level one instruction cache (L1I) 111 , level one data cache (L1D) 112 and level two combined instruction/data cache (L2) 113 are formed on a single integrated circuit. [0026] In a preferred embodiment this single integrated circuit also includes auxiliary circuits such as power control circuit 121 , emulation/trace circuits 122 , design for test (DST) programmable built-in self test (PBIST) circuit 123 and clocking circuit 124 . External to CPU 110 and possibly integrated on single integrated circuit 100 is memory controller 131 . [0027] CPU 110 operates under program control to perform data processing operations upon defined data. The program controlling CPU 110 consists of a plurality of instructions that must be fetched before decoding and execution. Single core processor 100 includes a number of cache memories. FIG. 1 illustrates a pair of first level caches. Level one instruction cache (L1I) 111 stores instructions used by CPU 110 . CPU 110 first attempts to access any instruction from level one instruction cache 121 . Level one data cache (L1D) 112 stores data used by CPU 110 . CPU 110 first attempts to access any required data from level one data cache 112 . The two level one caches (L1I 111 and L1D 112 ) are backed by a level two unified cache (L2) 113 . In the event of a cache miss to level one instruction cache 111 or to level one data cache 112 , the requested instruction or data is sought from level two unified cache 113 . If the requested instruction or data is stored in level two unified cache 113 , then it is supplied to the requesting level one cache for supply to central processing unit core 110 . As is known in the art, the requested instruction or data may be simultaneously supplied to both the requesting cache and CPU 110 to speed use. [0028] Level two unified cache 113 is further coupled to higher level memory systems via memory controller 131 . Memory controller 131 handles cache misses in level two unified cache 113 by accessing external memory (not shown in FIG. 1 ). Memory controller 131 handles all memory centric functions such as cacheabilty determination, error detection and correction, address translation and the like. Single core processor 100 may be a part of a multiprocessor system. In that case memory controller 131 handles data transfer between processors and maintains cache coherence among processors. [0029] FIG. 2 illustrates a dual core processor according to another embodiment of this invention. Dual core processor 200 includes first CPU 210 coupled to separate level one instruction cache (L1I) 211 and level one data cache (L1D) 212 and second CPU 220 coupled to separate level one instruction cache (L1I) 221 and level one data cache (L1D) 212 . Central processing units 210 and 220 are preferably constructed similar to CPU 110 illustrated in FIG. 1 . Dual core processor 200 includes a single shared level two combined instruction/data cache (L2) 231 supporting all four level one caches (L1I 211 , LID 212 , L1I 221 and LID 222 ). In the preferred embodiment CPU 210 , level one instruction cache (L1I) 211 , level one data cache (LID) 212 , CPU 220 , level one instruction cache (L1I) 221 , level one data cache (LID) 222 and level two combined instruction/data cache (L2) 231 are formed on a single integrated circuit. This single integrated circuit preferably also includes auxiliary circuits such as power control circuit 245 , emulation/trace circuits 116 , design for test (DST) programmable built-in self test (PBIST) circuit 117 and clocking circuit 118 . This single integrated circuit may also include memory controller 251 . [0030] FIGS. 3 and 4 illustrate single core and dual core processors similar to that shown respectively in FIGS. 1 and 2 . FIGS. 3 and 4 differ from FIGS. 1 and 2 in showing vector central processing units. As further described below Single core vector processor 300 includes a vector CPU 310 . Dual core vector processor 400 includes two vector CPUs 410 and 420 . Vector CPUs 310 , 410 and 420 include wider data path operational units and wider data registers than the corresponding scalar CPUs 110 , 210 and 220 . [0031] Vector CPUs 310 , 410 and 420 further differ from the corresponding scalar CPUs 110 , 210 and 220 in the inclusion of streaming engine 313 ( FIG. 3 ) and streaming engines 413 and 423 ( FIG. 5 ). Streaming engines 313 , 413 and 423 are similar. Streaming engine 313 transfers data from level two unified cache 313 (L2) to a vector CPU 310 . Streaming engine 413 transfers data from level two unified cache 431 to vector CPU 410 . Streaming engine 423 transfers data from level two unified cache 431 to vector CPU 420 . In accordance with the preferred embodiment each streaming engine 313 , 413 and 423 manages up to two data streams. [0032] Each streaming engine 313 , 413 and 423 transfer data in certain restricted circumstances. A stream consists of a sequence of elements of a particular type. Programs that operate on streams read the data sequentially, operating on each element in turn. Every stream has the following basic properties. The stream data have a well-defined beginning and ending in time. The stream data have fixed element size and type throughout the stream. The stream data have fixed sequence of elements. Thus programs cannot seek randomly within the stream. The stream data is read-only while active. Programs cannot write to a stream while simultaneously reading from it. Once a stream is opened the streaming engine: calculates the address; fetches the defined data type from level two unified cache; performs data type manipulation such as zero extension, sign extension, data element sorting/swapping such as matrix transposition; and delivers the data directly to the programmed execution unit within the CPU. Streaming engines are thus useful for real-time digital filtering operations on well-behaved data. Streaming engines free these memory fetch tasks from the corresponding CPU enabling other processing functions. [0033] The streaming engines provide the following benefits. The permit multi-dimensional memory accesses. They increase the available bandwidth to the functional units. They minimize the number of cache miss stall since the stream buffer can bypass LID cache and L2 cache. They reduce the number of scalar operations required in the loop to maintain. They manage the address pointers. They handle address generation automatically freeing up the address generation instruction slots and the .D unit for other computations. [0034] FIG. 5 illustrates construction of one embodiment of the CPU of this invention. Except where noted this description covers both scalar CPUs and vector CPUs. The CPU of this invention includes plural execution units multiply unit 511 (.M), correlation unit 512 (.C), arithmetic unit 513 (.L), arithmetic unit 514 (.S), load/store unit 515 (.D), branch unit 516 (.B) and predication unit 517 (.P). The operation and relationships of these execution units are detailed below. [0035] Multiply unit 511 primarily preforms multiplications. Multiply unit 511 accepts up to two double vector operands and produces up to one double vector result. Multiply unit 511 is instruction configurable to perform the following operations: various integer multiply operations, with precision ranging from 8-bits to 64-bits multiply operations; various regular and complex dot product operations; and various floating point multiply operations; bit-wise logical operations, moves, as well as adds and subtracts. As illustrated in FIG. 5 multiply unit 511 includes hardware for four simultaneous 16 bit by 16 bit multiplications. Multiply unit 511 may access global scalar register file 521 , global vector register file 522 and shared .M and C. local register 523 file in a manner described below. Forwarding multiplexer 530 mediates the data transfer between global scalar register file 521 , global vector register file 522 , the corresponding streaming engine and multiply unit 511 . [0036] Correlation unit 512 (.C) accepts up to two double vector operands and produces up to one double vector result. Correlation unit 512 supports these major operations. In support of WCDMA “Rake” and “Search” instructions correlation unit 512 performs up to 512 2-bit PN*8-bit I/Q complex multiplies per clock cycle. Correlation unit 512 performs 8-bit and 16-bit Sum-of-Absolute-Difference (SAD) calculations performing up to 512 SADs per clock cycle. Correlation unit 512 performs horizontal add and horizontal min/max instructions. Correlation unit 512 performs vector permutes instructions. Correlation unit 512 includes contains 8 256-bit wide control registers. These control registers are used to control the operations of certain correlation unit instructions. Correlation unit 512 may access global scalar register file 521 , global vector register file 522 and shared .M and C. local register file 523 in a manner described below. Forwarding multiplexer 530 mediates the data transfer between global scalar register file 521 , global vector register file 522 , the corresponding streaming engine and correlation unit 512 . [0037] CPU 500 includes two arithmetic units: arithmetic unit 513 (.L) and arithmetic unit 514 (.S). Each arithmetic unit 513 and arithmetic unit 514 accepts up to two vector operands and produces one vector result. The compute units support these major operations. Arithmetic unit 513 and arithmetic unit 514 perform various single-instruction-multiple-data (SIMD) fixed point arithmetic operations with precision ranging from 8-bit to 64-bits. Arithmetic unit 513 and arithmetic unit 514 perform various vector compare and minimum/maximum instructions which write results directly to predicate register file 526 (further described below). These comparisons include A=B, A>B, A≧B, A<B and A≦B. If the comparison is correct, a 1 bit is stored in the corresponding bit position within the predicate register. If the comparison fails, a 0 is stored in the corresponding bit position within the predicate register. Vector compare instructions assume byte (8 bit) data and thus generate 32 single bit results. Arithmetic unit 513 and arithmetic unit 514 perform various vector operations using a designated predicate register as explained below. Arithmetic unit 513 and arithmetic unit 514 perform various SIMD floating point arithmetic operations with precision ranging from half-precision (16-bits), single precision (32-bits) to double precision (64-bits). Arithmetic unit 513 and arithmetic unit 514 perform specialized instructions to speed up various algorithms and functions. Arithmetic unit 513 and arithmetic unit 514 may access global scalar register file 521 , global vector register file 522 , shared .L and .S local register file 524 and predicate register file 526 . Forwarding multiplexer 530 mediates the data transfer between global scalar register file 521 , global vector register file 522 , the corresponding streaming engine and arithmetic units 513 and 514 . [0038] Load/store unit 515 (.D) is primarily used for address calculations. Load/store unit 515 is expanded to accept scalar operands up to 64-bits and produces scalar result up to 64-bits. Load/store unit 515 includes additional hardware to perform data manipulations such as swapping, pack and unpack on the load and store data to reduce workloads on the other units. Load/store unit 515 can send out one load or store request each clock cycle along with the 44-bit physical address to level one data cache (LID). Load or store data width can be 32-bits, 64-bits, 256-bits or 512-bits. Load/store unit 515 supports these major operations: 64-bit SIMD arithmetic operations; 64-bit bit-wise logical operations; and scalar and vector load and store data manipulations. Load/store unit 515 preferably includes a micro-TLB (table look-aside buffer) block to perform address translation from a 48-bit virtual address to a 44-bit physical address. Load/store unit 515 may access global scalar register file 521 , global vector register file 522 and .D local register file 525 in a manner described below. Forwarding multiplexer 530 mediates the data transfer between global scalar register file 521 , global vector register file 522 , the corresponding streaming engine and load/store unit 515 . [0039] Branch unit 516 (.B) calculates branch addresses, performs branch predictions, and alters control flows dependent on the outcome of the prediction. [0040] Predication unit 517 (.P) is a small control unit which performs basic operations on vector predication registers. Predication unit 517 has direct access to the vector predication registers 526 . Predication unit 517 performs different bit operations on the predication registers such as AND, ANDN, OR, XOR, NOR, BITR, NEG, SET, BITCNT (bit count), RMBD (right most bit detect), BIT Decimate and Expand, etc. [0041] FIG. 6 illustrates global scalar register file 521 . There are 16 independent 64-bit wide scalar registers. Each register of global scalar register file 521 can be read as 32-bits scalar data (designated registers A 0 to A 15 601 ) or 64-bits of scalar data (designated registers EA 0 to EA 15 611 ). However, writes are always 64-bit, zero-extended to fill up to 64-bits if needed. All scalar instructions of all functional units can read or write to global scalar register file 521 . The instruction type determines the data size. Global scalar register file 521 supports data types ranging in size from 8-bits through 64-bits. A vector instruction can also write to the 64-bit global scalar registers 521 with the upper 192 bit data of the vector discarded. A vector instruction can also read 64-bit data from the global scalar register file 511 . In this case the operand is zero-extended in the upper 192-bit to form an input vector. [0042] FIG. 7 illustrates global vector register file 522 . There are 16 independent 256-bit wide vector registers. Each register of global vector register file 522 can be read as 32-bits scalar data (designated registers X 0 to X 15 701 ), 64-bits of scalar data (designated registers EX 0 to EX 15 711 ), 256-bit vector data (designated registers VX 0 to VX 15 721 ) or 512-bot double vector data (designated DVX 0 to DVX 12 , not illustrated). In the current embodiment only multiply unit 511 and correlation unit 512 may execute double vector instructions. All vector instructions of all functional units can read or write to global vector register file 522 . Any scalar instruction of any functional unit can also access the low 32 or 64 bits of a global vector register file 522 register for read or write. The instruction type determines the data size. [0043] FIG. 8 illustrates local vector register file 523 . There are 16 independent 256-bit wide vector registers. Each register of local vector register file 523 can be read as 32-bits scalar data (designated registers M 0 to M 15 701 ), 64-bits of scalar data (designated registers EM 0 to EM 15 711 ), 256-bit vector data (designated registers VM 0 to VM 15 721 ) or 512-bit double vector data (designated DVM 0 to DVM 7 , not illustrated). In the current embodiment only multiply unit 511 and correlation unit 512 may execute double vector instructions. All vector instructions of all functional units can write to local vector register file 523 . Only instructions of multiply unit 511 and correlation unit 512 may read from local vector register file 523 . The instruction type determines the data size. [0044] Multiply unit 511 may operate upon double vectors (512-bit data). Multiply unit 511 may read double vector data from and write double vector data to global vector register file 521 and local vector register file 523 . Register designations DVXx and DVMx are mapped to global vector register file 521 and local vector register file 523 as follows. [0000] TABLE 1 Instruction Register Designation Accessed DVX0 VX1:VX0 DVX1 VX3:VX2 DVX2 VX5:VX4 DVX3 VX7:VX6 DVX4 VX9:VX8 DVX5 VX11:VX10 DVX6 VX13:VX12 DVX7 VX15:VX14 DVM0 VM1:VM0 DVM1 VM3:VM2 DVM2 VM5:VM4 DVM3 VM7:VM6 DVM4 VM9:VM8 DVM5 VM11:VM10 DVM6 VM13:VM12 DVM7 VM15:VM14 Each double vector designation maps to a corresponding pair of adjacent vector registers in either global vector register 522 or local vector register 523 . Designations DVX 0 to DVX 7 map to global vector register 522 . Designations DVM 0 to DVM 7 map to local vector register 523 . [0045] Local vector register file 524 is similar to local vector register file 523 . There are 16 independent 256-bit wide vector registers. Each register of local vector register file 524 can be read as 32-bits scalar data (designated registers L 0 to L 15 701 ), 64-bits of scalar data (designated registers EL 0 to EL 15 711 ) or 256-bit vector data (designated registers VL 0 to VL 15 721 ). All vector instructions of all functional units can write to local vector register file 524 . Only instructions of arithmetic unit 513 and arithmetic unit 514 may read from local vector register file 524 . [0046] FIG. 9 illustrates local register file 525 . There are 16 independent 64-bit wide registers. Each register of local register file 525 can be read as 32-bits scalar data (designated registers D 0 to D 15 701 ) or 64-bits of scalar data (designated registers ED 0 to ED 15 711 ). All scalar and vector instructions of all functional units can write to local register file 525 . Only instructions of load/store unit 515 may read from local register file 525 . Any vector instructions can also write 64-bit data to local register file 525 with the upper 192 bit data of the result vector discarded. Any vector instructions can also read 64-bit data from the 64-bit local register file 525 registers. The return data is zero-extended in the upper 192-bit to form an input vector. The registers of local register file 525 can only be used as addresses in load/store instructions, not as store data or as sources for 64-bit arithmetic and logical instructions of load/store unit 515 . [0047] FIG. 10 illustrates the predicate register file 517 . There are sixteen registers 32-bit registers in predicate register file 517 . Predicate register file 517 contains the results from vector comparison operations executed by either arithmetic and is used by vector selection instructions and vector predicated store instructions. A small subset of special instructions can also read directly from predicate registers, performs operations and write back to a predicate register directly. There are also instructions which can transfer values between the global register files ( 521 and 522 ) and predicate register file 517 . Transfers between predicate register file 517 and local register files ( 523 , 524 and 525 ) are not supported. Each bit of a predication register (designated P 0 to P 15 ) controls a byte of a vector data. Since a vector is 256-bits, the width of a predicate register equals 256/8=32 bits. The predicate register file can be written to by vector comparison operations to store the results of the vector compares. [0048] A CPU such as CPU 110 , 210 , 220 , 310 , 410 or 420 operates on an instruction pipeline. This instruction pipeline can dispatch up to nine parallel 32-bits slots to provide instructions to the seven execution units (multiply unit 511 , correlation unit 512 , arithmetic unit 513 , arithmetic unit 514 , load/store unit 515 , branch unit 516 and predication unit 517 ) every cycle. Instructions are fetched instruction packed of fixed length further described below. All instructions require the same number of pipeline phases for fetch and decode, but require a varying number of execute phases. [0049] FIG. 11 illustrates the following pipeline phases: program fetch phase 1110 , dispatch and decode phases 1110 and execution phases 1130 . Program fetch phase 1110 includes three stages for all instructions. Dispatch and decode phases include three stages for all instructions. Execution phase 1130 includes one to four stages dependent on the instruction. [0050] Fetch phase 1110 includes program address generation stage 1111 (PG), program access stage 1112 (PA) and program receive stage 1113 (PR). During program address generation stage 1111 (PG), the program address is generated in the CPU and the read request is sent to the memory controller for the level one instruction cache L1I. During the program access stage 1112 (PA) the level one instruction cache L1I processes the request, accesses the data in its memory and sends a fetch packet to the CPU boundary. During the program receive stage 1113 (PR) the CPU registers the fetch packet. [0051] Instructions are always fetched sixteen words at a time. FIG. 12 illustrates this fetch packet. FIG. 12 illustrates 16 instructions 1201 to 1216 of a single fetch packet. Fetch packets are aligned on 512-bit (16-word) boundaries. The execution of the individual instructions is partially controlled by a p bit in each instruction. This p bit is preferably bit 0 of the instruction. The p bit determines whether the instruction executes in parallel with another instruction. The p bits are scanned from lower to higher address. If the p bit of and instruction is 1, then the next following instruction is executed in parallel with (in the same cycle as) that instruction I. If the p bit of an instruction is 0, then the next following instruction is executed in the cycle after the instruction. All instructions executing in parallel constitute an execute packet. An execute packet can contain up to nine instructions. Each instruction in an execute packet must use a different functional unit. An execute packet can contain up to nine 32-bit wide slots. A slot can either be a self-contained instruction or expand the constant field specified by the immediate preceding instruction. A slot can be used as conditional codes to apply to the instructions within the same fetch packet. A fetch packet can contain up to 2 constant extension slots and one condition code extension slot. [0052] There are up to 11 distinct instruction slots, but scheduling restrictions limit to 9 the maximum number of parallel slots. The maximum nine slots are shared as follows: multiply unit 511 ; correlation unit 512 ; arithmetic unit 513 ; arithmetic unit 514 ; load/store unit 515 ; branch unit 516 shared with predicate unit 517 ; a first constant extension; a second constant extension; and a unit less instruction shared with a condition code extension. The last instruction in an execute packet has a p bit equal to 0. [0053] The CPU and level one instruction cache L1I pipelines are de-coupled from each other. Fetch packet returns from level one instruction cache L1I can take different number of clock cycles, depending on external circumstances such as whether there is a hit in level one instruction cache L1I. Therefore program access stage 1112 (PA) can take several clock cycles instead of 1 clock cycle as in the other stages. [0054] Dispatch and decode phases 1110 include instruction dispatch to appropriate execution unit stage 1121 (DS), instruction pre-decode stage 1122 (D 1 ); and instruction decode, operand reads stage 1222 (D 2 ). During instruction dispatch to appropriate execution unit stage 1121 (DS) the fetch packets are split into execute packets and assigned to the appropriate functional units. During the instruction pre-decode stage 1122 (D 1 ) the source registers, destination registers, and associated paths are decoded for the execution of the instructions in the functional units. During the instruction decode, operand reads stage 1222 (D 2 ) more detail unit decodes are done, as well as reading operands from the register files. [0055] Execution phases 1130 includes execution stages 1131 to 1135 (E 1 to E 5 ). Different types of instructions require different numbers of these stages to complete their execution. These stages of the pipeline play an important role in understanding the device state at CPU cycle boundaries. [0056] During execute 1 stage 1131 (E 1 ) the conditions for the instructions are evaluated and operands are operated on. As illustrated in FIG. 11 , execute 1 stage 1131 may receive operands from a stream buffer 1141 and one of the register files shown schematically as 1142 . For load and store instructions, address generation is performed and address modifications are written to a register file. For branch instructions, branch fetch packet in PG phase is affected. As illustrated in FIG. 11 , load and store instructions access memory here shown schematically as memory 1151 . For single-cycle instructions, results are written to a destination register file. This assumes that any conditions for the instructions are evaluated as true. If a condition is evaluated as false, the instruction does not write any results or have any pipeline operation after execute 1 stage 1131 . [0057] During execute 2 stage 1132 (E 2 ) load instructions send the address to memory. Store instructions send the address and data to memory. Single-cycle instructions that saturate results set the SAT bit in the control status register (CSR) if saturation occurs. For 2-cycle instructions, results are written to a destination register file. [0058] During execute 3 stage 1133 (E 3 ) data memory accesses are performed. Any multiply instructions that saturate results set the SAT bit in the control status register (CSR) if saturation occurs. For 3-cycle instructions, results are written to a destination register file. [0059] During execute 4 stage 1134 (E 4 ) load instructions bring data to the CPU boundary. For 4-cycle instructions, results are written to a destination register file. [0060] During execute 5 stage 1135 (E 5 ) load instructions write data into a register. This is illustrated schematically in FIG. 11 with input from memory 1151 to execute 5 stage 1135 . [0061] FIG. 13 illustrates an example of the instruction coding of instructions used by this invention. Each instruction consists of 32 bits and controls the operation of one of the individually controllable functional units (multiply unit 511 , correlation unit 512 , arithmetic unit 513 , arithmetic unit 514 , load/store unit 515 ). The bit fields are defined as follows. The creg field and the z bit are optional fields used in conditional instructions. These bits are used for conditional instructions to identify the predicate register and the condition. The z bit (bit 28 ) indicates whether the predication is based upon zero or not zero in the predicate register. If z=1, the test is for equality with zero. If z=0, the test is for nonzero. The case of creg=0 and z=0 is treated as always true to allow unconditional instruction execution. The creg field and the z field are encoded in the instruction as shown in Table 2. [0000] TABLE 2 Conditional creg z Register 31 30 29 28 Unconditional 0 0 0 0 Reserved 0 0 0 1 A0 0 0 1 z A1 0 1 0 z A2 0 1 1 z A3 1 0 0 z A4 1 0 1 z A5 1 1 0 z Reserved 1 1 x x Note that “z” in the z bit column refers to the zero/not zero comparison selection noted above and “x” is a don't care state. This coding can only specify a subset of the 16 global scalar registers as predicate registers. This selection was made to preserve bits in the instruction coding. Note that unconditional instructions do not have these optional bits. For unconditional instructions these bits ( 28 to 31 ) are preferably used as additional opcode bits. However, if needed, an execute packet can contain a unique 32-bit condition code extension slot which contains the 4-bit creg/z fields for the instructions which are in the same execute packet. Table 3 shows the coding of such a condition code extension slot. [0000] TABLE 3 Bits Functional Unit  3:0 .L  7:4 .S 11:5 .D 15:12 .M 19:16 .C 23:20 .B 28:24 Reserved 31:29 Reserved Thus the condition code extension slot specifies bits decoded in the same way the creg/z bits assigned to a particular functional unit in the same execute packet. [0062] Special vector predicate instructions use the designated predicate register to control vector operations. In the current embodiment all these vector predicate instructions operate on byte (8 bit) data. Each bit of the predicate register controls whether a SIMD operation is performed upon the corresponding byte of data. The operations of predicate unit 517 permit a variety of compound vector SIMD operations based upon more than one vector comparison. For example a range determination can be made using two comparisons. A candidate vector is compared with a first vector reference having the minimum of the range packed within a first data register. A second comparison of the candidate vector is made with a second reference vector having the maximum of the range packed within a second data register. Logical combinations of the two resulting predicate registers would permit a vector conditional operation to determine whether each data part of the candidate vector is within range or out of range. [0063] The dst field specifies a register in a corresponding register file as the destination of the instruction results. [0064] The src2 field specifies a register in a corresponding register file as the second source operand. [0065] The src1/cst field has several meanings depending on the instruction opcode field (bits 2 to 12 and additionally bits 28 to 31 for unconditional instructions). The first meaning specifies a register of a corresponding register file as the first operand. The second meaning is an immediate constant. Depending on the instruction type, this is treated as an unsigned integer and zero extended to a specified data length or is treated as a signed integer and sign extended to the specified data length. [0066] The opcode field (bits 2 to 12 for all instructions and additionally bits 28 to 31 for unconditional instructions) specifies the type of instruction and designates appropriate instruction options. This includes designation of the functional unit and operation performed. A detailed explanation of the opcode is beyond the scope of this invention except for the instruction options detailed below. [0067] The p bit (bit 0 ) marks the execute packets. The p-bit determines whether the instruction executes in parallel with the following instruction. The p-bits are scanned from lower to higher address. If p=1 for the current instruction, then the next instruction executes in parallel with the current instruction. If p=0 for the current instruction, then the next instruction executes in the cycle after the current instruction. All instructions executing in parallel constitute an execute packet. An execute packet can contain up to eight instructions. Each instruction in an execute packet must use a different functional unit. [0068] Correlation unit 512 and arithmetic units 513 and 514 often operate in a single instruction multiple data (SIMD) mode. In this SIMD mode the same instruction is applied to packed data from the two operands. Each operand holds plural data elements disposed in predetermined slots. SIMD operation is enabled by carry control at the data boundaries. Such carry control enables operations on varying data widths. [0069] FIG. 14 illustrates the carry control. AND gate 1401 receives the carry output of bit N within the operand wide arithmetic logic unit (256 bits for arithmetic units 513 and 514 , 512 bits for correlation unit 512 ). AND gate 1401 also receives a carry control signal which will be further explained below. The output of AND gate 1401 is supplied to the carry input of bit N+1 of the operand wide arithmetic logic unit. AND gates such as AND gate 1401 are disposed between every pair of bits at a possible data boundary. For example, for 8-bit data such an AND gate will be between bits 7 and 8 , bits 15 and 16 , bits 23 and 24 , etc. Each such AND gate receives a corresponding carry control signal. If the data size is of the minimum, then each carry control signal is 0, effectively blocking carry transmission between the adjacent bits. The corresponding carry control signal is 1 if the selected data size requires both arithmetic logic unit sections. Table 4 below shows example carry control signals for the case of a 256 bit wide operand such as used in arithmetic units 513 and 514 which may be divided into sections of 8 bits, 16 bits, 32 bits, 64 bits or 128 bits. No control of the carry output of the most significant bit is needed, thus only 31 carry control signals are required. [0000] TABLE 4 Data Size Carry Control Signals 8 bits −000 0000 0000 0000 0000 0000 0000 0000 16 bits −101 0101 0101 0101 0101 0101 0101 0101 32 bits −111 0111 0111 0111 0111 0111 0111 0111 64 bits −111 1111 0111 1111 0111 1111 0111 1111 128 bits −111 1111 1111 1111 0111 1111 1111 1111 256 bits −111 1111 1111 1111 1111 1111 1111 1111 It is typical in the art to operate on data sizes that are integral powers of 2 (2 N ). However, this carry control technique is not limited to integral powers of 2. One skilled in the art would understand how to apply this technique to other data sizes and other operand widths. [0070] Memories and datapath registers in the preferred embodiment of this invention are protected from soft errors by ECC syndrome codes. The syndrome is not re-generated at every level where this data is accessed. Instead, the syndrome is passed along with the data to the next pipeline stage. The ECC syndrome is not re-generated every time the data is written, nor is the syndrome decoded for error detection and correction every time the data is read or accesses. The syndrome keeps getting passed along with the data through the system. Detection and correction are performed at the furthest level from the memory. This is usually the point at which the data is consumed or the last level cache. Thus any errors introduced at any point between the memory and the point at which the syndrome is used are corrected. This includes all the datapath registers, register files, discrete registers and any other intermediate data storage elements. Pipeline and datapath registers get ECC protection without the area and performance impact of conventional ECC detection and correction by transporting the syndrome along with data to the endpoint. [0071] Doing detection and correction at every level would require additional cycles to accomplish. This would degrade performance. The preferred embodiment of this invention avoids those additional cycles by doing the detection and correction at just one point. One advantage is that this enables current pipelines to stay unchanged. Another advantage is this supports ECC with zero additional cycles. This is achieved by doing the detection and correction closest to the CPU or when the granularity of the parity bits or ECC syndrome changes. [0072] The following is an example to describe this invention. In this example a CPU Read misses all levels of cache and hits the last level memory or cache. In this example the last level cache or memory has the syndrome along with data. In conventional architectures, a controller would decode the syndrome, detect any possible errors in the data and correct it. However, in this invention the syndrome is passed along with data to the next level of cache. Note that any soft error that may have been introduced in the memory remains uncorrected. This syndrome stays with the data all the way up to the CPU. The data and the corresponding syndrome passes through a number of interface and pipeline registers and stays in multiple queues. The data ultimately reaches and is consumed by the CPU. The data may also be cached or stored locally in a memory before it reaches the CPU. A soft error could be introduced in any of the registers and flip-flops when the data is present or in any of the cache or memories. This data reaches the CPU with the syndrome. In this example the CPU will decode the syndrome at that point and execute the detection and correction logic. Since the syndrome has stayed with the data, it qualifies the data and has protection built in to detect and correct errors. [0073] The same strategy is employed when data get written out from the CPU. The syndrome calculated by the CPU stays with the data. The syndrome is used for detection and correction when that data is consumed. Since CPU is not the only originator or consumer of data in the system, this strategy is used in multiple cases. These include but are not restricted to cache evictions and DMA's originated within the module. [0074] FIG. 15 illustrates another view of dual core vector processor 400 . This view in FIG. 15 emphasizes cache controllers: program memory controllers 1511 and 1521 controlling data transfer to and from level 1 program caches 411 and 421 ; data memory controllers 1512 and 1522 controlling data transfer into and out of level 1 data caches 412 and 422 . FIG. 15 also illustrates unified memory controller 1530 controlling data transfers to and from level two (L2) cache 431 . As illustrated in FIGS. 4 and 15 L2 cache 4312 is shared between the DSP cores 410 and 420 . [0075] FIG. 15 shows the interfaces between the various blocks. The dual core vector processor 400 consists of: two CPU cores 410 and 420 ; two L1 program cache controllers (PMC) 1511 and 1521 , each with its private 32 KB L1I cache 411 and 421 ; two L1 data cache controllers (DMC) 1512 and 1522 , each with its private 32 KB L1D cache 412 and 422 ; two Stream Buffers (SB) 413 and 423 , each with two streams; L2 Unified Cache Controller (UMC) 1530 , with a shared L2 cache and SRAM 431 up to 2M bytes. [0076] The memory system illustrated in FIG. 15 is the next generation caches and memory controller system for fixed and floating point DSP. The preferred embodiment can provide bandwidth of up to 2048-bits of data per cycles. The IAD caches 412 and 422 can sustain 512-bits of data to each CPU ( 410 , 420 ) every cycle, while the L2 cache 431 can provide 1024-bits of data to each stream buffer ( 413 , 423 ) every cycle. The L1 and L2 controllers have the ability to queue up multiple transactions out to the next level of memory, and can handle out of order data return. The L1P controllers 411 and 412 support branch exit prediction from the CPU and can queue up multiple prefetch misses to L2 431 . [0077] This memory system has full soft error correction (ECC) on its data and TAG rams. This novel ECC scheme cover many pipeline and interface registers, in addition to memories. This memory system support full memory coherency, where all the internal caches and memories (L1, L2) are kept coherent to each other and external caches and memories (MSMC, L3, DDR). The shared L2 controller keeps the multiple L1D's attached to it coherent to each other, and to the next level of caches (L2, L3, etc.) [0078] This memory system supports virtual memory, and includes as part of it address translation, micro-table look-aside buffers (μTLBs), L2 page table walk, L1P cache invalidates and DVM messages. The shared L2 controller can support up to two stream buffers, each with two streams. The stream buffers are kept coherent to the L1D cache, and have a pipelined high bandwidth interface to L2. [0079] The L1D cache is backed up by a victim cache, has a larger cache line size (128-bytes), and implements aggressive write merging. New features include Look-up table, Histogram, and Atomic accesses. Cache changes in the L1P include higher associativity (4-way), and a larger cache line size (64-bytes). The L2 cache also features higher associativity (8-ways). [0080] The data paths include: CPU-DMC 512-bit Read and 512-bit Write; CPU-PMC 512-bit Read and 32-bit Emulation Write; DMC-UMC 512-bit Read, 512-bit Write interfaces, that can do cache transactions, snoop and configuration accesses handling 2 dataphase transactions; PMC-UMC 512-bit Read, which supports 2 dataphase reads; SB-UMC 512-bit Read, which can be either 1 or 2 dataphases; UMC-MSMC 512 bit-Read and 512-bit Write, with Snoop and DMA transactions overlapped; MMU-UMC Page table walks from L2, and any DVM messages; and MMU-PMC pTLB miss to MMU. [0081] The two PMC controllers 1511 / 1521 are identical and the features listed here are supported on both. L1P Cache 411 and 421 have these attributes: 32 KB L1P cache; 4-Way Set Associative; 64-byte cache line size; Virtually Indexed and Virtually Tagged (48-bit virtual address); two dataphase data return on misses from L2, for prefetching. PMC controllers 1511 / 1521 support Prefetch and Branch Prediction with the Capability to queue up to a variable number (up to 8) fetch packet requests to UMC to enable deeper prefetch in program pipeline. PMC controllers 1511 / 1521 include Error Detection (ECC) having: parity protection on Data and Tag RAMs: 1-bit error detection for tag and data RAMs; Data RAM parity protection is on instruction width granularity (1 parity bit every 32 bits); and Auto-Invalidate and Re-Fetch on errors in TAG RAM. PMC controllers 1511 / 1521 support Global Cache coherence operations. PMC controllers 1511 / 1521 provide Virtual Memory by Virtual to Physical addressing on misses and have a pTLB to handle address translation and for code protection. PMC controllers 1511 / 1521 provide Emulation including access codes that will be returned on reads to indicate the level of cache that the data was read from and bus error codes will be returned to indicate pass/fail status of emulation reads and writes. PMC controllers 1511 / 1521 provide Extended Control Register Access including L1P ECR registers accessible from the CPU through a non-pipelined interface. These registers will not be memory mapped, and instead will be mapped to a MOVC CPU instruction. [0082] The two DMC controllers 1512 / 1522 are identical and the features listed here are supported on both. L1D Cache 412 and 422 are Direct Mapped Cache, in parallel with a 8/16 entry fully associative victim cache. L1D Cache 412 and 422 are 32 KB configurable down to 8 KB cache. L1D Cache 412 and 422 have a 128 byte cache line size. L1D Cache 412 and 422 are read Allocate Cache support for both Write-Back and Write-Through modes. L1D Cache 412 and 422 are Physically Indexed, Physically Tagged (44-bit physical address), support Speculative Loads, Hit under Miss, have posted write miss support and provide write Merging on all outstanding write transactions inside L1D. L1D Cache 412 and 422 support a FENCE operation on outstanding transactions. [0083] The L1D SRAM part of L1D Cache 412 and 422 support L1D SRAM accesses from CPU and DMA and have limited size configurability on SRAM. [0084] DMC controllers 1512 / 1522 include Lookup Table and Histogram capability to support 16 parallel table lookup and histogram. [0085] DMC controllers 1512 / 1522 have 512-bit CPU Load/Store Bandwidth, 1024 Bit L1D Memory bandwidth. DMC controllers 1512 / 1522 support 16 64-bit wide Banks with up to 8 outstanding load misses to L2. [0086] DMC controllers 1512 / 1522 includes Error Detection and Correction (ECC). DMC controllers 1512 / 1522 supports ECC Detection and Correction on a 32-bit granularity. This includes Full ECC on Data and Tag RAMs with 1-bit error correction and 2-bit error detection for both. DMC controllers 1512 / 1522 provide ECC syndrome on writes and victims out to L2. DMC controllers 1512 / 1522 receive ECC syndromes with read data from L2, and will do detection and correction before presenting this data to CPU. DMC controllers 1512 / 1522 provides full ECC on victim cache. DMC controllers 1512 / 1522 provide read-modify-write support to prevent parity corruption on half-word or byte writes. The ECC L2-L1D interface delays correction for Read-Response data pipeline ECC protection. [0087] DMC controllers 1512 / 1522 provide emulation by returning access codes on reads to indicate the level of cache that the data was read from. Bus error codes will be returned to indicate pass/fail status of emulation reads and writes. [0088] DMC controllers 1512 / 1522 provide atomic operations on Compare and Swap to cacheable memory space and increment to cacheable memory space. [0089] DMC controllers 1512 / 1522 provides coherence including fully MESI (modified, exclusive, shared, invalid) state support in both Main and Victim Cache. DMC controllers 1512 / 1522 support Global Cache coherence operations including snoops and Cache Maintenance operation support from L2, snoops for L2 SRAM, MSMC SRAM and External (DDR) addresses and full tag-RAM comparisons on Snoop and Cache Maintenance operations. [0090] DMC controllers 1512 / 1522 provide virtual Memory support for wider (44 bit) physical address. [0091] DMC controllers 1512 / 1522 support Extended Control Register Access. L1D ECR registers will be accessible from the CPU through a non-pipelined interface. These registers will not be memory mapped, and instead will be mapped to a MOVC CPU instruction. [0092] UMC 1530 controls data flow into and out of L2 cache 431 . L2 cache 431 is 8-Way Set Associative, supports cache sizes 64 KB to 1 MB. L2 cache 431 includes random least recently used (LRU). L2 cache 431 has a 128 byte cache line size. L2 cache 431 has a write-allocate policy and supports write-back and write-through modes. L2 cache 431 performs a cache Invalidate on cache mode change which is configurable and can be disabled. L2 cache 431 is physically Indexed, Physically Tagged (44-bit physical address) including 4 times banked TAG RAM's, which allow four independent split pipelines. L2 cache 431 supports 4 64 byte streams from two stream buffers, 2 L1D and 2 L1P caches and configuration and MDMA accesses on a unified interface to MSMC. L2 cache 431 caches MMU page tables. [0093] The L2 SRAM part of L2 cache 431 is 4 by 512-bit physical banks with 4 virtual bank each. Each bank has independent access control. L2 SRAM includes a security Firewall on L2 SRAM accesses. L2 SRAM supports DMA access on a merged MSMC I/F. [0094] UMC 1530 provides prefetch hardware and On-demand prefetch to External (DDR), MSMC SRAM and L2 SRAM. [0095] UMC 1530 provides Error Detection and correction (ECC) on a 256-bit granularity. There is full ECC Support for both TAG and Data RAMS with 1-bit error correction and 2-bit error detection for both. UMC 1530 provides ECC syndrome on writes and victims out to MSMC. UMC 1530 Read-Modify-Writes on DMA/DRU writes to keep parity valid and updated. ECC Correction and generation of multiple parity bits to L1P and Stream Buffer. This includes an auto-scrub to prevent accumulation of 1-bit errors, and to refresh parity. This clears and resets parity on system reset. [0096] UMC 1530 provide emulation by returning access codes on reads to indicate the level of cache that the data was read from. Bus error codes will be returned to indicate pass/fail status of emulation reads and writes. [0097] UMC 1530 supports full Coherence between 2 LiDs, 4 Streams, L2 SRAM, MSMC SRAM and External (DDR). This includes multiple L1D to shared L2 Coherence, snoops for L2 SRAM, MSMC SRAM and External (DDR) addresses. This coherence has full MESI support. UMC 1530 includes user Coherence commands from Stream Buffer and support for Global Coherence operations. [0098] UMC 1530 supports Extended Control Register Access. L1D ECR registers will be accessible from the CPU through a non-pipelined interface. These registers will not be memory mapped, and instead will be mapped to a MOVC CPU instruction. [0099] FIG. 16 illustrates the error detection and correction of this invention. Parts illustrated in FIGS. 4 and 15 are given the same reference numbers. FIG. 16 illustrates only one CPU core. The connections to the second core are identical. Illustration of the second core is omitted from FIG. 16 for simplicity. [0100] L1P cache 411 receives data from L2 SRAM/cache 431 via 2 by 256 bit correction unit 1631 and 16 by 32 bit parity generator 1632 . On supply of instructions to CPU core 410 the parity bits stored in L1P cache 411 are compared with newly calculated parity bits in 16 by 32 bit parity detector 1611 . If they match the instructions are supplied to CPU core 410 . If they do not match, the instructions are recalled from L2 SRAM/cache 431 , then subject to the parity test again. [0101] L1D cache 412 receives data from L2 SRAM/cache via 2 by 256 bit correction unit 1621 and 16 by 32 bit parity generator 1622 . On supply of data to CPU core 410 the parity bits stored in L1D cache 412 are compared with newly calculated parity bits in 16 by 32 bit parity detector 1623 . If they match the data is supplied to CPU core 410 . If they do not match, the data is recalled from L2 SRAM/cache 431 , then subject to the parity test again. [0102] Writes from CPU core 410 are subject to parity generation in 16 by 32 bit syndrome generator 1624 . The data received from CPU core 410 and the calculated parity bits are stored in L1D cache 412 . [0103] On write back from L1D cache 412 newly calculated parity bits and the stored parity are compared in 2 by 256 bit syndrome generator 2841 . If the match, the data is stored in L2 SRAM/cache 431 . If they do not match, 2 by 256 bit syndrome generator 2841 attempts correction. If the correction is achieved, the data is stored in L2 SRAM/cache 431 . Failure of correction generates a fault. [0104] Stream buffer 413 includes two streams 1610 and 1620 which operate similarly. Stream 1610 receives data from L2 SRAM/cache via 2 by 256 bit correction unit 1633 and 16 by 32 bit parity generator 1634 . On supply of data to CPU core 410 the parity bits stored in stream 1610 are compared with newly calculated parity bits in 16 by 32 bit parity detector 1631 . If they match the data is supplied to CPU core 410 . If they do not match, there is a fault. Stream 1620 receives data from L2 SRAM/cache via 2 by 256 bit correction unit 1635 and 16 by 32 bit parity generator 1636 . On supply of data to CPU core 410 the parity bits stored in stream 1620 are compared with newly calculated parity bits in 16 by 32 bit parity detector 1632 . If they match the data is supplied to CPU core 410 . If they do not match, there is a fault. [0105] L2 SRAM/cache 431 receives data from MSMC 451 via 2 by 256 bit syndrome generator 1641 . New parity is generated for storage in L2 SRAM/cache 431 and correction is attempted if needed. Upon a non-match and failure of correction, the data is recalled from MSMC 451 , then subject to the parity test again. There are no parity checks or correction on writes from L2 SRAM/cache 431 to MSMC 451 . [0106] The 2 by 256 bit syndrome generation 1643 and 2 by 256 correction 1644 periodically walk through the data stored in L2 SRAM/cache 431 . The data and parity is recalled, new parity generated and checked and correction attempted if needed. If the data is correct, there is no change made in L2 SRAM/cache 431 . If data is corrected, the corrected data is stored back in L2 SRAM/cache 431 . Failure of data correction generates a fault. [0107] FIG. 17 illustrates using this invention in a pipelined system. Data source 1701 is the source of data to enter phase of the pipelined system. Data source 1701 could be a register in another pipeline phase of the output of a functional unit. In this example data source 1701 supplies data bits only and does not supply ECC bits. The data bits are stored in register 1702 at the input of pipeline stage 0. Data bits from data source 1701 are also supplied to ECC bit generator 1703 . ECC bit generator 1703 combines the data from data source 1701 to generate appropriate ECC bits according to the know art. In this example, ECC bit generator 1703 produces enough ECC bit to detect and correct one bit errors in the data stored in register 1702 and detect two bit errors. The ECC bits from ECC bit generator 1703 are stored in register 1704 . Register 1704 is a companion to register 1702 . In a practical embodiment of this invention registers 1702 and 1704 may be a combined register large enough to store the data bits and the corresponding ECC bits. [0108] In this example the data stored in register 1702 is passed unchanged to register 1705 in normal operation. According to this invention, ECC bits stored in companion register 1704 are simultaneously stored in register 1706 , which is a companion to register 1705 . Registers 1705 and 1706 may be a combined register large enough to store the data bits and the corresponding ECC bits. Note that the ECC bits are not regenerated, they are passed unchanged from register 1704 to register 1706 . FIG. 17 illustrates this connection in dashed lines. It is feasible to include plural combined registers storing the data and the non-recomputed ECC bits in this datapath. [0109] Later in pipeline phase 1, the data in register 1705 passes to one input of multiplexer 1711 . The ECC bits pass from register 1706 to Error detection/correction unit 1712 . Error detection/correction unit 1712 also receives data from register 1705 . Error detection/correction unit 1712 recalculates the ECC bits from the data from register 1705 and compares it with the ECC bits from register 1706 . If these are identical, error detection/correction unit 1712 determines the data is correct. Error detection/correction unit 1712 signals multiplexer 1711 to select the data directly from register 1705 for storage in register 1713 . In that case, error detection/correction unit 1712 supplies the corresponding ECC bits for storage in register 1714 , which is a companion to register 1713 . As previously noted, registers 1713 and 1714 may be embodied by a single appropriate sized register. [0110] If the newly calculated ECC bits do not match the ECC bits received from register 1706 , error detection/correction unit 1712 determines whether it can recover from the detected error. In this example the number of ECC bits enable detection and correction of single bit errors. If data recovery is possible, error detection/correction unit 1712 calculates the corrected data and supplies this corrected data to the second input of multiplexer 1711 . Error detection/correction unit 1712 controls multiplexer 1711 to select this second input for storage in register 1713 . Error detection/correction unit 1712 also supplies the correct ECC bits for storage in companion register 1714 . [0111] If error detection/correction unit 1712 cannot correct the detected data error (for example, two or more bits are incorrect), then error detection/correction unit 1712 signals an error condition via a fault. The pipelines system handles this error in a manner not relevant to this invention. [0112] Existing solutions apply the detection and correction logic at the point when the data is read. The syndrome information is not carried forward with the data and is effectively lost. There is no protection for that data from that point until the syndrome is recomputed. Thus there are large pieces of the datapath susceptible to soft errors which are not protected. This invention tags the syndrome with the data and transmits it with the data through the system from the destination to the consumer. The entire datapath that carries the data with the syndrome thus receives soft error protection. [0113] This invention does not need any special cells for the registers. This invention does not need multiple detection and correction or syndrome generation hardware. Registers throughout the datapath get soft error protection. This protection is of the same quality as the protection of memories. This has a very positive impact on the soft error protection of the device. The cycles spent in detection and correction at every level are avoided. This avoids any area or performance impact of adding ECC protection at every level.

This invention is data processing apparatus and method. Data is protecting from corruption using an error correction code by generating an error correction code corresponding to the data. In this invention the data and the corresponding error correction code are carried forward to another set of registers without regenerating the error correction code or using the error correction code for error detection or correction. Only later are error correction detection and correction actions taken. The differing data/error correction code registers may be in differing pipeline phases in the data processing apparatus. This invention forwards the error correction code with the data through the entire datapath that carries the data. This invention provides error protection to the whole datapath without requiring extensive hardware or additional time.

CLAIM OF BENEFIT OF PROVISIONAL APPLICATION [0001] This application claims the benefit of U.S. provisional application Ser. No. 60/480,343 filed on Jun. 20, 2003, which is incorporated herein by reference in its entirety. BACKGROUND [0002] 1. Field [0003] The present disclosure relates to a wave antenna system. In particular, a wave antenna lens system comprising a double-ended array of wave antennas deployed in a lens shape is disclosed. [0004] The system disclosed in the present application can be applied to a wide range of microwave and millimeter wave antennas, where quasi-optical elements, i.e. elements having properties resembling those of optical elements, can improve performance, for example by focusing radiation in antenna systems. In particular, the lens system disclosed in the present application can be used to replace a fixed reflector or a lens, for example in satellite tracking applications. [0005] 2. Description of related art [0006] There are a number of mechanisms that are classically used to focus radiation in antenna systems: [0007] a) Mirrors and focal plane sensors, where a lens or a reflecting metal surface can be used to focus radiation. Typical satellite antennas are provided with a detector at the focus of an offset parabolic reflector, like for example in DirecTV or DirecPC applications. The parabola is offset for reasons related to beam blockage and diffraction by the supports. [0008] b) Lens systems. However, these kinds of systems are less used in the microwave bands because of the dimensions, performance (reflective losses) and costs of the lenses when compared with those of a metal mirror. In fact, while optical lenses can have anti-reflecting coatings, these coatings are often not suited to coherent microwaves. [0009] c) Thin lenses making use of Fresnel designs, such as used in the optical domain. However, for longer wavelengths, the step size must correspond to integer wavelengths, in order to avoid strong grating lobes due to diffraction at these locations. The grating lobe problem limits the utility of the lens for tracking. [0010] d) Transmitting Fresnel zone plates. Again, there are beam steering issues that make this difficult. [0011] e) Rotman-Turner lens, where a pair of one- or two-dimensional arrays of horns are connected together via waveguide links. Each link has a fixed phase delay designed to produce a phase shift equivalent to that of a lens. However, horns and metallic guides are needed. SUMMARY [0012] The present disclosure is suited to replace a lens for use with an antenna system with an array of antennas whose outer dimensions are similar to those of a lens. Such system has a lighter weight when compared with that of a lens, thus enabling simpler mounting and steering assemblies, and is capable of performing the function of an optical lens, such as focusing remote signals to a detector. The weight savings are a direct consequence of the empty space between the antennas forming the array. [0013] According to a first aspect, a wave antenna system is disclosed, having a plurality of wave antennas, each wave antenna comprising: a central dielectric portion having a first side and a second side opposite the first side; a first dielectric taper portion having a first dielectric taper portion proximal side connected with the first side of the central dielectric portion and a first dielectric taper portion distal side; and a second dielectric taper portion having a second dielectric taper portion proximal side connected with the second side of the central dielectric portion and a second dielectric taper portion distal side. [0014] According to a second aspect, a wave antenna is disclosed, comprising: a central dielectric portion, acting as a waveguide, having a first side and a second side opposite the first side; a first dielectric taper portion connected with the first side of the central dielectric portion; and a second dielectric taper portion connected with the second side of the central dielectric portion. [0015] According to a third aspect, an array of wave antennas is disclosed, each wave antenna comprising: a central dielectric portion, acting as a waveguide, having a first side and a second side opposite the first side; a first dielectric taper portion connected with the first side of the central dielectric portion; and a second dielectric taper portion connected with the second side of the central dielectric portion, wherein the central dielectric portions have a length, said length being variable among individual wave antennas, the array exhibiting a lens-shaped periphery by virtue of said variable length. [0016] According to a fourth aspect, an array of wave antennas is disclosed, each wave antenna comprising: a central dielectric portion, acting as a waveguide, having a first side and a second side opposite the first side; a first dielectric taper portion having a first dielectric taper proximate end connected with the first side of the central dielectric portion and a first dielectric taper distal end; and a second dielectric taper portion having a second dielectric taper proximate end connected with the second side of the central dielectric portion and a second dielectric taper distal end, wherein the distal ends of the first dielectric taper portions form a first surface of the array and the distal ends of the second taper portions form a second surface, and wherein incoming waves are captured by the first dielectric taper portions and re-emitted by the second taper portions. [0017] According to a fifth aspect, a wave antenna system comprising a plurality of spaced apart wave antennas is disclosed, each wave antenna comprising: a central dielectric portion having a first side and a second side opposite the first side; a first dielectric taper portion having a first dielectric taper portion proximal side connected with the first side of the central dielectric portion and a first dielectric taper portion distal side, the first dielectric taper portion proximal side having a first dielectric taper proximal width, the first dielectric taper portion distal side having a first dielectric taper distal width, the first dielectric taper proximal width being greater than the first dielectric taper distal width; and a second dielectric taper portion having a second dielectric taper portion proximal side connected with the second side of the central dielectric portion and a second dielectric taper portion distal side, the second dielectric taper portion proximal side having a second dielectric taper proximal width, the second dielectric taper portion distal side having a second dielectric taper distal width, the second dielectric taper proximal width being greater than the second dielectric taper distal width. [0018] According to a sixth aspect, a wave antenna is disclosed, comprising: a central dielectric portion, acting as a waveguide, having a first side and a second side opposite the first side; a first dielectric taper portion connected with the first side of the central dielectric portion, wherein a proximal thickness of the first dielectric taper portion proximal to the central dielectric portion is greater than a distal thickness of the first dielectric taper portion distal to the central dielectric portion; and a second dielectric taper portion connected with the second side of the central dielectric portion, wherein a proximal thickness of the second dielectric taper portion proximal to the central dielectric portion is greater than a distal thickness of the second dielectric taper portion distal to the central dielectric portion. [0019] Wave antennas, also known as tapered rod antennas or shaped-wave antennas, are known as such. An introductory description of wave antennas can be found in Antenna Handbook, Vol III, Antenna Applications, Y. T. Lo and S. W. Lee 1993, Van Nostrand Reinhold, NY, pages 17-36 to 17-48. See also U.S. Pat. No. 6,266,025 and U.S. Pat. No. 6,501,433, which disclose coaxial dielectric rod antennas with multi-frequency collinear apertures. [0020] The wave antenna elements of the array according to the present disclosure are thin dielectric rods tapered at their two ends. In the middle section, they behave like an optical waveguide. The central length of the guides is preferably varied to obtain the desired phase delay as a function of position across the aperture of the array, analogous to varying the thickness of a conventional dielectric lens with radius. [0021] Conventional lenses have a central thickness that is set by the lens maker formulas. For a fixed f-number, this thickness grows with the aperture of the lens. Large diameter lenses for use with microwaves and millimeter waves need to be made of low loss materials that tend to be expensive and heavy. For example, an 18″ lens, intended for focusing a satellite antenna, can exhibit a thickness of 3-4″. A billet of high quality dielectric of this size (for example Rexolite™), can have a cost of $500. [0022] A lens operates by introducing a phase shift in different parts of the wave as it passes through the lens. The portion of the wave passing through the thickest part of the lens gets the most phase shift. In a like manner, varying the length of the dielectric lens antenna elements across the face introduces varying phase shift to the wave as it passes through the array. [0023] By using the system as disclosed in the present application, there is empty space between the elements. This means that the volume of dielectric required in the wave antenna is much less. Also the system mass scales as the cube of the index of refraction n. Therefore, the material requirements and cost of the array can be less that those of a conventional lens if the index of refraction n is high. The array itself can be held in a low cost mounting plate or molded as a unit. [0024] The beam directivity gain and side lobe performance can be made to be equivalent to a reflector of similar dimensions. A lower reflective loss than a lens is also exhibited. [0025] Additionally, no horns or metallic waveguides are needed, as in the prior art Rotman-Turner lenses and therefore a lower-cost approach can be followed. BRIEF DESCRIPTION OF THE DRAWINGS [0026] The present invention will be understood and appreciated more fully from the following detailed description taken in conjunction with the drawings in which: [0027] [0027]FIG. 1 is a schematic diagram showing the basic elements of a prior art wave antenna; [0028] [0028]FIG. 2 is a perspective view showing a prior art configuration of an array of antennas; [0029] [0029]FIG. 3 shows a cross-section view of a back-to-back configuration of antennas according to a first embodiment of the present invention; [0030] [0030]FIG. 4 is a cross section view of an array of antennas according to a second embodiment of the present invention; [0031] [0031]FIG. 5 is a top plan view of an array of antennas according to the preferred embodiment of the present invention; and [0032] [0032]FIG. 6 is a schematic diagram showing the lens-like focusing action of the array according to the present invention. DETAILED DESCRIPTION [0033] [0033]FIG. 1 is a schematic diagram showing the basic elements of a wave antenna 5 . The wave antenna 5 comprises a dielectric waveguide 1 connected to a dielectric taper 2 . The cross section of the antenna is circular. [0034] The dielectric waveguide 1 supports an HE 11 mode, i.e. a hybrid electric mode in a dielectric, similar to the circular guide TE 11 mode, and matching boundary conditions in absence of a metal wall. The dielectric taper 2 transforms HE 11 modes into plane waves 3 moving in free space. [0035] The wave antenna 5 is used to couple a plane wave into a mating waveguide of diameter d<0.626 λ 0 /n. The gain G of the antenna is approximately proportional to the length L of the antenna (i.e. the combined length of the dielectric waveguide 1 and the dielectric taper 2 ), G=7L /λ 0 , and the half-power beam width is Δθ=55 (λ 0 /L) 1/2 . The sidelobe performance and directivity gain are equivalent to a parabolic dish if (L/λ 0 )˜(D/λ 0 ) 2 , where λ 0 is the free space wavelength, d is the wavelength diameter, θ is the beam angle, and D is the diameter of the antenna influence. [0036] As indicated by the dotted line 4 in FIG. 1, the influence of the antenna on the space around it extends radially outward, for a distance that is proportional to the square root of its length, according to the formula D/λ 0 ˜(L/λ 0 ) 1/2 [0037] [0037]FIG. 2 shows a prior art configuration of an array 10 of wave antennas or antenna elements 5 of the type described in FIG. 1. The base of each antenna 5 is provided with a resonant coupler and with diode sensors (not shown) for detecting the incoming signal at each array point. Due to the axial symmetry of the individual antenna elements 5 , the diode sensors may be oriented to electronically select the polarization of the wave of interest. The spacing of the antenna elements takes into account the beam pattern of each wave antenna, as well as the grating lobe contribution, due to the finite number of elements forming the array. The related mathematical analysis is similar to the analysis for an array of conventional horns or dish type antennas. Nominally, low gain array elements are spaced apart by ½ wave length. The gain of a wave antenna may extend from 10 dB upwards to 25 dB, enabling a somewhat wider element spacing. Design tradeoffs are associated with sparse arrays involving element spacing efficiency, and the field of view of the array. In particular, the field of view is best within the beam width of an array element that correspondingly varies from over 50° to less than 10°. [0038] According to the present disclosure, the dielectric sections of two like wave antennas are joined at their guide ends, in a back-to-back configuration. [0039] [0039]FIG. 3 shows a first embodiment according to the present invention, where a cross section of a linear array 20 of back-to-back antennas 21 connected across a central plane 32 , also shown in cross section, is provided. A two-dimensional array of this type acts as a passive repeater of an incident electromagnetic wave. In particular, arriving plane waves 22 are captured by the antenna elements 21 , delayed uniformly according to the length of the waveguides 23 linking them, and then re-emitted into the original direction as plane waves 26 . [0040] The central waveguide 23 , the upper taper 24 and the lower taper 25 of each antenna of the array are made of dielectric material. The best orientation of the array is perpendicular to the incoming radiation, in which case the propagation will be along the central axis. [0041] In the embodiment of FIG. 3, both the upper taper 24 and the lower taper 25 have a proximal side connected with the central waveguide 23 and a distal side, wherein the proximal side has a width or thickness which is greater than the width or thickness of the distal side. In this way, a symmetrical or substantially symmetrical configuration is advantageously obtained. [0042] According to the present disclosure, arriving plane waves are focused by varying the length of the central waveguides of the antenna elements. [0043] [0043]FIG. 4 is a cross-section view showing a second embodiment of the present invention, where the linear array of antennas has the outer dimensions of a lens, for example a double-convex lens, as indicated by dashed line 30 . In particular, according to this preferred embodiment, the length of the central waveguides 31 of the individual antennas is varied in the same manner as a conventional lens, while the length of the upper and lower tapered sections 33 , 34 is the same for all elements. In the case of FIG. 4, the lens is a positive lens intended for collimating a signal in a manner indicated in the subsequent FIG. 6. The person skilled in the art will recognize that other shapes of a lens are also possible, such as a plano-convex lens, a plano-concave lens, a double concave lens, etc. [0044] The central plane 32 crossed by the array of wave antennas may be constructed of different materials such as low index dielectrics (following fiber-optic design rules) or metals (following waveguide coupling design rules for conventional waveguide antennas) in order to avoid reflections at the mounting boundaries. Therefore, in the preferred embodiment, the central plane 32 both supports the antenna elements and minimizes reflections. Any shape of the central plane or spacing of elements is possible. [0045] Since most of the wave energy coupled is within the guide, the HE 11 mode can easily propagate through the interface with a low-cost low index dielectric, without significant loss. Reflective losses depend upon the taper. For example, with a dielectric index of ε=2.56, an aspect ratio in the shape of the taper of 3 or more would assure a reflection coefficient of around 2.5% or even less from each of the two surfaces. The equivalent factor in a solid dielectric lens, where the reflection coefficient of a lens surface is given by the formula [(1−n)/(1+n)] 2 , would be 19%. [0046] [0046]FIG. 5 shows a top or bottom view of the preferred embodiment of the array according to the present invention. The central plane 32 has a circular shape. The array of antennas is a substantially hexagonal arrangement of the elements 40 along the central plane 32 . The hexagonal array represents an efficient filling of a circular plane which at the same time balances the interaction of each element with its nearest neighbors. [0047] [0047]FIG. 6 shows the lens-like focusing action of the array shown in FIGS. 4 and 5, schematically indicated with numeral 50 . The Figure shows an incoming plane wave 51 (horizontal lines) which is focused (curved lines 52 ) when passing through the lens array 50 [0048] A number of choices exist for the type of taper to be used in the present invention, for example: a) circularly symmetric linear; b) circularly symmetric parabolic; c) linear with a full-prismatic cross-section; or d) linear with a half-prismatic cross section. See also Antenna Handbook, Vol III, supra, page 17-37. [0049] The high-dielectric wave-antenna parts may be cast or molded and later held in place with low-cost rigid foam. The resulting assembly will be overall light weight for tracking and mounting purposes. When the field of view can be reduced, the volumetric densities improve further, since higher elemental gain allows for less antenna elements. [0050] It will be appreciated that the present invention is not limited to what has been particularly shown and described herein above. Rather the scope of the present invention is defined by the claims which follow. [0051] For example, many other configurations, and lens types, may be formed by applying the above principles. Also, the person skilled in the art will appreciate, upon reading the present disclosure, that the tapered dielectric or the waveguide dielectric sections may be individually bent or aimed to adjust the pointing direction and overall gain of the array. Such additional control is not available in conventional lenses.

An array of dielectric wave antennas is disclosed. Each wave antenna has a central dielectric portion and two dielectric tapered portions, disposed on opposite sides of the central dielectric portion. The array is deployed in a lens shape and allows variation of the phase delay of an incident electromagnetic wave when passing through the array.

CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation of U.S. application Ser. No. 14/071,183 filed on Nov. 4, 2013, which is a continuation of U.S. application Ser. No. 11/454,614, filed Jun. 16, 2006, which issued as U.S. Pat. No. 8,576,805 on Nov. 5, 2013, which is a continuation of U.S. application Ser. No. 10/435,927, filed May 12, 2003 which issued as U.S. Pat. No. 7,072,316 on Jul. 4, 2006, which is a continuation of U.S. application Ser. No. 09/301,483, filed Apr. 28, 1999, which issued as U.S. Pat. No. 6,563,809 on May 13, 2003. The entire teachings of the above applications are incorporated herein by reference. BACKGROUND The present invention provides a subscriber-implemented registration technique for use in a CDMA communication system to uniformly distribute subscriber load among base stations. Typically in a CDMA system, when a subscriber terminal (“mobile station”) begins operation, it registers with a base station as part of its initialization operation. As part of registration, the mobile station typically identifies a pilot channel of a base station and communicates with the base station to identify the mobile station's presence in the base station's cell. The mobile station typically transmits a registration request message on an access channel associated with the base station or its pilot channel. When multiple pilot channels are detected, the mobile station typically registers with the base station whose pilot channel is associated with a highest quality reception. As is known, CDMA communication systems are “interference limited.” Unless determined by a communication protocol, a base station is not characterized by a fixed number of communication channels by which it may communicate user data to mobile stations. In theory, a “congested” base station may continue to add communication channels to satisfy increased demand for service, but the communication quality of each channel in the system would be diminished incrementally. In practice, the number of channels that may be satisfied by a base station is determined by minimum call quality standards that are to be maintained by the communication system. As is known, this number of channels also may be affected by environmental conditions in the cell that may contribute to quality degradations. However, it is desirable to limit unnecessary communication in a congested CDMA cell to improve the call quality of communication channels already in process and to reduce undesirable cross-channel interference. In traditional CDMA systems, a mobile station will attempt to register with a base station based solely on the mobile station's measurement of the received signal strength, E c /I o or SNR of the pilot channels. Although provisions exist in some CDMA systems for base stations to refuse to register a mobile station based upon congestion levels of the base station, registration in such systems typically includes a first transmitted registration request message from the mobile station to the congested based station followed by a second transmitted message from the congested base station to the mobile station denying registration. The mobile station then would attempt to register with the base station associated with the next strongest pilot channel. And, in systems employing soft handoff, if the mobile station succeeds in registering with the next strongest base station, the mobile station may retry registration with the congested base station upon expiration of a countdown timer. The registration request and denial transmissions that are used in these traditional CDMA systems consume precious bandwidth in an already-congested base station. They contribute to cross-channel interference with other channels already in progress and further consume processing resources in the already-congested base station. Accordingly, there is a need in the art for a low bandwidth registration protocol In a CDMA system, one that reduces processing demands upon a base station operating in a congested state. SUMMARY A method and apparatus for dynamic uplink communication in a wireless communication system are disclosed herein. The method includes receiving, by the mobile station, a first channel from a first base station, wherein the first channel includes an indication, wherein the indication has one of two states, wherein the base station transmits on forward link channels including a pilot channel, traffic channels and the first channel. The method also includes receiving, by the mobile station, a communication from the first base station on a condition that the indication has a first state of the two states, and selecting, by the mobile station, a second base station based on received pilot signals from a plurality of base stations on a condition that the indication has a second state of the two states. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a CDMA communication system. FIG. 2 is a flow diagram of a mobile station operating in accordance with a first embodiment of the present invention. FIG. 3 is a flow diagram of a mobile station operating in accordance with a second embodiment of the present invention. DETAILED DESCRIPTION The present invention relates to a registration technique for use in CDMA communication systems in which a mobile station determines which of a plurality of base stations it will register with. The mobile station makes its decision based on loading indicators transmitted globally from a base station to subscriber stations. FIG. 1 illustrates a typical CDMA communication system 100 . The communication system may be populated by a plurality of base stations 100 - 160 . The base stations 100 - 160 communicate with a plurality of mobile stations such as the mobile station 170 shown in FIG. 1 . Each base station typically broadcasts a plurality of logical channels on a physical channel including a pilot channel, a “sync” channel, a paging channel and a plurality of traffic channels. As is known, the pilot channel may be thought of as a “beacon” transmitted from a base station. Typically, the pilot channel constitutes a data signal having a predetermined pattern. The pilot channel typically carries no information. Mobile stations use the pilot channel on initialization to acquire carrier phase and timing relationships. Often, the same CDMA code that identifies the pilot channel of a first base station also is used to identify the pilot channel of other base stations. However, in such systems, neighboring base stations transmit the CDMA code using predetermined delay offsets with respect to each other that provide clear discrimination between base stations. However, the predetermined delay relationships of adjacent pilot channels permit a mobile station to quickly acquire the pilot channels of adjacent base stations once it has acquired the pilot channels of a first base station. A sync channel may be used by the base station to communicate administrative information to a mobile station. For example, a base station may transmit a base station ID to a user, a color code and administrative information identifying system status. Sync channels are transmitted globally within the cell; typically, mobile stations that are idle (are not engaged in active communication connections) monitor the sync channel. Each base station may transmit one or more paging channels. Paging channels typically are used to command a mobile station to set up traffic channels. Traffic channels may carry user data to mobile stations when the mobile stations participate in active communication connections. According to the principles of the present invention, the communication protocol of the sync channel may be modified to include a congestion indicator signal that identifies whether the base station is operating in a congested state. In a first simplest embodiment, the congestion indicator field simply may include a flag signal. When the base station is not operating in a congested state, the flag signal may be set to a first predetermined state indicating that a mobile station may attempt to register with the base station. When the base station is operating in a congested state, the flag signal may be set to a second predetermined state indicating that the mobile station should not attempt to register with the base station. According to this first embodiment of the present invention, mobile stations may register in accordance with the method 1000 illustrated in FIG. 2 . Upon start up, a mobile station 170 typically monitors received transmissions and searches for pilot channels of neighboring base stations (Step 1010 ). The number and identity of detected pilot channels may depend upon the topology of the system, the mobile station's location therein, and environmental conditions. Typically, when it detects a pilot channel from a first base station, a mobile station may exploit the predetermined timing offsets among the pilot channels in the system to facilitate acquisition of the pilot channels from other base stations. Depending upon ambient conditions, a mobile station may not detect pilot channels from all the base stations in a system. These are known characteristics of conventional CDMA systems. The mobile station may rank the base stations based upon the quality of the detected pilot channels (Step 1020 ). As a first indicator of quality, the mobile station may rank the base stations based upon a received power level associated with each pilot channel, called the 11 received signal strength indicator” (or “RSSI”) in connection with some known CDMA systems. Alternatively, the mobile station may rank the base stations based upon a measured bit error rate (“BER”) for the pilot channels. Further, the ranking of base stations may be made on the basis of ratios of energy per chip to aggregate received energy (commonly represented as E c /I o ). And, of course, the ranking may be performed based upon some combination of RSSI and BER and E c /I o measurements. The mobile station selects the base station that was ranked highest in pilot quality (Step 1030 ). It monitors the sync channel to acquire the congestion indicator signal (Step 1040 ) and determines whether the flag signal therein indicates that the base station is accepting additional registrations from mobile stations (Step 1050 ). If the base station is accepting new registrations, the mobile station attempts to register with the selected base station (Step 1060 ). If not, the mobile station selects the base station that appears next in its ranking of pilot quality (Step 1070 ). Thereafter, it returns to step 1040 , monitors that congestion indicator signal from the newly selected base station and determines whether to register to it. Theoretically, if severe loading conditions were present throughout a given system 100 , it is possible that a mobile station would cycle infinitely through a loop created by traversing steps 1040 - 1050 and 1070 , then returning again to step 1040 . According to an embodiment of the present invention, a mobile station may be programmed to discontinue the method of FIG. 2 if it cycles through steps 1040 - 1050 and 1070 a predetermined number of times without identifying a base station that will accept new registrations. Alternatively, the mobile station may be configured to discontinue the method of FIG. 2 if, at step 1070 , the mobile station selects a base station that is associated with pilot quality that is below a predetermined call quality threshold established for the system. As another alternative, the mobile station may interrupt the loop of steps 1040 - 1050 and 1070 if it traverses the entire set of pilot channels acquired at Step 1010 . Registration as represented in Step 1060 may be accomplished according to any of a number of well-known registration schemes and may include additional functionality not discussed herein. In an alternate embodiment of the system 100 , base stations may be configured to broadcast congestion indicator signals that report not only whether the transmitting base station is in a congested state but also identify a neighboring base station that is operating in a lightly congested state. In such an embodiment, registration of a mobile station may operate in accordance with the method 2000 of FIG. 3 . According to the method 2000 , a mobile station acquires pilot channels, ranks the pilot channels and monitors congestion indicator signals as is described above with respect to Steps 1010 - 1050 in FIG. 2 (Steps 2010 - 2050 ). If the highest quality base station is accepting registrations of new mobile stations, the mobile station registers with the base station (Step 2060 ). If the base station is operating in a congested state and is not accepting new registrations from mobile stations, the mobile station identifies a lightly loaded base station from the congestion indicator signal transmitted by the congested base station (Step 2070 ). The mobile station may determine if the measured pilot quality of the lightly loaded base station exceeds minimum call quality thresholds for the system (Step 2080 ). If so, the mobile station registers with the lightly loaded base station (Step 2090 ). Otherwise, the mobile station selects the base station of the next highest pilot quality and returns to Step 2040 (Step 2100 ). In an embodiment of the present invention, at Step 2080 , the mobile station may simply retrieve the pilot quality measurement that had been obtained according to the acquisition and ranking steps of Steps 2010 and 2020 . Having previously measured the quality of all pilot channels that were detectable, it is not necessary according to this embodiment for the mobile station to reacquire the pilot channel of the lightly loaded base station prior to attempting registration in Step 2090 . Optionally, however, according to other embodiments of the present invention, the mobile station may first monitor the congestion indicator of the lightly loaded base station prior to attempting registration. In this alternative, instead of advancing from Step 2080 to Step 2090 , the mobile station may simply select the lightly loaded base station (Step 2110 in phantom) and return to step 2040 . In this alternative, in addition to receiving the congestion indicator from the lightly loaded base station, the mobile station also may perform quality measurements upon the sync channel (step not shown). This alternate embodiment enjoys the additional advantage of permitting the mobile station to adapt to changing conditions in the communication system. If the lightly loaded base station experiences a sudden congestion event or if signal quality from the lightly loaded base station suddenly becomes unacceptable, the mobile station may determine not to attempt registration to that base station. As described above, a congested base station may include an identifier of a lightly loaded base station in the system. The identifier may be represented as an integer representing the differential delay offset between the pilot of the congested base station and the lightly loaded base station. As described above, different base stations in a CDMA system typically transmit the same pilot signal but at large relative delay offsets. For example, adjacent base stations participating in the known IS95 cellular system transmit pilot channels that are shifted with respect to each other by an integer multiple of 64 pilot code chips. IS-95 specifies a “PNINCREMENT” setting that determines the shift incremented of the pilot codes. According to an embodiment of the present invention, the identifier of the lightly congested base station maybe transmitted as an increment identifier representing an integer number of these predetermined shifts. In such an embodiment, the mobile station may attempt to acquire a new pilot channel shifted with respect to the present base station's pilot channel by the increment identifier. According to another embodiment of the present invention, the identifier optionally also may include a color code. If the mobile station receives a color code in the congestion indicator signal, it may receive the sync channel associated with any pilot received at the identified offset and compare a color code received therein with the identified color code. If the two color codes do not match, the mobile station may abort registration attempt and advance to step 2100 instead (step not shown). The registration protocol of the present invention provides an important advantage of reducing signal interference in a CDMA cell. In the present invention, the mobile station makes a determination of which base station it will attempt to register with based upon administrative information transmitted by base stations. The mobile station does not begin transmission until it has determined which base station it will register with. This technique reduces interference in a congested cell by eliminating the registration request and rejection messages that would otherwise be transmitted in the cell. Thus, the present invention contributes to reduced interference in a CDMA system by providing registration decision making in mobile stations rather than base stations. The subscriber controlled registration techniques of the present invention may find application in any of a number of CDMA communication systems. It may be integrated into the known IS-95 cellular communication protocol with minor modifications to the communication protocol of the IS-95 sync channel protocol. Further, it may be used in other CDMA communication systems such as the Tanlink communication system currently under development by the assignee of the present invention, Tantivy Communications, Inc. The Tanlink system is characterized as a “nomadic access” system. Mobile stations in present iterations of the Tanlink system typically possess directional antennae and register to one and only one base station. The subscriber controlled registration techniques of the present invention also may find application in other CDMA systems not described herein. Several embodiments of the present invention are specifically illustrated and described herein. However, it will be appreciated that modifications and variations of the present invention are covered by the above teachings and within the purview of the appended claims without departing from the spirit and intended scope of the invention.

A method and apparatus for dynamic uplink communication in a wireless communication system are disclosed herein. The method includes receiving, by the mobile station, a first channel from a first base station, wherein the first channel includes an indication, wherein the indication has one of two states, wherein the base station transmits on forward link channels including a pilot channel, traffic channels and the first channel. The method also includes receiving, by the mobile station, a communication from the first base station on a condition that the indication has a first state of the two states, and selecting, by the mobile station, a second base station based on received pilot signals from a plurality of base stations on a condition that the indication has a second state of the two states.

PRIOR RELATED APPLICATIONS [0001] This application claims priority to U.S. Ser. No. 62/298,875, filed Feb. 23, 2016, titled “Magnet Switch For Controlling Gene Delivery In Vivo,” and incorporated by reference herein in its entirety for all purposes. FEDERALLY SPONSORED RESEARCH STATEMENT [0002] This invention was made with government support under PN2EY018244 awarded by NIH. The government has certain rights in the invention. FIELD OF THE DISCLSOURE [0003] The disclosure generally relates to compositions, methods and systems of in vivo magnetic spatiFotemporal control of gene delivery and gene editing using baculovirus, magnetic nanoparticles and a strong magnetic field. BACKGROUND OF THE DISCLOSURE [0004] The CRISPR system is a revolutionary genome editing technology that can efficiently modify target genes in mammalian cells 1 . It targets a short stretch of DNA via the hybridization of a complementary guide RNA (gRNA) and binding of a CRISPR nuclease, such as CAS9, that recognizes a protospacer adjacent motif (PAM) in the target gene 1 . Preclinical studies have shown that the CRISPR system provides unprecedented opportunities for treating a variety of genetic diseases and infectious diseases 2-6 . [0005] Although the CRISPR system can have good targeting efficiency, gRNAs can also hybridize to DNA sequences containing base mismatches. Consequently, the CRISPR system can have off-target activities, causing gene mutations, deletions, inversions or translocations, which may lead to tumorigenic or other deleterious events 7-10 . Therefore, one of the major challenges for in vivo clinical applications of genome editing is to selectively activate the CRISPR system in the desired tissue or organ in order to maximize therapeutic efficacy and reduce genotoxicity. [0006] To improve the specificity of CRISPR systems, many tools have been developed for identifying potential gRNA off-target sites 11 , and CAS9 and other CAS nucleases have been designed with controllable nuclease activities 12,13 . For example, CAS9 proteins have been fragmented into nonfunctional units, which can dimerize to form active nucleases upon blue light radiation 13 . CAS9 can also be delivered as inducible transgenes that can only be translated in the presence of a chemical cue, e.g. doxycycline 12 . However, for in vivo applications, optical signals cannot penetrate deeply into the body owing to the strong absorption and scattering of light by biological tissues 14 , and the chemically-regulated CAS9 expression relies on the biodistribution of transgenes. [0007] An alternative approach to controlling in vivo genome editing is through targeted delivery of the CRISPR system. In particular, the viral vectors with tissue tropism, e.g., the adeno-associated viral vector (AAV) 15 , are being explored for tissue-specific genome editing in vivo 3,10,16 . However, most viral vectors for in vivo gene delivery are derived from viruses originating from human or other mammals. It is difficult to control the systemic dissemination and replication of these viral vectors used for in vivo genome editing, which increases the risk of genotoxicity 4,17 . Furthermore, vectors derived from small viruses, such as AAV and LV, have packaging limits, thus limiting the size of the genetic material that can be introduced. In addition, many viruses are targeted by the complement cascade for inactivation, thus limiting their efficiency. [0008] The Baculoviridae is a family of viruses that infect insects and are very large—their circular double-stranded genome ranging from 80-180 kbp. Because of this large size, they have great potential as a vector, and many such vectors are in use since Dr. Max Summers developed the first baculovirus expression vector system. [0009] The large size of BVs allows an extraordinary DNA packing capacity compared to most other viruses, thus enabling the integration of multiple gene expression cassettes into a single viral vector 23 . Although the baculovirus and their vectors lack the ability to replicate in mammalian cells, they can transduce mammalian cells with high efficiency and low cytotoxicity, providing a robust and transient gene expression 22-25 . However, there have been very limited in vivo applications of BVs because of their inactivation by the complement cascade in the serum 24,26 . [0010] The complement system represents a first-line host defense of the innate immune system designed to eliminate foreign elements, such as insect viruses. It has been well established that BV administrated intravenously can circulate throughout the body, and the complementary factor C3 in the blood will bind to circulating BV and initiate molecular events that eventually lead to BV inactivation ( FIG. 1 ) 26 . Indeed, triggering of the complement cascade is a major cause for the inactivation of a variety of currently used gene delivery vectors and contributes to inefficient gene transfer rates after in vivo application. [0011] Thus, what is needed in the art are better nucleic acid delivery methods, products, and systems that solve or at least mitigate one or more of the above limitations. The ideal gene delivery mechanism would allow targeted delivery of nucleic acid, and avoid off-target effects. SUMMARY OF THE DISCLOSURE [0012] This disclosure shows that by complexing magnetic nanoparticles (MNP) with recombinant baculovirus (BV) to form a delivery vehicle (MNP-BV), CRISPR mediated genome editing can be activated locally and transiently in vivo with an external magnetic field. Since BV delivered through intravenous injection will normally be inactivated due to innate immune response, it has not been used widely for in vivo gene delivery. We show herein that a locally applied magnetic field early in the process enhances the margination and endocytosis of circulating MNP-BV, thereby avoiding BV inactivation. The BV then triggers a transient transgene expression of the encoded CRISPR system in the target tissue, enabling tissue-specific in vivo genome editing. [0013] In the studies described herein, we prove that the serum inactivation can be utilized as an “off” switch to limit systemic or non-target activities of BV, and an external magnetic field can serve as an “on” switch for tissue-specific genome editing owing to the margination and internalization of the MNP-BV complex. This hybrid nanoparticle-viral vector system provides a unique delivery vehicle for CRISPR-mediated in vivo genome editing with precise spatiotemporal control. [0014] The magnetic nanoparticles overcome the serum-associated inactivation of baculovirus and allow for targeting a specific organ or tissue type by using an applied magnetic field. This is not just a concentration dependent effect, because using 10× as much BV does not improve efficiencies. Instead, the application of a magnetic field vastly improves the kinetics of uptake, possibly via increased margination of BV and cellular responses to the magnetic force exerted on the cell membrane, allowing the cells to take in the BV and their payload before the complement system can inactivate the virus. [0015] This technology has the ability to package plasmids or other vectors encoding CAS9 or other CAS proteins, single or multiple guide RNAs and the DNA donor template all into a single viral vector, and target a specific organ or tissue in vivo by targeted application of a magnetic field shortly after viral delivery, thus becoming a powerful tool for in vivo genome editing. The invention can also be used ex vivo, and transformed cells or tissue reintroduced back into a living system, but its real value lies in in vivo uses, where the complement system would otherwise inhibit BV transduction, and can be used to suppress off-target effects. [0016] The major steps involved are: (1) package the plasmids encoding a CAS protein such as CAS9, one or more guide RNA(s) and donor template into baculovirus; (2) attach magnetic nanoparticles to baculovirus; (3) introduce the MNP-BVs to an animal or patient, and (4) apply an magnetic field to activate the MNP-BV complex in a specific organ or tissue. [0017] As used herein a “CRISPR system” or “CRISPR gene editing system” includes the clustered regularly interspaced short palindromic repeats (pronounced crisper) that provides prokaryotic immune systems that confers resistance to foreign genetic elements. Generally, the system as modified for gene editing uses a CAS9-like protein, one or more guide RNA(s) and an optional donor template. However, other CAS proteins are known and could be used. [0018] As used herein, the term “CAS9” or “CRISPR associated protein 9” is a nuclease that functions in a CRISPR system. It is the most commonly used “CRIPSR nuclease.” The term CAS9 includes any member of the CAS9 family of genes/proteins or synthetic variants or fusion proteins thereof that function in a CRISPR system, as well as deactivated CAS9 (dCAS9). Examples include Streptococcus pyogenes CAS9 (SpCAS9) and Staphylococcus aureus (SaCAS9). The term “CAS9” also includes modified CAS9 or dCAS9 proteins with amino acid sequence deletion, insertion and/or mutation. [0019] Other CRISPR nucleases could be used as well, e.g., nuclease Cpfl discovered in the CRISPR/Cpf1 system of the bacterium Francisella novicida, and CjCAS9 from Campylobacter jejuni. Other CRISPR nucleases include Cas8a, Cas5, Cas8b, Cas8c, Cas10d, Cse1, Cse2, Csyl, Csy2, Csy3, GSU0054, Cas10, Csm2, Cmr5, Cas10 or Csx11, Csx10, Csf1, Csn2, Cas4, Cpf1, C2cI, C2c3, and C2c2 and more are being discovered all the time. [0020] As used herein the term “guide RNA” or “gRNA” includes crRNA, tracrRNA and their combination (sgRNA). A crRNA sequence contains the target RNA sequence to locate the correct section of DNA, which binds to e.g., a CAS9 nuclease-recruiting sequence “trans-activating crRNA” (tracrRNA) to form a single guide RNA (sgRNA). The term “guide RNA” or “gRNA” also includes crRNA, tracrRNA and sgRNA with chemical modifications, with additional RNA sequences for tagging and binding to other proteins. [0021] The “guide RNA” or “gRNA” acts as a guide for the endonuclease CAS9 and should be suitable for use with the selected CAS9 or dCAS9 or other nuclease proteins. [0022] It is known in the art how to design such gRNA sequences for the target gene of interest. Generally speaking, the 3′ end of the DNA target sequence must have a protospacer adjacent motif (PAM) sequence (e.g., 5′-NGG-3′ for SpCAS9). With SpCAS9, the 20 nucleotides upstream of the PAM sequence is the targeting sequence and CAS9 nuclease will cleave the DNA target sequence 3 bases upstream of the PAM. The best CAS9-based sgRNAs for several tested genes have a G at position 1 and an A or T at position 17. The target sequence can be on either DNA strand of the target gene. [0023] Note that while, the PAM sequence itself is absolutely required for cleavage, it is NOT part of the sgRNA target sequence. There are several online tools (e.g., CRISPR Design or CHOPCHOP) that detect PAM sequences and list possible crRNA sequences within a specific DNA region. These algorithms also predict off-target effects elsewhere in the genome, allowing one to choose the most specific crRNA for the application. [0024] As used herein, the “donor template” provides a copy of the gene or a part of the gene that is intended to replace the endogenous sequence (usually used to correct a defective gene), or to insert a DNA sequence. It is optional, however, and the same system without a donor template will typically modify a gene through small insertions and deletions (indels) as a result of non-homologous end joining (NHEJ) of the DNA double strand break (DSB) caused by the CRISPR system, or knock out a gene or genes through large deletions by two CRISPR/CAS9 induced DSBs. [0025] As used herein, “BV” usually means baculovirus vector, unless it is apparent that we are discussing the wild type virus from the context. The two are similar, but it is understood that the virus usually has been modified to make the vector by replacing the naturally occurring polyhedrin gene in the wild-type baculovirus genome with a recombinant gene or cDNA. Other modifications can also be included for efficiency, such as the inclusion of a multicloning site, selectable markers, a plasmid origin of replication, and the like. [0026] As used herein, “gene editing” includes both functional changes to a protein's activity as well as changes in gene regulation. Thus, the changes need not lie within the open reading frame but can significantly far up or downstream. [0027] As used herein, a “MNP” means a magnetically responsive particle of <200 nm average size, preferably <100 nm. [0028] One preferred MNP comprises a magnetic powder or crystal, such as magnetite (Fe 3 O 4 ), coated with a biocompatible and hydrophilic molecules. The coating molecules can chemically bind to the iron oxide surface via reactive groups such as amine, hydroxyl or carboxyl groups or physically absorbed onto the iron oxide surface via hydrophobic interactions, e.g. coating with a co-polymer of phospholipid and poly(ethylene glycol) that forms a micellar layer around the crystal. The coating molecules should be immunocompatible and/or nontoxic. Other targeting peptides, such as receptors or antibodies or cell penetrating peptides, such as TAT, can be conjugated to to MNP-BV complexes. [0029] As used herein “magnetically responsive element” can be any element or molecule that will create or respond to a magnetic field. The magnetically responsive element can be iron (I) oxide, iron (II) oxide, iron (III) oxide aka magnetite, Fe 16 N 2 , Iron-nickel, hematite, maghemite, iron oxide nanocrystals doped with other elements such as zinc, manganese, cobalt, and magnetic nanocrystals formed by other magnetic elements such as manganese, cobalt. These magnetically responsive elements are used in powdered or crystal form, with average diameter <100 nm, preferably <50 nm, or about 10-20 nm. The layer of the coating molecules on the magnetically responsive elements should be less than 20 nm in thickness and the entire coated particle is preferably less than 40 nm in diameter. [0030] “Magnet” refers to any material creating a magnetic field and can be a permanent magnet or an electromagnet. Preferably, a rare earth magnet is employed. Examples of rare earth magnets suitable for use with the present invention include, but are not limited to, neodymium rare earth magnets, samarium-cobalt rare earth magnets, Nd 2 Fe 14 B, SmCo 5 , Sm(Co,Fe,Cu,Zr) 7 , YCO 5 , or any combination thereof. [0031] Neodymium rare earth magnets are the strongest and most affordable type of permanent magnet, and are generally preferred, but samarium-cobalt magnets have a higher Curie temperature (the temperature at which the material loses its magnetism) and may be preferred for uses involving high sterilization temperatures. [0032] Particular types of rare earth magnets may also be selected as desired according to the conditions to which the rare earth magnets may be exposed. For example, any of the following factors may be considered in selecting a type of rare earth magnet: remanence (Br) (which measures the strength of the magnetic field), coercivity (Hci) (the material's resistance to becoming demagnetized), energy product (BHmax) (the density of magnetic energy), and the Curie temperature (Tc). Generally, rare earth magnets have higher remanence, much higher coercivity and energy product than other types of magnets. Where high magnetic anisotropy is desired, YCO 5 may be suitable for use. [0033] In place of or in addition to the rare earth magnets, powered magnets may be used in the methods of the invention, and batteries or grid power may be used to power the magnets as desired. Alternatively, RF or other electromagnetic radiation activated power sources can be used to power the magnet, such as is used with RFID tags. Such an embodiment may be particularly useful where a narrow, needle-like probe is inserted into the tissue of interest to create a strong local magnetic field. [0034] We can elaborate a number of principals for the selection of magnetic size, strength and shape. Firstly, the magnet size and shape are confined by the size of the body tissue with which it will be used, as excess magnet is both a waste of resources and expands the treatment area beyond the target tissue. Second, the distance of the magnet from the tissue can vary with increasing field strength, stronger magnets capable of being held farther away than weak magnets. These considerations must be balanced against the stength of the magnet (how far away the magnet can be and still attract MNP). [0035] The use of the word “a” or “an” when used in conjunction with the term “comprising” in the claims or the specification means one or more than one, unless the context dictates otherwise. [0036] The term “about” means the stated value plus or minus the margin of error of measurement or plus or minus 10% if no method of measurement is indicated. [0037] The use of the term “or” in the claims is used to mean “and/or” unless explicitly indicated to refer to alternatives only or if the alternatives are mutually exclusive. [0038] The terms “comprise”, “have”, “include” and “contain” (and their variants) are open-ended linking verbs and allow the addition of other elements when used in a claim. [0039] The phrase “consisting of” is closed, and excludes all additional elements. [0040] The phrase “consisting essentially of” excludes additional material elements, but allows the inclusions of non-material elements that do not substantially change the nature of the invention. [0041] The following abbreviations may be used herein: [0000] ABBRE- VIATION TERM ALT Alanine transaminase AMS Adult mouse serum AST aspartate aminotransferase AVV Adeno-associated virus BV Baculovirus or baculovirus vector Cas CRISPR-associated genes, e.g., CAS9 crRNA CRISPR RNA Csn1 a CRISPR-associated protein containing two nuclease domains, that is programmed by small RNAs to cleave DNA dCAS9 deactivated CAS9 DSB Double-Stranded Break DSPE 1,2-Distearoyl-sn-glycero-3-phosphoethanolamine Fe(acac) 3 Iron(III) acetylacetonate gRNA guide RNA HDR Homology-Directed Repair HNH an endonuclease domain named for characteristic histidine and asparagine residues HUVEC Human umbilical vein endothelial cells Indel insertion and/or deletion LV Lentivirus MF Magnetic field MTT 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide MOI Multiplicity of infection MPEG methoxypoly(ethylene glycol) NHEJ Non-Homologous End Joining RAM Protospacer-Adjacent Motif PEG poly(ethylene glycol) PFU Plaque forming unit ROI Region of interest RuvC an endonuclease domain named for an E. coli protein involved in DNA repair SEM standard error of the mean sgRNA single guide RNA TALEN Transcription-Activator Like Effector Nuclease TEM Transmission electron microscopy tracrRNA, trans-activating crRNA trRNA WT Wild type ZFN Zinc-Finger Nuclease BRIEF DESCRIPTION OF THE DRAWINGS [0042] The patent or application file contains at least one drawing executed in color. [0043] Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee. [0044] FIG. 1 . Genome Editing using CRISPR/CAS9. The simplicity of the CRISPR nuclease system, with only three components (CAS9, crRNA and trRNA) makes this system amenable to adaptation for genome editing. By combining the crRNA and trRNA into a single synthetic guide RNA (sgRNA), a further simplified two component system can be used to introduce a targeted double stranded break. This break activates repair through error prone non-homologous end joining (NHEJ) or Homology directed Repair (HDR). In the presence of a donor template with homology to the targeted locus, the HDR pathway operates allowing for precise changes to be made to the target gene. In the absence of a template, NHEJ is activated resulting in insertions and/or deletions (indels) which disrupt the target locus. [0045] FIG. 2 . BV inactivation by complement, and protective effective of magnetic nanoparticles. BV administrated systemically will distribute throughout the body by blood circulation. However, complementary factor, C3, binds to circulating BV and initiates viral inactivation (1). With an applied magnetic field, MNP-BV is pulled toward the cell surface and rapidly internalized by the cells through endocytosis (2), thus avoiding the C3-mediated inactivation pathway. Once internalized, MNP-BV enters endosomes (3) and releases its genomic content into the cytoplasm upon endosomal escape (4). The large BV genome enables encoding each of the CAS9 nuclease and multiple guide RNAs and optionally donor templates for genome editing in transduced cells, (5-6). Site-specific genome editing can thus be achieved by overcoming C3-mediated viral inactivation, locally with MNP-BV and an applied magnetic field. [0046] FIG. 3( a )-( b ) . Nanomagnets improve endocytosis of BV. (a) Representative TEM images of MNPs, BVs, and MNP-BV hybrids via TAT. The samples were negatively stained with phosphotungstic acid. In the left panel, the white corona surrounding the dark cores is the phospholipid coating layer of MNPs. The right panel shows multiple MNPs (red arrows) may be associated with a single BV through TAT. (b) MNPs under the external magnetic field enhanced endocytosis of BV. Cells incubated with BV alone (left panel) or MNP-BV (right panel) under a magnetic field were stained and examined with fluorescence microscopy. Blue, nucleus; Green, actin fibers; Red, BV stained with an anti-VP39 antibody to detect the BV capsid protein. In the presence of an external magnetic field, BV complexed with MNPs are rapidly internalized by cells compared to BV alone. [0047] FIG. 4( a )-( d ) . Nanomagnets improve BV-mediated transgene expression in vitro. (a) Expression vectors carrying the plasmids for luciferase (BV-LUC) and eGFP (BV-eGFP) respectively were used for this proof of concept experiment. Hepa 1-6 cells (a mouse liver tumor line, ATCC CRL-1830) were incubated with BV or MNP-BV for 30 minutes with or without a magnetic field directing the MNP-BV complexes to the cell surface. (b) Fluorescence images of BV-mediated eGFP expression. (c) Co-localization of eGFP (green) and MNPs (red) in the cells treated with MNP-BV-eGFP. (d) BV-mediated luciferase expression. The luciferase activity was normalized with that from the cells incubated with BV alone for 4 hours. The transgene expression of BV was enhanced by the combination treatment with MNPs and a magnetic field, while the effect of MNPs or the magnetic field alone was negligible. Data represent mean ±standard error of the mean (SEM); n =3 per group. [0048] FIG. 5( a )-( b ) . Nanomagnets help BV overcome serum inactivation in vitro. (a) In vitro activation of transgene expression against adult mouse serum (AMS). Hepa 1-6 cells were incubated with BV or MNP-BV for 30 minutes in a culture medium contained 50% AMS. With BV alone (−/−), AMS completely inhibited BV transgene expression. Either the magnetic field alone (+/−) or MNPs alone (−/+) could not prevent BV inactivation. In contrast, MNP-BV under magnetic field (+/+) showed strong luciferase activity, indicating that both MNPs and the magnetic field are required to protect BV from serum deactivation. The luciferase activity was normalized with that from cells incubated with BV alone for 4 hours without AMS. (b) Nanomagnet induced BV activation is location-dependent. The cells cultured in a chamber slide were incubated with MNP-BV-eGFP in the culture medium containing 50% of AMS for 30 minutes, while the left half of the chamber was placed on a block magnet. Most eGFP positive cells localized in the area on top of the magnet. Data represent mean±SEM; n=3 per group. This in vitro experiment confirms our hypothesis that a strong magnetic field can protect BV-MNPs from inactivation by the complement system, allowing the expression of genes in the BV. [0049] FIG. 6( a )-( h ) . Magnetic field enables tissue-specific transgene expression in vivo. (a) BV-LUC expression vector. (b) Schematic diagram of in vivo MNP-BV-based transgene delivery. The hybrid vehicle with luciferase expressing cassette was administrated to the mouse through intravenous injection. A block magnet was pressed by pressing against the belly to trigger local transgene expression in the mouse liver. The contour plot indicated the magnetic force applied to individual MNPs at a distance of 1 mm from the top of the magnet. (c) and (d) Bioluminescence analysis of transgene expression. Nude mice were injected with PBS, BV alone, MNP-BV, and MNP-BV followed with magnetic field (MF) treatment for 60 minutes. In the positive control, C3 knockout mice were injected with BV alone. In all groups, the dosage of the virus was 10 9 PFU per mouse. After 24 hours post-injection, the mice were imaged using an IVIS™ small animal live imaging system. Panel (d) plots the bioluminescence value in a region of interest (ROI) enclose the liver. Note that the magnetic field (MF) triggered high transgene expression in mice injected with MNP-BV, while without the magnetic treatment, the signal was negligible due to serum inactivation. Panels (e) and (f) show in vivo biodistribution of transgene expression. In MNP-BV+MF group, the organs were isolated 24 hours after injection, and bioluminescence of vital organs was measured ex vivo. As shown in the inset, the liver showed a high level of transgene expression, while bioluminescence was undetectable in the lung, kidney, spleen, and heart. All luminescence activity was normalized to the peak value in the plot. Panels (g) and (h) show in vivo transgene expression at 24 hours and 48 hours post-injection. Data represent mean±SEM; n=3 per group. [0050] FIG. 7( a )-( e ) . Magnetic field enables spatial control of genome editing. (a) BV-CRISPR expression vectors. eGFP expression cassette, guide RNA and CAS9 expression cassette can all be integrated into one vector. eGFP was used for identifying transduced cells. (b) Magnetic field-triggered mouse VEGFR2 gene editing in vitro. The cells were incubated with MNP-BV (MOI 100) in culture medium containing 50% of AMS for 30 minutes in the presence of a magnetic field generated with a NdFeB block magnet. Transgene expression was examined by eGFP fluorescence at 24 hours after transduction. There was no transgene expression in the cells without the magnetic treatment. The level of transgene expression increased with the strength of the magnetic field, which was controlled by the distance between the cells and the magnet. After 48 hours, the cells were harvested and examined with the T7E1 assay, which detects heteroduplex DNA that results from annealing DNA stands that have been modified after a sgRNA/CAS9 mediated cut to DNA strands without modifications. We use this assay to obtain a first estimate of whether our targeting was successful or not. Consistent with the trend in eGFP expression, the CRISPR-mediated VEGFR2 disruption correlated with the magnetic field strength. (c) Flow chart of cell purification of CRISPR/CAS9 targeted cells from the mouse liver. (d) Analysis of in vivo mouse VEGFR2 gene editing using T7E1 assay. (e) Representative mutation patterns detected by deep sequencing of mouse VEGFR2 locus. Top, wild-type sequence and PAM sequence marked in magenta; blot, deleted bases; blue bases, insertions or mutations (indels). [0051] FIG. 8A-B . Factors regulating BV-mediated transgene delivery. FIG. 8A . The transduction efficiency increases with the magnetic field strength. The magnetic field strength was controlled by changing the distance between Hepa 1-6 cells and the magnet. The distance between the cells and the N52 grade NdFeB magnet was 0.05 mm and 0.5 mm in high MF and low MF conditions, respectively. FIG. 8B . The transduction efficiency increases with the length of magnet treatment, efficiency increasing significantly at 1 hr. C. The transduction efficiency increases with the ratio between MNP and BV. The viruses (10 6 PFU) were mixed with designated amount of MNPs for 20 minutes. The cells were incubated with the mixture for 30 minutes in a magnetic field. The transduction dosage was 100 PFU per cell. Data represent mean ±SEM; n =4 per group. [0052] FIG. 9A-B . Numerical simulation of the magnetic force field generated by a NdFeB block magnet. A magnet will produce a magnetic field that varies according to shape and distance from the magnet. Therefore, a magnet is typically easily characterized by a single value, and we have therefore produced a numerical simulation of the field for the magnet employed. The dimension of the magnet is L×W×H=1″×½″×½″ and the remanent magnetization is 1.48 Tesla along the z-axis. The magnetic field and the magnetic force exerted on individual MNPs were simulated with COMSOL Multiphysics. A. The distribution of the magnetic force along z-direction on xy-, yz- and zx-planes at the corner of the block magnetic. B. The distribution of magnetic force along z-direction on the zx-plane in (A). DETAILED DESCRIPTION [0053] We have combined two important tools (CRISPR and BV) to develop a novel way of genome editing. In order to overcome serum inactivation of the insect virus, we combine the virus with magnetic nanoparticles, inject or otherwise introduce the virus in vivo, and then subject the target tissue to a strong magnetic field within 30 minutes, preferably within 10″, of viral introduction. This allows the virus to escape complement inactivation and allows transient expression of the CRISPR payload. Meanwhile, tissues that are not suject to the magnetic field will not take up virus, because any virus outside the target zone will be inactivated. [0054] We have exemplified the method using a CAS9/CRISPR genomic editing tool, but the method is of broader application and can be used to deliver other genome editing tools or other agents, such as drugs or other DNAs or RNAs and the like. [0055] In more detail, the invention includes any one or more of the following in any combination(s) thereof: [0000] A method of targeted in vivo gene editing, said method comprising: a) packaging an expression vector (V) encoding a gene editing system; b) attaching a plurality of magnetic nanoparticles to said V to make MNP-V; c) introducing said MNP-V to a patient having a gene to be edited; d) applying a magnetic field to a targeted tissue, without applying said magnetic field to nontargeted tissue, so that the MNP-V are only taken up and expressed in cells in said targeted tissue; and e) thereby editing said gene in said targeted tissue in said patient. A method of targeted in vivo gene editing, said method comprising: a) packaging an expression vector encoding a CAS9 or dCAS9 protein, single or multiple guide RNAs and an optional donor template into a baculovirus vector (BV), wherein said guide RNA and said optional donor template have homology to one or more gene(s) that is to be edited; b) attaching a plurality of magnetic nanoparticles to said BV to make MNP-BV; c) introducing said MNP-BV to a patient comprising said gene(s) to be edited; d) applying a magnetic field to a targeted tissue, without applying said magnetic field to nontargeted tissue, so that the MNP-BV are only taken up and expressed in cells in said targeted tissue; and e) thereby editing said gene(s) in said targeted tissue in said patient. A method of targeted in vivo gene editing, said method comprising: a) packaging an expression vector encoding a CRISPR nuclease, single or multiple guide RNAs and an optional donor template into a baculovirus vector (BV), wherein said guide RNA and said donor template have homology to one or more gene(s) that is to be edited in a targeted tissue; b) attaching a plurality of magnetic nanoparticles to said BV to make MNP-BV wherein a ratio of MNP to BV is at least 500:1; c) introducing said MNP-BV to a patient having said gene to be edited; d) applying a magnetic field of at least 0.1 Tesla and 0.1 Tesla/m to said targeted tissue within 10 minutes of said introducing step c, without applying said magnetic field to nontargeted tissue, so that the MNP-BV are only taken up and transiently expressed in cells in said targeted tissue; and e) thereby editing said gene in said targeted tissue in said patient. Any method herein described, wherein said magnetic field is at least 0.1 Tesla. Any method herein described, wherein said gradient of the magnetic field is at least 0.1 Tesla/m. Any method herein described, wherein said magnetic field is applied within 5″, 10″, or 30″ of said introducing step c. Any method herein described, wherein said magnetic field is applied for at least 30 minutes, or at least an hour or more. Any method herein described, wherein said MNP:BV ratio is at least 500:1. Any method herein described, wherein said guide RNA is a synthetic guide RNA comprising a gRNA and a trRNA. Any method herein described, wherein said magnetic field is at least 0.1 Tesla and the gradient of the magnetic field is at least 0.1 Tesla/m. Any method herein described, wherein said expression vector is a baculovirus vector and said gene editing system comprises a CRISPR system. Any method herein described, wherein said MNP are made with iron oxide nanoparticles. Any method herein described, wherein said MNP are made with iron(III) oxide nanoparticles and said nanoparticles are coated with one or more biocompatible polymers. Any method herein described, wherein said MNP are made with magnetite crystals of 10-50 nm and said crystals inside a biocompatible phospholipid micelle. Any method herein describes, which is performed on ex vivo tissue rather than a whole animal. An MNP-BV made by the methods herein described. A transformed cell or tissue or animal made by the methods herein described. Methods [0056] Production of BV vector: BV constructs including BV-LUC, BV-eGFP and BV-CRISPR, were generated using pFB-CMV-LUC, pFB-EF1a-eGFP and pFB-EF1a-eGFP-U6-sgRNA-CBh-CAS9, respectively, and propagated in Sf9 insect cells using the Bac-to-Bac Baculovirus Expression System (Thermo Fisher) according to the distributor's protocol. [0057] Synthesis of MNPs: Magnetic iron oxide nanoparticles (MNPs) were synthesized according to previously published protocols 29,30 . In brief, magnetite nanocrystals were synthesized through thermodecomposition of iron(III) acetylacetonate (Fe(acac) 3 , Sigma) in benzyl ether using oleic acid (Sigma) and oleylamine (Sigma) as the capping molecules. [0058] As-synthesized nanocrystals were subsequently coated with DSPE-mPEG2000 (Avanti lipids) and DSPE-PEG-maleimide (Avanti lipids) at a molar ratio of 9:1 using a dual solvent exchange method. [0059] To conjugate TAT peptides to the surface of MNPs, freshly coated MNPs were mixed with cys-TAT peptides (CGYGRKKRRQRRR, Genscript) at a molar ratio of 1:400 in PBS and incubated overnight. Unconjugated TAT peptides were removed by washing the nanoparticles with deionized water in centrifugal filter tubes (cutoff mol. wt.=100 kDa). The physical properties of the MNPs were characterized using transmitted electron microscopy (TEM), dynamic light scattering (DLS) (Mobius, Wyatt) and SQUID (MPMS, Quantum Design). [0060] In vitro BV transduction: Hepa 1-6 mouse liver cell line was purchased from ATCC (CLR-1830). Human umbilical vein endothelial cells (HUVEC) were purchased from Lonza (CC-2517). These cell lines were tested for mycoplasma contamination but not authenticated after receiving them. All cells were cultured according to the standard protocols from the distributors. [0061] In a typical in vitro BV transduction experiment, the cells were seeded in a chamber slide. Before BV transduction, 2 μL of BV suspension was mixed with 4 μL of MNPs for 20 minutes. The cells were then incubated with the mixture for 30 minutes with or without the magnet. In each group, the cells were transduced with BV at an MOI of 100 PFU per cell unless otherwise specified. After transduction, the cells were incubated with fresh medium. After 24 hours post transduction, luciferase activity was measured using an in vitro luciferase kit in a microplate reader (ONE-GloTM Luciferase Assay System, Promega). EGFP fluorescence was examined using flowcytometry or fluorescence microscopy. [0062] In vitro gDNA analysis: Hepa 1-6 cells were seeded in chamber slides and transduced with BV or MNP-BV as discussed above. Genomic DNA was extracted from treated cells with a DNeasy Blood and Tissue Kit (Qiagen). The amplicon containing the CRISPR cutting site was amplified with the indicated primers (F: CCCCCATTCGCTAGTGTGTA (SEQ ID NO:1); R: AGCACGGAGTGATTGATGCC (SEQ ID NO:2)) using Platinum® PCR SuperMix High Fidelity kit (Invitrogen). The PCR products were purified with a PCR purification kit (Qiagen) and denatured, reannealed and digested with a T7E1 nuclease (New England BioLabs). The fragments were examined by gel electrophoresis in 1.5% agarose gel. [0063] Cytotoxicity study: Hepa 1-6 cells were cultured in 96-well plates and incubated with BV at designated MOIs with or without MNPs for 12 hours. After treatment, the cells were incubated in fresh medium for 3 days and cell viability was evaluated by MTT assay. In brief, MTT was dissolved in sterile PBS at 5 mg/mL and added to the culture medium at 20 μL per well. After 4 hour incubation, the supernatant was removed and DMSO was added to the cells at 150 μL per well to dissolve the formazan generated by the cells. The optical density of the solutions was measured at 490 nm using a microplate reader. [0064] Immunostaining: The cells were seeded in chamber slides and incubated with BV or MNP-BV under designated conditions. After treatment, the cells were fixed in 4% paraformaldehyde for 20 minutes, permeabilized with PBS containing 0.1% Triton for 3 minutes and blocked with 5% BSA for 1 hour at room temperature. BV was detected by incubating the cells with an antibody against VP39 (the late capsid protein of BV, kindly provided by Prof. Loy Volkman and Dr. Taro Ohkawa) overnight at 4° C. followed by an Alexa Fluor 647 goat anti-mouse IgG antibody (Abcam) 35 . After that, the cells were stained with Hoechst 33342 (Thermo Fisher) and Alexa Fluor 488 phalloidin (Thermo Fisher). The images were acquired with a confocal microscope (Zeiss LSM 710). [0065] In vivo BV transduction: All animal studies were approved. Athymic nude mice ˜25 g body weight were purchased from Charles River. C3 knockout mice were purchased from the Jackson Laboratory. The mice were randomly allocated to the experimental groups (n=3 per group) without blinding. The mice were injected with BV (10 9 PFU) with or without MNPs (0.1 mg Fe) dispersed in 200 μL sterile PBS through the tail vein. [0066] Injected mice were placed on an N52 grade NdFeB block magnet (L×W×H=1″½″×½″) (K&J Magnetics) for one hour under anesthesia ( FIG. 6 b ). The magnetic field and the magnetic force exerted on individual MNPs were simulated with COMSOL Multiphysics ( FIG. 9 ). To examine the luciferase activity resulting from BV transduction, each mouse was injected with in vivo luciferase substrate (Promega) intraperitoneally (i.p.) and imaged using an IVIS Kinetic III live imaging system (Perkin Elmer). [0067] To examine the outcomes of genome editing, organs were harvested at 1 or 4 days after injection of baculovirus. Individual liver cells were isolated from the liver tissue using Liver Dissociation Kit (Miltenyi Biotec). Genome editing was evaluated with next generation sequencing using the following primers: F—TGAAAGAACACCCAAGGGAGG (SEQ ID NO:3) and R—GGGACGGAGAAGGAGTCTGT (SEQ ID NO:4). [0068] To examine the in vivo toxicity of MNP-BV, vital organs and blood were harvested from treated mice after 10 days post injection. The organs were fixed in 10% formalin solution overnight and embedded in paraffin. Histology evaluation was performed in tissue sections stained with hematoxylin and eosin. Alanine transaminase (ALT) and aspartate aminotransferase (AST) levels in the blood were measured using the ALT ELISA Kit (Biocompare) and AST Colorimetric Kit (Biovision) respectively, according to the manufacturer's instructions. [0069] Statistics: SPSS Statistics (SPSS) was used for all calculations. Data was analyzed using Student's t-tests or one-way ANOVA and post hoc multiple comparison tests. The difference with p<0.05 was considered statistically significant (* denotes p<0.05; # denotes p<0.01). Results and Discussion [0070] Recombinant BV was produced as described above. Magnetic iron oxide nanoparticles (MNPs) that can bind to BV were synthesized in three steps. First, magnetite nanocrystals were synthesized through thermodecomposition of iron acetylacetonate in benzyl ether 29 . As-synthesized nanocrystals were 15.5±1.1 nm in diameter and had a saturation magnetization of 87.2 emu/g, similar to that of bulk magnetite. [0071] Water-dispersible MNPs were then generated by coating the nanocrystals with copolymers of phospholipid and poly(ethylene glycol) using a dual solvent exchange method 25 to form micelles around the crystals. MNPs were then conjugated with the TAT peptide, a positively charged peptide that can attach to the BV surface ( FIG. 3 a ) 30,31 . However, this step is optional as the MNPs were sufficient to protect and deliver the BV to the cells without the TAT. TAT peptide conjugation to MNP was confirmed by zeta potential measurements and DNA retardation assay. When TAT-conjugated MNPs were mixed with BVs in phosphate buffered saline (PBS), multiple MNPs could attach to a single BV to form the BV-MNP hybrid, presumably due to electrostatic interactions ( FIG. 3 a ). [0072] MNPs can disperse in aqueous buffers with negligible magnetic interactions, but upon exposure to a magnetic field, they migrate against the field gradient as nanomagnets. In this study, the magnetic field was generated by using NdFeB magnets with a residual induction of 1.48 Tesla (see FIG. 9 ). When a mixture of BV and MNP were infused through a silicone tubing at physiologically relevant flow rates, more than 50% of BV could be captured by a block magnet placed next to the tubing, as determined by a viral titration assay. This suggests that hybrids of BV and MNP were formed and that the block magnet was effective in attracting the BV-MNP complex to a specific location. [0073] We next investigated the effect of nanomagnets on the interactions of BV with cultured Hepa 1-6 cells, which are known to have high BV infectibility 32 . BV alone exhibited negligible attachment to the cell surface as examined by immunostaining with the anti-vp39 antibody, which detects a BV capsid protein ( FIG. 3 b ) 33,32 . In contrast, with the applied magnetic field, a large amount of MNP-BV complexes became attached to the cell surface and entered the cytoplasm after 10 min incubation ( FIG. 3 b ). TEM images of cell cross-sections show co-existence of MNP and BV in the lysosomes, indicating cellular internalization of the MNP-BV hybrids. [0074] To examine the effect of nanomagnets on BV-induced transgene expression in vitro, BV-LUC and BV-eGFP, containing luciferase and eGFP plasmids respectively, were constructed ( FIG. 4 a ). BV-eGFP was mixed with MNPs, and the mixture was incubated with Hepa 1-6 cells under a magnetic field for 30 minutes. We found that under the applied magnetic field, the BV-MNP complex induced higher eGFP expression compared with BV alone ( FIG. 4 b ). When BV-eGFP was mixed with MNPs labeled with a fluorophore, DiI (a fluorescent lipophilic cationic indocarbocyanine dye, ex/em=549/565 nm), MNPs could be observed in perinuclear vesicles in the cells that had a strong eGFP expression, indicating that MNPs enhanced BV uptake, and without interfering its endosomal escape ( FIG. 4 c ). The BV transduction efficiency was determined by quantifying luciferase activity in the cells incubated with BV-LUC ( FIG. 2 d ). [0075] We found that MNPs or the magnetic field alone did not affect the transgene expression. Having MNPs mixed with BVs and applying magnetic field could increase the BV transduction by 2.4 fold compared with that by BV alone. No significant cell death was found following BV treatment, even at an MOI of 500, nor for the cells incubated with MNP-BV at different concentrations. [0076] The results shown in FIG. 4 were obtained with an MNP to BV ratio of ˜10 4 :1 in the MNP-BV mixture, so the vast majority of MNPs were not attached to BV. Using MNPs without the TAT peptide conjugation, we also found that nanomagnets alone could enhance the cellular uptake of BV as well as BV-LUC induced transgene expression (data not shown). The transduction efficiency of BV increases with the ratio between MNP and BV, the strength of the magnetic field and the incubation time (see FIG. 8 ). [0077] It has been shown that cellular uptake of BV is mediated by actin filaments in the cells 25 . We consistently found that Hepa 1-6 cells treated with cytochalasin D, an actin depolymerization agent, showed disrupted actin filament structure and reduced BV uptake compared to control cells (not shown). However, subsequent use of MNPs together with the applied magnetic field could partially restore actin filament formation and BV uptake. These results suggest that the increase in the cellular uptake of MNP-BV complexes may be due to magnetic force-induced mechano-transduction that involves actin filaments 19,34 . This result is quite surprising, as one might have predicted that the magnetic field effect was the result of local increases in the concentration of BV. However, if that were true, then increasing the concentration of BV should improve efficacy and it did not (data not shown). [0078] To determine if MNPs can protect BVs from serum inactivation similar to that of polymer coating or ligand displaying 22,24,25 , we performed BV transduction in a culture medium containing 50% of adult mouse serum (AMS), which contains the complement system to inactivate BV. When the cells were incubated with BV alone, BV transduction was abolished by AMS as indicated by the negligible luciferase expression in the cells ( FIG. 5 a ). Neither MNPs nor the applied magnetic field alone could rescue BV-LUC transgene expression. In contrast, in the presence of the applied magnetic field, BV-LUC associated with MNPs gave a high level of luciferase expression in Hepa 1-6 cells. We found that AMS had essentially no effect when MNP-BV-LUC was used together with an applied magnetic field, however, the transgene expression was greatly suppressed by AMS without MNP or magnetic field alone ( FIGS. 4 d and 5 a ). These results indicate that MNPs coupled with the magnetic field induce a rapid cellular uptake of BV, suggesting a drastically increased kinetic process for BV transduction that outpaced AMS-induced BV inactivation. [0079] We also investigated if the serum inactivation and magnetic activation could be combined to provide spatial control of BV transduction. Cells in a chamber slide were incubated with MNP-BV-eGFP in the presence of AMS; only half of the chamber was placed on a block magnet. We found that after 12 hours post transduction, most eGFP-positive cells were in the area above the magnet ( FIG. 5 b ). [0080] As further proof, an artificial vein was created by growing a layer of endothelial cells in a silicone tubing. The MNP-BV-eGFP vector in culture medium containing AMS was infused into the tubing at a flow rate of 7 mm/s. A section of the tubing was placed along a block magnet during the infusion. After overnight incubation, we found that only the cells in the tubing next to the magnet showed eGFP fluorescence (data not shown), further demonstrating the ability to provide accurate spatial control of BV transduction. [0081] It was been well established that BV administrated intravenously can circulate throughout the body, where the complementary factor C3 in the blood will bind to circulating BV and initiate molecular events that lead to BV inactivation ( FIG. 2 , ( 1 )) 26 . In contrast, a magnetic field applied to target cells can drive MNP-BV toward cell surface and enhance its cellular uptake with faster kinetics, which overcomes BV inactivation by the complementary factor C3 ( FIG. 2 , ( 2 )). [0082] Once inside the cell, MNP-BV can escape from endosomes and releases its genomic content into the cytoplasm ( FIG. 2 , ( 3 - 4 )). For in vivo genome editing, the released pDNA will express encoded gRNA and CAS9 in transduced cells ( FIG. 2 , ( 5 - 6 )). Therefore, magnetic activation of BV will enable selective in vivo genome editing in just those tissues exposed to the applied magnetic field. [0083] We tested this nanomagnet-based approach for localized gene editing in live mouse liver, which can be readily targeted with a block magnet applied externally. MNP-BV carrying the plasmid encoding luciferase ( FIG. 6 a ) was administrated systemically through tail vein injection, and the mouse was positioned on top of a block magnet for 1 hour belly side down ( FIG. 6 b ). The transgene expression was evaluated by examining the luciferase activity with live animal imaging. [0084] Consistent with the results from our in vitro studies, the mice treated with MNP-BV-LUC and subjected to an applied magnet field showed strong luminescence in the liver, whereas there was no luminescence in the mice treated with BV-LUC alone, or with MNP-BV-LUC but without applying a magnetic field ( FIG. 6 c - d ). [0085] Ex vivo examination confirmed that the high luciferase expression was only in the liver tissue exposed to the magnetic field; other vital organs including heart, lung, spleen and kidney did not show luminescence signal ( FIG. 6 e - f ). The level of luciferase expression in the liver also increased with the strength of the magnetic field (not shown). Importantly, the luciferase expression in mouse liver lasted less than 48 hours, and the MNP-BV-LUC did not induce significant acute liver damage (not shown). These results confirm that the nanomagnets induced transgene expression in vivo can be switched on remotely and locally, and the expression is transient, resulting in good spatiotemporal control. Further, the components of the method do not appear to be toxic. [0086] To further demonstrate the spatiotemporal control of in vivo genome editing, we integrated the cassettes encoding eGFP, the Streptococcus pyogenes (Spy) CAS9, and gRNA targeting mouse VEGFR2 gene into one plasmid for BV packaging, thanks to its large DNA loading capacity (>38 kb) ( FIG. 7 a ). The fluorescence from eGFP was used to determine the transduction efficiency and isolate transduced mouse cells. When delivered as plasmid and using the BV-CRISPR vector respectively into mouse Hepa 1-6 cells, the CRISPR/CAS9 system had cutting efficiencies of 9-30% of the mouse VEGFR2 gene (not shown). When Hepa 1-6 cells were incubated with the MNP-BV vector carrying CRISPR/CAS9 (MNP-BV-CRISPR) in the medium containing 50% AMS, both the eGFP expression and the CRISPR/CAS9 induced gene modification rate increased with the strength of the applied magnetic field ( FIG. 7 b ). Without applying a magnetic field to overcome BV inactivation by AMS, there was no eGFP expression or site-specific VEGFR2 gene modification in Hepa 1-6 cells ( FIG. 7 b ). [0087] For in vivo genome editing, mice were injected with MNP-BV-CRISPR and subjected to a magnetic field targeting mouse liver similar to that shown in FIG. 6 b . Following the workflow illustrated in FIG. 7 c , after 24 hours post MNP-BV-CRISPR delivery, the eGFP positive cells were harvested from mouse liver and T7E1 assays performed to quantify the gene modification rate. [0088] We found that the nanomagnets induced site-specific gene modification in transduced mouse liver cells with a ˜50% indel rate ( FIG. 7 d ), which is higher than that in mouse liver cells treated in vitro with MNP-BV-CRISPR as a positive control. A representative pattern of the indels at the VEGFR2 target locus is shown in FIG. 7 e . Our next-generation sequencing analysis suggested that ˜86% of mutations (3N+1, 3N+2) may lead to a frameshift. In a parallel experiment, mouse organs beyond the range of the magnetic field, including heart, lung, spleen, and kidney, were harvested 4 days post MNP-BV-CRISPR delivery and the genomic DNA was extracted for sequence analysis. No site-specific gene modification was detected in these off-target organs. [0089] We also evaluated some of the factors affecting efficiency of the system. The transduction efficiency of MNP-BV increases with the magnetic field strength ( FIG. 8 ). The transduction efficiency also increases as the length of magnetic treatment increases from 5 to 60 minutes, or when the ratio between MNP and BV increases from 500:1 to 10,000:1. [0090] Taken together, the results conclusively demonstrate that the MNP-BV system can deliver CRISPR/CAS9 in vivo, and the nuclease activity in target tissues/organ can be induced by an external magnetic field in a site-specific manner. The MNP-BV based delivery system takes advantage of the ability of nanomagnets to overcome BV serum-inactivation locally, thus enabling spatiotemporal control of in vivo genome editing. Owing to the large DNA loading capacity of BV, this system has the potential to facilitate multiplexed genome editing in vivo. [0091] The following references are incorporated by reference herein in its entirety for all purposes: 1. Sander, J. D. & Joung, J. K. CRISPR-Cas systems for editing, regulating and targeting genomes. Nat Biotechnol 32, 347-355 (2014). 2. Cong, L. et al. Multiplex Genome Engineering Using CRISPR/Cas Systems. Science 339, 819-823 (2013). 3. Yin, H. et al. Genome editing with CAS9 in adult mice corrects a disease mutation and phenotype. Nat Biotechnol 32, 551-553 (2014). 4. Swiech, L. et al. In vivo interrogation of gene function in the mammalian brain using CRISPR-CAS9. Nat Biotechnol 33, 102-106 (2015). 5. Cox, D. B., Platt, R. J. & Zhang, F. Therapeutic genome editing: prospects and challenges. Nat Med 21, 121-131 (2015). 6. Liao, H.K. et al. Use of the CRISPR/CAS9 system as an intracellular defense against HIV-1 infection in human cells. Nat Commun 6, 6413 (2015). 7. Lin, Y. N. et al. CRISPR/CAS9 systems have off-target activity with insertions or deletions between target DNA and guide RNA sequences. Nucleic Acids Research 42, 7473-7485 (2014). 8. Cradick, T. J., Fine, E. J., Antico, C. J. & Bao, G. CRISPR/CAS9 systems targeting beta-globin and CCRS genes have substantial off-target activity. Nucleic Acids Research 41, 9584-9592 (2013). 9. Fu, Y. et al. High-frequency off-target mutagenesis induced by CRISPR-Cas nucleases in human cells. Nat Biotechnol 31, 822-826 (2013). 10. Hsu, P. D. et al. DNA targeting specificity of RNA-guided CAS9 nucleases. Nat Biotechnol 31, 827-832 (2013). 11. Lee, C. M., Cradick, T. J., Fine, E. J. & Bao, G. Nuclease Target Site Selection for Maximizing On-target Activity and Minimizing Off-target Effects in Genome Editing. Mol Ther 24, 475-487 (2016). 12. Dow, L. E. et al. Inducible in vivo genome editing with CRISPR-CAS9. Nat Biotechnol 33, 390-394 (2015). 13. Nihongaki, Y., Kawano, F., Nakajima, T. & Sato, M. Photoactivatable CRISPR-CAS9 for optogenetic genome editing. Nat Biotechnol 33, 755-760 (2015). 14. Pansare, V., Hejazi, S., Faenza, W. & Prud'homme, R. K. Review of Long-Wavelength Optical and NIR Imaging Materials: Contrast Agents, Fluorophores and Multifunctional Nano Carriers. Chem Mater 24, 812-827 (2012). 15. Zincarelli, C., Soltys, S., Rengo, G. & Rabinowitz, J. E. Analysis of AAV Serotypes 1-9 Mediated Gene Expression and Tropism in Mice After Systemic Injection. Molecular Therapy 16, 1073-1080 (2008). 16. Yin, H. et al. Therapeutic genome editing by combined viral and non-viral delivery of CRISPR system components in vivo. Nat Biotechnol 34, 328-333 (2016). 17. Wang, Y. et al. Systemic dissemination of viral vectors during intratumoral injection. Mol Cancer Ther 2, 1233-1242 (2003). 18. Stanley, S. A., Sauer, J., Kane, R. S., Dordick, J. S. & Friedman, J. M. Remote regulation of glucose homeostasis in mice using genetically encoded nanoparticles. Nat Med 21, 92-98 (2015). 19. Mannix, R.J. et al. Nanomagnetic actuation of receptor-mediated signal transduction. Nat Nanotechnol 3, 36-40 (2008). 20. Wheeler, M. A. et al. Genetically targeted magnetic control of the nervous system. Nat Neurosci 19, 756-761 (2016). 21. Sammet, S. Magnetic resonance safety. Abdom Radiol 41, 444-451 (2016). 22. Airenne, K. J. et al. Baculovirus: an insect-derived vector for diverse gene transfer applications. Mol Ther 21, 739-749 (2013). 23. Mansouri, M. et al. Highly efficient baculovirus-mediated multigene delivery in primary cells. Nat Commun 7, 11529 (2016). 24. Chen, C. Y., Lin, C. Y., Chen, G. Y. & Hu, Y. C. Baculovirus as a gene delivery vector: recent understandings of molecular alterations in transduced cells and latest applications. Biotechnol Adv 29, 618-631 (2011). 25. Kost, T. A., Condreay, J. P. & Jarvis, D. L. Baculovirus as versatile vectors for protein expression in insect and mammalian cells. Nat Biotechnol 23, 567-575 (2005). 26. Hofmann, C. & Strauss, M. Baculovirus-mediated gene transfer in the presence of human serum or blood facilitated by inhibition of the complement system. Gene Ther 5, 531-536 (1998). 27. Kaikkonen, M. U., Maatta, A. I., Yla-Herttuala, S. & Airenne, K. J. Screening of complement inhibitors: shielded baculoviruses increase the safety and efficacy of gene delivery. Mol Ther 18, 987-992 (2010). 28. Raty, J. K. et al. Enhanced gene delivery by avidin-displaying baculovirus. Mol Ther 9, 282-291 (2004). 29. Sun, S. et al. Monodisperse MFe2O4 (M═Fe, Co, Mn) nanoparticles. J Am Chem Soc 126, 273-279 (2004). 30. Tong, S., Hou, S., Ren, B., Zheng, Z. & Bao, G. Self-assembly of phospholipid-PEG coating on nanoparticles through dual solvent exchange. Nano Lett 11, 3720-3726 (2011). 31. Torchilin, V. P. Tat peptide-mediated intracellular delivery of pharmaceutical nanocarriers. Adv Drug Deliv Rev 60, 548-558 (2008). 32. Boyce, F. M. & Bucher, N. L. R. Baculovirus-mediated gene transfer into mammalian cells. P Natl Acad Sci USA 93, 2348-2352 (1996). 33. Matilainen, H. et al. Baculovirus entry into human hepatoma cells. J Virol 79, 15452-15459 (2005). 34. Romet-Lemonne, G. & Jegou, A. Mechanotransduction down to individual actin filaments. European journal of cell biology 92, 333-338 (2013). 35. Danquah, J. O., Botchway, S., Jeshtadi, A. & King, L. A. Direct interaction of baculovirus capsid proteins VP39 and EXON0 with kinesin-1 in insect cells determined by fluorescence resonance energy transfer-fluorescence lifetime imaging microscopy. J Virol 86, 844-853 (2012).

This disclosure describes a composition and method of magenitic nanoparticles (MNP) that are bound to a baculovirus (BV). The MNP-BV can be systemically administered to a patient, and a strong magnetic field applied to the target btissue, thus allowing uptake and expression only in the target tissue. Off-target effects are not seen because the MNP-BC is inactivated by the complement system outside of the magnetic field.

TECHNICAL BACKGROUND [0001] The invention relates to a stereoscopic image capture system. Such a system commonly comprises a device described as a 3D camera, or stereoscopic camera. [0002] The invention particularly considers a stereoscopic image capture system that provides depth information, or equivalent information. The cameras of these systems are described as depth sensors, or depth cameras. These sensors make it possible to obtain images captured from two points of view, which, after processing, make it possible to obtain depth information, or any equivalent information, generally described as disparity information. It is obtained point by point (pixel by pixel) in the image, and referred to as a depth map. [0003] The invention in particular relates to a stereoscopic image capture system for capturing images while moving, at low or high speed, within an environment made up of stationary or static objects that are opposite the device for capturing images of the relative movements. [0004] Depth cameras are known based on the measurement of a time of flight of a light wave emitted by illumination means such as LEDs, and reflected the encountered objects. The wave may be an infrared wave. The time of flight, measured pixel by pixel, makes it possible to determine the distance of the reflective surface from the transmitting device. Time of flight cameras have the flaw of being sensitive to disruptions, such as infrared waves emitted by the environment, in particular the sun, or interference, in particular coming from other time of flight cameras, for example encountered during the movement of the vehicle with the camera on board and that passes other vehicles with similar cameras on board. [0005] LIDAR (light detection and ranging) systems, or laser radars, are also known reading (scanning) the environment with a generally coherent light, emitted by scanning using a heavy mechanical system that must be very precise. The system is cumbersome, and requires regular maintenance, due to the mechanical scanner system. It is more expensive for these two reasons. It is also blinded in case of rain and fog by the reflection caused by the cloudiness. [0006] Also known is document US 20070296846, which discloses a stereoscopic camera comprising two digital image sensors placed at a distance from one another by a chassis. The positioning of the sensors is obtained by a precise mechanical engagement between the parts. Also known is a stereoscopic camera called Bumblebee comprising two or three digital image sensors, communicating using a FireWire interface (IEEE-1394) and a GPIO (General-Purpose Input/Output) port, having a fixed image capture frequency and a fixed resolution. A first computer program is run on a microcomputer connected to the camera by the two connections, and makes it possible to control the camera, while a second computer program run on the microcomputer makes it possible to perform stereoscopic correlations to generate an image of the disparities. But since the resolution and the image capture frequency are fixed, it is not possible to use this camera dynamically and adaptively in an environment in which some objects are observed in rapid relative movement, and others in slow relative movement. [0007] Also known is a stereoscopic camera called Duo3D, in which the image capture frequency is configurable by a programming interface command, related in predefined modes to resolutions in both dimensions of the image that are modified by binning. However, this camera is configured for the computerized perception of objects at a short distance, and is not suitable for observing an environment during movement. [0008] There is therefore a need for a stereoscopic image capture system providing adaptive image capture in the face of relative movements of objects around the image capture device. SUMMARY OF THE INVENTION [0009] To resolve this problem, a system is proposed for capturing three-dimensional images during a movement, comprising: [0010] an image capture device including at least two digital image sensors synchronized with one another and arranged to perform a stereoscopic image capture, [0011] processing means to obtain disparity information associated with the digital images obtained by the image capture device as well as a movement speed of elements in said images, [0012] a means for transmitting digital images to make it possible to control the movement based on said digital images and the associated disparity information, and [0013] a control means to command the image capture device by optimizing, to facilitate said movement control, the choice of the dimensions of the field of view of the sensors and the frequency of the image capture, taking into account a maximum throughput tolerated by the transmission means and said movement speed. [0014] Owing to this system, it is possible to provide a device for controlling the movement of images captured with a frequency and a field of view suitable for the movement, in light of the relative speeds of the objects around the image capture device, with respect to the image capture device, which is then onboard the moving object needing to be controlled. [0015] Advantageously, the image capture system according to the invention may comprise at least one of the following technical features: [0016] said speed is assessed by a contrast gradient calculation done on the digital images, [0017] the means for transmitting digital images comprises a USB 3.0 connection, a Giga Ethernet connection or a Thunderbolt connection, [0018] the processing means comprises a computer program to be run on a microcomputer, [0019] the processing means comprises a chipset on a printed circuit substrate, [0020] the dimensions of the field of view used by the sensors and the image capture frequency can also be set by a user, [0021] the two sensors are master and slave, respectively, for synchronization purposes, [0022] the image capture device comprises a digital image processing controller placed on a printed circuit substrate shared by the two sensors, [0023] the means for transmitting digital images comprises a means for transmitting said images between the image capture device and at least one of the processing means, [0024] the means for transmitting digital images comprises a means for transmitting said images and the disparity information to a means for controlling the movement, [0025] if elements are observed that are moving quickly, the capture frequency is increased, while the field of view is restricted, and if elements are observed moving slowly, said frequency is decreased, while the field of view is extended. [0026] The invention also relates to an object provided with movement means and comprising an image capture system according to the invention, said object comprising means for sending a human operator or an electronic module the disparity information associated with the digital images produced by said system for three-dimensional image capture, in order to control the movement of said object. [0027] The object may additionally comprise means for moving in the context of autonomous navigation by using the disparity information associated with the digital images obtained by said system for three-dimensional image capture. BRIEF DESCRIPTION OF DRAWING FIGURES [0028] The invention will be better understood, and other aims, features, details and advantages thereof will appear more clearly, in the following explanatory description done in reference to the appended drawings, provided solely as an example illustrating one embodiment of the invention, and in which: [0029] FIG. 1 is a general view in space of one embodiment of an image capture device according to the invention, [0030] FIG. 2 is a diagram showing the operation of the elements of one embodiment of an image capture device according to the invention, [0031] FIG. 3 is one aspect of the operation of an image capture device according to the invention, [0032] FIG. 4 shows an outside view of one embodiment of an image capture device according to the invention, [0033] FIGS. 5 and 6 show example embodiments of the image capture device according to the invention. DETAILED DESCRIPTION OF THE INVENTION [0034] FIG. 1 provides a schematic view of an electronic board of an image capture device 10 according to one embodiment of the invention. The board 10 is formed by a single printed circuit substrate supporting electronic components. The image capture device board 10 comprises a first digital image sensor 100 and a second digital image sensor 110 , which can be CCD (charge-coupled device) sensors or sensors using another technology, such as the CMOS technology, and receive light through an optical lens focusing system (not shown). [0035] The selected sensors 100 and 110 have an active surface that can be controlled by a command outside the sensor, and which can be used for different viewing angle dimensions, or different resolutions. They may also be controlled to capture images at different frequencies. [0036] The sensors 100 and 110 are both positioned on a printed circuit substrate 120 . The substrate 120 can be an elongated rectangle, the large dimension of which is placed along a direction X, and the two sensors are then placed substantially at both ends of the rectangle in the direction X. The two sensors 100 and 110 are positioned with their sensitive surfaces oriented opposite the substrate 120 , turned substantially in a direction Z perpendicular to the direction X, and normal to the plane of the printed circuit substrate 120 . [0037] On the printed circuit substrate 120 is a controller 130 , in the form of an integrated circuit electrically connected to the two sensors 100 and 110 . The controller 130 receives commands from third-party components and provides operating parameters to the sensors 100 and 110 . It furthermore verifies that these commands have indeed been received and understood by the sensors 100 and 110 . [0038] Additionally, the printed circuit substrate 120 bears a connector 140 , making it possible to connect the image capture device 10 to a third-party device. [0039] FIG. 2 functionally shows the image capture device board 10 , and its interaction with an outside processing and control unit 20 . The first sensor 100 and the second sensor 110 are again shown, as well as the controller 130 and the connector 140 . The controller 130 runs several programs constituting several modules 131 , 132 , 133 at 134 that will be outlined later. The controller 130 , the sensors 100 and 110 and the connector 140 communicate via tracks of conductive material (copper) of the board 10 . [0040] Each of the first and second sensors 100 and 110 captures digital images at an identical frequency for both sensors, and set by the controller 130 , which executes a program forming an image sensor processing module 133 . This module 133 sends control commands of the first sensor C 1 and control commands of the second center C 2 to both sensors, in particular to define the capture frequency of the images. [0041] The first sensor 100 regularly sends a synchronization message M 1 to the second sensor 110 , to allow the latter to align the capture moments of its images with the capture moments of the images by the first sensor 100 . This involves a master-slave mode synchronization, the first sensor 100 acting as master, imposing the capture moments, and the second sensor 110 acting as slave, applying the instruction received to implement the image capture. [0042] The sensors 100 and 110 send the images they capture to the controller 130 , via messages I 1 and I 2 comprising the color and brightness information of the pixels. The captured and transmitted images are rectangular, the rectangles of the two sensors being identical (same width, same height, same orientation). [0043] A first program constitutes a receiving and resynchronization module 131 , responsible for receiving the digital images captured by the sensors 100 and 110 and re-synchronizing them such that the following programs implemented by the controller 130 are able to recognize the pairs of images sent by the first and second sensors 100 and 110 . [0044] A second program constitutes a merging module 132 responsible for merging the two images taken at the same time by the two sensors, and transmitted by the module 131 . The two images are merged into a single digital image, as will be described in connection with FIG. 3 . The single merged image is sent to the following module. [0045] The following module, already described, constitutes an image sensor processing (ISP) module 133 . In some embodiments, it may perform parallel calculations to specify the color and light of each pixel. Once its processing is complete, it sends the image to the following module. [0046] The next program defines a fourth module, which is a conversion module 134 , responsible for converting the data making up the digital images, and potentially other information, into a format compatible with the transmission via a wired connector 150 connected to the connector 140 , and conversely, extracting the information received by the wired connector 150 and the connector 140 to send it to the image sensor processing module 133 . [0047] The wired module 150 , which for example is flexible, connects the connector 140 to a connector 201 of the outside processing and control unit 20 . The wired connector 150 can perform an electrical or optical transmission. [0048] The outside processing and control unit 20 comprises a connector 201 , and a processor 200 that runs a processing and control program 202 . It also comprises a conversion module 204 for the reception and sending of data by the connector 201 , which may be run by the processor 200 or a dedicated controller. [0049] In one embodiment, the transmission by the wired connector 150 is done according to standard USB 3.0. The conversion module 134 and the wired connector 150 , as well as the connectors 140 and 201 , are configured to implement standard USB 3.0. Other standards can be used, in particular the Gigethernet and Thunderbolt standards. [0050] The processor 200 implements the processing and control program 202 , which uses the digital images transmitted by the image sensor processing module 133 . In particular, the disparity or depth information is calculated for each pair of synchronized images. [0051] Furthermore, a contrast gradient calculation makes it possible to assess the presence of motion blurring in the images. [0052] The processing and control program 202 is also able to send commands to the controller 130 of the image capture device 10 , for example via the wired connector 150 , or by another wired or wireless means. [0053] Depending on the result of the contrast gradient calculation, the processing and control program 202 is able to command automatically, or with agreement from a user to whom the command is suggested by the program, a change in the choice of the dimensions of the field of view of the sensors 100 and 110 and the image capture frequency by the sensors. This choice is framed by the relationship [0000] width×height×16×frequency max throughput [0054] wherein the width and height are expressed in pixels and the maximum throughput in bits/s. The maximum throughput is that of the connection between the image capture device 10 and the outside processing and control unit 20 , which is for example the maximum throughput of a USB 3.0 connection. [0055] If motion blurring is detected, it is then chosen to decrease the field of view and increase the image capture frequency, to improve the vision of the objects in relative movement around the image capture device 10 . [0056] If little or no motion blurring is observed, it is chosen to increase the field of view and decrease the image capture frequency, to improve the perception of the environment, including on the sides. [0057] The outside processing and control unit 20 includes a second connector 203 , as well as a second conversion module 205 for the reception and transmission of data by the connector 203 , which can be done by the processor 200 or a dedicated controller. [0058] The outside processing and control unit 20 can assume the form of a multifunctional computer or a unit dedicated to controlling the image capture device 10 . In the second case, it may for example be built in the form of a single printed circuit board bearing the connectors 201 and 203 , as well as a processor 200 , which can then run both the program 202 and the modules 204 and 205 . [0059] The module 205 allows the outside processing and control unit 20 to communicate with a third-party device, via a second wired connection means 250 . The second wired connector 250 can perform an electrical or optical transmission. [0060] This is for example a USB 3.0 cable, or a Giga Ethernet or Thunderbolt connection. [0061] The processing and control unit 20 sends the stereoscopic digital images and the disparity or depth information associated therewith via the wired connector 250 . Thus, a three-dimensional depiction of the image captured by the image capture device 10 is provided, either to a human user, or to a software program capable of exploiting it. [0062] FIG. 3 shows the merging process implemented by the merging module 132 . [0063] Two images 1000 and 1001 have been captured by the sensors 100 and 110 ( FIG. 1 ). Their content is referenced G and D in the figure, to indicate that these are images captured by the left and right sensors, respectively, of the image capture device 10 . The two images are each a rectangular set of pixels with the same heights and the same lengths. They are subject to merging by the merging module 132 , which creates a single image 2000 made up of a rectangular set of pixels, of the same height as the two images 1000 and 1001 and twice the length relative to the length of the images 1000 and 1001 . The left side of the right image D is placed next to the right side of the left image G. [0064] FIG. 4 shows a three-dimensional view of one embodiment of the image capture device. It may for example assume the form of a box 10 ′ generally in the shape of a rectangular rhomb or the like, in which the electronic components of the device are contained, and which has two openings to the light on one face, through which the first and second sensors 100 and 110 expose their respective sensitive surfaces to capture digital images. The wired connector 250 allowing the extraction of the digital data is not visible. [0065] FIG. 5 shows a use of an image acquisition device box 10 ′ in a flying object 5000 of the drone type capable of moving without human intervention, or remotely controlled by a human. The flying object 5000 carries an image acquisition device box 10 ′, as well as an outside processing and control unit 20 , connected by a wired connection means 150 . It also comprises an autonomous navigation module 5100 , interacting with the outside processing and control unit 20 , via a wired connection means 250 . The autonomous navigation unit 5100 uses the stereoscopic images provided by the image capture device and the associated disparity or depth information, pixel by pixel, to make navigation decisions. The navigation decisions are of better quality if the dimensions of the field of view of the sensors and the image capture frequency have been chosen carefully and are readjusted regularly, reactively based on the environment and objects observed in the images and their relative speed with respect to the flying object 5000 . [0066] Likewise, in FIG. 6 , the same principle is presented, this time with a rolling object 6000 of the autonomous car type capable of moving without human intervention in a complex environment, for example a road or urban environment. The vehicle can also be a construction vehicle or a wagon moving in a warehouse, for example. [0067] For the objects 5000 and 6000 , the navigation can be autonomous or computer-assisted navigation, the decision-making in this case always being done by a human, but the latter having additional information obtained owing to the image capture device and the associated system. [0068] In one alternative, the box 10 ′ of the image capture device can incorporate the control unit 20 inside it, and be on board a vehicle such that the user simply connects the box 10 ′, which is then the only one, to the autonomous navigation module 5100 or 6100 using the wired connection means 250 . The wired connection means 150 is then inside the box 10 ′. [0069] Within the single box 10 ′, in one alternative, the processor 200 can also be mounted on the board 10 , and communicate via a connection using conductive metal tracks (copper), with the module 133 of the controller 130 , in place of the communication via the wired connection means 150 , the connectors 140 and 201 and the conversion module 134 . [0070] The maximum throughput value used to command a change in the choice of dimensions of the field of view of the sensors 100 and 110 and the image capture frequency by the sensors is in this case that of the wired connection means 250 . [0071] In another alternative, the control unit 20 and the autonomous navigation unit 5100 or 6100 are embodied by a same piece of computer equipment, having a processor that runs both the autonomous navigation program and the processing and control program 202 . The connection 250 , the connector 203 and the conversion module 205 are then absent. [0072] In general, the maximum throughput value used to command a change in the choice of the dimensions of the field of view of the sensors 100 and 110 and the image capture frequency by the sensors is that of the most limiting connection for the transmission of the digital images to obtain disparity information and to send digital images to the navigation module. [0073] The invention is not limited to the described embodiment, but extends to all alternatives within the scope of the claims.

A system for three-dimensional image capture while moving. The system includes: an image capture device including at least two digital image sensors placed to capture a stereoscopic image; a processor for obtaining disparity information, associated with the digital images obtained by the image capture device and movement speed of elements in the digital images; a transmitter for sending the digital images to enable control of movement based on the digital images and the associated disparity information; and a controller for controlling the image capture device.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] The present application is a continuation of U.S. patent application Ser. No. 13/930,863 filed Jun. 28, 2013, which is a continuation of U.S. patent application Ser. No. 13/619,851 filed Sep. 14, 2012, now U.S. Pat. No. 8,548,600, which is a continuation of U.S. patent application Ser. No. 12/777,892, filed May 11, 2010, which is a continuation of U.S. patent application Ser. No. 11/782,451, filed Jul. 24, 2007, now abandoned, which is a divisional of U.S. patent application Ser. No. 11/129,765, filed May 13, 2005, now U.S. Pat. No. 7,653,438, which claims the benefit of U.S. Provisional Patent Application No. 60/616,254, filed Oct. 5, 2004, and U.S. Provisional Patent Application No. 60/624,793, filed Nov. 2, 2004. [0002] U.S. patent application Ser. No. 11/129,765, filed May 13, 2005, now U.S. Pat. No. 7,653,438 is also a continuation-in-part of U.S. patent application Ser. No. 10/408,665, filed Apr. 8, 2003, now U.S. Pat. No. 7,162,303, which claims the benefit of U.S. Provisional Patent Application Nos. (a) 60/370,190, filed Apr. 8, 2002; (b) 60/415,575, filed Oct. 3, 2002; and (c) 60/442,970, filed Jan. 29, 2003. The disclosures of these applications are incorporated herein by reference in their entireties. INCORPORATION BY REFERENCE [0003] All publications and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference. TECHNICAL FIELD [0004] The present invention relates to methods and apparatus for renal neuromodulation. More particularly, the present invention relates to methods and apparatus for achieving renal neuromodulation via a pulsed electric field and/or electroporation or electrofusion. BACKGROUND [0005] Congestive Heart Failure (“CHF”) is a condition that occurs when the heart becomes damaged and reduces blood flow to the organs of the body. If blood flow decreases sufficiently, kidney function becomes impaired and results in fluid retention, abnormal hormone secretions and increased constriction of blood vessels. These results increase the workload of the heart and further decrease the capacity of the heart to pump blood through the kidney and circulatory system. [0006] This reduced capacity further reduces blood flow to the kidney, which in turn further reduces the capacity of the heart. It is believed that progressively decreasing perfusion of the kidney is a principal non-cardiac cause perpetuating the downward spiral of CHF. Moreover, the fluid overload and associated clinical symptoms resulting from these physiologic changes are predominant causes for excessive hospital admissions, terrible quality of life and overwhelming costs to the health care system due to CHF. [0007] While many different diseases may initially damage the heart, once present, CHF is split into two types: Chronic CHF and Acute (or Decompensated-Chronic) CHF. Chronic Congestive Heart Failure is a longer term, slowly progressive, degenerative disease. Over years, chronic congestive heart failure leads to cardiac insufficiency. Chronic CHF is clinically categorized by the patient's ability to exercise or perform normal activities of daily living (such as defined by the New York Heart Association Functional Class). Chronic CHF patients are usually managed on an outpatient basis, typically with drugs. [0008] Chronic CHF patients may experience an abrupt, severe deterioration in heart function, termed Acute Congestive Heart Failure, resulting in the inability of the heart to maintain sufficient blood flow and pressure to keep vital organs of the body alive. These Acute CHF deteriorations can occur when extra stress (such as an infection or excessive fluid overload) significantly increases the workload on the heart in a stable chronic CHF patient. In contrast to the stepwise downward progression of chronic CHF, a patient suffering acute CHF may deteriorate from even the earliest stages of CHF to severe hemodynamic collapse. In addition, Acute CHF can occur within hours or days following an Acute Myocardial Infarction (“AMI”), which is a sudden, irreversible injury to the heart muscle, commonly referred to as a heart attack. [0009] As mentioned, the kidneys play a significant role in the progression of CHF, as well as in Chronic Renal Failure (“CRF”), End-Stage Renal Disease (“ESRD”), hypertension (pathologically high blood pressure) and other cardio-renal diseases. The functions of the kidney can be summarized under three broad categories: filtering blood and excreting waste products generated by the body's metabolism; regulating salt, water, electrolyte and acid-base balance; and secreting hormones to maintain vital organ blood flow. Without properly functioning kidneys, a patient will suffer water retention, reduced urine flow and an accumulation of waste toxins in the blood and body. These conditions resulting from reduced renal function or renal failure (kidney failure) are believed to increase the workload of the heart. In a CHF patient, renal failure will cause the heart to further deteriorate as the water build-up and blood toxins accumulate due to the poorly functioning kidneys and, in turn, cause the heart further harm. [0010] The primary functional unit of the kidneys that is involved in urine formation is called the “nephron”. Each kidney consists of about one million nephrons. The nephron is made up of a glomerulus and its tubules, which can be separated into a number of sections: the proximal tubule, the medullary loop (loop of Henle), and the distal tubule. Each nephron is surrounded by different types of cells that have the ability to secrete several substances and hormones (such as renin and erythropoietin). Urine is formed as a result of a complex process starting with the filtration of plasma water from blood into the glomerulus. The walls of the glomerulus are freely permeable to water and small molecules but almost impermeable to proteins and large molecules. Thus, in a healthy kidney, the filtrate is virtually free of protein and has no cellular elements. The filtered fluid that eventually becomes urine flows through the tubules. The final chemical composition of the urine is determined by the secretion into, and re-absorption of substances from, the urine required to maintain homeostasis. [0011] Receiving about 20% of cardiac output, the two kidneys filter about 125 ml of plasma water per minute. Filtration occurs because of a pressure gradient across the glomerular membrane. The pressure in the arteries of the kidney pushes plasma water into the glomerulus causing filtration. To keep the Glomerulur Filtration Rate (“GFR”) relatively constant, pressure in the glomerulus is held constant by the constriction or dilatation of the afferent and efferent arterioles, the muscular walled vessels leading to and from each glomerulus. [0012] In a CHF patient, the heart will progressively fail, and blood flow and pressure will drop in the patient's circulatory system. During acute heart failure, short-term compensations serve to maintain perfusion to critical organs, notably the brain and the heart that cannot survive prolonged reduction in blood flow. However, these same responses that initially aid survival during acute heart failure become deleterious during chronic heart failure. [0013] A combination of complex mechanisms contribute to deleterious fluid overload in CHF. As the heart fails and blood pressure drops, the kidneys cannot function and become impaired due to insufficient blood pressure for perfusion. This impairment in renal function ultimately leads to the decrease in urine output. Without sufficient urine output, the body retains fluids, and the resulting fluid overload causes peripheral edema (swelling of the legs), shortness of breath (due to fluid in the lungs), and fluid retention in the abdomen, among other undesirable conditions in the patient. [0014] In addition, the decrease in cardiac output leads to reduced renal blood flow, increased neurohormonal stimulus, and release of the hormone renin from the juxtaglomerular apparatus of the kidney. This results in avid retention of sodium and, thus, volume expansion. Increased renin results in the formation of angiotensin, a potent vasoconstrictor. Heart failure and the resulting reduction in blood pressure also reduce the blood flow and perfusion pressure through organs in the body other than the kidneys. As they suffer reduced blood pressure, these organs may become hypoxic, resulting in a metabolic acidosis that reduces the effectiveness of pharmacological therapy and increases a risk of sudden death. [0015] This spiral of deterioration that physicians observe in heart failure patients is believed to be mediated, at least in part, by activation of a subtle interaction between heart function and kidney function, known as the renin-angiotensin system. Disturbances in the heart's pumping function results in decreased cardiac output and diminished blood flow. The kidneys respond to the diminished blood flow as though the total blood volume was decreased, when in fact the measured volume is normal or even increased. This leads to fluid retention by the kidneys and formation of edema, thereby causing the fluid overload and increased stress on the heart. [0016] Systemically, CHF is associated with an abnormally elevated peripheral vascular resistance and is dominated by alterations of the circulation resulting from an intense disturbance of sympathetic nervous system function. Increased activity of the sympathetic nervous system promotes a downward vicious cycle of increased arterial vasoconstriction (increased resistance of vessels to blood flow) followed by a further reduction of cardiac output, causing even more diminished blood flow to the vital organs. [0017] In CHF via the previously explained mechanism of vasoconstriction, the heart and circulatory system dramatically reduce blood flow to the kidneys. During CHF, the kidneys receive a command from higher neural centers via neural pathways and hormonal messengers to retain fluid and sodium in the body. In response to stress on the heart, the neural centers command the kidneys to reduce their filtering functions. While in the short term, these commands can be beneficial, if these commands continue over hours and days they can jeopardize the person's life or make the person dependent on artificial kidney for life by causing the kidneys to cease functioning. [0018] When the kidneys do not fully filter the blood, a huge amount of fluid is retained in the body, which results in bloating (fluid retention in tissues) and increases the workload of the heart. Fluid can penetrate into the lungs, and the patient becomes short of breath. This odd and self-destructive phenomenon is most likely explained by the effects of normal compensatory mechanisms of the body that improperly perceive the chronically low blood pressure of CHF as a sign of temporary disturbance, such as bleeding. [0019] In an acute situation, the body tries to protect its most vital organs, the brain and the heart, from the hazards of oxygen deprivation. Commands are issued via neural and hormonal pathways and messengers. These commands are directed toward the goal of maintaining blood pressure to the brain and heart, which are treated by the body as the most vital organs. The brain and heart cannot sustain low perfusion for any substantial period of time. A stroke or a cardiac arrest will result if the blood pressure to these organs is reduced to unacceptable levels. Other organs, such as the kidneys, can withstand somewhat longer periods of ischemia without suffering long-term damage. Accordingly, the body sacrifices blood supply to these other organs in favor of the brain and the heart. [0020] The hemodynamic impairment resulting from CHF activates several neurohormonal systems, such as the renin-angiotensin and aldosterone system, sympatho-adrenal system and vasopressin release. As the kidneys suffer from increased renal vasoconstriction, the GFR drops, and the sodium load in the circulatory system increases. Simultaneously, more renin is liberated from the juxtaglomerular of the kidney. The combined effects of reduced kidney functioning include reduced glomerular sodium load, an aldosterone-mediated increase in tubular reabsorption of sodium, and retention in the body of sodium and water. These effects lead to several signs and symptoms of the CHF condition, including an enlarged heart, increased systolic wall stress, an increased myocardial oxygen demand, and the formation of edema on the basis of fluid and sodium retention in the kidney. Accordingly, sustained reduction in renal blood flow and vasoconstriction is directly responsible for causing the fluid retention associated with CHF. [0021] CHF is progressive, and as of now, not curable. The limitations of drug therapy and its inability to reverse or even arrest the deterioration of CHF patients are clear. Surgical therapies are effective in some cases, but limited to the end-stage patient population because of the associated risk and cost. Furthermore, the dramatic role played by kidneys in the deterioration of CHF patients is not adequately addressed by current surgical therapies. [0022] The autonomic nervous system is recognized as an important pathway for control signals that are responsible for the regulation of body functions critical for maintaining vascular fluid balance and blood pressure. The autonomic nervous system conducts information in the form of signals from the body's biologic sensors such as baroreceptors (responding to pressure and volume of blood) and chemoreceptors (responding to chemical composition of blood) to the central nervous system via its sensory fibers. It also conducts command signals from the central nervous system that control the various innervated components of the vascular system via its motor fibers. [0023] Experience with human kidney transplantation provided early evidence of the role of the nervous system in kidney function. It was noted that after transplant, when all the kidney nerves were totally severed, the kidney increased the excretion of water and sodium. This phenomenon was also observed in animals when the renal nerves were cut or chemically destroyed. The phenomenon was called “denervation diuresis” since the denervation acted on a kidney similar to a diuretic medication. Later the “denervation diuresis” was found to be associated with vasodilatation of the renal arterial system that led to increased blood flow through the kidney. This observation was confirmed by the observation in animals that reducing blood pressure supplying the kidneys reversed the “denervation diuresis”. [0024] It was also observed that after several months passed after the transplant surgery in successful cases, the “denervation diuresis” in transplant recipients stopped and the kidney function returned to normal. Originally, it was believed that the “renal diuresis” was a transient phenomenon and that the nerves conducting signals from the central nervous system to the kidney were not essential to kidney function. Later discoveries suggested that the renal nerves had a profound ability to regenerate and that the reversal of “denervation diuresis” could be attributed to the growth of new nerve fibers supplying the kidneys with necessary stimuli. [0025] Another body of research focused on the role of the neural control of secretion of the hormone renin by the kidney. As was discussed previously, renin is a hormone responsible for the “vicious cycle” of vasoconstriction and water and sodium retention in heart failure patients. It was demonstrated that an increase or decrease in renal sympathetic nerve activity produced parallel increases and decreases in the renin secretion rate by the kidney, respectively. [0026] In summary, it is known from clinical experience and the large body of animal research that an increase in renal sympathetic nerve activity leads to vasoconstriction of blood vessels supplying the kidney, decreased renal blood flow, decreased removal of water and sodium from the body, and increased renin secretion. It is also known that reduction of sympathetic renal nerve activity, e.g., via denervation, may reverse these processes. [0027] It has been established in animal models that the heart failure condition results in abnormally high sympathetic stimulation of the kidney. This phenomenon was traced back to the sensory nerves conducting signals from baroreceptors to the central nervous system. Baroreceptors are present in the different locations of the vascular system. Powerful relationships exist between baroreceptors in the carotid arteries (supplying the brain with arterial blood) and sympathetic nervous stimulus to the kidneys. When arterial blood pressure was suddenly reduced in experimental animals with heart failure, sympathetic tone increased. Nevertheless, the normal baroreflex likely is not solely responsible for elevated renal nerve activity in chronic CHF patients. If exposed to a reduced level of arterial pressure for a prolonged time, baroreceptors normally “reset”, i.e., return to a baseline level of activity, until a new disturbance is introduced. Therefore, it is believed that in chronic CHF patients, the components of the autonomic-nervous system responsible for the control of blood pressure and the neural control of the kidney function become abnormal. The exact mechanisms that cause this abnormality are not fully understood, but its effects on the overall condition of the CHF patients are profoundly negative. [0028] End-Stage Renal Disease is another condition at least partially controlled by renal neural activity. There has been a dramatic increase in patients with ESRD due to diabetic nephropathy, chronic glomerulonephritis and uncontrolled hypertension. Chronic Renal Failure slowly progresses to ESRD. CRF represents a critical period in the evolution of ESRD. The signs and symptoms of CRF are initially minor, but over the course of 2-5 years, become progressive and irreversible. While some progress has been made in combating the progression to, and complications of, ESRD, the clinical benefits of existing interventions remain limited. [0029] It has been known for several decades that renal diseases of diverse etiology (hypotension, infection, trauma, autoimmune disease, etc.) can lead to the syndrome of CRF characterized by systemic hypertension, proteinuria (excess protein filtered from the blood into the urine) and a progressive decline in GFR ultimately resulting in ESRD. These observations suggest that CRF progresses via a common pathway of mechanisms and that therapeutic interventions inhibiting this common pathway may be successful in slowing the rate of progression of CRF irrespective of the initiating cause. [0030] To start the vicious cycle of CRF, an initial insult to the kidney causes loss of some nephrons. To maintain normal GFR, there is an activation of compensatory renal and systemic mechanisms resulting in a state of hyperfiltration in the remaining nephrons. Eventually, however, the increasing numbers of nephrons “overworked” and damaged by hyperfiltration are lost. At some point, a sufficient number of nephrons are lost so that normal GFR can no longer be maintained. These pathologic changes of CRF produce worsening systemic hypertension, thus high glomerular pressure and increased hyperfiltration. Increased glomerular hyperfiltration and permeability in CRF pushes an increased amount of protein from the blood, across the glomerulus and into the renal tubules. This protein is directly toxic to the tubules and leads to further loss of nephrons, increasing the rate of progression of CRF. This vicious cycle of CRF continues as the GFR drops with loss of additional nephrons leading to further hyperfiltration and eventually to ESRD requiring dialysis. Clinically, hypertension and excess protein filtration have been shown to be two major determining factors in the rate of progression of CRF to ESRD. [0031] Though previously clinically known, it was not until the 1980s that the physiologic link between hypertension, proteinuria, nephron loss and CRF was identified. In 1990s the role of sympathetic nervous system activity was elucidated. Afferent signals arising from the damaged kidneys due to the activation of mechanoreceptors and chemoreceptors stimulate areas of the brain responsible for blood pressure control. In response, the brain increases sympathetic stimulation on the systemic level, resulting in increased blood pressure primarily through vasoconstriction of blood vessels. When elevated sympathetic stimulation reaches the kidney via the efferent sympathetic nerve fibers, it produces major deleterious effects in two forms. The kidneys are damaged by direct renal toxicity from the release of sympathetic neurotransmitters (such as norepinephrine) in the kidneys independent of the hypertension. Furthermore, secretion of renin that activates Angiotensin II is increased, which increases systemic vasoconstriction and exacerbates hypertension. [0032] Over time, damage to the kidneys leads to a further increase of afferent sympathetic signals from the kidney to the brain. Elevated Angiotensin II further facilitates internal renal release of neurotransmitters. The feedback loop is therefore closed, which accelerates deterioration of the kidneys. [0033] In view of the foregoing, it would be desirable to provide methods and apparatus for the treatment of congestive heart failure, renal disease, hypertension and/or other cardio-renal diseases via renal neuromodulation and/or denervation. SUMMARY [0034] The present invention provides methods and apparatus for renal neuromodulation (e.g., denervation) using a pulsed electric field (PEF). Several aspects of the invention apply a pulsed electric field to effectuate electroporation and/or electrofusion in renal nerves, other neural fibers that contribute to renal neural function, or other neural features. Several embodiments of the invention are intravascular devices for inducing renal neuromodulation. The apparatus and methods described herein may utilize any suitable electrical signal or field parameters that achieve neuromodulation, including denervation, and/or otherwise create an electroporative and/or electrofusion effect. For example, the electrical signal may incorporate a nanosecond pulsed electric field (nsPEF) and/or a PEF for effectuating electroporation. One specific embodiment comprises applying a first course of PEF electroporation followed by a second course of nsPEF electroporation to induce apoptosis in any cells left intact after the PEF treatment, or vice versa. An alternative embodiment comprises fusing nerve cells by applying a PEF in a manner that is expected to reduce or eliminate the ability of the nerves to conduct electrical impulses. When the methods and apparatus are applied to renal nerves and/or other neural fibers that contribute to renal neural functions, this present inventors believe that urine output will increase and/or blood pressure will be controlled in a manner that will prevent or treat CHF, hypertension, renal system diseases, and other renal anomalies. [0035] Several aspects of particular embodiments can achieve such results by selecting suitable parameters for the PEFs and/or nsPEFs. Pulsed electric field parameters can include, but are not limited to, field strength, pulse width, the shape of the pulse, the number of pulses and/or the interval between pulses (e.g., duty cycle). Suitable field strengths include, for example, strengths of up to about 10,000 V/cm. Suitable pulse widths include, for example, widths of up to about 1 second. Suitable shapes of the pulse waveform include, for example, AC waveforms, sinusoidal waves, cosine waves, combinations of sine and cosine waves, DC waveforms, DC-shifted AC waveforms, RF waveforms, square waves, trapezoidal waves, exponentially-decaying waves, combinations thereof, etc. Suitable numbers of pulses include, for example, at least one pulse. Suitable pulse intervals include, for example, intervals less than about 10 seconds. Any combination of these parameters may be utilized as desired. These parameters are provided for the sake of illustration and should in no way be considered limiting. Additional and alternative waveform parameters will be apparent. [0036] Several embodiments are directed to percutaneous intravascular systems for providing long-lasting denervation to minimize acute myocardial infarct (“AMI”) expansion and for helping to prevent the onset of morphological changes that are affiliated with congestive heart failure. For example, one embodiment of the invention comprises treating a patient for an infarction, e.g., via coronary angioplasty and/or stenting, and performing an intra-arterial pulsed electric field renal denervation procedure under fluoroscopic guidance. Alternatively, PEF therapy could be delivered in a separate session soon after the AMI had been stabilized. Renal neuromodulation also may be used as an adjunctive therapy to renal surgical procedures. In these embodiments, the anticipated increase in urine output and/or control of blood pressure provided by the renal PEF therapy is expected to reduce the load on the heart to inhibit expansion of the infarct and prevent CHF. [0037] Several embodiments of intravascular pulsed electric field systems described herein may denervate or reduce the activity of the renal nervous supply immediately post-infarct, or at any time thereafter, without leaving behind a permanent implant in the patient. These embodiments are expected to increase urine output and/or control blood pressure for a period of several months during which the patient's heart can heal. If it is determined that repeat and/or chronic neuromodulation would be beneficial after this period of healing, renal PEF treatment can be repeated as needed. [0038] In addition to efficaciously treating AMI, several embodiments of systems described herein are also expected to treat CHF, hypertension, renal failure, and other renal or cardio-renal diseases influenced or affected by increased renal sympathetic nervous activity. For example, the systems may be used to treat CHF at any time by advancing the PEF system to a treatment site via a vascular structure and then delivering a PEF therapy to the treatment site. This may, for example, modify a level of fluid offload. [0039] Embodiments of intravascular PEF systems described herein may be used similarly to angioplasty or electrophysiology catheters which are well known in the art. For example, arterial access may be gained through a standard Seldinger Technique, and an arterial sheath optionally may be placed to provide catheter access. A guidewire may be advanced through the vasculature and into the renal artery of the patient, and then an intravascular PEF may be advanced over the guidewire and/or through the sheath into the renal artery. The sheath optionally may be placed before inserting the PEF catheter or advanced along with the PEF catheter such that the sheath partially or completely covers the catheter. Alternatively, the PEF catheter may be advanced directly through the vasculature without the use of a guide wire and/or introduced and advanced into the vasculature without a sheath. [0040] In addition to arterial placement, the PEF system may be placed within a vein. Venous access may, for example, be achieved via a jugular approach. PEF systems may be utilized, for example, within the renal artery, within the renal vein or within both the renal artery and the renal vein to facilitate more complete denervation. [0041] After the PEF catheter is positioned within the vessel at a desired location with respect to the target neurons, it is stabilized within the vessel (e.g., braced against the vessel wall) and energy is delivered to the target nerve or neurons. In one variation, pulsed RF energy is delivered to the target to create a non-thermal nerve block, reduce neural signaling, or otherwise modulate neural activity. Alternatively or additionally, cooling, cryogenic, thermal RF, thermal or non-thermal microwave, focused or unfocused ultrasound, thermal or non-thermal DC, as well as any combination thereof, may be employed to reduce or otherwise control neural signaling. [0042] In still other embodiments of the invention, other non-renal neural structures may be targeted from within arterial or venous conduits in addition to or in lieu of renal neural structures. For instance, a PEF catheter can be navigated through the aorta or the vena cava and brought into apposition with various neural structures to treat other conditions or augment the treatment of renal-cardiac conditions. For example, nerve bodies of the lumbar sympathetic chain may be accessed and modulated, blocked or ablated, etc., in this manner. [0043] Several embodiments of the PEF systems may completely block or denervate the target neural structures, or the PEF systems may otherwise modulate the renal nervous activity. As opposed to a full neural blockade such as denervation, other neuromodulation produces a less-than-complete change in the level of renal nervous activity between the kidney(s) and the rest of the body. Accordingly, varying the pulsed electric field parameters will produce different effects on the nervous activity. [0044] In one embodiment of an intravascular pulsed electric field system, the device includes one or more electrodes that are configured to physically contact a target region of a renal vasculature for delivery of a pulsed electric field. For example, the device can comprise a catheter having an expandable helical section and one or more electrodes at the helical section. The catheter may be positioned in the renal vasculature while in a low profile configuration. The expandable section can then be expanded to contact the inner surface of the vessel wall. Alternatively, the catheter can have one or more expandable helical electrodes. For example, first and second expandable electrodes may be positioned within the vessel at a desired distance from one another to provide an active electrode and a return electrode. The expandable electrodes may comprise shape-memory materials, inflatable balloons, expandable meshes, linkage systems and other types of devices that can expand in a controlled manner. Suitable expandable linkage systems include expandable baskets, having a plurality of shape-memory wires or slotted hypotubes, and/or expandable rings. Additionally, the expandable electrodes may be point contact electrodes arranged along a balloon portion of a catheter. [0045] Other embodiments of pulsed electric field systems include electrodes that do not physically contact the vessel wall. RF energy, both traditional thermal energy and relatively non-thermal pulsed RF, are examples of pulsed electric fields that can be conducted into tissue to be treated from a short distance away from the tissue itself. Other types of pulsed electric fields can also be used in situations in which the electrodes do not physically contact the vessel wall. As such, the pulsed electric fields can be applied directly to the nerve via physical contact between the electrode contacts and the vessel wall or other tissue, or the pulsed electric fields can be applied indirectly to the nerve without physically contacting the electrode contacts with the vessel wall. The term “nerve contact” accordingly includes physical contact of a system element with the nerve and/or tissue proximate to the nerve, and also electrical contact alone without physically contacting the nerve or tissue. To indirectly apply the pulsed electrical field, the device has a centering element configured to position the electrodes in a central region of the vessel or otherwise space the electrodes apart from the vessel wall. The centering element may comprise, for example, a balloon or an expandable basket. One or more electrodes may be positioned on a central shaft of the centering element—either longitudinally aligned with the element or positioned on either side of the element. When utilizing a balloon catheter, the inflated balloon may act as an insulator of increased impedance for orienting or directing a pulsed electric field along a desired electric flow path. As will be apparent, alternative insulators may be utilized. [0046] In another embodiment of the system, a combination apparatus includes an intravascular catheter having a first electrode configured to physically contact the vessel wall and a second electrode configured to be positioned within the vessel but spaced apart from the vessel wall. For example, an expandable helical electrode may be used in combination with a centrally-disposed electrode to provide such a bipolar electrode pair. [0047] In yet another embodiment, a radial position of one or more electrodes relative to a vessel wall may be altered dynamically to focus the pulsed electric field delivered by the electrode(s). In still another variation, the electrodes may be configured for partial or complete passage across the vessel wall. For example, the electrode(s) may be positioned within the renal vein, then passed across the wall of the renal vein into the perivascular space such that they at least partially encircle the renal artery and/or vein prior to delivery of a pulsed electric field. [0048] Bipolar embodiments of the present invention may be configured for dynamic movement or operation relative to a spacing between the active and ground electrodes to achieve treatment over a desired distance, volume or other dimension. For example, a plurality of electrodes may be arranged such that a bipolar pair of electrodes can move longitudinally relative to each other for adjusting the separation distance between the electrodes and/or for altering the location of treatment. One specific embodiment includes a first electrode coupled to a catheter and a moveable second electrode that can move through a lumen of the catheter. In alternative embodiments, a first electrode can be attached to a catheter and a second electrode can be attached to an endoluminally-delivered device such that the first and second electrodes may be repositioned relative to one another to alter a separation distance between the electrodes. Such embodiments may facilitate treatment of a variety of renal vasculature anatomies. [0049] Any of the embodiments of the present invention described herein optionally may be configured for infusing agents into the treatment area before, during or after energy application. The infused agents can be selected to enhance or modify the neuromodulatory effect of the energy application. The agents can also protect or temporarily displace non-target cells, and/or facilitate visualization. [0050] Several embodiments of the present invention may comprise detectors or other elements that facilitate identification of locations for treatment and/or that measure or confirm the success of treatment. For example, the system can be configured to also deliver stimulation waveforms and monitor physiological parameters known to respond to stimulation of the renal nerves. Based on the results of the monitored parameters, the system can determine the location of renal nerves and/or whether denervation has occurred. Detectors for monitoring of such physiological responses include, for example, Doppler elements, thermocouples, pressure sensors, and imaging modalities (e.g., fluoroscopy, intravascular ultrasound, etc.). Alternatively, electroporation may be monitored directly using, for example, Electrical Impedance Tomography (“EIT”) or other electrical impedance measurements. Additional monitoring techniques and elements will be apparent. Such detector(s) may be integrated with the PEF systems or they may be separate elements. [0051] Still other specific embodiments include electrodes configured to align the electric field with the longer dimension of the target cells. For instance, nerve cells tend to be elongate structures with lengths that greatly exceed their lateral dimensions (e.g., diameter). By aligning an electric field so that the directionality of field propagation preferentially affects the longitudinal aspect of the cell rather than the lateral aspect of the cell, it is expected that lower field strengths can to be used to kill or disable target cells. This is expected to conserve the battery life of implantable devices, reduce collateral effects on adjacent structures, and otherwise enhance the ability to modulate the neural activity of target cells. [0052] Other embodiments of the invention are directed to applications in which the longitudinal dimensions of cells in tissues overlying or underlying the nerve are transverse (e.g., orthogonal or otherwise at an angle) with respect to the longitudinal direction of the nerve cells. Another aspect of these embodiments is to align the directionality of the PEF such that the field aligns with the longer dimensions of the target cells and the shorter dimensions of the non-target cells. More specifically, arterial smooth muscle cells are typically elongate cells which surround the arterial circumference in a generally spiraling orientation so that their longer dimensions are circumferential rather than running longitudinally along the artery. Nerves of the renal plexus, on the other hand, run along the outside of the artery generally in the longitudinal direction of the artery. Therefore, applying a PEF which is generally aligned with the longitudinal direction of the artery is expected to preferentially cause electroporation in the target nerve cells without affecting at least some of the non-target arterial smooth muscle cells to the same degree. This may enable preferential denervation of nerve cells (target cells) in the adventitia or periarterial region from an intravascular device without affecting the smooth muscle cells of the vessel to an undesirable extent. BRIEF DESCRIPTION OF THE DRAWINGS [0053] Several embodiments of the present invention will be apparent upon consideration of the following detailed description, taken in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout, and in which: [0054] FIG. 1 is a schematic view illustrating human renal anatomy. [0055] FIG. 2 is a schematic detail view showing the location of the renal nerves relative to the renal artery. [0056] FIGS. 3A and 3B are schematic side- and end-views, respectively, illustrating a direction of electrical current flow for selectively affecting renal nerves. [0057] FIG. 4 is a schematic side-view, partially in section, of an intravascular catheter having a plurality of electrodes in accordance with one embodiment of the invention. [0058] FIG. 5 is a schematic side-view, partially in section, of an intravascular device having a pair of expanding helical electrodes arranged at a desired distance from one another in accordance with another embodiment of the invention. [0059] FIG. 6 is a schematic side-view, partially in section, of an intravascular device having a first electrode on an expandable balloon, and a second electrode on a catheter shaft in accordance with another embodiment of the invention. [0060] FIG. 7 is a schematic side-view, partially in section, of an intravascular device having an expanding first electrode delivered through the lumen of a catheter and a complementary second electrode carried by the catheter in accordance with another embodiment of the invention. [0061] FIG. 8 is a schematic side-view, partially in section, of an intravascular device having an expandable basket and a plurality of electrodes at the basket in accordance with another embodiment of the invention. [0062] FIG. 9 is a schematic detail view of the apparatus of FIG. 8 illustrating one embodiment of the electrodes in accordance with another embodiment of the invention. [0063] FIG. 10 is a schematic side-view, partially in section, of an intravascular device having expandable ring electrodes for contacting the vessel wall and an optional insulation element in accordance with another embodiment of the invention. [0064] FIGS. 11A-11C are schematic detail views of embodiments of different windings for the ring electrodes of FIG. 10 . [0065] FIG. 12 is a schematic side-view, partially in section, of an intravascular device having ring electrodes of FIG. 10 with the windings shown in FIGS. 11A-11C . [0066] FIG. 13 is a schematic side-view, partially in section, of an intravascular device having a ring electrode and a luminally-delivered electrode in accordance with another embodiment of the invention. [0067] FIG. 14 is a schematic side-view, partially in section, of an intravascular device having a balloon catheter and expandable point contact electrodes arranged proximally and distally of the balloon in accordance with another embodiment of the invention. [0068] FIG. 15 is a schematic side-view of an intravascular device having a balloon catheter and electrodes arranged proximally and distally of the balloon in accordance with another embodiment of the invention. [0069] FIGS. 16A and 16B are schematic side-views, partially in section, illustrating stages of a method of using the apparatus of FIG. 15 in accordance with an embodiment of the invention. [0070] FIG. 17 is a schematic side-view of an intravascular device having a balloon catheter and a plurality of dynamically operable electrodes in accordance with another embodiment of the invention. [0071] FIG. 18 is a schematic side-view of an intravascular device having a distal electrode deployed through a lumen of the balloon catheter in accordance with another embodiment of the invention. [0072] FIGS. 19A and 19B are side-views, partially in section, illustrating methods of using the intravascular device shown in FIG. 18 to modulate renal neural activity in patients with various renal vasculatures. [0073] FIG. 20 is a side view, partially in section, illustrating an intravascular device having a plurality of electrodes arranged along the shaft of, and in line with, a centering element in accordance with another embodiment of the invention. [0074] FIG. 21 is a side-view, partially in section, illustrating an intravascular device having electrodes configured for dynamic radial repositioning to facilitate focusing of a pulsed electric field in accordance with another embodiment of the invention. [0075] FIG. 22 is a side-view, partially in section, of an intravascular device having an infusion/aspiration catheter in accordance with another embodiment of the invention. [0076] FIGS. 23A-23C are, respectively, a side-view, partially in section, and cross-sectional views along section line A-A of FIG. 23A , illustrating a method of using an intravascular device in accordance with an embodiment of the invention configured for passage of electrode(s) at least partially across the vessel wall. [0077] FIGS. 24A and 24B are side-views, partially in section, illustrating an intravascular device having detectors for measuring or monitoring treatment efficacy in accordance with another embodiment of the invention. DETAILED DESCRIPTION A. Overview [0078] The present invention relates to methods and apparatus for renal neuromodulation and/or other neuromodulation. More particularly, the present invention relates to methods and apparatus for renal neuromodulation using a pulsed electric field to effectuate electroporation or electrofusion. As used herein, electroporation and electropermeabilization are methods of manipulating the cell membrane or intracellular apparatus. For example, short high-energy pulses cause pores to open in cell membranes. The extent of porosity in the cell membrane (e.g., size and number of pores) and the duration of the pores (e.g., temporary or permanent) are a function of the field strength, pulse width, duty cycle, field orientation, cell type and other parameters. In general, pores will generally close spontaneously upon termination of lower strength fields or shorter pulse widths (herein defined as “reversible electroporation”). Each cell type has a critical threshold above which pores do not close such that pore formation is no longer reversible; this result is defined as “irreversible electroporation,” “irreversible breakdown” or “irreversible damage.” At this point, the cell membrane ruptures and/or irreversible chemical imbalances caused by the high porosity occur. Such high porosity can be the result of a single large hole and/or a plurality of smaller holes. Certain types of electroporation energy parameters also appropriate for use in renal neuromodulation are high voltage pulses with a duration in the sub-microsecond range (nanosecond pulsed electric fields, or nsPEF) which may leave the cellular membrane intact, but alter the intracellular apparatus or function of the cell in ways which cause cell death or disruption. Certain applications of nsPEF have been shown to cause cell death by inducing apoptosis, or programmed cell death, rather than acute cell death. Also, the term “comprising” is used throughout to mean including at least the recited feature such that any greater number of the same feature and/or additional types features are not precluded. [0079] Several embodiments of the present invention provide intravascular devices for inducing renal neuromodulation, such as a temporary change in target nerves that dissipates over time, continuous control over neural function, and/or denervation. The apparatus and methods described herein may utilize any suitable electrical signal or field parameters, e.g., any electric field, that will achieve the desired neuromodulation (e.g., electroporative effect). To better understand the structures of the intravascular devices and the methods of using these devices for neuromodulation, it is useful to understand the renal anatomy in humans. B. Selected Embodiments of Methods for Neuromodulation [0080] With reference now to FIG. 1 , the human renal anatomy includes kidneys K that are supplied with oxygenated blood by renal arteries RA, which are connected to the heart by the abdominal aorta AA. Deoxygenated blood flows from the kidneys to the heart via renal veins RV and the inferior vena cava IVC. FIG. 2 illustrates a portion of the renal anatomy in greater detail. More specifically, the renal anatomy also includes renal nerves RN extending longitudinally along the lengthwise dimension L of renal artery RA generally within the adventitia of the artery. The renal artery RA has smooth muscle cells SMC that surround the arterial circumference spiral around the angular axis θ of the artery, i.e., around the circumference of the artery. The smooth muscle cells of the renal artery accordingly have a lengthwise or longer dimension extending transverse (i.e., non-parallel) to the lengthwise dimension of the renal artery. The misalignment of the lengthwise dimensions of the renal nerves and the smooth muscle cells is defined as “cellular misalignment.” [0081] Referring to FIGS. 3A and 3B , the cellular misalignment of the renal nerves and the smooth muscle cells may be exploited to selectively affect renal nerve cells with reduced effect on smooth muscle cells. More specifically, because larger cells require less energy to exceed the irreversibility threshold of electroporation, several embodiments of electrodes of the present invention are configured to align at least a portion of an electric field generated by the electrodes with or near the longer dimensions of the cells to be affected. In specific embodiments, the intravascular device has electrodes configured to create an electrical field aligned with or near the lengthwise dimension of the renal artery RA to affect renal nerves RN. By aligning an electric field so that the field preferentially affects the lengthwise aspect of the cell rather than the diametric or radial aspect of the cell, lower field strengths may be used to necrose cells. As mentioned above, this is expected to reduce power consumption and mitigate effects on non-target cells in the electric field. [0082] Similarly, the lengthwise or longer dimensions of tissues overlying or underlying the target nerve are orthogonal or otherwise off-axis (e.g., transverse) with respect to the longer dimensions of the nerve cells. Thus, in addition to aligning the PEF with the lengthwise or longer dimensions of the target cells, the PEF may propagate along the lateral or shorter dimensions of the non-target cells (i.e. such that the PEF propagates at least partially out of alignment with non-target smooth muscle cells SMC). Therefore, as seen in FIGS. 3A and 3B , applying a PEF with propagation lines Li generally aligned with the longitudinal dimension L of the renal artery RA is expected to preferentially cause electroporation, electrofusion, denervation or other neuromodulation in cells of the target renal nerves RN without unduly affecting the non-target arterial smooth muscle cells SMC. The pulsed electric field may propagate in a single plane along the longitudinal axis of the renal artery, or may propagate in the longitudinal direction along any angular segment θ through a range of 0°-360°. [0083] Embodiments of the method shown in FIGS. 3A and 3B may have particular application with the intravascular methods and apparatus of the present invention. For instance, a PEF catheter placed within the renal artery may propagate an electric field having a longitudinal portion that is aligned to run with the longitudinal dimension of the artery in the region of the renal nerves RN and the smooth muscle cell SMC of the vessel wall so that the wall of the artery remains at least substantially intact while the outer nerve cells are destroyed. C. Embodiments of Systems and Additional Methods for Neuromodulation [0084] FIG. 4 shows one embodiment of an intravascular pulsed electric field apparatus 200 in accordance with the present invention that includes one or more electrodes configured to physically contact a target region within the renal vasculature and deliver a pulsed electric field across a wall of the vasculature. The apparatus 200 is shown within a patient's renal artery RA, but it can be positioned in other intravascular locations (e.g., the renal vein). This embodiment of the apparatus 200 comprises an intravascular catheter 210 having a proximal section 211 a, a distal section 211 b, and a plurality of distal electrodes 212 at the distal section 211 b. The proximal section 211 a generally has an electrical connector to couple the catheter 210 to a pulse generator, and the distal section 211 b in this embodiment has a helical configuration. The apparatus 200 is electrically coupled to a pulsed electric field generator 100 located proximal and external to the patient; the electrodes 212 are electrically coupled to the generator via catheter 210 . The generator 100 may be utilized with any embodiment of the present invention described hereinafter for delivery of a PEF with desired field parameters. It should be understood that electrodes of embodiments described hereinafter may be connected to the generator, even if the generator is not explicitly shown or described with each variation. [0085] The helical distal section 211 b of catheter 210 is configured to appose the vessel wall and bring electrodes 212 into close proximity to extra-vascular neural structures. The pitch of the helix can be varied to provide a longer treatment zone, or to minimize circumferential overlap of adjacent treatments zones in order to reduce a risk of stenosis formation. This pitch change can be achieved by combining a plurality of catheters of different pitches to form catheter 210 , or by adjusting the pitch of catheter 210 through the use of internal pull wires, adjusting mandrels inserted into the catheter, shaping sheaths placed over the catheter, or by any other suitable means for changing the pitch either in-situ or before introduction into the body. [0086] The electrodes 212 along the length of the pitch can be individual electrodes, a common but segmented electrode, or a common and continuous electrode. A common and continuous electrode may, for example, comprise a conductive coil formed into or placed over the helical portion of catheter 210 . A common but segmented electrode may, for example, be formed by providing a slotted tube fitted onto or into the helical portion of the catheter, or by electrically connecting a series of individual electrodes. [0087] Individual electrodes or groups of electrodes 212 may be configured to provide a bipolar signal, or all or a subset of the electrodes may be used together in conjunction with a separate external patient ground for monopolar use (the ground pad may, for example, be placed on the patient's leg). Electrodes 212 may be dynamically assignable to facilitate monopolar and/or bipolar energy delivery between any of the electrodes and/or between any of the electrodes and an external ground. [0088] Catheter 210 may be delivered to renal artery RA in a low profile delivery configuration within sheath 150 . Once positioned within the artery, the catheter may self-expand or may be expanded actively, e.g., via a pull wire or a balloon, into contact with an interior wall of the artery. A pulsed electric field then may be generated by the PEF generator 100 , transferred through catheter 210 to electrodes 212 , and delivered via the electrodes 212 across the wall of the artery. In many applications, the electrodes are arranged so that the pulsed electric field is aligned with the longitudinal dimension of the artery to modulate the neural activity along the renal nerves (e.g., denervation). This may be achieved, for example, via irreversible electroporation, electrofusion and/or inducement of apoptosis in the nerve cells. [0089] FIG. 5 illustrates an apparatus 220 for neural modulation in accordance with another embodiment of the invention. The apparatus 220 includes a pair of catheters 222 a and 222 b having expandable distal sections 223 a and 223 b with helical electrodes 224 a and 224 b, respectively. The helical electrodes 224 a and 224 b are spaced apart from each other by a desired distance within a patient's renal vasculature. Electrodes 224 a - b may be actuated in a bipolar fashion such that one electrode is an active electrode and the other is a return electrode. The distance between the electrodes may be altered as desired to change the field strength and/or the length of nerve segment modulated by the electrodes. The expandable helical electrodes may comprise shape-memory properties that facilitate self-expansion, e.g., after passage through sheath 150 , or the electrodes may be actively expanded into contact with the vessel wall, e.g., via an inflatable balloon or via pull wires, etc. The catheters 222 a - b preferably are electrically insulated in areas other than the distal helices of electrodes 224 a - b. [0090] FIG. 6 illustrates an apparatus 230 comprising a balloon catheter 232 having expandable balloon 234 , a helical electrode 236 arranged about the balloon 234 , and a shaft electrode 238 on the shaft of catheter 232 . The shaft electrode 238 can be located proximal of expandable balloon 234 as shown, or the shaft electrode 238 can be located distal of the expandable balloon 234 . [0091] When the apparatus 230 is delivered to a target vessel, e.g., within renal artery RA, the expandable balloon 234 and the helical electrode 236 are arranged in a low profile delivery configuration. As seen in FIG. 6 , once the apparatus has been positioned as desired, expandable balloon 234 may be inflated to drive the helical electrode 236 into physical contact with the wall of the vessel. In this embodiment, the shaft electrode 238 does not physically contact the vessel wall. [0092] It is well known in the art of both traditional thermal RF energy delivery and of relatively non-thermal pulsed RF energy delivery that energy may be conducted to tissue to be treated from a short distance away from the tissue itself. Thus, it may be appreciated that “nerve contact” comprises both physical contact of a system element with a nerve, as well as electrical contact alone without physical contact, or a combination of the two. A centering element optionally may be provided to place electrodes in a central region of the vessel. The centering element may comprise, for example, an expandable balloon, such as balloon 234 of apparatus 230 , or an expandable basket as described hereinafter. One or more electrodes may be positioned on a central shaft of the centering element—either longitudinally aligned with the element or positioned on one or both sides of the element—as is shaft electrode 238 of apparatus 230 . When utilizing a balloon catheter such as catheter 232 , the inflated balloon may act as an insulator of increased impedance for directing a pulsed electric field along a desired electric flow path. As will be apparent, alternative insulators may be utilized. [0093] As seen in FIG. 6 , when the helical electrode 236 physically contacts the wall of renal artery RA, the generator 100 may generate a PEF such that current passes between the helical electrode 236 and the shaft electrode 238 in a bipolar fashion. The PEF travels between the electrodes along lines Li that generally extend along the longitudinal dimension of the artery. The balloon 234 locally insulates and/or increases the impedance within the patient's vessel such that the PEF travels through the wall of the vessel between the helical and shaft electrodes. This focuses the energy to enhance denervation and/or other neuromodulation of the patient's renal nerves, e.g., via irreversible electroporation. [0094] FIG. 7 illustrates an apparatus 240 similar to those shown in FIGS. 4-6 in accordance with another embodiment of the invention. The apparatus 240 comprises a balloon catheter 242 having an expandable balloon 244 and a shaft electrode 246 located proximal of the expandable balloon 244 . The apparatus 240 further comprises an expandable helical electrode 248 configured for delivery through a guidewire lumen 243 of the catheter 242 . The helical electrode 248 shown in FIG. 7 is self-expanding. [0095] As seen in FIG. 7 , after positioning the catheter 242 in a target vessel (e.g. renal artery RA), the balloon 244 is inflated until it contacts the wall of the vessel to hold the shaft electrode 246 at a desired location within the vessel and to insulate or increase the impedance of the interior of the vessel. The balloon 244 is generally configured to also center the shaft electrode 246 within the vessel or otherwise space the shaft electrode apart from the vessel wall by a desired distance. After inflating the balloon 244 , the helical electrode 248 is pushed through lumen 243 until the helical electrode 248 extends beyond the catheter shaft; the electrode 248 then expands or otherwise moves into the helical configuration to physically contact the vessel wall. A bipolar pulsed electric field may then be delivered between the helical electrode 248 and the shaft electrode 246 along lines Li. For example, the helical electrode 248 may comprise the active electrode and the shaft electrode 246 may comprise the return electrode, or vice versa. [0096] With reference now to FIG. 8 , apparatus comprising an expandable basket having a plurality of electrodes that may be expanded into contact with the vessel wall is described. Apparatus 250 comprises catheter 252 having expandable distal basket 254 formed from a plurality of circumferential struts or members. A plurality of electrodes 256 are formed along the members of basket 254 . Each member of the basket illustratively comprises a bipolar electrode pair configured to contact a wall of renal artery RA or another desired blood vessel. [0097] Basket 254 may be fabricated, for example, from a plurality of shape-memory wires or ribbons, such as Nitinol, spring steel or elgiloy wires or ribbons, that form basket members 253 . When the basket members comprise ribbons, the ribbons may be moved such that a surface area contacting the vessel wall is increased. Basket members 253 are coupled to catheter 252 at proximal and distal connections 255 a and 255 b, respectively. In such a configuration, the basket may be collapsed for delivery within sheath 150 , and may self-expand into contact with the wall of the artery upon removal from the sheath. Proximal and/or distal connection 255 a and 255 b optionally may be configured to translate along the shaft of catheter 252 for a specified or unspecified distance in order to facilitate expansion and collapse of the basket. [0098] Basket 254 alternatively may be formed from a slotted and/or laser-cut hypotube. In such a configuration, catheter 252 may, for example, comprise inner and outer shafts that are moveable relative to one another. Distal connection 255 b of basket 254 may be coupled to the inner shaft and proximal connection 255 a of the basket may be coupled to the outer shaft. Basket 254 may be expanded from a collapsed delivery configuration to the deployed configuration of FIG. 8 by approximating the inner and outer shafts of catheter 252 , thereby approximating the proximal and distal connections 255 a and 255 b of the basket and expanding the basket. Likewise, the basket may be collapsed by separating the inner and outer shafts of the catheter. [0099] As seen in FIG. 9 , individual electrodes may be arranged along a basket strut or member 253 . In one embodiment, the strut is formed from a conductive material coated with a dielectric material, and the electrodes 256 may be formed by removing regions of the dielectric coating. The insulation optionally may be removed only along a radially outer surface of the member such that electrodes 256 remain insulated on their radially interior surfaces; it is expected that this will direct the current flow outward into the vessel wall. [0100] In addition, or as an alternative, to the fabrication technique of FIG. 9 , the electrodes may be affixed to the inside surface, outside surface or embedded within the struts or members of basket 254 . The electrodes placed along each strut or member may comprise individual electrodes, a common but segmented electrode, or a common and continuous electrode. Individual electrodes or groups of electrodes may be configured to provide a bipolar signal, or all or a subset of the electrodes may be actuated together in conjunction with an external patient ground for monopolar use. [0101] One advantage of having electrodes 256 contact the vessel wall as shown in the embodiment of FIG. 8 is that it may reduce the need for an insulating element, such as an expandable balloon, to achieve renal denervation or other neuromodulation. However, it should be understood that such an insulating element may be provided and, for example, expanded within the basket. Furthermore, having the electrodes contact the wall may provide improved field geometry, i.e., may provide an electric field more aligned with the longitudinal axis of the vessel. Such contacting electrodes also may facilitate stimulation of the renal nerves before, during or after neuromodulation to better position the catheter 252 before treatment or for monitoring the effectiveness of treatment. [0102] In a variation of apparatus 250 , electrodes 256 may be disposed along the central shaft of catheter 252 , and basket 254 may simply center the electrodes within the vessel to facilitate more precise delivery of energy across the vessel wall. This configuration may be well suited to precise targeting of vascular or extra-vascular tissue, such as the renal nerves surrounding the renal artery. Correctly sizing the basket or other centering element to the artery provides a known distance between the centered electrodes and the arterial wall that may be utilized to direct and/or focus the electric field as desired. This configuration may be utilized in high-intensity focused ultrasound or microwave applications, but also may be adapted for use with any other energy modality as desired. [0103] Referring now to FIG. 10 , it is expected that electrodes forming a circumferential contact with the wall of the renal artery may provide for more complete renal denervation or renal neuromodulation. In FIG. 10 , a variation of the present invention comprising ring electrodes is described. Apparatus 260 comprises catheter 262 having expandable ring electrodes 264 a and 264 b configured to contact the wall of the vessel. The electrodes may be attached to the shaft of catheter 262 via struts 266 , and catheter 262 may be configured for delivery to renal artery RA through sheath 150 in a low profile configuration. Struts 266 may be self-expanding or may be actively or mechanically expanded. Catheter 262 comprises guidewire lumen 263 for advancement over a guidewire. Catheter 262 also comprises optional inflatable balloon 268 that may act as an insulating element of increased impedance for preferentially directing current flow that is traveling between electrodes 264 a and 264 b across the wall of the artery. [0104] FIGS. 11A-11C illustrate various embodiments of windings for ring electrodes 264 . As shown, the ring electrodes may, for example, be wound in a coil ( FIG. 11A ), a zigzag ( FIG. 11B ) or a serpentine configuration ( FIG. 11C ). The periodicity of the winding may be specified, as desired. Furthermore, the type of winding, the periodicity, etc., may vary along the circumference of the electrodes. [0105] With reference to FIG. 12 , a variation of apparatus 260 is described comprising ring electrodes 264 a ′ and 264 b ′ having a sinusoidal winding in one embodiment of the serpentine winding shown in FIG. 11C . Struts 266 illustratively are attached to apexes of the sinusoid. The winding of electrodes 264 a ′ and 264 b ′ may provide for greater contact area along the vessel wall than do electrodes 264 a and 264 b, while still facilitating sheathing of apparatus 260 within sheath 150 for delivery and retrieval. [0106] FIG. 13 illustrates another variation of apparatus 260 comprising a proximal ring electrode 264 a, and further comprising a distal electrode 270 delivered through guidewire lumen 263 of catheter 262 . The distal electrode 270 is non-expanding and is centered within the vessel via catheter 262 . The distal electrode 270 may be a standard guide wire which is connected to the pulsed electric field generator and used as an electrode. However, it should be understood that electrode 270 alternatively may be configured for expansion into contact with the vessel wall, e.g., may comprise a ring or helical electrode. [0107] Delivering the distal electrode through the lumen of catheter 262 may reduce a delivery profile of apparatus 260 and/or may improve flexibility of the device. Furthermore, delivery of the distal electrode through the guidewire lumen may serve as a safety feature that ensures that the medical practitioner removes any guidewire disposed within lumen 263 prior to delivery of a PEF. It also allows for customization of treatment length, as well as for treatment in side branches, as described hereinafter. [0108] Ring electrodes 264 a and 264 b and 264 a ′ and 264 b ′ optionally may be electrically insulated along their radially inner surfaces, while their radially outer surfaces that contact the vessel wall are exposed. This may reduce a risk of thrombus formation and also may improve or enhance the directionality of the electric field along the longitudinal axis of the vessel. This also may facilitate a reduction of field voltage necessary to disrupt neural fibers. Materials utilized to at least partially insulate he ring electrodes may comprise, for example, PTFE, ePTFE, FEP, chronoprene, silicone, urethane, Pebax, etc. With reference to FIG. 14 , another variation of apparatus 260 is described, wherein the ring electrodes have been replaced with point electrodes 272 disposed at the ends of struts 266 . The point electrodes may be collapsed with struts 266 for delivery through sheath 150 and may self-expand with the struts into contact with the vessel wall. In FIG. 14 , catheter 262 illustratively comprises four point electrodes 272 on either side of balloon 268 . However, it should be understood that any desired number of struts and point electrodes may be provided around the circumference of catheter 262 . [0109] In FIG. 14 , apparatus 260 illustratively comprises four struts 266 and four point electrodes 272 on either side of balloon 268 . By utilizing all of the distally disposed electrodes 272 b as active electrodes and all proximal electrodes 272 a as return electrodes, or vice versa, lines Li along which the electric field propagates may be aligned with the longitudinal axis of a vessel. A degree of line Li overlap along the rotational axis of the vessel may be specified by specifying the angular placement and density of point electrodes 272 about the circumference of the catheter, as well as by specifying parameters of the PEF. [0110] With reference now to FIG. 15 , another variation of an intravascular PEF catheter is described. Apparatus 280 comprises catheter 282 having optional inflatable balloon or centering element 284 , shaft electrodes 286 a and 286 b disposed along the shaft of the catheter on either side of the balloon, as well as optional radiopaque markers 288 disposed along the shaft of the catheter, illustratively in line with the balloon. Balloon 284 serves as both a centering element for electrodes 286 and as an electrical insulator for directing the electric field, as described previously. [0111] Apparatus 280 may be particularly well-suited for achieving precise targeting of desired arterial or extra-arterial tissue, since properly sizing balloon 284 to the target artery sets a known distance between centered electrodes 286 and the arterial wall that may be utilized when specifying parameters of the PEF. Electrodes 286 alternatively may be attached to balloon 284 rather than to the central shaft of catheter 282 such that they contact the wall of the artery. In such a variation, the electrodes may be affixed to the inside surface, outside surface or embedded within the wall of the balloon. [0112] Electrodes 286 arranged along the length of catheter 282 can be individual electrodes, a common but segmented electrode, or a common and continuous electrode. Furthermore, electrodes 286 may be configured to provide a bipolar signal, or electrodes 286 may be used together or individually in conjunction with a separate patient ground for monopolar use. [0113] Referring now to FIGS. 16A and 16B , a method of using apparatus 280 to achieve renal denervation is described. As seen in FIG. 16A , catheter 282 may be disposed at a desired location within renal artery RA, balloon or centering element 284 may be expanded to center electrodes 286 a and 286 b and to optionally provide electrical insulation, and a PEF may be delivered, e.g., in a bipolar fashion between the proximal and distal electrodes 286 a and 286 b. It is expected that the PEF will achieve renal denervation and/or neuromodulation along treatment zone one T 1 . If it is desired to modulate neural activity in other parts of the renal artery, balloon 284 may be at least partially deflated, and the catheter may be positioned at a second desired treatment zone T 2 , as in FIG. 16B . The medical practitioner optionally may utilize fluoroscopic imaging of radiopaque markers 288 to orient catheter 282 at desired locations for treatment. For example, the medical practitioner may use the markers to ensure a region of overlap O between treatment zones T 1 and T 2 , as shown. [0114] With reference to FIG. 17 , a variation of apparatus 280 is described comprising a plurality of dynamically controllable electrodes 286 a and 286 b disposed on the proximal side of balloon 284 . In one variation, any one of proximal electrodes 286 a may be energized in a bipolar fashion with distal electrode 286 b to provide dynamic control of the longitudinal distance between the active and return electrodes. This alters the size and shape of the zone of treatment. In another variation, any subset of proximal electrodes 286 a may be energized together as the active or return electrodes of a bipolar electric field established between the proximal electrodes and distal electrode 286 b. [0115] Although the apparatus 280 shown in FIG. 17 has three proximal electrodes 286 a 1 , 286 a 2 and 286 a 3 , it should be understood that the apparatus 280 can have any alternative number of proximal electrodes. Furthermore, the apparatus 280 can have a plurality of distal electrodes 286 b in addition, or as an alternative, to multiple proximal electrodes. Additionally, one electrode of a pair may be coupled to the catheter 282 , and the other electrode may be delivered through a lumen of the catheter, e.g., through a guidewire lumen. The catheter and endoluminally-delivered electrode may be repositioned relative to one another to alter a separation distance between the electrodes. Such a variation also may facilitate treatment of a variety of renal vasculature anatomies. [0116] In the variations of apparatus 280 described thus far, distal electrode 286 b is coupled to the shaft of catheter 282 distal of balloon 284 . The distal electrode may utilize a lumen within catheter 282 , e.g., for routing of a lead wire that acts as ground. Additionally, the portion of catheter 282 distal of balloon 284 is long enough to accommodate the distal electrode. [0117] Catheters commonly are delivered over metallic and/or conductive guidewires. In many interventional therapies involving catheters, guidewires are not removed during treatment. As apparatus 280 is configured for delivery of a pulsed electric field, if the guidewire is not removed, there may be a risk of electric shock to anyone in contact with the guidewire during energy delivery. This risk may be reduced by using polymer-coated guidewires. [0118] With reference to FIG. 18 , another variation of apparatus 280 is described wherein distal electrode 286 b of FIGS. 16 and 17 has been replaced with a distal electrode 270 configured to be moved through a lumen of the catheter as described previously with respect to FIG. 13 . As will be apparent, proximal electrode 286 a alternatively may be replaced with the luminally-delivered electrode, such that electrodes 286 b and 270 form a bipolar electrode pair. Electrode 270 does not utilize an additional lumen within catheter 282 , which may reduce profile. Additionally, the length of the catheter distal of the balloon need not account for the length of the distal electrode, which may enhance flexibility. Furthermore, the guidewire must be exchanged for electrode 270 prior to treatment, which reduces a risk of inadvertent electrical shock. In one variation, electrode 270 optionally may be used as the guidewire over which catheter 282 is advanced into position prior to delivery of the PEF, thereby obviating a need for exchange of the guidewire for the electrode. Alternatively, a standard metallic guidewire may be used as the electrode 270 simply by connecting the standard guidewire to the pulsed electric field generator. The distal electrode 270 may be extended any desired distance beyond the distal end of catheter 282 . This may provide for dynamic alteration of the length of a treatment zone. Furthermore, this might facilitate treatment within distal vasculature of reduced diameter. [0119] With reference to FIGS. 19A and 19B , it might be desirable to perform treatments within one or more vascular branches that extend from a main vessel, for example, to perform treatments within the branches of the renal artery in the vicinity of the renal hilum. Furthermore, it might be desirable to perform treatments within abnormal or less common branchings of the renal vasculature, which are observed in a minority of patients. As seen in FIG. 19A , distal electrode 270 may be placed in such a branch of renal artery RA, while catheter 282 is positioned within the main branch of the artery. As seen in FIG. 19B , multiple distal electrodes 270 might be provided and placed in various common or uncommon branches of the renal artery, while the catheter remains in the main arterial branch. [0120] Referring to FIG. 20 , yet another variation of an intravascular PEF catheter is described. Apparatus 290 comprises catheter 292 having a plurality of shaft electrodes 294 disposed in line with centering element 296 . Centering element 296 illustratively comprises an expandable basket, such as previously described expandable basket 254 of FIG. 8 . However, it should be understood that the centering element alternatively may comprise a balloon or any other centering element. Electrodes 294 may be utilized in a bipolar or a monopolar fashion. [0121] Referring now to FIG. 21 , another variation of the invention is described comprising electrodes configured for dynamic radial repositioning of one or more of the electrodes relative to a vessel wall, thereby facilitating focusing of a pulsed electric field delivered by the electrodes. Apparatus 300 comprises catheter 302 having electrodes 304 disposed in line with nested expandable elements. The nested expandable elements comprise an inner expandable element 306 and an outer expandable centering element 308 . Electrodes 304 are disposed along the inner expandable element, while the outer expandable centering element is configured to center and stabilize catheter 302 within the vessel. Inner element 306 may be expanded to varying degrees, as desired by a medical practitioner, to dynamically alter the radial positions of electrodes 304 . This dynamic radial repositioning may be utilized to focus energy delivered by electrodes 304 such that it is delivered to target tissue. [0122] Nested elements 306 and 308 may comprise a balloon-in-balloon arrangement, a basket-in-basket arrangement, some combination of a balloon and a basket, or any other expandable nested structure. In FIG. 21 , inner expandable element 306 illustratively comprises an expandable basket, while outer expandable centering element 308 illustratively comprises an expandable balloon. Electrodes 302 are positioned along the surface of inner balloon 306 . [0123] Any of the variations of the present invention described herein optionally may be configured for infusion of agents into the treatment area before, during or after energy application, for example, to enhance or modify the neurodestructive or neuromodulatory effect of the energy, to protect or temporarily displace non-target cells, and/or to facilitate visualization. Additional applications for infused agents will be apparent. If desired, uptake of infused agents by cells may be enhanced via initiation of reversible electroporation in the cells in the presence of the infused agents. Infusion may be especially desirable when a balloon centering element is utilized. The infusate may comprise, for example, saline or heparinized saline, protective agents, such as Poloxamer- 188 , or anti-proliferative agents. Variations of the present invention additionally or alternatively may be configured for aspiration. For example, infusion ports or outlets may be provided on a catheter shaft adjacent a centering device, the centering device may be porous (for instance, a “weeping” balloon), or basket struts may be made of hollow hypotubes and slotted or perforated to allow infusion or aspiration. [0124] With reference to FIG. 22 , a variation of the present invention comprising an infusion/aspiration PEF catheter is described. Apparatus 310 comprises catheter 312 having proximal and distal inflatable balloons 314 a and 314 b, respectively. Proximal shaft electrode 316 a is disposed between the balloons along the shaft of catheter 312 , while distal electrode 316 b is disposed distal of the balloons along the catheter shaft. One or more infusion or aspiration holes 318 are disposed along the shaft of catheter 312 between the balloons in proximity to proximal electrode 316 a. [0125] Apparatus 310 may be used in a variety of ways. In a first method of use, catheter 312 is disposed within the target vessel, such as renal artery RA, at a desired location. One or both balloons 314 are inflated, and a protective agent or other infusate is infused through hole(s) 318 between the balloons in proximity to electrode 316 a. A PEF suitable for initiation of reversible electroporation is delivered across electrodes 316 to facilitate uptake of the infusate by non-target cells within the vessel wall. Delivery of the protective agent may be enhanced by first inflating distal balloon 314 b, then infusing the protective agent, which displaces blood, then inflating proximal balloon 314 a. [0126] Remaining infusate optionally may be aspirated such that it is unavailable during subsequent PEF application when irreversible electroporation of nerve cells is initiated. Aspiration may be achieved by at least partially deflating one balloon during aspiration. Alternatively, aspiration may be achieved with both balloons inflated, for example, by infusing saline in conjunction with the aspiration to flush out the vessel segment between the inflated balloons. Such blood flushing may reduce a risk of clot formation along proximal electrode 316 a during PEF application. Furthermore, flushing during energy application may cool the electrode and/or cells of the wall of the artery. Such cooling of the wall cells might protect the cells from irreversible electroporative damage, possibly reducing a need for infusion of a protective agent. [0127] After infusion and optional aspiration, a PEF suitable for initiation of irreversible electroporation in target nerve cells may be delivered across electrodes 316 to denervate or to modulate neural activity. In an alternative method, infusion of a protective agent may be performed during or after initiation of irreversible electroporation in order to protect non-target cells. The protective agent may, for example, plug or fill pores formed in the non-target cells via the irreversible electroporation. [0128] In another alternative method, a solution of chilled (i.e., less than body temperature) heparinized saline may be simultaneously infused and aspirated between the inflated balloons to flush the region between the balloons and decrease the sensitivity of vessel wall cells to electroporation. This is expected to further protect the cells during application of the PEF suitable for initiation of irreversible electroporation. Such flushing optionally may be continuous throughout application of the pulsed electric field. A thermocouple or other temperature sensor optionally may be positioned between the balloons such that a rate of chilled infusate infusion may be adjusted to maintain a desired temperature. The chilled infusate preferably does not cool the target tissue, e.g., the renal nerves. A protective agent, such as Poloxamer-188, optionally may be infused post-treatment as an added safety measure. [0129] Infusion alternatively may be achieved via a weeping balloon catheter. Further still, a cryoballoon catheter having at least one electrode may be utilized. The cryoballoon may be inflated within a vessel segment to locally reduce the temperature of the vessel segment, for example, to protect the segment and/or to induce thermal apoptosis of the vessel wall during delivery of an electric field. The electric field may, for example, comprise a PEF or a thermal, non-pulsed electric field, such as a thermal RF field. [0130] Referring now to FIGS. 23A, 23B and 23C , a variation of a PEF catheter configured for passage of electrode(s) at least partially across the vessel wall is described. For example, the electrode(s) may be positioned within the renal vein and then passed across the wall of the renal vein such that they are disposed in Gerota's or renal fascia and near or at least partially around the renal artery. In this manner, the electrode(s) may be positioned in close proximity to target renal nerve fibers prior to delivery of a pulsed electric field. [0131] As seen in FIG. 23A , apparatus 320 comprises catheter 322 having needle ports 324 and centering element 326 , illustratively an inflatable balloon. Catheter 322 also optionally may comprise radiopaque markers 328 . Needle ports 324 are configured for passage of needles 330 therethrough, while needles 330 are configured for passage of electrodes 340 . [0132] Renal vein RV runs parallel to renal artery RA. An imaging modality, such as intravascular ultrasound, may be used to identify the position of the renal artery relative to the renal vein. For example, intravascular ultrasound elements optionally may be integrated into catheter 322 . Catheter 322 may be positioned within renal vein RV using well-known percutaneous techniques, and centering element 326 may be expanded to stabilize the catheter within the vein. Needles 330 then may be passed through catheter 322 and out through needle ports 324 in a manner whereby the needles penetrate the wall of the renal vein and enter into Gerota's or renal fascia F. Radiopaque markers 328 may be visualized with fluoroscopy to properly orient needle ports 324 prior to deployment of needles 330 . [0133] Electrodes 340 are deployed through needles 330 to at least partially encircle renal artery RA, as in FIGS. 23A and 23B . Continued advancement of the electrodes may further encircle the artery, as in FIG. 23C . With the electrodes deployed, stimulation and/or PEF electroporation waveforms may be applied to denervate or modulate the renal nerves. Needles 330 optionally may be partially or completely retracted prior to treatment such that electrodes 340 encircle a greater portion of the renal artery. Additionally, a single electrode 340 may be provided and/or actuated in order to provide a monopolar PEF. [0134] Infusate optionally may be infused from needles 330 into fascia F to facilitate placement of electrodes 340 by creating a space for placement of the electrodes. The infusate may comprise, for example, fluids, heated or chilled fluids, air, CO 2 , saline, contrast agents, gels, conductive fluids or any other space-occupying material—be it gas, solid or liquid. Heparinized saline also may be injected. Saline or hypertonic saline may enhance conductivity between electrodes 340 . Additionally or alternatively, drugs and/or drug delivery elements may be infused or placed into the fascia through the needles. [0135] After treatment, electrodes 340 may be retracted within needles 330 , and needles 330 may be retracted within catheter 322 via needle ports 324 . Needles 330 preferably are small enough that minimal bleeding occurs and hemostasis is achieved fairly quickly. Balloon centering element 326 optionally may remain inflated for some time after retrieval of needles 330 in order to block blood flow and facilitate the clotting process. Alternatively, a balloon catheter may be advanced into the renal vein and inflated after removal of apparatus 320 . [0136] Referring to FIGS. 24A and 24B , variations of the invention comprising detectors or other elements for measuring or monitoring treatment efficacy are described. Variations of the invention may be configured to deliver stimulation electric fields, in addition to denervating or modulating PEFs. These stimulation fields may be utilized to properly position the apparatus for treatment and/or to monitor the effectiveness of treatment in modulating neural activity. This may be achieved by monitoring the responses of physiologic parameters known to be affected by stimulation of the renal nerves. Such parameters comprise, for example, renin levels, sodium levels, renal blood flow and blood pressure. Stimulation also may be used to challenge the denervation for monitoring of treatment efficacy: upon denervation of the renal nerves, the known physiologic responses to stimulation should no longer occur in response to such stimulation. [0137] Efferent nerve stimulation waveforms may, for example, comprise frequencies of about 1-10 Hz, while afferent nerve stimulation waveforms may, for example, comprise frequencies of up to about 50 Hz. Waveform amplitudes may, for example, range up to about 50V, while pulse durations may, for example, range up to about 20 milliseconds. When the nerve stimulation waveforms are delivered intravascularly, as in several embodiments of the present invention, field parameters such as frequency, amplitude and pulse duration may be modulated to facilitate passage of the waveforms through the wall of the vessel for delivery to target nerves. Furthermore, although exemplary parameters for stimulation waveforms have been described, it should be understood that any alternative parameters may be utilized as desired. [0138] The electrodes used to deliver PEFs in any of the previously described variations of the present invention also may be used to deliver stimulation waveforms to the renal vasculature. Alternatively, the variations may comprise independent electrodes configured for stimulation. As another alternative, a separate stimulation apparatus may be provided. [0139] One way to use stimulation to identify renal nerves is to stimulate the nerves such that renal blood flow is affected—or would be affected if the renal nerves had not been denervated or modulated. Stimulation acts to reduce renal blood flow, and this response may be attenuated or abolished with denervation. Thus, stimulation prior to neural modulation would be expected to reduce blood flow, while stimulation after neural modulation would not be expected to reduce blood flow to the same degree when utilizing similar stimulation parameters and location(s) as prior to neural modulation. This phenomenon may be utilized to quantify an extent of renal neuromodulation. Variations of the present invention may comprise elements for monitoring renal blood flow or for monitoring any of the other physiological parameters known to be affected by renal stimulation. [0140] In FIG. 24A , a variation of apparatus 280 of FIG. 16 is described having an element for monitoring of renal blood flow. Guidewire 350 having Doppler ultrasound sensor 352 has been advanced through the lumen of catheter 282 for monitoring blood flow within renal artery RA. Doppler ultrasound sensor 352 is configured to measure the velocity of flow through the artery. A flow rate then may be calculated according to the formula: [0000] Q=VA   (1) [0000] where Q equals flow rate, V equals flow velocity and A equals cross-sectional area. A baseline of renal blood flow may be determined via measurements from sensor 352 prior to delivery of a stimulation waveform, then stimulation may be delivered between electrodes 286 a and 286 b, preferably with balloon 284 deflated. Alteration of renal blood flow from the baseline, or lack thereof, may be monitored with sensor 352 to identify optimal locations for neuromodulation and/or denervation of the renal nerves. [0141] FIG. 24B illustrates a variation of the apparatus of FIG. 24A , wherein Doppler ultrasound sensor 352 is coupled to the shaft of catheter 282 . Sensor 352 illustratively is disposed proximal of balloon 284 , but it should be understood that the sensor alternatively may be disposed distal of the balloon. [0142] In addition or as an alternative to intravascular monitoring of renal blood flow via Doppler ultrasound, such monitoring optionally may be performed from external to the patient whereby renal blood flow is visualized through the skin (e.g., using an ultrasound transducer). In another variation, one or more intravascular pressure transducers may be used to sense local changes in pressure that may be indicative of renal blood flow. As yet another alternative, blood velocity may be determined, for example, via thermodilution by measuring the time lag for an intravascular temperature input to travel between points of known separation distance. [0143] For example, a thermocouple may be incorporated into, or provided in proximity to, each electrode 286 a and 286 b, and chilled (i.e., lower than body temperature) fluid or saline may be infused proximally of the thermocouple(s). A time lag for the temperature decrease to register between the thermocouple(s) may be used to quantify flow characteristic(s). A baseline estimate of the flow characteristic(s) of interest may be determined prior to stimulation of the renal nerves and may be compared with a second estimate of the characteristic(s) determined after stimulation. [0144] Commercially available devices optionally may be utilized to monitor treatment. Such devices include, for example, the SmartWire™, F 1 oWire™ and WaveWire™ devices available from Volcano™ Therapeutics Inc., of Rancho Cordova, Calif., as well as the PressureWire® device available from RADI Medical Systems AB of Uppsala, Sweden. Additional commercially available devices will be apparent. An extent of electroporation additionally or alternatively may be monitored directly using Electrical Impedance Tomography (“EIT”) or other electrical impedance measurements, such as an electrical impedance index. [0145] Although preferred illustrative variations of the present invention are described above, it will be apparent to those skilled in the art that various changes and modifications may be made thereto without departing from the invention. For example, although the variations primarily have been described for use in combination with pulsed electric fields, it should be understood that any other electric field may be delivered as desired. It is intended in the appended claims to cover all such changes and modifications that fall within the true spirit and scope of the invention.

Methods and apparatus are provided for renal neuromodulation using a pulsed electric field to effectuate electroporation or electrofusion. It is expected that renal neuromodulation (e.g., denervation) may, among other things, reduce expansion of an acute myocardial infarction, reduce or prevent the onset of morphological changes that are affiliated with congestive heart failure, and/or be efficacious in the treatment of end stage renal disease. Embodiments of the present invention are configured for percutaneous intravascular delivery of pulsed electric fields to achieve such neuromodulation.

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of U.S. patent application Ser. No. 11/586,859, filed on Oct. 26, 2006, which claims the benefit of claims the benefit of U.S. Provisional Application Nos. 60/748,937, filed on Dec. 9, 2005 and 60/808,077, filed on May 24, 2006. The disclosures of the above applications are incorporated herein by reference in their entirety. FIELD The present disclosure relates to wireless network devices, and more particularly to a coexistence system for wireless network devices having multiple wireless sub-clients that share components. BACKGROUND In a Wireless Local Area Network (WLAN), client stations can communicate with other client stations in an ad hoc mode or with an access point (AP) in an infrastructure mode. WLANs typically have a range in the hundreds of feet. The client stations typically include a wireless network interface that is associated with a host device. The host device can be a desktop computer, a personal digital assistant (PDA), a mobile phone, a laptop, a personal computer (PC), a printer, a digital camera, an internet protocol (IP) phone, etc. The AP provides connectivity to a network, such as the Internet or other network. The wireless network interface may be compatible with Worldwide Interoperability for Microwave Access (WiMAX). WiMAX systems schedule communications with client stations by allocating a time slot. Initially, the client station registers with a base station. The base station transmits MAPs that indicate when the client station should transmit and receive data. When the WiMAX client does not transmit or receive data during the regularly scheduled MAP, the base station may deregister the client. Bluetooth is another wireless standard that operates at shorter ranges than WLAN. When implemented by the same device, WiMAX, WLAN, and Bluetooth clients may share components to reduce the cost of the device. Shared components may include the antenna, radio frequency (RF) subsystems, such as transmitters and receivers, baseband processors, etc. The sharing of components should be coordinated. Further, WiMAX, WiFi, and Bluetooth may use the same frequency or nearby frequencies, which may cause interference. SUMMARY A network interface is provided and includes a radio frequency system connected to an antenna and a media access controller. The media access controller includes client modules and a control module. The client modules include a first client module and a second client module. Each of the client modules wirelessly communicates with a network via (i) the radio frequency system and (ii) the antenna. Each of the client modules is controllable to be in an active state or a sleep state. The control module is configured to (i) determine a first priority level of the first client module, and (ii) determine a second priority level of the second client module. The control module is also configured to, based on the first priority level and the second priority level, (i) control the first client module to be in the active state to permit communication between the first client module and the radio frequency system, and (ii) control the second client module to be in the sleep state to prevent communication between the second client module and the radio frequency system. A wireless network interface includes a component, a first sub-client module that operates using a first wireless protocol, and a second sub-client module that operates using a second wireless protocol. The first and second wireless protocols are different. The first and second sub-client modules share use of the component. A component sharing control module selectively transitions the first sub-client module into and out of a state to allow the second sub-client module to use the component during the state. In another feature, at least one of the first sub-client module and the second sub-client module includes an active sub-client. At least one of the first sub-client module and the second sub-client module includes at least one of a Worldwide Interoperability for Microwave Access (WiMAX) sub-client module, a Wireless Local Area Network (WLAN) sub-client module, and a Bluetooth sub-client module. In other features, the state includes a sleep state. The first sub-client module sends a signal to the second sub-client module indicating the first sub-client module is entering the sleep state. At least one of the first sub-client module and the component sharing control module prevents the second sub-client module from using the component within a predetermined time in which the first sub-client module is scheduled to receive a transmission. In other features, the component includes at least one of an antenna and a radio frequency (RF) subsystem. The RF subsystem includes at least one of a filter, a switch, a transmitter (Tx), a receiver (Rx), and a base band processor (BBP) module. The first sub-client module selectively reduces signal power to decrease signal interference with signals from the second sub-client module. In other features, at least one of the first sub-client module and the component sharing control module prevents the second sub-client module from receiving transmissions within a predetermined time in which the first sub-client module is scheduled to receive a transmission. The state includes at least one of an idle state and a low power state. In still other features, the first sub-client module includes a WiMAX sub-client module and the second sub-client module includes a WLAN sub-client module. The WLAN sub-client module transmits a reserve signal to the component sharing control module to reserve the component for a duration of time when the WiMAX sub-client module is due to receive a MAP. The reserve signal includes a CTS-Self protocol. The WLAN sub-client module receives transmissions from a network. The WLAN sub-client module sends transmissions to a network. In other features, a system includes the wireless network interface and a base station that communicates with a network. The WiMAX sub-client module transmits a busy signal to the base station during WLAN sub-client module use of the component. In other features, a system includes the wireless network interface. The WLAN sub-client module detects a WiMAX signal through at least one of a repeated MAP transmission and a signal from the WiMAX sub-client module. The system further includes a first access point (AP) for the WLAN sub-client module. The WLAN sub-client module informs the first AP of interference with the WiMAX signal and that the first AP should switch transmission channels. The WLAN sub-client module scans for a second AP. In still other features, the first sub-client module includes a WLAN sub-client module and the second sub-client module includes a WiMAX sub-client module. The component includes radio frequency (RF) subsystems that selectively switch from a WLAN frequency to a WiMAX frequency during the state. The WLAN sub-client module periodically receives signals during the state. At least one of the periodic signals is skipped when the WiMAX sub-client module is due to receive signals. The component sharing control module selectively determines the state with a base station when WLAN sub-client module network connection quality is above a WLAN network disconnect threshold. The base station communicates with the WiMAX sub-client module. The component sharing control module includes a medium access control module (MAC). In other features, a system includes the wireless network interface and further includes access points (AP) and base stations. The MAC includes a mobility manager module that selectively connects the first sub-client module and the second sub-client module to each of the APs and base stations. The MAC further includes a coexistence control module that controls states of the first sub-client module and the second sub-client module. The states comprise idle, scan, network entry, registered, and active. The coexistence control module determines which of the first sub-client and the second sub-client has priority for the component and controls the selective transitions based on the priority. In still other features, a wireless network interface method includes operating a first sub-client module using a first wireless protocol and operating a second sub-client module using a second wireless protocol. The first and second wireless protocols are different. The first and second sub-client modules share use of component. The method selectively transitions the first sub-client module into and out of a state to allow the second sub-client module to use the component during the state. In a wireless network interface method, at least one of the first sub-client module and the second sub-client module includes an active sub-client. At least one of the first sub-client module and the second sub-client module includes at least one of a WiMAX sub-client module, a WLAN sub-client module, and a Bluetooth sub-client module. In the wireless network interface method, selectively transitioning the first sub-client module into and out of the state includes selectively transitioning the first sub-client module into and out of a sleep state. In other features, the first sub-client module sends a signal to the second sub-client module indicating the first sub-client module is entering the sleep state. The wireless network interface method further includes preventing the second sub-client module from using the component within a predetermined time in which the first sub-client module is scheduled to receive a transmission. The component includes at least one of an antenna and an RF subsystem. In other features, the RF subsystem includes at least one of a filter, a switch, a Tx, an Rx, and a BBP module. The wireless network interface method further includes selectively reducing signal power to decrease signal interference with signals from the second sub-client module. The wireless network interface method further includes preventing the second sub-client module from receiving transmissions within a predetermined time in which the first sub-client module is scheduled to receive a transmission. Selectively transitioning the first sub-client module into and out of the state includes selectively transitioning the first sub-client module into and out of at least one of an idle state and a low power state. In other features, the first sub-client module includes a WiMAX sub-client module and the second sub-client module includes a WLAN sub-client module. The wireless network interface method further includes transmitting a reserve signal to the component sharing control module. The method also includes reserving the component for a duration of time when the WiMAX sub-client module is due to receive a MAP. For the wireless network interface method, the reserve signal includes a CTS-Self protocol. The WLAN sub-client module receives transmissions from a network. The WLAN sub-client module sends transmissions to a network, and a base station communicates with the network. The WiMAX sub-client module transmits a busy signal to the base station during WLAN sub-client module use of the component. In other features, the wireless network interface method further includes detecting a WiMAX signal through at least one of a repeated MAP transmission and a signal from the WiMAX sub-client module. The method further includes informing the first AP of interference with the WiMAX signal and that the first AP should switch transmission channels. The method further includes scanning for a second AP. In still other features, the first sub-client module includes a WLAN sub-client module and the second sub-client module includes a WiMAX sub-client module. The wireless network interface method further includes selectively switching from a WLAN frequency to a WiMAX frequency during the state. The wireless network interface method further includes the WLAN sub-client module periodically receiving signals during the state. The wireless network interface method further includes skipping at least one of the periodic signals when the WiMAX sub-client module is due to receive signals. The wireless network interface method further includes selectively determining the state with a base station when WLAN sub-client module network connection quality is above a WLAN network disconnect threshold. In other features, the component sharing control module includes a medium MAC. The wireless network interface method further includes a mobility manager module within the MAC selectively connecting the first sub-client module and the second sub-client module to each of multiple APs and base stations. The method further includes a coexistence control module within the MAC controlling states of the first sub-client module and the second sub-client module. The states comprise idle, scan, network entry, registered, and active. The method further includes determining which of the first sub-client and the second sub-client has priority for the component, and controlling the selective transitions based on the priority. In still other features, a wireless network interface includes a component for interacting with a network. The interface includes first sub-client module for operating with a first wireless protocol and second sub-client module for operating with a second wireless protocol. First and second wireless protocols are different. The first and second sub-client module share use of the component. The interface also includes component sharing module for selectively transitioning the first sub-client module into and out of a state to allow the second sub-client module to use the component during the state. In other features, at least one of the first sub-client module and the second sub-client module is active. At least one of the first sub-client module and the second sub-client module includes at least one of sub-client module for using WiMAX, sub-client module for using WLAN, and sub-client module for using Bluetooth. In other features, the state includes a sleep state. The first sub-client module sends a signal to the second sub-client module indicating the first sub-client module is entering the sleep state. At least one of the first sub-client module and the component sharing module prevents the second sub-client module from using the component within a predetermined time. The predetermined time is the duration during which the first sub-client module is scheduled to receive a transmission. The component includes at least one of antenna for receiving signals and RF subsystem for processing the signals. The RF subsystem includes at least one of filter for filtering the signals, switch for forwarding the signals, transmitter for transmitting the signals, receiver for receiving the signals, and base band processor for processing a base band of the signals. The first sub-client module selectively reduces signal power to decrease signal interference with signals from the second sub-client module. At least one of the first sub-client module and the component sharing module prevents the second sub-client module from receiving transmissions within a predetermined time in which the first sub-client module is scheduled to receive a transmission. The state includes at least one of an idle state and a low power state. The first sub-client module includes sub-client module for using WiMAX and the second sub-client module includes sub-client module for using a WLAN. The WLAN sub-client module transmits a reserve signal to the component sharing module to reserve the component for a duration of time when the WiMAX sub-client module is due to receive a MAP. The reserve signal includes a CTS-Self protocol. The WLAN sub-client module receives transmissions from network for communicating between devices. The WLAN sub-client module sends transmissions to the network. In other features, a system includes the wireless network interface. The system also includes a base station for communicating with the network. The WiMAX sub-client module transmits a busy signal to the base station during WLAN sub-client module use of the component. In other features, the WLAN sub-client module detects a WiMAX signal through at least one of a repeated MAP transmission and a signal from the WiMAX sub-client module. The system further includes a first AP for accessing the network for the WLAN sub-client module. The WLAN sub-client module informs the first AP of interference with the WiMAX signal and that the first AP should switch transmission channels. The WLAN sub-client module scans for a second AP for accessing the network. In still other features, the first sub-client module includes sub-client module for operating WLAN and the second sub-client module includes sub-client module for operating WiMAX. The component includes radio frequency (RF) subsystems that selectively switch from a WLAN frequency to a WiMAX frequency during the state. The WLAN sub-client module periodically receives signals during the state. At least one of the periodic signals is skipped when the WiMAX sub-client module is due to receive signals. The component sharing module selectively determines the state with base station for communicating with the network when network connection quality for the WLAN sub-client module is above a WLAN network disconnect threshold. The base station communicates with the WiMAX sub-client module. The component sharing module includes a MAC for accessing the network. In other features, a system includes the wireless network interface and further includes APs for accessing the network and base station for accessing the network. The MAC includes mobility manager module for selectively connecting the first sub-client module and the second sub-client module to each of the APs and the base station. The MAC further includes coexistence control module for controlling states of the first sub-client module and the second sub-client module. The states comprise idle, scan, network entry, registered, and active. The coexistence control module determines which of the first sub-client module and the second sub-client module has priority for the component and controls the selective transitions based on the priority. In still other features, a computer program stored for use by a processor for operating a wireless network interface includes operating a first sub-client module using a first wireless protocol and operating a second sub-client module using a second wireless protocol. The first and second wireless protocols are different. The first and second sub-client modules share use of a component. The computer program selectively transitions the first sub-client module into and out of a state to allow the second sub-client module to use the component during the state. In other features, at least one of the first sub-client module and the second sub-client module includes an active sub-client. At least one of the first sub-client module and the second sub-client module includes at least one of a WiMAX sub-client module, a WLAN sub-client module, and a Bluetooth sub-client module. In the computer program, selectively transitioning the first sub-client module into and out of the state includes selectively transitioning the first sub-client module into and out of a sleep state. In other features, the first sub-client module sends a signal to the second sub-client module indicating the first sub-client module is entering the sleep state. The computer program further includes preventing the second sub-client module from using the component within a predetermined time in which the first sub-client module is scheduled to receive a transmission. The component includes at least one of an antenna and a radio frequency (RF) subsystem. In other features, the RF subsystem includes at least one of a filter, a switch, a Tx, an Rx, and a BBP module. The computer program further includes selectively reducing signal power to decrease signal interference with signals from the second sub-client module. The computer program further includes preventing the second sub-client module from receiving transmissions within a predetermined time in which the first sub-client module is scheduled to receive a transmission. The computer program selectively transitions the first sub-client module into and out off at least one of an idle state and a low power state. In other features, the first sub-client module includes a WiMAX sub-client module and the second sub-client module includes a WLAN sub-client module. The computer program further includes transmitting a reserve signal to the component sharing control module. The computer program also reserves the component for a duration of time when the WiMAX sub-client module is due to receive a MAP. The reserve signal includes a CTS-Self protocol. In other features, the WLAN sub-client module receives transmissions from a network, and the WLAN sub-client module sends transmissions to a network. A base station communicates with a network, and the WiMAX sub-client module transmits a busy signal to the base station during WLAN sub-client module use of the component. In other features, the computer program further includes detecting a WiMAX signal through at least one of a repeated MAP transmission and a signal from the WiMAX sub-client module. The computer program further includes informing the first AP of interference with the WiMAX signal and that the first AP should switch transmission channels. The computer program further includes scanning for a second AP. In other features, the first sub-client module includes a WLAN sub-client module and the second sub-client module includes a WiMAX sub-client module. The computer program further includes selectively switching from a WLAN frequency to a WiMAX frequency during the state. The computer program further includes the WLAN sub-client module periodically receiving signals during the state. The computer program further includes skipping at least one of the periodic signals when the WiMAX sub-client module is due to receive signals. The computer program further includes selectively determining the state with a base station when WLAN sub-client module network connection quality is above a WLAN network disconnect threshold. In other features, the component sharing control module includes a medium MAC. The computer program further includes selectively connecting the first sub-client module and the second sub-client module to each of multiple APs and base stations. The computer program further includes controlling states of the first sub-client module and the second sub-client module. The states comprise idle, scan, network entry, registered, and active. The computer program further includes determining which of the first sub-client and the second sub-client has priority for the component and controlling the selective transitions based on the priority. Further areas of applicability of the present disclosure will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure. BRIEF DESCRIPTION OF DRAWINGS The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein: FIG. 1 is a functional block diagram of a coexistence system for wireless network devices; FIG. 2 is a sequence diagram illustrating a method for sharing components; FIG. 3 is a state transition diagram for a WLAN sub-client; FIG. 4 is a state transition diagram for a WiMAX sub-client; FIG. 5 is a sequence diagram illustrating a method for sharing components; FIG. 6 is a sequence diagram illustrating a method for sharing components; FIG. 7 is a block diagram illustrating a method for supporting coexistence of multiple sub-clients; FIG. 8 is a block diagram illustrating a method for handoff of components between multiple sub-clients; FIG. 9 is WiMAX signal time frame diagram including scheduled WLAN activation periods; FIG. 10 is a protocol diagram for Unsolicited Automatic Power Save Delivery (U-APSD) for a WLAN sub-client; FIG. 11A is a functional block diagram of a vehicle control system; FIG. 11B is a functional block diagram of a cellular phone; FIG. 11C is a functional block diagram of a set top box; and FIG. 11D is a functional block diagram of a media player. DESCRIPTION The following description is merely exemplary in nature and is in no way intended to limit the disclosure, its application, or uses. For purposes of clarity, the same reference numbers will be used in the drawings to identify similar elements. As used herein, the term module, circuit and/or device refers to an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A or B or C), using a non-exclusive logical or. It should be understood that steps within a method may be executed in different order without altering the principles of the present disclosure. The present disclosure includes a coexistence system and method for wireless network devices with wireless network interfaces that support a variety of sub-clients including, for example, a Wireless Local Area Network (WLAN) sub-client, a Worldwide Interoperability for Microwave Access (WiMAX) sub-client, and a Bluetooth (BT) sub-client, which share components. Referring now to FIG. 1 , a coexistence system 10 for wireless network devices having multiple sub-clients that share components is shown. Wireless access points (AP) 12 - 1 , 12 - 2 , . . . , and 12 -X (collectively APs 12 ) and/or base stations 13 - 1 , 13 - 2 , . . . , and 13 -X (collectively base stations 13 ) provide connections between a host 14 having a wireless network interface 16 and networks 18 - 1 , 18 - 2 , . . . , and 18 -Z, that may include the Internet 19 . The APs 12 and base stations 13 may communicate with the networks through associated routers 20 - 1 , 20 - 2 , . . . , and 20 -Z. The wireless network interface 16 communicates with the APs 12 , the base stations 13 and/or other wireless client stations 17 . The host 14 may be a personal digital assistant (PDA), mobile phone, laptop, personal computer (PC), printer, digital camera, or internet protocol (IP) phone. The wireless network interface 16 may include shared components such as an antenna 22 , radio frequency (RF) subsystems 23 (such as a filter 24 , a switch 25 , a transmitter (Tx) 26 , a receiver (Rx) 27 , and/or a base band processor (BBP) module 28 ). Further, each sub-client may include an antenna, a filter, a switch, a Tx, an Rx, and/or a BBP module. The wireless communications can be compliant with various protocols including at least one of the Institute of Electrical and Electronics Engineers (IEEE) standards 802.11, 802.11a, 802.11b, 802.11g, 802.11h, 802.11n, 802.16, 802.16a, 802.16e, 802.16-2004, and 802.20, and/or the Bluetooth standard published by the Bluetooth Special Interest Group (SIG). The aforementioned standards are hereby incorporated by reference in their entirety. The antenna 22 and RF subsystems 23 communicate with a media access control module (MAC) 29 , which is also referred to herein as a component sharing control module. The MAC 29 may include a mobility manager module 30 that receives information about the availability and signal strength of the APs 12 and/or base stations 13 . The mobility manager module 30 also selects one of the sub-clients to connect to the appropriate AP 12 and/or base station 13 and informs a coexistence control module 31 . Illustrated are a WLAN (WiFi) sub-client module 32 , a WiMAX sub-client module 34 , and/or a Bluetooth sub-client module 35 . The MAC 29 communicates with the host 14 through I/O modules 33 , 37 and also communicates with a processor module 38 , which may perform processing for the network interface 16 . The WLAN, WiMAX, and Bluetooth sub-client modules 32 , 34 , 35 may be in various states or modes, such as, but not limited to, idle, scan, network entry, registered, and active. These states may be controlled by the coexistence control module 31 or the sub-client modules 32 , 34 . When in the idle state, a sub-client module 32 , 34 is not connected to an AP or base station and is also not scanning. When in the scan state, the sub-client module 32 , 34 is not connected to an AP or base station but is receiving beacons or MAPs. When in the network entry state, the sub-client module 32 , 34 has identified an AP or base station and is in the process of undergoing network entry to register with the AP or base station. When in the registered state, the sub-client module 32 , 34 has completed network entry and has registered to the AP or base station but is not passing user data. When in the active state, the sub-client module 32 , 34 is passing user data. When multiple wireless access devices are in a single handheld device, the coexistence control module 31 limits network entry to one sub-client module at a time. Further, the sub-client modules 32 , 34 can transition to any other states independently to avoid simultaneous active state interference. Regardless of the state, when transmitting and/or receiving, the sub-client module may require use of shared components (antenna, RF subsystem, etc.). In each state, the power save properties, transmission, and reception requirements are different. In the idle state, both the transmitter and receiver are inactive; and the sub-client module is consuming very low power. In the low power state, which may be any state other than active and idle states, the sub-client module is transmitting or receiving data at a very low rate or not at all. In the active state, the sub-client module is actively transmitting and receiving data. Further, the sub-client modules may enter a sleep state that may include temporarily entering an idle state or a low power state. Referring now to FIG. 2 , a method 100 for operating the coexistence control module 31 is illustrated. In step 102 , the coexistence control module 31 may define a state of each sub-client module to indicate the activation state of the sub-client module (idle, low power, active) and a priority of the sub-client module for component priority. The component priority may depend on the type of data (voice, non voice, management message etc.) to be transmitted. In step 104 , a first sub-client module may activate (change state to active) when all other sub-clients are idle. In step 106 , the first sub-client module rechecks the state of other sub-clients to verify that no race (i.e. two sub-client modules attempting to use shared components) condition exists. If no other sub-client is competing for the components, in step 108 , the first sub-client module continues using the shared components. Otherwise, in step 110 , the sub-client with higher priority gains access to the shared components. Referring now to FIG. 3 , a state transition diagram 200 for a WLAN sub-client module 32 is illustrated. In state 202 , after receiving a power up complete signal, the WLAN sub-client module 32 enters an idle state for a predetermined amount of time (or until commanded to scan by the host 14 ) prior to scanning. In state 204 , the WLAN sub-client module 32 enters a scan state to scan for available APs until the coexistence control module 31 commands the WLAN sub-client module 32 to perform network entry with an appropriate AP. In state 206 , the WLAN sub-client module 32 enters the network. In state 208 , after registering with the AP, the WLAN sub-client module 32 enters into a low power state maintaining the connection with the AP but not passing data to the AP. In state 210 , when informed by the coexistence control module 31 , the WLAN sub-client module 32 transitions to the active state to pass user data to the AP. If the WiMAX sub-client module 34 is used for data, the coexistence control module 31 transitions the WLAN sub-client module 32 to a low power state, e.g., a registered state, as in state 208 . If the WLAN link drops, the WLAN sub-client module 32 goes back to the idle state, as in state 202 . In state 212 , the WLAN sub-client module 32 or the AP can deregister the WLAN sub-client module 32 . The WLAN sub-client module 32 can return to the registered state as in state 208 . The WLAN sub-client module 32 can also return to the idle state, as in state 202 , and then scan for available APs. Referring now to FIG. 4 , a state transition diagram 200 for a WiMAX sub-client module 34 is illustrated. In state 220 , after receiving a power up complete signal, the WiMAX sub-client module 34 enters an idle state for a predetermined amount of time (or until commanded to scan by the host 14 ) prior to scanning. In state 222 , the WiMAX sub-client module 34 enters a scan state to scan for available base stations until the coexistence control module 31 commands the WiMAX sub-client module 34 to enter the network. In state 224 , the WiMAX sub-client module 34 enters the network. In state 226 , after registering with the base station, the WiMAX sub-client module 34 enters into a low power state maintaining the connection with the base station but not passing data to the base station. In state 228 , when informed by the coexistence control module 31 , the WiMAX sub-client module 34 transitions to the active state to pass user data to the base station. If the WLAN sub-client module 32 is used for user data, the coexistence control module 31 transitions the WiMAX sub-client module 34 to a registered state, as in state 226 . If the WiMAX link drops, the WiMAX sub-client module 34 goes back to the idle state, as in state 220 . In state 230 , the WiMAX sub-client module 34 or the base station can deregister the WiMAX sub-client module 34 . The WiMAX sub-client module 34 can return to the registered state as in state 226 . The WiMAX sub-client module 34 can also return to the idle state, as in state 218 , and then scan for available base stations. Referring now to FIG. 5 , a sequence diagram 250 of a method for sharing components between a low power sub-client 252 and an active sub-client 254 is illustrated. Either or both the low power and active sub-clients may be WiMAX, WLAN, and/or Bluetooth sub-clients. When the low power sub-client 252 requires network interaction, the low power sub-client 252 sends a request 256 to the active sub-client 254 for the shared components. The active sub-client 254 complies with the request 256 , which may include acknowledging pending automatic repeat request (ARQ) packets, informing the AP that the active sub-client 254 will enter a sleep state for a fixed duration, etc. Within a predetermined time 257 , the active sub-client 254 sends an acknowledge signal 258 (ACK). The low power sub-client 252 then performs the intended functions (e.g., transmitting or receiving on the shared components.) and, within a predetermined expiration time 260 , sends a transmit/receive completed message 264 to the active sub-client 254 . The active sub-client 254 then responds with an acknowledge signal 266 . The messages 256 , 258 , 264 , 266 can be sent through a set of registers or shared memory within the host 14 . The sub-clients 252 , 254 can also use either polling during a common time base or alternately interrupt requests (IRQ) to send and receive the messages 256 , 258 , 264 , 266 . In an alternate example, two sub-clients may be in a low power state. When the first low power sub-client requires the shared components, an interrupt is sent by either the first low power sub-client or the coexistence control module to the second low power sub-client, which activates to service the interrupt. The first low power sub-client can check the status of the second low power sub-client, and when the second low power sub-client is active, the sub-clients may follow the sequence diagram, as shown in FIG. 5 . When the second low power sub-client is in low power state, the first low power sub-client may take control of the shared components. After completing a transmit/receive, the first low power sub-client may relinquish control of the shared components. In an exemplary embodiment, if the WLAN client knows when the WiMAX client is expecting a MAP, it can transmit a CTS-Self reserving the medium for a fixed duration of time. The WiMAX client can then receive the MAP without WLAN interference. This feature may be applied to ensure reception of all downlink or uplink transmissions. Referring now to FIG. 6 , an exemplary coexistence system is illustrated. The Bluetooth sub-client 272 is shown interfacing with the WLAN sub-client. When the WLAN sub-client is in an active state, the WLAN sub-client may abort transmissions and transfer shared component access to the Bluetooth sub-client. When the WLAN sub-client is in a low power state, i.e. a low power sub-client 252 , and the WiMAX sub-client is in an active state, i.e. the active sub-client 254 , the Bluetooth sub-client 272 may send a priority request 274 to the WLAN low power sub-client 252 for access to the shared components. This request 274 may include setting a clear channel assessment (CCA) signal of the WLAN sub-client high. When a clear channel assessment signal is held high, the WiMAX active sub-client 254 may abort active state transmissions of units of data (packets). The WiMAX re-transmits the units of data at a later scheduled transmission period. Within the predetermined time 257 , the active (WiMAX) sub-client 254 sends an acknowledge signal 258 . The low power (WLAN) sub-client 252 then sends an acknowledgement signal 276 to the Bluetooth sub-client 272 , which performs the intended functions 278 (e.g., transmitting or receiving on the shared components.). The low power sub-client 252 , within the predetermined expiration time 260 , sends a signal 280 indicating that the low power sub-client 252 is resuming control of the components. The low power sub-client 252 then sends a transmit/receive completed message 264 to the active sub-client 254 also within the predetermined expiration time 260 . The active sub-client sends an acknowledgement 266 . The predetermined expiration time 260 corresponds to the regularly scheduled MAP and thus allows the active WiMAX sub-client 254 to avoid deregistration through interference from other sub-client operations. To further ensure that the WiMAX sub-client will send or receive during the regularly scheduled MAP period without interference, the WiMAX sub-client may pass an offset value to the Bluetooth sub-client to offset Bluetooth transmit/receive processes. Alternately, the Bluetooth sub-client may send a Bluetooth transmission/reception schedule to the WiMAX sub-client during a prescheduled time interval. The coexistence control module may rearrange transmissions of the WiMAX sub-client to minimize Bluetooth WiMAX interference. When both WLAN and WiMAX sub-client modules are active at the same time, the coexistence control module 31 checks that interference between WiMAX and WLAN sub-client modules is minimized. This includes checking that the WLAN sub-client module is associated with a particular AP and restricting the WLAN sub-client module transmissions to a portion of a WiMAX uplink period. Both WLAN and WiMAX sub-client modules may also fragment transmitted units of data or lower power output to ensure minimal interference. Also, one of the WLAN, WiMAX, and Bluetooth sub-clients may selectively reduce signal power to decrease signal interference with signals from another one of the sub-client modules. Important to note is that alternate embodiments of the present disclosure do not require the WLAN sub-client to wake up to service the Bluetooth sub-client. Further, the coexistence control module 31 may run constantly to track or detect which sub-client(s) is in sleep mode and which sub-client(s) is in active mode. Based on this coexistence control module 31 , sharing of common resources may simply be achieved between the sub-client that requests the resource and the active sub-client. Referring now to FIG. 7 , a method 300 for managing coexistence of multiple sub-client modules is illustrated. In step 302 , the low power (inactive) sub-client module requests components from the active sub-client module. In step 304 , the active sub-client module selectively transitions to a sleep state or pattern and/or reserves a channel for a fixed amount of time with the coexistence control module. The active sub-client module then sends indication back to the low power sub-client module that the components are available. In step 306 , the low power sub-client module transmits/receives with or through the components; and in step 308 , within a predetermined time duration, the low power sub-client module hands back components to the active sub-client module. The active sub-client module and/or the low power sub-client module may be one of WiMAX, WLAN, or Bluetooth. Prior to or during the sleep state of an active WiMAX sub-client module, busy pattern is transmitted to the WiMAX base station. A base station scheduler (not shown) may use the busy pattern to schedule transmissions (uplink and downlink) to and from the active WiMAX sub-client module. The busy pattern may include: Start frame, Offset, Interval, Busy duration, and Busy because of Bluetooth or WLAN. This pattern generally indicates a Bluetooth sub-client module or WLAN sub-client module is using the shared components. When one sub-client module is expecting a downlink transmission, the sub-client module may set a carrier detect signal in the other sub-client module, thereby preventing the other sub-client module from transmitting and causing the other sub-client module to enter a random back-off state. Low power sub-client modules may also hold an “Abort Transmit” signal in the active sub-client module to check that the active sub-client module aborts transmission when the low power sub-client modules are receiving beacons, etc. The WLAN sub-client module may detect a WiMAX signal either through a repeated MAP transmission or through an indication from the WiMAX sub-client module and inform the WLAN AP that it is experiencing interference in the channel and that the AP should switch to a new channel. Repeated MAP transmissions may be detected based on frame duration for WiMAX, which is typically 5 ms. The uplink and/or downlink duty cycle could be ⅔ or ½ of the frame duration. Based on the frame duration interference pattern, the WLAN base station or access point can detect the presence of a WiMAX system. Also the WLAN sub-client or the co-existence control module could implement a preamble detector to detect the transmission of WiMAX. If the AP does not switch to a new channel, the WLAN sub-client module scans for APs on different channels. The channel selection may be based on measured signal-to-noise ratio (SNR) during WiMAX interference, which is a periodic interference. The channel selection may also be based on some average signal-to-noise ratio over a greater time duration than the WiMAX time frame duration. Referring now to FIG. 8 , a handoff method 350 is illustrated where the sub-client module (e.g. WLAN sub-client module) after reaching a low signal quality threshold with the network, initiates handoff transmissions to the other sub-client module (e.g. WiMAX sub-client module). For seamless handoff, no units of data (e.g. voice-over Internet protocol (VoIP), streaming video, or video conferencing units of data) should be dropped. Referring now to FIG. 9 in view of FIG. 8 , a portion of a WiMAX operation time frame is illustrated. In step 352 , when transmit/receive signal quality drops below a disconnect (i.e., link lost) threshold for the WLAN sub-client module, the WLAN sub-client module sends a trigger 353 to the network (or an AP communicating with a WiMAX network). The trigger 353 is sent to a WIMAX base station to indicate that the WLAN sub-client module is initiating a handoff to the WiMAX sub-client module (i.e. that a WiMAX client wants to enter the network.). In step 354 , after the WLAN sub-client module receives a confirmation from the network (or the AP), the WLAN sub-client module begins the handoff to the WiMAX sub-client module. In step 356 , the radio frequency subsystem switches from WLAN frequency to a WiMAX frequency. In step 374 , the WiMAX sub-client module initiates a scan 359 for available WiMAX base stations within selectively determined sleep pattern openings 361 . The openings 361 may be dedicated by the WLAN sub-client module through an Unsolicited Automatic Power Save Delivery (U-APSD) protocol. Referring now to FIG. 10 , a U-APSD protocol 362 is illustrated for a WLAN sub-client module to transmit voice signals at low power. A WLAN sub-client module quality of service enhanced station (QSTA) (not shown) sends quality of service (QoS) signal data 367 to an AP. The AP acknowledges the signal (i.e., sends an ACK 369 ) and sends VoIP data 371 to the QSTA. The WLAN wakes up after a predetermined time (e.g., 20 ms) and sends another QoS data signal 373 , etc. Referring again to FIGS. 8 and 9 , step 374 may include scanning for a single base station or all available base stations. In step 376 , the WiMAX sub-client module or the mobility manager module checks that received base station information matches desired base station information. For a negative response, step 374 is repeated. Otherwise, in step 378 , the WiMAX sub-client module starts a network entry procedure 379 . During network entry, the WiMAX sub-client module receives a downlink MAP for receiving data and an uplink MAP for transmitting data. The sleep pattern openings 361 are not synchronous to the downlink MAP or uplink MAP reception. The WLAN sub-client module therefore modifies the sleep openings accordingly. When the uplink MAP indicates a transmit opportunity for the WiMAX sub-client module, and the WLAN station is transmitting units of data during a sleep pattern opening, the sleep pattern opening transmission 365 may be skipped. WiMAX transmissions may also be skipped during important WLAN operations for later retransmission. In step 380 , after completing network entry, the WiMAX sub-client module carries downlink and uplink traffic. The WiMAX sub-client module may therefore remain synchronized with a base station while a WLAN sub-client module is receiving and transmitting data. Referring now to FIGS. 11A-11D , various exemplary implementations of the present disclosure are shown. Referring now to FIG. 11A , the present disclosure may implement and/or be implemented in a wireless module 448 of a vehicle 430 . A powertrain control system 432 receives inputs from one or more sensors such as temperature sensors, pressure sensors, rotational sensors, airflow sensors and/or any other suitable sensors and/or that generates one or more output control signals such as engine operating parameters, transmission operating parameters, and/or other control signals. The present disclosure may also be implemented in other control systems 440 of the vehicle 430 . The control system 440 may likewise receive signals from input sensors 442 and/or output control signals to one or more output clients 444 . In some implementations, the control system 440 may be part of an anti-lock braking system (ABS), a navigation system, a telematics system, a vehicle telematics system, a lane departure system, an adaptive cruise control system, a vehicle entertainment system such as a stereo, DVD, compact disc and the like. Still other implementations are contemplated. The powertrain control system 432 may communicate with mass data storage 446 that stores data in a nonvolatile manner. The mass data storage 446 may include optical and/or magnetic storage clients for example hard disk drives HDD and/or DVDs. The HDD may be a mini HDD that includes one or more platters having a diameter that is smaller than approximately 1.8″. The powertrain control system 432 may be connected to memory 447 such as RAM, ROM, low latency nonvolatile memory such as flash memory and/or other suitable electronic data storage. The powertrain control system 432 also may support connections with a wireless system via wireless module 448 . Vehicle 430 may also include a power supply 433 . Referring now to FIG. 11B , the present disclosure can be implemented in a cellular phone 450 that may include a cellular antenna 451 . The present disclosure may implement and/or be implemented in a wireless module 468 . In some implementations, the cellular phone 450 includes a microphone 456 , an audio output 458 such as a speaker and/or audio output jack, a display 460 and/or an input client 462 such as a keypad, pointing client, voice actuation and/or other input client. The signal processing and/or control circuits 452 and/or other circuits (not shown) in the cellular phone 450 may process data, perform coding and/or encryption, perform calculations, format data and/or perform other cellular phone functions. The cellular phone 450 may communicate with mass data storage 464 that stores data in a nonvolatile manner such as optical and/or magnetic storage clients for example hard disk drives HDD and/or DVDs. The HDD may be a mini HDD that includes one or more platters having a diameter that is smaller than approximately 1.8″. The cellular phone 450 may be connected to memory 466 such as RAM, ROM, low latency nonvolatile memory such as flash memory and/or other suitable electronic data storage. The cellular phone 450 also may support connections with a wireless system via wireless module 468 . Cellular phone 450 may also include a power supply 453 . Referring now to FIG. 11C , the present disclosure can be implemented in a set top box 480 . The present disclosure may implement and/or be implemented in a wireless module 496 . The set top box 480 receives signals from a source such as a broadband source and outputs standard and/or high definition audio/video signals suitable for a display 488 such as a television and/or monitor and/or other video and/or audio output clients. The signal processing and/or control circuits 484 and/or other circuits (not shown) of the set top box 480 may process data, perform coding and/or encryption, perform calculations, format data and/or perform any other set top box function. The set top box 480 may communicate with mass data storage 490 that stores data in a nonvolatile manner. The mass data storage 490 may include optical and/or magnetic storage clients for example hard disk drives HDD and/or DVDs. The HDD may be a mini HDD that includes one or more platters having a diameter that is smaller than approximately 1.8″. The set top box 480 may be connected to memory 494 such as RAM, ROM, low latency nonvolatile memory such as flash memory and/or other suitable electronic data storage. The set top box 480 also may support connections with a wireless system via wireless module 496 . Set top box 480 may also include a power supply 483 . Referring now to FIG. 11D , the present disclosure can be implemented in a media player 500 . The present disclosure may implement and/or be implemented in a wireless module 516 . In some implementations, the media player 500 includes a display 507 and/or a user input 508 such as a keypad, touchpad and the like. In some implementations, the media player 500 may employ a graphical user interface (GUI) that typically employs menus, drop down menus, icons and/or a point-and-click interface via the display 507 and/or user input 508 . The media player 500 further includes an audio output 509 such as a speaker and/or audio output jack. The signal processing and/or control circuits 504 and/or other circuits (not shown) of the media player 500 may process data, perform coding and/or encryption, perform calculations, format data and/or perform any other media player function. The media player 500 may communicate with mass data storage 510 that stores data such as compressed audio and/or video content in a nonvolatile manner. In some implementations, the compressed audio files include files that are compliant with MP3 format or other suitable compressed audio and/or video formats. The mass data storage may include optical and/or magnetic storage clients for example hard disk drives HDD and/or DVDs. The HDD may be a mini HDD that includes one or more platters having a diameter that is smaller than approximately 1.8″. The media player 500 may be connected to memory 514 such as RAM, ROM, low latency nonvolatile memory such as flash memory and/or other suitable electronic data storage. The media player 500 also may support connections with a wireless system via wireless module 516 . Media player 500 may also include a power supply 513 . Still other implementations in addition to those described above are contemplated. Those skilled in the art can now appreciate from the foregoing description that the broad teachings of the present disclosure can be implemented in a variety of forms. Therefore, while this disclosure has been described in connection with particular examples thereof, the true scope of the disclosure should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, the specification and the following claims.

A network interface includes a radio frequency system and a media access controller. The media access controller includes first and second client modules and a control module. Each of the client modules wirelessly communicates with a network via the radio frequency system and the antenna. Each of the client modules is controllable to be in an active state or a sleep state. The control module determines priority levels of the first client module and the second client module. The control module also, based on the priority levels, (i) controls the first client module to be in the active state to permit communication between the first client module and the radio frequency system, and (ii) controls the second client module to be in the sleep state to prevent communication between the second client module and the radio frequency system.

FIELD OF THE INVENTION This invention relates to syringes and, in particular embodiments, to a disposable syringe that has improved disabling and safety characteristics. BACKGROUND OF THE INVENTION Traditionally, disposable "one-time use" syringes have been the most prevalently used devices worldwide for invasive delivery of medication. However, because the syringe is an invasive device, after a use on a patient, the syringe's needle may become a deadly transmitter of infectious diseases, such as Acquired Immune Deficiency Syndrome (AIDS), hepatitis or the like. Thus, syringes present a growing and ever present health hazard to patient care givers and patients in either institutional or home use settings. In addition, used, discarded syringes pose a real threat to anyone coming in contact with them. It is also noted that conventional disposable one-time use syringes have often been associated with illicit drug users, who administer multiple injections from the same needle. This practice causes cross-contamination and results in the rapid spread of infectious diseases among these users. In the past, to overcome these dangers, safe disposal of used syringes has been left entirely up to either the patient care giver or the patient. For example, conscientious disposal of syringes entails an elaborate and often dangerous procedure. First, the needle point is manually broken with a specially designed device; then, the syringe and the needle are separately disposed of in a special canister designed for safe storage and transportation of contaminated waste products. However, this procedure provides numerous opportunities for contact with a used syringe and increases the chance of being accidentally stuck by potentially contaminated needles. Also, the special canister itself, once filled with exposed needle points and used syringes, is itself a health and safety hazard. Because of the past difficulties in safely handling, disposing and destroying used syringes, a growing number of health care professionals and other individuals have been infected by contaminated body fluids through accidental punctures and scratches from these dangerous devices. For this reason, patient care givers have been extremely vulnerable to and fearful about contracting a variety of infectious diseases from accidental needle injury. In addition to the risk from needle sticks by legitimate drug users, disposable syringes are the most prevalent device for administering illicit drugs by drug abusers. Typically, in these situations, each single-use syringe will be used to administer multiple injections, and it is not unusual for a single syringe to be employed by more than one individual. SUMMARY OF THE DISCLOSURE It is an object of an embodiment of the present invention to provide an improved disposable safety syringe, which obviates for practical purposes, the above-mentioned limitations. According to an embodiment of the invention, a medication delivery device for delivering medication uses a piercing member. The medication delivery device includes a housing, a piercing member holder, a delivery actuator and a sealing diaphragm. The housing is for holding medication to be delivered and includes a piercing member end and a delivery actuator end. The piercing member holder is coupled to the housing at the piercing member end and is adapted to secure the piercing member to the housing. The piercing member holder includes a sealing member that contacts the housing, a slideable protective cover coupled to the sealing member that slides over and contains the piercing member after a delivery of medication is delivered, and a disabling member for holding the piercing member, which is coupled to the housing at the piercing member end and configured to contact the sealing member to form a sealed passage for medication contained in the housing. The delivery actuator member is coupled to the delivery actuator end of the housing and adapted to expel the medication from the housing. The sealing diaphragm is coupled to one end of the delivery actuator to minimize contact of the medication with the delivery actuator and to substantially prevent leakage of medication through the delivery actuator. As an injection is completed, the disabling member of the piercing member holder contacts the sealing diaphragm and breaks it so that it is rendered incapable of performing future injections, and the delivery actuator member displaces the sealing member of the piercing member holder to slide the slidable cover over the piercing member to cover the piercing member and render it incapable of performing future injections. In preferred embodiments, the medication delivery device is a syringe, the piercing member is a needle, and the actuator member is a plunger rod. The needle is inserted under the skin to deliver medication, and medication is delivered by axial displacement of the plunger rod in the housing towards the piercing member holder. Also, the plunger rod is hollow and the disabling member is a spear-like member that ruptures the sealing diaphragm covering the plunger rod. Further, the sealing member is formed from an elastic material having an axial bore, the disabling member is a spear-like member also having a bore and holding the needle, and wherein the axial bore of the sealing member and the disabling member bore provide a passage way for medication to be delivered from the housing to the needle. In particular embodiments, the slidable protective cover is connected to the sealing member by a friction fit, and the sealing member has an axial bore to permit passage around the disabling member. Thus, when an injection is completed, the sealing member is axially displaced by the plunger rod to move the protective cover over the needle to render the needle unusable for future injections. In further embodiments, the slidable protective cover may be omitted and the medication delivery device is disabled by rupturing the sealing diaphragm coupled to the one end of the delivery actuator. Alternatively, the sealing diaphragm may remain intact during and after an injection and the medication delivery device is disabled by covering the piercing member with the slidable protective cover. Other features and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings which illustrate, by way of example, various features of embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS A detailed description of embodiments of the invention will be made with reference to the accompanying drawings, wherein like numerals designate corresponding parts in the several figures. FIG. 1 is a side exterior view of a disposable safety syringe in accordance with an embodiment of the present invention. FIG. 2 is an end exterior view of the disposable safety syringe shown in FIG. 1. FIG. 3 is a cross-sectional view of the disposable safety syringe of FIG. 1 containing medication for an injection. FIG. 4 is a cross-sectional view of the disposable safety syringe of FIG. 1 after completion of an injection and prior to disabling. FIG. 5 is a cross-sectional view of the disposable safety syringe of FIG. 1 after the syringe is disabled. FIG. 6 is a side exterior view of a slidable protective cap used with the embodiment of FIG. 1. FIG. 7 is another exterior view of a needle holder used with the embodiment of FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in the drawings for purposes of illustration, the invention is embodied in a disposable safety syringe. In preferred embodiments of the present invention, the disposable safety syringe is loaded with medication, used for an injection and then discarded. However, it will be recognized that further embodiments of the invention may be used with pre-filled syringes or other invasive injection devices that utilize sharp invasive implements, piercing members, or the like for delivering substances into the body. Embodiments of the present invention provide a relatively "passive" system for disabling a used syringe and safe-guarding a needle from re-use and accidental contact with a patient or caregiver after an injection. The disposable safety syringe utilizes an essentially continuous stroke for disabling and enclosing a needle on the disposable syringe, which does not rely on an entire range of complex human activity. The use of a continuous stroke increases compliance with bio-hazard disposal protocols to improve public safety in general and to aid in the control of infectious diseases. Use of the disabling feature of these safety syringes, for legitimate medical purposes after a single use, helps prevent the syringes from becoming available for illegal purposes (such as IV drug abuse and the like). Thus, embodiments of the safety syringe are primarily directed to a safety improvement in disposable fixed needle syringes that utilize a self-encapsulating needle coupled with a self-disabling plunger to effectively eliminate the dangers of cross-contamination through accidental needle sticks or the possibility of a second injection being given with a used syringe. Preferably, after an injection of medication, the forward motion of this safety syringe's plunger is continued, and a permanent, non-removable protective cover slips over and encloses the needle point while simultaneously destroying the syringe by piercing the plunger diaphragm so that is can no longer be used to displace medication. Therefore, embodiments of the syringe operate reliably and efficiently to provide protection from syringe re-use as well as from accidental needle sticks. Generally, embodiments of the safety syringe can be manufactured in all of the present disposable syringe sizes and may be useable for a variety of medical capacities, with various needle gauges, and for different medication applications. A disposable safety syringe 10 in accordance with an embodiment of the present invention is shown in FIGS. 1-5. The syringe 10 includes a housing 12, a plunger 14, a plunger diaphragm 16, a sealing gasket 18, a needle holder 20 including a spear-like member 22, a slideable protective cap 24, and a needle 26. In preferred embodiments, the housing 12 is manufactured from a clear polymer material that is certified for use in medical devices and syringes. During the initial stage of manufacturing, the housing 12 is injection molded with both ends of the housing 12 being open to facilitate proper sterilization and later assembly. In alternative embodiments, the housing 12 may be formed out of other materials, such as plastic, glass, metal, composites, a combination of materials, and the like, and may be formed by casting or die striking, or from multiple pieces that are either snap fitted or adhered together, or the like. The housing 12 has a plunger end 28 for receiving the plunger 14 and a piercing member end 30 for receiving the needle 26 and other members associated with the needle 26. At the plunger end 28 of the housing 12, there are integral finger supports 32 that are used to stabilize the syringe 10 during medication delivery. The exterior of the plunger portion 28 of the housing 12 includes radial markers that are graduated for accurate measurement of medication. The radial markers may also contain numbers which indicate fractional amounts of a CC or multiple CCs, depending on the size of the syringe and its medical application. In alternative embodiments, different markers or marking methods may used to accurately indicate the amount of medication contained in the syringe 10. An axial bore 34 is located through a centerline of the housing 12 extending from the plunger end 28 to the piercing member end 30 to contain measured amounts of medication. The axial bore 34 is also adapted to accept the plunger diaphragm 16 attached to the plunger 14 with a slight interference fit (created by the raised sealing rings 36) facilitating a proper seal to prevent or substantially reduce medication leakage during draw-up of medication and during delivery. The piercing member end 30 of the housing 12 is expanded in diameter relative to the plunger end 28 to contain the sealing gasket 18, the slideable protective cover or sheath 24 and the needle holder that includes the plunger diaphragm piercing device or spear-like member 22 that holds the needle 26. In alternative embodiments, the piercing member end 30 may be of a larger or smaller diameter, compared to the plunger end 28, with the relative size dependent on the size of the needle, protective cover, the size of the syringe and/or the environment in which the syringe will be used. In accordance with the embodiment of FIGS. 1-5, the plunger 14 is a hollow tube with one end 38 covered by the pierceable plunger diaphragm 16. The other end 40 of the plunger 14 includes enlarged finger rests 42 to provide stability and facilitate medication delivery when pushing the plunger 14 towards the piercing member end 30 of the housing 12. Once the end 38 is covered by the plunger diaphragm 16, the plunger 14 can be used to push the medication through the axial bore 34 of the housing 12 of the syringe 10. Preferably, the plunger 14 is manufactured from a semi-rigid polymer material which is certified for use on medical devices. However, in alternative embodiments, other materials such as plastics, glass, ceramics, metal, composites, or the like may be used. In addition, it is preferred that the end 40 is also open and connected to the end 38 of the hollow plunger 14 to further facilitate disabling of the syringe once the plunger diaphragm 16 is ruptured. This will allow medication to escape through the hollow plunger 14. However, in alternative embodiments, the end 40 may be closed off, and the hollow plunger may be open at end 38 to the interior of the hollow plunger, such that the hollow plunger 14 is only hollow for a sufficient length to permit rupturing of the plunger diaphragm 16. In further embodiments, the interior of the hollow plunger 14 is formed with barbs, or the like (not shown), to engage and lock the plunger 14 to the spear-like member 22 after the spear-like member 22 has ruptured the plunger diaphragm 16. In still further embodiments of the present invention, the hollow plunger rod may be formed with additional locking tabs, barbs, or the like (not shown) formed near the enlarged finger rests 42 to lock the plunger 14 into the housing 12 once the disabling continuous stroke is completed. In preferred embodiments, the plunger diaphragm 16 is an elastic cap that fits over the end 38 of the hollow plunger 14 to close off and seal the end 38 of the hollow plunger 14. In addition, the exterior surface of the plunger diaphragm 16 includes sealing rings 36 to provide a leak resistant seal between the plunger 14 and the interior of the axial bore 34 of the housing 12, which contains the medication. The plunger diaphragm 16 is pierceable by a push through detent needle, awl, or the spear-like member 22 that ruptures or tears the plunger diaphragm 16 after an injection to prevent the syringe 10 and the plunger diaphragm 16 from being utilized for future injections. Generally, the plunger diaphragm 16 is secured to the plunger 14 prior to final assembly and insertion into the axial bore of the plunger end 28 of the housing 12. In preferred embodiments, the plunger diaphragm 16 is formed from a molded elastic material, and is either glued on, snap fitted or secured by friction to the plunger 14. The plunger diaphragm is a molded product which is manufactured from a material that is certified for use in this type of medical device. In preferred embodiments, the plunger diaphragm is made of rubber. However, in alternative embodiments, the plunger diaphragm may be formed from plastic, polymers, foils, composites or other elastic materials. A soft pliable sealing gasket 18 is placed inside the piercing member end 30 of the housing 12 such that the sealing gasket 18 is in contact with the sides 44 of the piercing member end 28 to prevent or substantially reduce leakage of medication around the sealing gasket 18 during draw-up or an injection of medication. In preferred embodiments, the portion of the sealing gasket 18 that faces the axial bore 34 of the housing 12 includes a sealing ring to ensure proper sealing during draw-up and delivery of medication. The sealing gasket 18 also includes an axial bore 46 to form a part of a passage for a medication contained in the axial bore 34 of the housing 12 that is to be delivered to the needle 26. In preferred embodiments, the bore 46 is tapered to facilitate guidance of medication to the needle 26 and to handle hydraulic loads created during an injection better. However, other bore shapes and diameters may be used, with the choice being dependent on the size of the syringe, the type of medication, the size of the needle, and/or the like. The axial bore 46 is also used to form a substantially leak-proof seal with the spear-like member 22. The sealing gasket 18 has a circular recess 48, which is located and formed on a face 50 of the sealing gasket 18 that faces the spear-like member 22. The circular recess 48 is shaped to accept and retain gripping members 52 on the end of the slidable protective cap 24. In preferred embodiments, the sealing gasket 18 has an outer diameter near the face 50 that is slightly undersized from the inner diameter of the piercing member end 30 of the housing 12. This allows for displacement of the sealing gasket 18 during the continuous stroke associated with the displacement of the slideable protective cap 24 over the needle 26 which is carried out simultaneously with the puncturing the plunger diaphragm 16. In alternative embodiments, the sealing gasket 18 may use a segmented recess or have an outer diameter that is equal to or larger than the piercing member end 30 of the housing 12. Preferably, the slideable protective cap 24 is manufactured from a polymer which is certified for use in this type of medical device. However, in alternative embodiments, other suitable medical materials such as plastics, composites, metal, or the like may be used. As shown in FIG. 6, the slidable protective cap 24 is generally cylindrical in shape and segmented around the diameter of the slidable protective cap 24 to form one or more protective panels 54 having ends 56 forming a slot 58 to permit assembly of the various components and to act as a guide for the slidable protective cover 24 as it covers the needle 26 after completion of an injection. In preferred embodiments, there are four protective panels 54; however, in alternative embodiments, there may be one protective panel 54 and slot 58 or there may be a greater number of protective panels and slots with the number being dependent on the size of the syringe 10 and the materials that the slidable protective cap 24 and needle holder 20 are formed from. The slideable protective cover 24 includes the gripping members 52 at the end and on the inner surface of the protective panels 54, which are used to grip and secure the slidable protective cap 24 to the sealing gasket 18. The slidable protective cap 24 also includes locking members 60 on the exterior surface of the protective panels 54, which are used to lock the slidable protective cover 24 to the top and sides of the needle holder 20 after completion of an injection. In preferred embodiments, the gripping members 52 and the locking members 60 extend around the inner and outer circumference, respectively, of each protective panel 54. However, in alternative embodiments, the gripping members 52 and locking members 60 may be formed as short discrete tabs, nubs, teeth or the like. In preferred embodiments the gripping members 54 and locking members 60 have a triangular cross-section to secure the members to the sealing gasket and top and sides of the needle holder 20. However, in alternative embodiments, other cross-sections may be used to provide the locking and gripping functions. As shown in FIG. 7, the end of the needle holder 20 includes a needle bore 62 for securing the needle 26 and for providing a passage for the medication to travel through the spear-like member 22 to the needle 26 during an injection. Preferably, the top of the needle holder 20 has sides 64 around the outer diameter of the needle holder 20, and one or more spokes 66 extending from the sides 64 to a center support 68 of the needle holder 20 containing the needle bore 62. The area between the sides 64, spokes 66 and center support 68 forms ports 70 that permit the protective panels 54 of the slidable protective cap 24 to be inserted and slid down during assembly and to be slid up during the continuous stroke that disables the syringe 10 after an injection. In preferred embodiments, the top of the needle holder 20 includes four spokes 66 and four ports 70. However, in alternative embodiments, the top of the needle holder 20 may include as little as one spoke and one large port 70 or more spokes and ports with the number being dependent on the size of the syringe 10 and the materials from which the needle holder 20 and slidable protective cap 24 are formed. Attached to an underside of the center support 68 of the needle holder 20 is the spear-like member 22 that provides for fluid transfer to the needle 26, ruptures the plunger diaphragm 16 after an injection and assists in retaining the needle 26. Preferably, the needle holder 20 and the spear-like member 22 are formed as a single, integral piece from a "hard" polymer that is certified for use in this type of medical device. However, in alternative embodiments, the needle holder 20 and spear-like member may be formed from multiple parts and formed from other suitable medical materials, such as plastics, metal, glass, ceramics, composites, or the like. An end 72 of the spear-like member 22 mates with the internally tapered bore 46 of the sealing gasket 18 to provide a leak-proof or resistant seal with the housing 12 to provide a passage for the medication to be transferred from the housing 12 to the needle 26 during an injection. As discussed above, the end 72 of the spear-like member 22 is used to puncture or rupture the plunger diaphragm 16 when the user of the syringe has completed the medication injection delivery stroke. In preferred embodiments, the spear-like member is smooth to slide easily through the bore 34 of the sealing gasket 18 and the hollow plunger 14 after piercing the plunger diaphragm 16. However, in alternative embodiments, the spear-like member 22 may include ridges or barbs that resist attempts to reset the syringe 10, once the disabling procedure has begun. Disabling of the syringe 10 is accomplished by a continuous stroke after completion of an injection. The rupturing of the plunger diaphragm 16 is accomplished by a continued push through linear motion (e.g., the continuous stroke) of the plunger 14 at the end of the medication delivery stroke. This motion simultaneously pushes the end 72 through the bore 46 of the sealing gasket 18, through the plunger diaphragm 16 and into the hollow plunger 14. The spear-like member 22 also acts as a directional guide for the sealing gasket 18 and the slidable protective cap 24 as it slides to cover the needle 26. As the slidable protective cap 24 moves to cover the needle 26, the locking members 60 on the exterior of the protective panels 54 of the slidable protective cap 24 slide past the sides 64 of the top of the needle holder 20, and then the locking members 60 move outward to engage the top surface of the sides 64 of the needle holder 20 to prevent the slideable protective cap 24 from being pressed back into the piercing member end 30 of the housing 12 to re-expose the needle 26. Locking the slidable protective cap 24 in position also guards against accidental retraction of the slidable protective cap 24 during handling of the disabled syringe 10. In further embodiments, the completion of the continuous disabling stroke locks a portion of the hollow plunger 14 inside the axial bore 34 of the housing 12 near the plunger end 28 to prevent the plunger 14 from being withdrawn from the disabled device. To assemble the syringe 10, the end 38 of the plunger 14 is covered with the plunger diaphragm 16 to prepare the plunger 14 for insertion in the plunger end 28 of the housing 12. At this point, the plunger 14 may be inserted in the plunger end 28 of the housing 12 or may be inserted at the completion of the assembly process. Next, a needle 26 is secured in the needle bore 62 of the center support 68 in the top of the needle holder 20. However, in alternative embodiments, the needle 26 may be coupled to the needle bore 62 at the completion of the assembly of the sealing gasket, the needle holder 20 and the slideable protective cap 24. Then the protective panels 54 of the slidable protective cap 24 are slid through the corresponding ports 70 in the top of the needle holder 20. To facilitate passing the protective panels through the posts 70 and to avoid the locking members 60 from engaging with the sides 64 of the top of the needle holder 20, the protective panels 54 are preferably bent inward towards the center support 68 to provide sufficient clearance of the locking members 60. Once the slidable protective cap 24 is slid all the way down, until the end of the slidable protective cap 24 contacts the top of the needle holder 20, the sealing gasket is pressed against the end 72 of the spear-like member 22 and the gripping members 52 of the slidable protective cap 24. The sealing gasket 18 is then pressed to engage the end 72 of the spear-like member 22 in the bore 46 and to position the gripping members 52 in the recess 50 to secure the sealing gasket 18, needle holder 20 and slideable protective cap together as a unit. It should be noted that once the gripping members 52 of the protective panels 54 are secured in the recess of the sealing gasket 18, it is difficult to bend the protective panels 54 sufficiently inward to permit the locking members 60 to pass back over the sides 64 of the top of the needle holder 20 after the syringe 10 is disabled. At this point, the entire assembly of the sealing gasket 18, the needle holder 20 and the slidable protective cap 24 are inserted and slid into the piercing member end 30 of the housing 12 until the sealing gasket 18 contacts an end 74 of the housing 12. The top of the needle holder 20 is then spot welded, glued, snap fitted, or otherwise secured by a procedure acceptable for medical device, to the walls 44 of the piercing member end of the housing to secure the assembly in position. If a needle 26 has not yet been mounted in the needle bore 62, it is attached at the post. Once it is attached, the needle 26 and assembly are sterilized and a protective cover is attached to the housing 12 or the top of the needle holder 20 to maintain sterilization and protect the needle 26 during transport. In alternative embodiments, the protective cover 100 (not shown) can be secured to the end of the slidable protective cap 24 if it can be removed without pulling the slidable protective cap 24 and the sealing gasket 18 forward. In preferred embodiments, the protective cap is secured by spot welding. However, in alternative embodiments gluing, snap fits or the like may be used. If the plunger 14 has not yet been inserted in the plunger end 28 of the housing 12, the plunger 14 is inserted and slid until the plunger diaphragm 16 contacts the sealing gasket 18 at the end of the axial bore 34. Finally, the entire syringe is sterilized again and a protective end cap (not shown) is placed over the enlarged finger rests 42 to maintain sterilization and protect the plunger 14 from being depressed during transport. In preferred embodiments, the protective cap is secured by spot welding. However, in alternative embodiments gluing, snap fits or the like may be used. In preferred embodiments, the syringe 10 is assembled and sterilized using automated manufacturing processes. However, in alternative embodiments, the syringe 10 may be assembled by hand or by using a combination of hand and automated processes. While the description above refers to particular embodiments of the present invention, it will be understood that many modifications may be made without departing from the spirit thereof. The accompanying claims are intended to cover such modifications as would fall within the true scope and spirit of the present invention. The presently disclosed embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims, rather than the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

A medication delivery device for delivering medication using a piercing member. The medication delivery device includes a housing, a piercing member holder, a delivery actuator and a sealing diaphragm. The housing is for holding medication to be delivered, and includes a piercing member end and a delivery actuator end. The piercing member holder is coupled to the housing at the piercing member end and is adapted to secure the piercing member to the housing. The piercing member holder includes a sealing member that contacts the housing, a slideable protective cover coupled to the sealing member that slides over and contains the piercing member after a delivery of medication is delivered, and a disabling member for holding the piercing member, which is coupled to the housing at the piercing member end and configured to contact the sealing member to form a sealed passage for medication contained in the housing. The delivery actuator member is coupled to the delivery actuator end of the housing and adapted to expel the medication from the housing. The sealing diaphragm is coupled to one end of the delivery actuator to minimize contact of the medication with the delivery actuator and to substantially prevent leakage of medication through the delivery actuator. As an injection is completed, the disabling member of the piercing member holder contacts the sealing diaphragm and breaks it so that it is rendered incapable of performing future injections, and the delivery actuator member displaces the sealing member of the piercing member holder to slide the slidable cover over the piecing member to cover the piercing member and render it incapable of performing future injections.

CROSS REFERENCE TO RELATED APPLICATION The present invention is related to the following U.S. Patent Applications which are incorporated by reference: Ser. No. 10/116,612, filed Apr. 4, 2002, entitled, “Circuits And Systems For Limited Switch Dynamic Logic;” and Ser. No. 10/242,214 entitled “A Limited Switch Dynamic Logic Circuit” filed concurrently herewith. TECHNICAL FIELD The present invention relates to dynamic logic circuits, and in particular, to dynamic logic circuits for single and multilevel selection where the dynamic logic circuits have a dynamic switching factor to reduce power consumption. BACKGROUND INFORMATION Modern data processing systems may perform Boolean operations on a set of signals using dynamic logic circuits. Dynamic logic circuits are clocked. During the precharge phase of the clock, the circuit is preconditioned, typically, by precharging an internal node (dynamic node) of the circuit by coupling to a power supply rail. During an evaluate phase of the clock, the Boolean function being implemented by the logic circuit is evaluated in response to the set of input signal values appearing on the inputs during the evaluate phase. (For the purposes herein, it suffices to assume that the input signals have settled to their “steady-state” values for the current clock cycle, recognizing that the input value may change from clock cycle to clock cycle.) Such dynamic logic may have advantages in both speed and the area consumed on the chip over static logic. However, the switching of the output node with the toggling of the phase of the clock each cycle may consume power even when the logical value of the output is otherwise unchanged. This may be appreciated by referring to FIG. 1.1 illustrating an exemplary three-input OR dynamic logic gate, and the accompanying timing diagram, FIG. 1.2 . Dynamic logic 100 , FIG. 1.1 , includes three inputs a, b and c coupled to a corresponding gate of NFETs 102 a- 102 c . During an evaluate phase of clock 104 , N 1 , NFET 106 is active, and if any of inputs a, b or c are active, dynamic node 108 is pulled low, and the output OUT goes “high” via inverter 110 . Thus, referring to FIG. 1.2 , which is illustrative, at t 1 input a goes high during a precharge phase N 2 of clock 104 . During the precharge phase N 2 of clock 104 , dynamic node 108 is precharged via PFET 112 . Half-latch PFET 114 maintains the charge on dynamic node 108 through the evaluate phase, unless one or more of inputs a, b or c is asserted. In the illustrative timing diagrams in FIG. 1.2 , input a is “high” having a time interval t 1 through t 2 that spans approximately 2½ cycles of clock 104 , which includes evaluation phases, 116 and 118 . Consequently, dynamic node 108 undergoes two discharge-precharge cycles, 124 and 126 . The output node similarly undergoes two discharge-precharge cycles, albeit with opposite phase, 124 and 126 . Because the output is discharged during the precharge phase of dynamic node 108 , even though the Boolean value of the logical function is “true” (that is, “high” in the embodiment of OR gate 100 ) the dynamic logic dissipates power even when the input signal states are unchanged. Additionally, dynamic logic may be implemented in a dual rail embodiment in which all of the logic is duplicated, one gate for each sense of the data. That is, each logic element includes a gate to produce the output signal, and an additional gate to produce its complement. Such implementations may exacerbate the power dissipation in dynamic logic elements, as well as obviate the area advantages of dynamic logic embodiments. Selection circuits, including shifting circuits and multiplexors, are used extensively within computer systems. Some of these selection circuits require multiple levels of selection, for example, a first input is selected from a plurality of first inputs wherein each of the first inputs are additionally selected from a plurality of second inputs. Computer systems employing dynamic logic may find that it is difficult to implement selection circuits for single and multilevel selection from many inputs because of the limitations of required precharge and evaluation times as well as the fact that outputs are not held during the precharge cycle. Limited switching dynamic logic (LSDL) circuits produce circuits which mitigate the dynamic switching factor of dynamic logic gates with the addition of static logic devices which serve to isolate the dynamic node from the output node. Co-pending U.S. Patent Application entitled, “CIRCUITS AND SYSTEMS FOR LIMITED SWITCH DYNAMIC LOGIC,” Ser. No. 10/116,612 filed Apr. 4, 2002 and commonly owned, recites such circuits. Additionally, LSDL circuits and systems maintain the area advantage of dynamic logic over static circuits, and further provide both logic senses, that is, the output value and its complement. Therefore, there is a need for the advantages of LSDL to be used to implement multilevel selection circuits with large numbers of inputs. SUMMARY OF THE INVENTION The aforementioned needs are addressed by the present invention. Accordingly, there is an LSDL circuit configuration with a dynamic logic circuit having a corresponding dynamic node, and a plurality of logic input signals and selection signals, wherein the dynamic node has a precharge value during a first phase of a clock signal and an asserted value corresponding to a Boolean function of one or more input signals during the second phase of the clock signal. The value of the Boolean function is generated on one or more common nodes that are exclusively coupled to the dynamic node in response to one or more select signals. The dynamic node is further coupled to a static logic circuit which further generates an output and complement output of the LSDL circuit that is the value corresponding to the Boolean function of the values of the input signals selected by one of the select signals. The static logic section outputs the values of the dynamic node during the first phase of the clock signal and holds the value of the dynamic node during the second phase of the clock signal. Additionally, there are provided an integrated circuit (IC) and a data processing system including a plurality of logic devices for asserting a selected Boolean function of one or more input signals on a dynamic node. Also included is a static logic circuit coupled to the dynamic node wherein the static logic is configured to output the value of the dynamic node during a first phase of the clock signal while maintaining the output value of the logic device during a second phase of the clock signal; the output value represents the selected Boolean function of one or more input signals asserted on the dynamic node. Also a duration of the first phase of the clock signal is less than a duration of the second phase of the clock signal. The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. BRIEF DESCRIPTION OF THE DRAWINGS For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings in which: FIG. 1.1 illustrates, in partial schematic form, a dynamic logic gate which may be used in conjunction with the present invention; FIG. 1.2 illustrates a timing diagram corresponding to the logic gate embodiment illustrated in FIG. 1.1 ; FIG. 2.1 illustrates, in partial schematic form, a standard LSDL device illustrating the static logic devices for isolating the dynamic node from the output node; FIG. 2 . 2 . 1 illustrates, in partial schematic form, circuitry for incorporation in the logic tree of FIG. 2.1 whereby the logic function performed is the logical OR of three input signals; FIG. 2 . 2 . 2 illustrates, in partial schematic form, another circuit for incorporation in the logic tree of FIG. 2.1 whereby the logic function performed is the logical AND of three input signals; FIG. 2.3 illustrates a timing diagram corresponding to an embodiment of the dynamic logic device of FIG. 2.1 in which the logic function performed is the logical OR of three input signals; FIG. 3.1 illustrates, in block diagram form, an LSDL system that may incorporate LSDL selection circuits in accordance with embodiments of the present invention; FIG. 3.2 illustrates a two-phase clock which may be used in conjunction with the logic system of FIG. 3.1 ; FIG. 4 illustrates a high level block diagram of selected operational blocks within a central processing unit (CPU) incorporating the present inventive principles; FIG. 5 illustrates a data processing system configured in accordance with the present invention; FIGS. 6.1 and 6 . 2 are block diagrams of selection options used between an input and output word in an LSDL system employing embodiments of the present invention; FIG. 7.1 is a circuit diagram of a selection circuit according to embodiments of the present invention; FIG. 7.2 is a circuit diagram of another selection circuit according to embodiments of the present invention; and FIG. 8 is a generalized circuit diagram of a selection circuit according to embodiments of the present invention. DETAILED DESCRIPTION In the following description, numerous specific details are set forth to provide a thorough understanding of the present invention. For example, specific logic functions and the circuitry for generating them may be described; however, it would be recognized by those of ordinary skill in the art that the present invention may be practiced without such specific details. In other instances, well-known circuits have been shown in block diagram form in order not to obscure the present invention in unnecessary detail. Refer now to the drawings wherein depicted elements are not necessarily shown to scale and wherein like or similar elements are designated by the same reference numeral by the several views. FIG. 2.1 illustrates a limited switch dynamic logic (LSDL) device 200 used in accordance with the present inventive principles. In general, LSDL device 200 receives a plurality, n, of inputs 202 a . . . 202 d provided to logic tree 204 , and outputs a Boolean combination of the inputs. The particular Boolean function performed by LSDL device 200 is reflected in the implementation of logic tree 204 (accounting for the inversion performed by the inverter formed by n-channel field effect transistor (NFET) 206 and p-channel field effect transistor (PFET) 208 ). Logic tree 204 is coupled between the drain of PFET 212 and the drain of NFET 214 , node 216 . The junction of the logic tree 204 and the drain of PFET 212 forms dynamic node 210 . For example, FIG. 2 . 2 . 1 illustrates logic tree 230 including three parallel connected NFETs, 231 , 233 and 235 . Logic tree 230 may be used to provide a logic device generating the logical NOR of the three input signals coupled to corresponding ones of the gates of NFETs 231 , 233 and 235 , a, b and c (as indicated by the Boolean expression 250 in FIG. 2 . 2 . 1 ) and accounting for the inversion via NFET 206 and PFET 208 . Similarly, FIG. 2 . 2 . 2 illustrates a logic tree 240 including three serially connected NFETs 237 , 239 and 241 . Logic tree 240 may be used in conjunction with the logic device 200 to generate the logical NAND of the three input signals a, b and c (as indicated by the Boolean expression 260 in FIG. 2 . 2 . 2 ). Returning to FIG. 2 . 2 . 1 , dynamic node 210 is coupled to the common junction of the gates of NFET 206 and PFET 208 which invert the signal on dynamic node 210 . The inversion of the signal on dynamic node 210 is provided on Out 218 a . The transistor pair, 206 and 208 , is serially coupled to parallel NFETs 220 and 222 . NFET 220 is switched by clock signal 224 . Thus, during the evaluate phase of clock signal 224 , the inverter pair, NFET 206 and PFET 208 are coupled between the supply rails by the action of NFET 220 . The operation of LSDL device 200 during the evaluate phase, N 1 , may be further understood by referring to FIG. 2.3 illustrating an exemplary timing diagram corresponding to the dynamic logic circuit of FIG. 2.1 in combination with a logic tree embodiment 230 of FIG. 2 . 2 . 1 . In this way, for purposes of illustration, the timing diagram in FIG. 2.3 is the counterpart to the timing diagram in FIG. 1.2 for the three-input OR gate 100 depicted in FIG. 1.1 . As shown, input a is “high” or “true” between t 1 , and t 2 . In the evaluate phase, N 1 of clock signal 224 , dynamic node 210 is pulled down (intervals T 1 ). In these intervals, Out 218 a is held high by the action of the inverter formed by transistors 206 and 208 , which inverter is active through the action of NFET 220 as previously described. In the intervening intervals, T 2 , dynamic node 210 is pulled up via the action of the precharge phase, N 2 of clock signal 224 , and PFET 212 . In these intervals, the inverter is inactive as NFET 220 is off. Out 218 a is held “high” by the action of inverter 226 and PFET 228 . Note also that the output of inverter 226 may provide a complementary output, Out N 218 b . (Thus, with respect to the three-input logic trees in FIGS. 2 . 2 . 1 and 2 . 2 . 2 , the corresponding logic device represents a three-input OR gate and a three-input AND gate, respectively.) Returning to FIG. 2.1 , if the logic tree evaluates “high”, that is the Boolean combination of inputs 202 a . . . 202 d represented by logic tree 204 , evaluate high, whereby dynamic node 210 maintains its precharge, Out 218 a is discharged via NFET 206 and NFET 220 . In the subsequent precharge phase, N 2 , of clock signal 224 , Out 218 a is latched via the action of inverter 226 and NFET 222 . Thus, referring again to FIG. 2.3 , corresponding to the three input OR embodiment of logic device 200 and logic tree 230 (FIG. 2 . 2 . 1 ) at t 2 input a falls, and in the succeeding evaluate phase of clock signal 224 , dynamic node 210 is held high by the precharge. The inverter pair, NFETs 206 and 208 , are active in the evaluate phase of N 1 , of clock signal 224 because of the action of NFET 220 . Consequently, Out 218 a falls (t 3 ). In the succeeding precharge phase, N 2 of clock signal 224 , Out 218 a is latched in the “low” state, as previously described. In this way, LSDL device 200 in FIG. 2.1 , may provide a static switching factor on Out 218 a , and likewise with respect to the complementary output Out N 218 b . It would also be recognized by artisans of ordinary skill that although LSDL device 200 , FIG. 2.1 , has been described in conjunction with the particular logic tree embodiments of FIG. 2 . 2 . 1 and FIG. 2 . 2 . 2 , the principles of the present invention apply to alternative embodiments having other logic tree implementations, and such alternative embodiments fall within the spirit and the scope of the present invention. Note too, as illustrated in the exemplary timing diagram in FIG. 2.3 , the duty factor of the clock signal may have a value that is less than fifty percent (50%). In such an embodiment, the evaluate phase, N 1 , of the clock signal may be shorter in duration than the precharge phase, N 2 . A clock signal having a duty factor less than fifty percent (50%) may be referred to as a pulse (or pulsed) clock signal. Note that a width of the evaluate phase may be sufficiently short that leakage from the dynamic node may be inconsequential. That is, leakage does not affect the evaluation of the node. In such a clock signal embodiment, the size of the precharge device (PFET 212 in the embodiment of FIG. 2.1 ) may be reduced. It would be recognized by those of ordinary skill in the art that a symmetric clock signal has a fifty percent (50%) duty cycle; in an embodiment in which the duty cycle of the clock signal is less than fifty percent (50%), the size of the precharge device may be reduced concomitantly. In particular, an embodiment of the present invention may be implemented with a clock signal duty cycle of approximately thirty percent (30%). Additionally, while logic device 200 has been described from the perspective of “positive” logic, alternative embodiments in accordance with the present inventive principles may be implemented in the context of “negative” logic and such embodiments would also fall within the spirit and scope of the present invention. PFETs 208 and 228 , NFETs 206 , 220 , and 222 , and inverter 226 make an implementation of a static latching portion of LSDL 200 that is used in LSDL selection circuits according to embodiments of the present invention. A dotted line has been drawn around this group of devices designating it as static latch portion (SLP) 250 . This designation is used in the following sections to simplify explanation of principles of the present invention. The preceding example in FIG. 2.1 explains the operation of an LSDL circuit used to generate a Boolean combination of a number of inputs. In other logic circuits, it is desirable to generate selector functions wherein LSDL circuits are used to select between multiple inputs and direct the inputs to selected outputs. A selection circuit is often called a multiplexor (MUX) if it makes a selection between a plurality of inputs and directs one of the inputs to a particular output. MUX circuits are used extensively in computers. Because of the wide data busses used in modem computers, MUX circuits may require a large number of inputs. MUX circuits may be used to direct a particular bit (e.g., bit IB 0 ) from multiple input bytes (e.g., input byte 0 through byte N) to same bit (e.g., bit OB 0 ) in an output byte (e.g., output byte 0 ). Other types of selector circuits are used to permutate bits such that a particular bit (e.g., bit B 0 ) in a byte may be selected from multiple bits in another byte (e.g., bit B 0 or B 1 ). These selector circuits may be termed shift circuits or permutation circuits. Generally in logic permutation, a binary word has its bits reordered (permuted) and the number of possibilities is N factorial (N!) where N is the total number of bits in the word. Shifting may be thought of as a sub-set of general permutation. FIGS. 6.1 and 6 . 2 are block diagrams illustrating how bits in an input word 620 comprising Byte 0 601 , Byte 1 602 through Byte N 603 may be directed to an output word 630 comprising Bytes 0 604 , Byte 1 605 through Byte N 606 . In FIG. 6.1 , bit 0 of Byte 0 601 may be directed on path 610 to bit 0 of Byte 0 604 , path 611 to bit 0 of Byte 1 605 through Byte N 606 . FIG. 6.1 represents a MUX function where one input (e.g., bit 0 of Byte 0 601 ) may be selectively directed to several outputs (e.g., bit 0 of Byte 0 604 to bit 0 of Byte N 606 ). FIG. 6.2 represents more of a shift or permute function where multiple bits in particular bytes (e.g., bits 0 and 1 of Byte 0 601 ) may be directed to a particular bit (e.g., bit 0 of Byte 0 601 ). The operation illustrated in FIG. 6.1 requires N selection devices (not shown) between the N bytes of the input word 620 and a particular bit (e.g., bit 0 of Byte 0 604 ) in the output word 630 . FIG. 7.1 is a circuit diagram of an LSDL selection circuit according to embodiments of the present invention. Byte 0 701 represents an output byte of an output word (e.g., output word 630 ) which is selectively receiving data from a plurality of bytes from an input word (e.g., input word 620 ). Exemplary Byte 0 701 has eight bits, bit 0 702 through bit 7 704 . Each bit has a corresponding SLP circuit (e.g., SLP 706 ) substantially the same as SLP 280 explained in FIG. 2.1 . The selection circuitry is shown for only SLP 706 and SLP 708 . Clock 705 is directed to each SLP circuit in Byte 0 701 . While each SLP circuit generates an output and complement output, only one output is shown for simplicity. The input to SLP 706 is coupled to dynamic node 711 which is precharged with precharge PFET 709 during the logic zero phase of clock signal 705 . Clock signal 705 is also coupled to the gate of NFET 731 which serves to isolate the circuitry between dynamic node 711 and node 733 . During the logic zero phase of clock signal 705 , NFET 731 is gated OFF allowing dynamic node 711 to precharge regardless of the states of the devices between dynamic node 711 and node 733 . A plurality of logic trees are coupled between dynamic node 711 and node 733 . In this example, the logic trees make up a MUX for data bit 0 from N input bytes. In the circuit of FIG. 7.1 , data bit 0 from the N input bytes may be selectively coupled to bit 0 702 of Byte 0 701 . Since there are N bit zeroes (bit 0 ), there are N logic trees. NFET 713 and NFET 725 make up the logic tree for data bit 0 of input Byte 0 (D B 00 ), NFET 714 and NFET 726 make up the logic tree for data bit 0 of input Byte 1 (D B 10 ), and sequentially through to NFET 715 and NFET 727 which make up the logic tree from data bit 0 of input Byte N (D BN 0 ). NFET 713 , NFET 714 , and NFET 715 selectively couple their corresponding common nodes 719 , 720 and 721 to dynamic node 711 in response to their select signals S 1 B 00 , S 1 B 10 and S 1 BN 0 , respectively. The select signals (S 1 B 00 , S 1 B 10 and S 1 BN 0 ) are termed “one hot” signals which indicates that at any one select time only one signal is a logic true activating its corresponding select device (e.g., NFET 713 ). Because of the previously explained latching function of the SLP circuits, the precharge portion of the clock signal 705 is longer than the evaluate portion. Since the precharge time is longer, the precharge devices are smaller and have less capacitance. This allows many parallel devices to be coupled to dynamic node 711 resulting in a large number of inputs forming a many to one MUX function. All the bits in Byte 0 701 have a corresponding selection circuit. The circuitry for bit 7 of Byte 0 701 is also shown for example. Similar to bit 0 , data bit 7 from the N input bytes may be selectively coupled to bit 7 704 of Byte 0 701 . Since there are N bit sevens (bit 7 ), again there are N logic trees. NFET 716 and NFET 728 make up the logic tree for data bit 7 of input Byte 0 (D B 07 ), NFET 717 and NFET 729 make up the logic tree for data bit 7 of input Byte 1 (D B 17 ), and sequentially through to NFET 718 and NFET 730 which make up the logic tree from data bit 7 of input Byte N (D BN 7 ). NFET 716 , NFET 717 , and NFET 718 selectively couple their corresponding common nodes 722 , 723 and 724 to dynamic node 712 in response to their select signals S 1 B 00 , S 1 B 10 and S 1 BN 0 , respectively. In the example of FIG. 7.1 , the selection is byte-wise. This means that if any bit in a particular input byte (e.g., input Byte 1 ) is directed to output Byte 0 701 , then all the bits of that byte are directed to Byte 0 701 . This would insure that all the select signals (S 1 B 00 -S 1 BN 0 ) are the same for each bit in the byte. To further explain the operation of the selection circuitry of FIG. 7.1 , only one bit need be explained in detail as the selection of all other bits operate the same. Assume then that S 1 Bl 0 is a logic one and all other selection signals are a logic zero (one-hot principle). This means that the bits from input Byte 1 are directed to output Byte 0 701 . Also assume that the particular bit 0 from Byte 1 of the input word (D B 10 ) is also a logic one. S 1 B 10 is activated coincident with the precharge phase (logic zero) of clock signal 705 . PFET 709 turns ON and NFET 731 turns OFF isolating the logic trees, and in particular, the logic tree comprising the series connection of NFET 714 and NFET 726 . Since S 1 B 10 is a logic one both dynamic node 711 and common node 720 are precharged during the precharge phase of clock signal 705 . This insures that when the values asserted on dynamic node 711 by the state of D B 10 during the evaluation phase of clock signal 705 is correct. For example, assume the previous state of D B 10 was a logic one and common node 720 was discharged to ground. If the next state of D B 10 is a logic zero, then node 720 would modify dynamic node 711 if it had not also been precharged along with dynamic node 711 during the precharge phase of clock signal 705 . When clock signal 705 transitions to its evaluate phase, PFET 709 is turned OFF and NFET 731 is turned on allowing a logic one state of D B 10 to discharge dynamic node 711 or a logic zero state of D B 10 to leave dynamic node 711 in a logic one charged state. SLP 706 asserts the logic one value of dynamic node 711 to output bit 0 702 of Byte 0 701 . Feedback from the output of SLP 706 then latches the output state so that it remains during the next precharge phase of clock signal 705 . FIG. 7.2 is another selection circuit according to embodiments of the present invention illustrating multilevel selection. Again, Byte 0 701 represents an output byte of an output word (e.g., output word 630 ) which is selectively receiving data from a plurality of bytes from an input word (e.g., input word 620 ). Exemplary Byte 0 701 has eight bits, bit 0 702 through bit 7 704 . Each bit has a corresponding SLP circuit (e.g., SLP 706 ) substantially the same as SLP 280 , explained in FIG. 2.1 . The selection circuitry is shown for only SLP 706 and SLP 708 . Clock 705 is directed to each SLP circuit in Byte 0 701 . While each SLP circuit generates an output and complement output, only one output is shown for simplicity. PFET 709 turns ON and NFETs 760 and 761 are gated OFF during the precharge phase of clock signal 705 . Dynamic node 741 is precharged by PFET 709 during the precharge phase of clock signal 705 . Section circuit 772 , comprising NFET 750 and NFET 751 , selectively couples dynamic node 741 to node 763 and 762 in response to select signals S 20 and S 20 N. S 20 and S 20 N are complement logic signals and therefore are one-hot select signals. The logic tree coupled to common node 763 selects between D B 01 and D B 11 (bit 0 and bit 1 of input Byte 1 ) in response to select signals S 10 and S 10 N. Likewise, the logic tree coupled to common node 762 selects between D B 02 and D B 12 (bit 0 and bit 1 of input Byte 2 ) in response to select signals S 10 and S 10 N. If S 10 is a logic one, then the value of D B 01 or D B 02 will be asserted on dynamic node 741 depending on the states of S 20 and S 20 N during the assertion phase of clock signal 705 . During the precharge phase, either common node 763 or 762 will be precharged along with dynamic node 741 guaranteeing that whichever logic tree is selected by S 20 /S 20 N will have its common node precharged. Other logic tree configurations may be used with the one-hot selection and still be within the scope of the present invention. FIG. 8 is a circuit diagram illustrating a generalized selection circuit according to embodiments of the present invention. An SLP 801 having output 818 and complementary output 819 is coupled to clock signal 804 and a dynamic node 806 . A plurality of logic trees (e.g., 802 and 803 ) are coupled to dynamic node 806 with devices NFETs 810 and 811 in response to one-hot selection signals 1 HS 1 and 1 HSn. The logic trees coupled to a dynamic node 806 may have different numbers of multiple inputs (e.g., 814 and 815 ) and may differ in their functionality. There is a practical limit in the number of series devices between a dynamic node 806 and an assertion device (e.g., NFET 816 and NFET 817 ). The one-hot principle for controlling the selection devices (e.g., 1 HS 1 and 1 HSn) is required to insure that the common node on the logic trees is precharged along with the dynamic node. FIG. 3.1 illustrates a portion 300 of a data processing system incorporating LSDL circuits in accordance with the present inventive principles. System portion 300 may be implemented using a two-phase clock signal (denoted clock 1 and clock 2 ). A timing diagram which may be associated with system portion 300 will be discussed in conjunction with FIG. 3.2 . LSDL blocks 302 b that may be clocked by a second clock signal phase, clock 2 , alternates with LSDL block 302 a clocked by the first clock signal phase, clock 1 . Additionally, system portion 300 may include static logic elements 304 between LSDL blocks. Typically, static circuit blocks 304 may include gain stages, inverters or static logic gates. Static circuit blocks 304 are differentiated from LSDL blocks 302 a and 302 b as they do not have dynamic nodes that have a precharge cycle. However, alternative embodiments may include any amounts of static logic. Additionally, as previously mentioned, an embodiment of system portion 300 may be implemented without static circuit blocks 304 . FIG. 3.2 illustrates a timing diagram which may correspond to logic system employing a two-phase, pulsed clock signal, such as system portion 300 , FIG. 3.1 , in accordance with the present inventive principles. The LSDL circuits evaluate during the LSDL evaluate, or drive, portion 306 of their respective clock signals. As previously described, the duty factor of each of clock 1 and clock 2 may be less than fifty percent (50%). The width of the LSDL drive portions 306 of the clock signals need only be sufficiently wide to allow the evaluate node (such as dynamic node 210 , FIG. 2.1 ) to be discharged through the logic tree (for example, logic tree 204 , FIG. 2 . 1 ). As previously described, the duration of the drive portion may be sufficiently narrow that leakage from the evaluation may be inconsequential. Consequently, LSDL circuits are not particularly sensitive to the falling edge of the clock signals, and in FIG. 3.2 , the falling portion of the evaluate phase 306 of the clock signals has been depicted with cross-hatching. As noted herein above, the duty factor of clock 1 and clock 2 may be approximately thirty percent (30%) in an exemplary embodiment of the present invention. (It would be appreciated, however, that the present inventive principles may be incorporated in alternative embodiments which have other duty factors.) During the precharge portion 308 of the clock signals, the dynamic node (for example, dynamic node 210 , FIG. 2.1 ) is precharged, as previously discussed. Clock 2 is 180° (π radians) out of phase with clock 1 (shifted in time one-half of period T). Thus as shown, the evaluate portion 306 of clock 2 occurs during the precharge phase 308 of clock 1 . Because in LSDL circuits, the output states may not change during the evaluate phase of the driving clock signal; the inputs to LSDL blocks, for example, LSDL blocks 302 b , FIG. 3.1 , are stable during the evaluate phase of the corresponding driving clock signal, clock 2 . The time interval, between the end of the evaluate portion 306 of clock 1 and the rising edge of clock 2 may be established by the setup time of the LSDL, and the evaluation time of the static blocks, if any (for example, static blocks 304 , FIG. 3 . 1 ). The time, Tau 301 , together with duty factor may determine the minimum clock signal period for a particular LSDL circuit implementation. Thus, a system portion 300 , FIG. 3.1 having a two-phase clock signal effects two dynamic evaluations per period, T, of the driving clock signals. It would be further appreciated by those of ordinary skill in the art that, in general, the present inventive principles may be incorporated in alternative embodiments of an LSDL system having a plurality, n, of clock signal phases. Such alternative embodiments would fall within the spirit and scope of the present invention. An LSDL system in accordance with the principles of the present invention, such as system 300 , FIG. 3.1 , may be used, in an exemplary embodiment, in an arithmetic logic unit (ALU). A typical ALU architecture requires a significant number of exclusive-OR (XOR) operations. The XOR of two Boolean values requires having both senses of each of the Boolean values, that is, both the value and its complement (a⊕b=ab′+a′b). As previously described, use of dual rail dynamic logic to implement such functionality obviates the advantages in area and power otherwise obtained by dynamic logic. A data processing system including an ALU embodying the present inventive principles is illustrated in FIG. 4 . The MUX function illustrated in FIG. 7.1 is also used in many areas of a data processing system when data from many sources may be selectively coupled to a single processing unit. The function illustrated in FIG. 7.2 may be used to modify or permutate the bits in a byte for example by shifting bit 1 to bit 0 , bit 2 to bit 1 , etc. The permute function is common in many microprocessor media units. FIG. 4 is a high level functional block diagram of selected operational blocks that may be included in a central processing unit (CPU) 400 . In the illustrated embodiment, CPU 400 includes internal instruction cache (I-cache) 440 and data cache (D-cache) 442 which are accessible to memory (not shown in FIG. 4 ) through bus 412 , bus interface unit 444 , memory subsystem 438 , load/store unit 446 and corresponding memory management units: data MMU 450 and instruction MMU 452 . In the depicted architecture, CPU 400 operates on data in response to instructions retrieved from I-cache 440 through instruction dispatch unit 448 . Dispatch unit 448 may be included in instruction unit 454 which may also incorporate fetch unit 456 and branch processing unit 458 which controls instruction branching. An instruction queue 460 may interface fetch unit 456 and dispatch unit 448 . In response to dispatched instructions, data retrieved from D-cache 442 by load/store unit 446 can be operated upon by one of fixed point unit (FXU) 460 , FXU 462 or floating point execution unit (FPU) 464 . Additionally, CPU 400 provides for parallel processing of multiple data items via vector execution unit (VXU) 466 . VXU 466 includes vector permute unit 468 which performs permutation operations on vector operands, and vector arithmetic logic unit (VALU) 470 which performs vector arithmetic operations, which may include both fixed-point and floating-point operations on vector operands. VALU 470 may be implemented using LSDL in accordance with the present inventive principles, and in particular may incorporate LSDL systems, of which LSDL system 300 , FIG. 3.1 is exemplary. Other units may employ LSDL selection circuits according to embodiments of the present invention. A representative hardware environment 500 for practicing the present invention is depicted in FIG. 5 , which illustrates a typical hardware configuration of a data processing system in accordance with the subject invention having CPU 400 , incorporating LSDL selection circuits according to the present inventive principles, and a number of other units interconnected via system bus 412 . The data processing system shown in FIG. 5 includes random access memory (RAM) 514 , read only memory (ROM) 516 , and input/output (I/O) adapter 518 for connecting peripheral devices such as disk units 520 to bus 412 , user interface adapter 522 for connecting keyboard 524 , mouse 526 , and/or other user interface devices such as a touch screen device (not shown) to bus 412 , communication adapter 534 for connecting the system to a data processing network, and display adapter 536 for connecting bus 412 to display device 538 . Note that CPU 400 may reside on a single integrated circuit. Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

Selector circuits and systems for single and multilevel selection within one clock cycle having a static switching factor on the output of a dynamic logic circuit. A logic device for single and multilevel selection having a dynamic logic circuit portion and a static logic circuit portion is implemented. In this way, an output logic state is maintained so long as the value of the Boolean operation being performed by the logic device does not change. Additionally, static logic elements may perform the inversions necessary to output both logic senses, mitigating the need to provide for dual-rail dynamic logic implementations. An asymmetric clock permits a concomitant decrease in the size of the precharge transistors thus ameliorating the area required by the logic element and obviating a need for keeper device.

[0001] Portions of this invention were made using funding from the National Institutes of Health (NIH/NCMHD Grant No. 1P60-MD002256), and the U.S. Government has certain rights in this invention. BACKGROUND [0002] 1. Field of the Invention [0003] The invention is generally related to increasing the bioavailability of bioactive compounds which are administered or taken orally, and more particularly, to using compounds which are generally regarded as safe (GRAS), particularly certain phenolic compounds, to prevent or decrease pre-systemic or systemic metabolism or clearance of the bioactive compounds. [0004] 2. Description of the Prior Art [0005] Increasing the bioavailablity of compounds provided to a subject to treat various diseases has been a subject of intense investigation for a number of years. Furthermore, there have been a number of approaches that have employed compositions that include a drug in combination with substances that are Generally Regarded As Safe (GRAS) compounds. [0006] U.S. Pat. No. 5,972,382 to Majeed et al. teaches compositions and methods for the improvement of gastrointestinal absorption and systemic utilization of nutrients and nutritional supplements by combining them with piperine, an alkaloid derived from black pepper. Majeed does not discuss the delivery of drugs per se, and piperine is not a GRAS compound. [0007] U.S. Pat. No. 7,576,124 to Harris describes “first-pass” inhibiting furocoumarin compounds that are purportedly safe and effective. The furocoumarins are citrus-derived substances prepared from, e.g., grapefruit. Harris does not identify which components of pre-systemic metabolism are inhibited, but the cytochrome P450 family of enzymes is referenced. The furocoumarins are not described as GRAS. [0008] U.S. Pat. No. 7,125,564 to Chen et al. discusses problems associated with first-pass degradation of bioactive treatment compounds, and teaches the use of water-soluble complexes with glycyrrhizin, which is the main sweet-tasting compounds from licorice root. Glycyrrhizin is described as GRAS. Chen does not indicate that glycyrrhizin can inhibit first pass metabolism; rather, Chen discusses having the compositions parenterally administered to avoid the first-pass effect. [0009] U.S. Pat. No. 7,070,814 to Qazi et al. teaches compositions which are purportedly bioenhancing/bioavailability-facilitating. These compositions include an extract and/or at least one bioactive fraction from the Cuminum cyminum plant (i.e., the plant from which the spice cumin is derived). This extract is combined with drugs, nutrients, vitamins, nutraceuticals, herbal drugs/products, micro nutrients, and antioxidants, along with pharmaceutically acceptable additives/excipients. Similar to the Majeed patent, Qazi discusses optionally including piperine (or extract/fraction of piper nigrum or piper longum ) to purportedly increase the beneficial effect of the extract. Qazi is particularly focused on the problem of pre-systemic metabolism of drugs and suggests that the compositions described in the patent may function by inhibiting or reducing the rate of biotransformation of drugs in the liver or intestines. Qazi does not identify the extract as including GRAS compounds. [0010] U.S. Pat. No. 6,180,666 to Wacher et al. describes orally co-administering a compound of interest with a gallic acid ester such as octyl gallate, propyl gallate, lauryl gallate, and methyl gallate. Gallic acid is a trihydroxybenzoic acid, a type of organic phenolic acid found in plants such as gallnuts, sumac, witch hazel, tea leaves, and oak bark. The gallic acid ester is purportedly present in order to inhibit biotransformations of drugs that are carried out e.g. by cytochromes P450. The esters are described as GRAS compounds. [0011] U.S. Pat. No. 6,121,234 to Benet et al., describes a method for purportedly increasing bioavailability and reducing inter- and intra-individual variability of an orally administered hydrophobic pharmaceutical compound. In Benet, the pharmaceutical compound is orally co-administered with an essential oil or essential oil component. Benet suggests that the role of the essential oil may be to inhibit drug biotransformation in the gut. Essential oils are described as GRAS compounds. [0012] US patent application 2003/0215462 to Wacher et al. describes using UDP-glucuronosyltrasnsferase (UGT) inhibitors to increase the bioavailability orally administered drugs. Wacher suggests the formulation may be used with 2-methoxyestradiol, raloxifene, irinotecan, SN-38, estradiol, labetalol, dilevalol, zidovudine (AZT) and morphine. The UDP-inhibitors are generally natural products and include epicatechin gallate, epigallocatechin gallate, octyl gallate, propyl gallate, quercetin, tannic acid, benzoin gum, capsaicin, dihydrocapsaicin, eugenol, gallocatechin gallate, geraniol, menthol, menthyl acetate, naringenin, allspice berry oil, N-vanillylnonanamide, clovebud oil, peppermint oil, silibinin, and silymarin. Wacher does not list resveratrol and phenylephrine as exemplary drugs, nor are the GRAS substances propyl paraben, vanillin, vitamin C and curcumin identified as being useful in Wacher. The objective of the Wacher technology appears to be the identification of specific combinations of drugs and inhibitors that work well together. Wacher notes that “ . . . a compound that inhibits the glucuronidation of one substrate does not necessarily prevent the glucuronidation of all UGT substrates . . . ”. [0013] US patent applications 2006/0040875 and 2009/0093467 to Oliver et al. describe UGT2B inhibitors that can increase the bio-availability of drugs. Specifically named inhibitors are natural products such as capillarisin, isorhamnetin, β-naphthoflavone, α-naphthoflavone, hesperetin, terpineol, (+)-limonene, β-myrcene, swertiamarin, eriodictyol, cineole, apigenin, baicalin, ursolic acid, isovitexin, lauryl alcohol, puerarin, trans-cinnamaldehyde, 3-phenylpropyl acetate, isoliquritigenin, paeoniflorin, gallic acid, genistein, glycyrrhizin, protocatechuic acid, ethyl myristate, and umbelliferone. Suggested drugs for which bioavailability can be increased include morphine, naloxone, nalorphine, oxymorphone, hydromorphone, dihydromorphine, codeine, naltrexone, naltrindole, nalbuphine and buprenorphine. The focus of Oliver is on the delivery of analgesics. [0014] US patent application 2010/0087493 to Kaivosaari et al. teaches a method for increasing bioavailability of a pharmacologically active agent that undergoes direct N-glucuronidation by UDP-glucuronosyltransferase isoenzyme UGT2B10 by administering an UGT2B10 modulator, e.g. an inhibitor of UGT2B10 (preferably selectively for UGT2B10 over UGT1A4). The drugs for which bioavailability may be increased are described as having a nucleophilic nitrogen atom, including primary, secondary and tertiary aryl- and alkylamines, sulfonamides and aromatic or aliphatic heterocyclic compounds having one or more nitrogen atoms as heteroatoms. Nicotine is identified as an example. The inhibitors are not described in detail, and only Levomedetomidine is provided as an example. [0015] WO/2011/026112 describes methods of increase bioavailability of a pharmaceutically active agent by using specific inhibitors of a UGT that glucuronidates the pharmaceutically active agent. However, in WO/2011/026112, the inhibitors are described as comprising an N-acyl phenylaminoalcohol residue and a uridine moiety connected by a spacer. Thus, the use of GRAS compounds does not described in WO/2011/026112. [0016] WO 2010015636 20100211 teaches beta-carbolin-derivatives to inhibit UGTs and thereby increase bioavailability of drugs such as antibiotics. However, the use of GRAS compounds for this purpose is not discussed. [0017] Prior to the present invention, there has been little work on strategies to increase phenylephrine oral bioavailability, and no approaches which target enzymes which target phenylyephrine metabolism and which avoid enzymes which can result in toxicity and adverse effects. SUMMARY [0018] Phenolic compounds are commonly substrates for vigorous metabolism processes in the body of a subject, or are substrates for efflux transporters, or can function as substrates for both processes. These phenolic compounds often have rapid pre-systemic and/or systemic clearance, or insufficient tissue distribution. As a result, metabolism and transport processes often limit the medical utility of various phenolic compounds as pharmacologic agents. An embodiment of the invention uses one or more compounds to inhibit enzymes responsible for the rapid pre-systemic metabolism, and thus allows drugs to be absorbed in the body intact. Preferably, the compounds are “generally recognized as safe” (“GRAS”) by the US Food and Drug Administration (FDA) or are dietary in nature. Exemplary compounds can be vitamins and nutrients such as ascorbic acid and niacin, phenolic flavoring agents such as vanillin and eugenol, antioxidants such as propylgallate and propylparaben, and dietary polyphenols such as quercetin, and combinations thereof. Compounds, and combinations of compounds, and particularly phenolic compounds useful in the practice of the invention are discussed in more detail below. [0019] One barrier to attaining high systemic levels of a bioactive (e.g., a drug, neutraceutical, or other entity which causes and increase or decrease of an activity of interest in a cell) in a recipient is that the body (e.g. the digestive system or gut) has a number of enzymes which rapidly modify molecules prior to their entry into the circulatory system. This pre-systemic metabolism (also known as the “first-pass” effect), converts drugs to forms that are biologically less active, or even inactive, and/or which generally have low bioavailability. Examples of such enzymes include sulfotransferases (SULT's), glucuronosyltransferases (UGT's), members of the cytochrome P450 (CYP) family, catechol-O-methyltransferase (COMT), and monoamine oxidases (MAO's). By administering drugs or agents of interest together with one or more GRAS compounds or phenolic compounds or other compounds described herein which are inhibitors of these metabolic enzymes, inhibition of the enzymes can be achieved, and the drugs or other bioactive agents to be provided therewith are not modified (or are modified to a lesser extent) and retain their active form upon entering systemic circulation. [0020] In addition, toxicity that may be associated with high doses of a bioactive compound is reduced by 1) using only GRAS compounds and 2) administering a combination of different GRAS compounds, each of which is used in lesser amounts than if administered alone. A combination may include compounds from different GRAS categories e.g. vitamins, phenolic flavoring agents, antioxidants, etc. Examples of drugs or bioactives which may be successfully administered in this manner include phenylephrine, albuterol, 2-methoxyestradiol, and (the natural products) silybin, raspberry ketone, pinoresinol, magnolol, α-mangostin, and resveratrol; however, it will be recognized by those of skill in the art that the invention can be practiced with a number of different bioactive agents. [0021] The 2006 Stop Meth Act resulted in the substitution of phenylephrine for pseudophedrin in many high volume over the counter (OTC) products. Unfortunately, many patients have been unsatisfied with phenylephrine products, and this is likely due to low oral bioavailability. An embodiment of this invention pertains to a strategy to improve the absorption of phenylephrine using a safe and selective approach to inhibit phenylephrine metabolism. Since the availability of pseudoephedrine for non-prescription usage has been limited, many cold/flu products have been substituted with phenylephrine. However, phenylephrine has low oral bioavailability (<38%) and erratic absorption. (Hengstmann and Goronzy, 1982; Kanfer et al., 1993; Stockis et al., 1995) Phenylephrine is extensively presystemically metabolized by three major metabolic pathways: sulfation (mostly in the gut), oxidative deamination, and glucuronidation, and of these sulfation is the major route. (Hengstmann and Goronzy, 1982) Due to its low oral bioavailability, an embodiment of this invention employs a strategy that increases the bioavailability, and thus clinical efficacy, of an oral phenylephrine product. [0022] The specific enzyme isoforms responsible for metabolizing phenylephrine in humans have not been clearly established, despite decades of clinical utility. However, one may infer its metabolic route from available data. First, the major metabolite of phenylephrine (PE) following an oral dose is phenylephrine-3-O-sulfate (PE-3S), but when the drug is given intravenously it is mainly oxidatively deaminated. (Hengstmann and Goronzy, 1982) As a result, it is inferred that the sulfotransferases (SULTs) in the intestinal wall are mainly responsible for phenylephrine sulfation. As a phenolic monoamine, PE bears structural similarities with compounds such as dopamine, serotonin, and terbutaline which are good substrates for SULT isoform 1A3 (SULT1A3). (Pacifici and Coughtrie, 2005) Furthermore, other data show that SULT1A3 protein is more highly expressed and has higher enzymatic activity in the small intestine compared to the liver, where it is very low or absent. (Pacifici and Coughtrie, 2005; Riches et al., 2009) Besides catecholamines, SULT1A3 also conjugates many monoamines including serotonin and the β-adrenergic agonists such as salbutamol (albuterol) and terbutaline. (Pacifici and Coughtrie, 2005) In fact, SULT1A3 has been proposed as the causative factor in the very low oral bioavailability (14±2%) of terbutaline. (Pearson and Wienkers, 2009) [0023] In an embodiment of the invention, one or more inhibitor compounds (e.g. SULT, UGT, CYP, COMT and/or MAO inhibitors) are combined with a bioactive (e.g., phenylephrine). On oral administration of the combination to a subject (e.g., human or animal), the one or more inhibitor compounds inhibit the enzymes responsible for the rapid pre-systemic metabolism, thus allowing the drug to be absorbed intact. The inhibitor compounds are preferably chosen from the FDA's list of GRAS compounds, or the FDA's list of food additives (EAFUS), or other dietary compounds including dietary supplements. Combinations of inhibitor compounds can be used to synergize inhibitory effects while minimizing toxicity of each compound used. Combinations of compounds from the same or different categories (including but not limited to vitamins and nutrients such as ascorbic acid and niacin; phenolic flavoring agents such as vanillin and eugenol; antioxidants such as propylgallate and propylparaben; and dietary polyphenols such as quercetin) can be used. [0024] In an exemplary embodiment of the invention, a subject (human or animal) is provided with an oral dose of a bioactive in combination with one or more enzymatic inhibitors (sulfotransferases (SULTs), glucouronosyltransferases (UGTs), members of the cytochrome P450 (CYP) family, catechol-o-methyltransferases (COMTs), and monoamine oxidases (MAOs)). Exemplary bioactives can include phenylephrine, albuterol, 2-methoxyestraodiol, silybin, raspberry ketone, pinoresinol, magnolol, α-mangostin, resveratrol, raloxifene, estradiol, ethinyl estradiol, terbutaline, etilephrine, synephrine, octopamine, pterostilbene, mangiferin, puerarin, salvianolic acid A, tyrosol, honokiol, marsupsin, irigenin, caffeic acid phenethyl ester (CAPE), nimbidiol, dobutamine, prenalterol, ritodrine, nadolol, labetalol, isoproterenol, L-dopa, methyldopa, salsolinol, hordenine, rosmarinic acid, ellagic acid, emodin, and amentoflavone. In some embodiments the one or more bioactives are present in a dose ranging from 0.1 mg to 200 mg, and said one or more enzymatic inhibitors are present in a dose ranging from 0.25 mg to 225 mg. DESCRIPTION OF THE DRAWINGS [0025] FIG. 1 is a schematic drawing of a synthesis procedure [0026] FIGS. 2A-F are graphs showing test results for various compounds incubated with LS180 cells as described above in the absence or presence of inhibitor treatment combinations A or B (see Example 4) DETAILED DESCRIPTION [0027] SULT1A3 is a major isoform highly expressed in the intestine, but poorly expressed (or undetectable) in the liver. (Riches et al., 2009) Furthermore, the activity of human gastrointestinal SULTs has been characterized, and the dopamine sulfation activity (which includes SULT1A3 and 1A1) was much higher in the small intestine than the stomach or colon; it was also three-fold higher than the liver. (Chen et al., 2003) These data have been considered and integrated into pharmacokinetic models, which assert that intestinal sulfation (particularly mediated by SULT1A3) is the major determinant of pre-systemic metabolism of terbutaline and salbutamol (albuterol). (Mizuma et al., 2005; Mizuma, 2008) [0028] Additionally, SULT1A1 is expressed in both the small intestine and the liver, although its expression and activity are higher in the liver, and it exhibits a more general substrate selectivity toward phenols. (Pacifici and Coughtrie, 2005) Furthermore, SULT1B1 is the most highly expressed isoform in the human intestine, and is capable of sulfating thyroid hormones as well as other prototypical SULT substrates including 1-naphthol and p-nitrophenol; beyond this, its substrate selectivity is poorly understood. (Riches et al., 2009) SULT2A1 is also expressed in the human intestine and sulfates phenols. (Riches et al., 2009) Other SULTs are expressed at low levels in the intestine and/or do not accept phenols/monoamines as substrates. (Pacifici and Coughtrie, 2005; Riches et al., 2009) [0029] From the data discussed above, the inventors of the present invention infer that SULTs (including isoforms 1A1, 1B1, 2A1, and especially 1A3) play an important role in the intestinal presystemic metabolism of phenylephrine, and may play an important role in the intestinal presystemic metabolism of a number of other bioactives. The approach for increasing the bioavailability of phenylephrine (or other bioactive) described herein operates on the premise that intestinal SULT activity is the major determinant of presystemic metabolism of phenylephrine, and that inhibiting intestinal SULT results in a significant increase in oral bioavailability of phenylephrine (or other bioactives, e.g., 2-methoxyestrodiol, resveratrol, etc.). To increase bioavailability of a bioactive, a sufficient quantity of one or more SULT inhibitors should be combined with the bioactive (e.g., PE), so that the when the combination is taken orally, a greater amount of the PE remains intact for absorption into the circulatory system than if the SULT inhibitors were not included. [0030] An oral dose of PE is substantially glucuronidated to form phenylephrine-3-O-glucuronide (PE 3G). (Hengstmann and Goronzy, 1982) As with the other metabolic pathways, it is not known which isoform of uridine diphosphate glucuronosyltransferase (UGT) is most responsible for the glucuronidation of PE in either the intestine or the liver. However, since UGT1A1, 1A6, and 1A9 glucuronidate phenols, serotonin, and propofol (respectively), (Court, 2005) their activity toward phenylephrine may be inferred. Inhibition of intestinal and/or hepatic UGTs may help to improve the oral bioavailability of phenylephrine, and this approach may also be effective with other bioactives. In some applications, combining one or more inhibitors of SULTs with one or more inhibitors of UGTs may be advantageous for increasing the bioavailability of bioactives. To increase bioavailability of a bioactive, a sufficient quantity of one or more SULT inhibitors and one or more UGT inhibitors should be combined with the bioactive (e.g., PE), so that the when the combination is taken orally, a greater amount of the PE remains intact for absorption into the circulatory system than if the SULT inhibitors and/or UGT inhibitors were not included. [0031] In addition, monoamine oxidase isoforms A and B (MAO-A and MAO-B) are implicated in the oxidative deamination of phenylephrine. (Kanfer et al., 1993) As a result, phenylephrine is contraindicated in patients taking monoamine oxidase inhibitors, including selegiline, pargyline, and clorgyline for various psychiatric and neurological conditions. (Lexi-Comp Online) It is not known whether MAO-A or MAO-B plays a more important role in phenylephrine metabolism. However, upon intravenous PE dosing, the metabolism of PE occurs mainly through oxidative deamination to form 3-hydroxymandelic acid (3HMA), (Hengstmann and Goronzy, 1982) suggesting the liver's role in this pathway. As a result, inhibition of MAO enzymes in the intestine alone may not significantly improve the oral bioavailability of phenylephrine (or other bioactives). Furthermore, inhibition of MAO in the intestine and the liver should be avoided to minimize the possibility of adverse effects of dietary and biogenic amines on the nervous system. Therefore, in an embodiment of the inventive strategy set forth herein avoids compounds with MAO inhibition. However, in some applications, combining one or more inhibitors of SULTs with one or more inhibitors of MAOs may be advantageous for increasing the bioavailability of bioactives. To increase bioavailability of a bioactive, a sufficient quantity of one or more SULT inhibitors and one or more MAO inhibitors should be combined with the bioactive (e.g., PE), so that the when the combination is taken orally, a greater amount of the PE remains intact for absorption into the circulatory system than if the SULT inhibitors and/or MAO inhibitors were not included. [0032] Interpreting the data published by Hengstmann, the mass balance of total radioactivity excreted into urine following an oral dose was 92% of what was recovered following an intravenous dose, so that phenylephrine would therefore be considered a “high permeability” compound. (Hengstmann and Goronzy, 1982; Amidon et al., 1995) Combining this with its high aqueous solubility, phenylephrine would be classified as a Biopharmaceutical Classification System (BCS) class 1 compound. (Amidon et al., 1995) As a BCS class 1 compound, PE disposition is expected mainly to be due to metabolism, and formulation changes which do not affect dissolution are not expected to change bioavailability. (Amidon et al., 1995; Wu and Benet, 2005) Therefore, to improve the oral bioavailability of PE, a metabolism-targeted approach would be most useful. [0033] As a result, a premise of the inventive approach to improve PE (or other bioactive) bioavailability described herein is to escape the intestinal presystemic metabolism. An aspect of the strategy selectively inhibits the enzymes in the gut metabolizing PE, without affecting their activity in the liver. In such a way, oral bioavailability of PE would be increased, while adverse drug interactions or systemic toxicity would be avoided. [0034] Preferred inhibitors would have similar solubility compared to PE, and would not exhibit toxicities of their own. Furthermore, they would not inhibit the systemic metabolism of neurotransmitters (dopamine, norepinephrine, serotonin) so that adverse effects on the central nervous system and the cardiovascular system could be avoided. Compounds on the FDA “generally recognized as safe” (GRAS) list, as well as certain food additives (“everything added to food in the United States,” EAFUS) and dietary supplements (DS), would be likely to be safe, and facilitate regulatory approval. [0035] The inhibitors which can be used in the practice of the invention are wide ranging. Tables 1 and 2 show results with a number of different compounds which can function as inhibitors of SULT, MAO, CYP, COMT or UGT enzymes, or which otherwise may be used to increase the bioavailability of the exemplary bioactive phenylephrine. Table 1 shows the effect of combinations of phenolic compounds for inhibiting PE metabolism as indicated by a decrease in PE disappearance, and Table 2 shows the same effect as indicated by the loss of PE sulfate formation. In Tables 1 and 2, human LS180 intestinal cells were used for screening the inhibition of PE metabolism. For the experiment which produced the results in Table 1, the concentration of PE was 50M; the concentration of vitamin C (where present) was 1 mM; the total concentration of other inhibitors was 100 μM. Cells were incubated at 37° C. for 14 to 17.5 hours, as indicated. The LS180 model provides an inexpensive method to imitate the human intestine, with regards to PE metabolism. Unlike animal models or recombinant enzymes, this system has the advantages of being of human origin (thus avoiding species differences) and including some consideration of the ability of the inhibitors to cross the cell membranes and reach the enzymes. For the LS180 experiments, LS180 cells are seeded at the concentration of 1.9×10 5 cells/ml in 12-well plate. Cells are incubated with 0.5 ml DMEM containing 1% non-essential amino acid (pH 7.4) with phenylephrine (50 μM)/inhibitor (100 μM) (except ascorbic acid: 1000 μM) for 14 hr to 17.5 hr at 37° C. with 5% CO 2 . After incubation, medium is removed and stored at −80° C. until analysis. The metabolic reactions are quenched by placing 12-well plate on ice and quickly rinsing each well. The cell extraction of metabolites is carried out with 1 ml 2% acetic acid solution in methanol. Cells are scraped and collected in centrifuge tubes. The suspension is mixed for 2-3 min and centrifuged at 18,000 rcf for 5 min. Supernatants (800 μl) are collected. After scraping, each well is washed twice as above. The washing solution is collected with the supernatant and dried under reduced pressure. The residue is re-suspended in 35 μl water and analyzed by HPLC. All the samples are analyzed for PE by HPLC with a phenyl column (150×3.2 mm, 5 μm, 55° C.) at the flow rate of 0.75 ml (20% methanol and 80% (aqueous 1% acetic acid)) and detected by fluorescence (excitation 270 nm, emission 305 nm). The data are processed with one-way ANOVA followed by Dunnett's post test; * indicates p<0.05. [0000] TABLE 1 Table 1: Extent of PE (50 μM) Disappearance with Phenolic Dietary Compounds Extent of PE Disappearance (as Incubation Compound % of control) SD Time (hr) propylparaben 53.80% 75.30% 14 propylparaben + ascorbic acid 56.40% 77.90% 14 vanillin 90.20% 42.30% 14 propyl gallate 114.30% 48.50% 14 *curcumin 24.50% 24.20% 17 *eugenol + propylparaben + 31.10% 18.80% 17 vanillin + ascorbic acid *propylparaben + vanillin 37.00% 19.40% 17 *eugenol + propylparaben 42.60% 14.50% 17 *zingerone 52.40% 25.20% 17 methylparaben 75.90% 24.30% 17 ethylvanillin 76.50% 19.10% 17 *resveratrol 14.20% 48.50% 17.5 quercetin 48.70% 16.00% 17.5 *eugenol + vanillin 57.50% 35.70% 17.5 naringin 75.70% 14.40% 17.5 eugenol 133.00% 52.70% 17.5 *curcumin + resveratrol 0.00% — 18.5 *curcumin + pterostilbene + 0.00% — 18.5 resveratrol + zingerone *pterostilbene + zingerone 36.50% 12.20% 18.5 *guaiacol 51.30% 13.90% 18.5 *pterostilbene + zingerone 41.80% 7.40% 19 *pterostilbene 70.60% 7.20% 19 *isoeugenol 73.90% 7.50% 19 [0000] TABLE 2 Inhibition of PE Sulfate Formation with Phenolic Dietary Compounds PE Sulfate Formation Incubation Compound (as % of control) SD Time (hr) *guaiacol 33.00% 7.34% 18.5 *curcumin + resveratrol 0.10% — 18.5 *pterostilbene + zingerone 28.30% 4.49% 18.5 *curcumin + pterostilbene + 0.70% — 18.5 resveratrol + zingerone [0036] These results in Tables 1 and 2 demonstrate the extent to which exemplary combinations of inhibitors inhibit the metabolism of phenylephrine (PE) in the LS180 intestinal cell culture model. Note that some combination treatments were more effective than single agent treatments. While vanillin and eugenol failed to inhibit PE metabolism alone, in combination together or with other agents they significantly and synergistically inhibited it. Curcumin and resveratrol were more effective in combination(s). [0037] In connection with the data above, FIG. 1 illustrates an exemplary synthesis route for phenylephrine 3-O-Sulfate. Phenylephrine 3-O-sulfate was dissolved in 2 molar equivalents of trifluoroacetic anhydride and incubated at room temperature for 15 minutes to protect the alkyl hydroxyl and the secondary amine. The product was purified by silica gel chromatography. It was then dissolved in pyridine with 3-4 molar equivalents of pyridine-sulfur trioxide complex with heat and stirring. Pyridine was evaporated, followed by hydrolysis in aqueous potassium bicarbonate at room temperature overnight, and purified by HILIC-amide chromatography. LC-MS/MS (ESI−) reveals a 246>166 mass transition indicating the loss of SO3 from the phenol. This synthesis enables the detection of the main metabolic product of the SULT enzyme activity on phenylephrine, as shown in Table 2. [0038] In addition to the compounds and combinations of compounds indicated to have inhibitory capacity, and thus, the capacity to increase the bioavailability of PE (as well as other bioactives), other compounds which may be employed to increase the bioavailability of orally provided bioactives may be selected from methyl paraben, ethyl paraben, propyl paraben, butyl paraben, (−)-Homoeriodictyol; 2,6-dimethoxyphenol; 2-isopropylphenol; 2-methoxy-4-methylphenol; 2-methoxy-4-propylphenol; 4-(1,1-dimethylethyl)phenol; 4-allylphenol; 4-ethylguaiacol; 4-ethylphenol; anisyl alcohol; butylated hydroxyanisole; butylated hydroxytoluene; carvacrol; carveol; dimethoxybenzene; divanillin; essential oils+extracts (e.g., clove, cinnamon, nutmeg, rosemary, citrus, vanilla, ginger, guaiac, turmeric, grape seed, black pepper, etc.); ethyl p-anisate; eugenyl acetate; eugenyl formate; isoeugenol (acetate, formate, or benzoate); L-tyrosine; methyl anisate; methylphenyl ether; methylphenyl sulfide; O-(ethoxymethyl)phenol; O-cresol; O-propylphenol; resorcinol; salicylates (amyl, benzyl, butyl, ethyl, methyl, etc.); thymol; trans-anethole; vanillin propylene glycol acetal; vanillyl acetate; vanillyl alcohol; vanillyl ethyl ether; vanillylidene acetone; veratraldelhyde; and xylenols (2,6-; 2,5-; 3,4-). Other herbal/natural compounds not on GRAS/EAFUS list which may be used to increase the bioavailability of orally provided bioactives include hesperetin; eriodictyonone; 5,3′-Dihydroxy-7,4′-dimethoxyflavanone; isorhamnetol; tamarixetin; syringetin; 3′,7-Dimethylquercetin; and methylated and/or dehydroxylated analogs of quercetin. [0039] Other flavonoids which may be used include but are not limited to flavanols (such as catechin, gallocatechin, epicatechin, catechin gallate, gallocatechin gallate, epigallocatechin, epicatechin gallate, epigallocatechin gallate, leucoanthocyanidin, and proanthocyanidins), flavones (such as luteolin, apigenin, tangeretin), flavonols (such as quercetin, kaempferol, myricetin, fisetin, isorhamnetin, pachypodol, rhamnazin), flavanones (such as hesperetin, hesperidin, eriodictyol, homoeriodictyol), flavanonols (such as taxifolin, dihydroquercetin, dihydrokaempferol), anthocyanidins (such as anthocyanidin, cyanidin, delphidin, malvidin, pelargonidin, peonidin, petunidin), isoflavones (such as genistein, daidzein, glycitein), isoflavanes (such as equol, lonchocarpane, laxiflorane), and neoflavonoids (such as dalbergin, nivetin, coutareagenin, dalbergichromene). Glycosides of the flavanols, flavonol, flavones, flavanones, flavanonols, anthocyanidins, isoflavones, isoflavanes, and neoflavonoids may also be used. [0040] Flavonolignans (such as silybin, silybinin A, silybin B, silydianin, silychristin, isosilychristin, isosilybin A, isosilybin B, silibinin, silychristin, silydianin, dehydrosilybin, deoxysilycistin, deoxysilydianin, silandrin, silybinome, silyhermin and neosilyhermin, silyamandin, hydnocarpin, scutellaprostin A, B, C, D, E and F; hydnowightin, palstatin, salcolin A and salcolin B, rhodiolin) and their glycosides may also be used in the practice of the invention. Lignans (pinoresinol, steganacin, enterodiol, enterolactone, lariciresinol, secoisolariciresinol, matairesinol, hydroxymatairesinol, syringaresinol and sesamin) and their glycosides would be included. Xanthones (alpha-mangostin, beta-mangostin, gamma-mangostin, garcinone, garcinone A, garcinone C, garcinone D, mangostanol, gartanin) and their glycosides may be used in the practice of the invention. Miscellaneous natural phenolic compounds may also be included such as hydroxy-methoxy-coumarins, hydroxy-chalcones, biochanin A, prunetin, kavalactones (11-hydroxyyangonin; 11-methoxy-12-hydroxydehydrokavain; 5-hydroxykavain), ellagic acid, rosmarinic acid, emodin, and amentoflavone. [0041] Furthermore, suitable inhibitory compounds for use in the practice of the invention can be readily identified using enzymatic activity assays. Exemplary assays are set forth below: [0042] SULTs: [0043] Selected recombinant SULT isoforms (including 1A1, 1A3, 1B1, 2A1) are available commercially from a variety of sources including Xenotech. Appropriate control substrates should be used; for example, 4-methylumbelliferone for SULT1A1 and 1B1; 1-naphthol for SULT1A3; estradiol for SULT2A1. (Pacifici and Coughtrie, 2005) Assays should be performed according to the manufacturer's instructions (Cypex/Xenotech LLC). Briefly, substrates should be incubated at 37° C. in the presence or absence of 3′-phosphoadenosine 5′-phosphosulfate (PAPS; 20 μM) in 50 mM potassium phosphate buffer (pH 7.4) containing 5 mM magnesium chloride and 10 mM dithiothreitol. Initial substrate concentration should be 2 μM, with a protein concentration of 2.5 μg/ml, incubating for 5-60 minutes. Reactions should be stopped with acetonitrile, and analyzed by reversed-phase HPLC to determine disappearance of the control substrate (and/or formation of the metabolites), and PE (or other bioactive) and/or their metabolites should be analyzed. [0044] UGTs: [0045] Selected recombinant UGT isoforms (including 1A1, 1A6, 1A9) are commercially available from a variety of sources including BD Biosciences. Appropriate control substrates should be used; for example, estradiol, 1-naphthol, and propofol should be used as control substrates for UGT1A1, 1A6, and 1A9, respectively. (Court, 2005) Determinations should be performed in Tris-HCl buffer (50 mM; pH 7.5) containing magnesium chloride 8 mM, alamethicin 25 μg/ml, incubated at 37° C. in the presence or absence of 2 mM uridine 5′-diphospho-glucuronic acid (UDPGA). Initial substrate concentration should be 1 μM, with a protein concentration of 200 μg/ml, incubating for 5-60 minutes. [0046] MAOs: [0047] Recombinant MAO isoforms (A and B) are commercially available from a variety of sources including BD Biosciences. Appropriate control substrates should be used; for example, kynuramine is a substrate of both isoforms forming a fluorescent product by oxidative deamination. (Herraiz and Chaparro, 2006) Determinations should be performed in 100 mM potassium phosphate buffer (pH 7.4), incubated at 37° C. The initial substrate concentrations should be 1 μM, with a protein concentration of 50 μg/ml, incubating for 5-60 minutes. [0048] While the data are particularly compelling in terms of showing that certain inhibitory compounds or combinations of compounds can prevent the metabolism of phenylephrine, the invention may be practiced with a variety of other bioactives including the following: albuterol, raloxifene, estradiol, ethinyl estradiol, terbutaline, etilephrine, synephrine, octopamine, resveratrol, pterostilbene, magnolol, mangiferin, puerarin, resveratrol, salvianolic acid A, rasketone (a.k.a. “raspberry ketone”), tyrosol, honokiol, marsupsin, irigenin, caffeic acid phenethyl ester (phenylethyl caffeate; “CAPE”), and nimbidiol. [0049] Clinically, the inhibitors utilized in the practice of the invention are preferably acceptable to regulatory bodies (such as the FDA) and without adverse effects. For example, the acceptable daily intake of eugenol, ethyl vanillin, and vanillin are 2.5, 3.0, and 10 mg/kg/day, respectively (Fenaroli, 2010). As another example, pterostilbene is FDA approved as a GRAS compound in dosages of 30 mg/kg/day. Quercetin is a GRAS substance which is also marketed as a dietary supplement in dosages reaching 500 mg/day, while resveratrol and curcumin as dietary supplements are used in doses of 250 mg or 500 mg/day, respectively. Propylparaben is FDA-approved as an antioxidant/preservative food additive amounting to 0.1% w/w food fat content, thus individual dosages in excess of 10 mg are expected to be permissible. Doses of each inhibitor is expected to be such that when dissolved in GI fluid (250 ml) concentration will be between 10-3000 μM: minimum dose=2.5 μmol (0.25-0.75 mg); maximum dose=750 μmol (75-225 mg), assuming approximate molecular weights of inhibitors in the range of 100-300 Daltons. Bioactive ingredients would be dosed ranging from 0.5 to 200 mg, depending upon the compound and the therapeutic application. [0050] Many natural phenolic compounds have very low oral bioavailability, thus they often fail to result in clinical benefits. This technology would enable the biological activities of many natural phenolic compounds to be realized by inhibiting their presystemic metabolism thereby improving their oral bioavailability. Examples of clinical utilities would include diabetes (especially pre-diabetes and type 2 diabetes), heart disease (including hyperlipidemia), liver disease (including cholestasis and hepatoprotection), obesity, metabolic syndrome, various cancers, inflammatory diseases (including arthritis), and anti-aging (antioxidant) activities. EXAMPLES Example 1 In Vitro Inhibition of Phenylephrine (PE) Sulfation by Phenolic Dietary Compounds [0051] Background. [0052] This in vitro study aimed to investigate the feasibility of inhibiting the pre-systemic sulfation of PE. [0053] Methods. [0054] Phenolic compounds were selected from FDA's “GRAS” list, approved food additives, or dietary supplements. LS180 cells were used as a model to test the effect of these phenolic compounds on the pre-systemic sulfation of PE. The cells were incubated in 0.5 ml medium with PE (50 μM)±inhibitor (100 μM) overnight. Extracellular buffer was collected and cells were extracted with methanol. PE was determined by reversed-phase HPLC with fluorescence detection. The formation of PE-sulfate was analyzed by LC-MS/MS. Results (n=3 per group) were analyzed by one-way ANOVA with Dunnett's post-test (p<0.05; Prism 5). [0055] Results. [0056] The extent of disappearance of PE (control=503±127 pmol/hr) was significantly (p<0.05) decreased to the following (mean±SD, as % of control): curcumin 24±24%, guaiacol 51±14%, isoeugenol 74±8%, pterostilbene 71±7%, resveratrol 14±48%, zingerone 52±25%, and the combinations eugenol+propylparaben 43±15%, vanillin+propylparaben 37±19%, eugenol+propylparaben+vanillin+ascorbic acid 31±19%, eugenol+vanillin 58±36%, and pterostilbene+zingerone 37±12%. The combinations of curcumin+resveratrol and curcumin+pterostilbene+resveratrol+zingerone almost completely inhibited PE disappearance. Correspondingly, PE-sulfate formation was inhibited by guaiacol to 33±7% (control=100%; 6650±260 μV*s) and by pterostilbene+zingerone to 28±4%. The combinations of curcumin+resveratrol and curcumin+pterostilbene+resveratrol+zingerone inhibited ≧99% of PE-sulfate formation. However, when propyl gallate, vanillin, or eugenol was used alone, they had no significant effect on PE disappearance, suggesting synergy when vanillin or eugenol was used with other compounds. [0057] Conclusion. [0058] Several compounds and combinations including resveratrol inhibit the pre-systemic sulfation of PE and can improve its oral bioavailability. Example 2 [0059] Resveratrol (RES; 25 μM) was incubated with LS180 cells for 4 hours (as described in Example 1) in the absence or presence of the inhibitors (100 μM) listed below. The compounds marked with asterisks indicate a significant inhibition of resveratrol metabolism (disappearance) compared to controls in the absence of the inhibitors. Methylparaben and ethyl vanillin showed the greatest extent of inhibition of resveratrol metabolism, while cinnamic acid, piperine, eugenol, vanillin, propylgallate, and propylparaben also showed significant inhibition. [0000] TABLE 3 Extent of Resveratrol Disappearance with Phenolic Dietary Compounds. Extent of RES Disappearance Incubation Compound (as % of control) SD Time (hr) *methylparaben 0.4% n/a 4 *ethylvanillin 8.1% 377.0% 4 *cinnamic acid 16.3% 63.8% 4 *piperine 26.4% 67.6% 4 *eugenol 38.3% 25.8% 4 *vanillin 44.8% 16.6% 4 *propyl gallate 51.2% 14.5% 4 *propylparaben 57.8% 20.1% 4 *sinapic acid 86.1% 11.7% 4 zingerone 83.7% 40.9% 4 caffeic acid 91.1% 9.3% 4 ferulic acid 100.2% 37.9% 4 vanillic acid 102.9% 37.4% 4 Example 3 [0060] 2-Methoxyestradiol (2-ME; 10 μM) was incubated with LS180 cells for 4 hours (as described above) in the absence or presence of the inhibitors (100 μM) listed below. The compounds marked with asterisks indicate a significant inhibition of 2-methoxyestradiol metabolism (disappearance) compared to controls in the absence of the inhibitors. Significant inhibition of 2ME metabolism was observed with eugenol, vanillin, propyl gallate, and propylparaben. [0000] TABLE 4 Extent of 2-Methoxyestradiol Disappearance with Phenolic Dietary Compounds Extent of 2-ME Disappearance Incubation Compound (as % of control) SD Time (hr) *eugenol 21.2% 54.8% 1 *eugenol 33.9% 26.9% 1 *vanillin 39.4% 21.4% 1 *propyl gallate 42.8% 24.7% 1 *propyl gallate 50.4% 14.1% 1 *vanillin 51.2% 14.5% 1 *propylparaben 51.7% 20.6% 1 *propylparaben 57.7% 13.7% 1 cinnamaldehyde 87.6% 13.1% 1 cinnamaldehyde 93.9% 9.0% 1 *sinapic acid 88.1% 10.4% 1 caffeic acid 93.3% 10.0% 1 vanillic acid 99.1% 7.9% 1 gallic acid 101.5% 10.8% 1 ferulic acid 101.7% 10.2% 1 Example 4 [0061] Compounds were incubated with LS180 cells as described above in the absence or presence of inhibitor treatment combinations A or B or resveratrol. Combination A comprises quercetin 50 μM, ethyl vanillin 25 μM, isoeugenol 25 μM, and propylparaben 25 μM; Combination B comprises 25 μM each of resveratrol, curcumin, zingerone, and pterostilbene; the 3rd treatment is resveratrol 100 μM. The compounds, their concentrations, and incubation times were 4-methylumbelliferone (1 μM; 1.5 hrs.; FIG. 2A ), 1-naphthol (1 μM, 0.5 hrs; FIG. 2B ), raspberry ketone (2.5 μM, 15 hrs.; FIG. 2C ), pinoresinol (1 μM, 1.5 hrs.; FIG. 2D ), magnolol (1 μM, 1.5 hrs.; FIG. 2E ), and α-mangostin (1 μM, 1.5 hrs.; FIG. 2F ). To control for any effects of the inhibitors on the stability of the compounds, solutions lacking LS180 cells were incubated under the same conditions and used to correct for the expected concentrations of the compounds in the absence of metabolism. Samples were analyzed by reversed phase HPLC with ultraviolet and/or fluorescence detection, results were compared by one-way ANOVA with Dunnett's post test. FIGS. 2A-2F show that LS180 cells were able to metabolize >50% of the compounds in the absence of any inhibitor treatment (controls). The data show that Combination A was the most effective treatment for inhibiting metabolism of 4-methylumbelliferone, 1-naphthol, pinoresinol, magnolol, and α-mangostin, while Combination B was the most effective for inhibiting metabolism of raspberry ketone. [0062] Compounds such as raspberry ketone, pinoresinol, magnolol, and α-mangostin have preclinical biological activities which would be useful in the treatment or prevention of diseases such as hyperlipidemia, diabetes, obesity, cancer, and inflammation. However, these compounds also have very low oral bioavailability due to presystemic metabolism, which masks their clinical utility. Our data show that the inhibitor combinations described herein can decrease the intestinal metabolism of selected phenolic compounds. These phenolic natural compounds, when utilized with our inhibitor combinations to improve their oral bioavailability, can be used more effectively to achieve a clinical benefit. Example 5 [0063] Silybin (20 μM) and albuterol hemisulfate salt (20 μM) were incubated for 15 hours with LS180 cells as described in Example 4, in the presence or absence of Combination A. Albuterol metabolism was significantly inhibited by Combination A (p<0.05). The appearance of an unknown metabolite of silybin was significantly inhibited by Combination A (p<0.05). REFERENCES [0000] Amidon G L, Lennernas H, Shah V P and Crison J R (1995) A theoretical basis for a biopharmaceutic drug classification: the correlation of in vitro drug product dissolution and in vivo bioavailability. Pharm Res 12:413-420. Burdock G A (2005) Fenaroli's Handbook of Flavor Ingredients. 6th Edition, CRC Press, New York. Chen G, Zhang D, Jing N, Yin S, Falany C N and Radominska-Pandya A (2003) Human gastrointestinal sulfotransferases: identification and distribution. Toxicol Appl Pharmacol 187:186-197. Court M H (2005) Isoform-selective probe substrates for in vitro studies of human UDP-glucuronosyltransferases. Methods Enzymol 400:104-116. Hengstmann J H and Goronzy J (1982) Pharmacokinetics of 3H-phenylephrine in man. Eur J Clin Pharmacol 21:335-341. Herraiz T and Chaparro C (2006) Human monoamine oxidase enzyme inhibition by coffee and beta-carbolines norharman and harman isolated from coffee. Life Sci 78:795-802. Kanfer I. Dowse R and Vuma V (1993) Pharmacokinetics of oral decongestants. Pharmacotherapy 13:116 S-128S; discussion 143S-146S. Mizuma T (2008) Assessment of presystemic and systemic intestinal availability of orally administered drugs using in vitro and in vivo data in humans: intestinal sulfation metabolism impacts presystemic availability much more than systemic availability of salbutamol, SULT1A3 substrate. J Pharm Sci 97:5471-5476. Mizuma T, Kawashima K, Sakai S, Sakaguchi S and Hayashi M (2005) Differentiation of organ availability by sequential and simultaneous analyses: intestinal conjugative metabolism impacts on intestinal availability in humans. J Pharm Sci 94:571-575. Pacifici G M and Coughtrie M W (2005) Human Cytosolic Sulfotransferases . CRC Press: Taylor & Francis Group, Boca Raton, Fla. Pearson P G and Wienkers L C (2009) Handbook of Drug Metabolism . Informa Healthcare, New York. Riches Z, Stanley E L, Bloomer J C and Coughtrie M W H (2009) Quantitative Evaluation of the Expression and Activity of Five Major Sulfotransferases (SULTs) in Human Tissues: The SULT “Pie”. Drug Metab Dispos 37:2255-2261. Stockis A, Deroubaix X, Jeanbaptiste B, Lins R, Allemon A M and Laufen H (1995) Relative bioavailability of carbinoxamine and phenylephrine from a retard capsule after single and repeated dose administration in healthy subjects. Arzneimittelforschung 45:1009-1012. 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Presystemic metabolism in intestine of bioactives such as phenylephrine is avoided by administering a subject (human or animal) the bioactive (e.g., phenylephrine) in combination with one or more inhibitors of sulfation (e.g., sulfotransferase enzymes aka SULTs). This can also be enhanced be co-administering inhibitors of monoamine oxidases aka, MAOs, and uridine diphosphate glucoronysl transferases, aka UGTs. Preferably the inhibitors are GRAS compounds. The one or more inhibitor compounds inhibit the enzymes responsible for rapid presystemic metabolism, thus allowing the bioactives (e.g., phenylephrine) to be more readily absorbed intact into the circulatory system.

This is a continuation of application Ser. No. 09/349,925, filed Jul. 8, 1999, which issued as U.S. Pat. No. 6,777,236, on Aug. 17, 2004, and which is a continuation of application Ser. No. 08/465,712, filed Jun. 6, 1995, which issued as U.S. Pat. No. 6,452,066 on Sep. 17, 2002, which in turn is a continuation of application Ser. No. 08/358,627, filed Dec. 14, 1994, which issued as U.S. Pat. No. 6,177,242 on Jan. 23, 2001, all of which are incorporated herein by reference. BACKGROUND OF THE INVENTION Field of the Invention This invention relates to DNA and clones of β2-subunit of neuronal nicotinic acetylcholine receptor (nAChR) sequences. This invention also relates to genomic DNA fragments containing regulatory and coding sequences for the β2-subunit neuronal nAChR and transgenic animals made using these fragments or mutated fragments. The 5′ flanking sequences contain a promoter, which confers neuron-specific expression. The genomic clones demonstrate the importance of the β2-subunit gene in the nicotinic system and in the pharmacological response to nicotine. The invention also relates to vectors containing the DNA sequences, cells transformed with the vectors, transgenic animals carrying the sequences, and cell lines derived from these transgenic animals. In addition, the invention describes the uses of all of the above. References cited in this specification appear at the end by author and publication year or by cite number. Neuron-specific expression. Many recombinant DNA-based procedures require tissue-specific expression. Unwanted or potentially harmful side-effects of gene transfer therapies and procedures can be reduced through correct tissue-specific expression. Furthermore, the ability to direct the expression of certain proteins to one cell type alone advances the ability of scientists to map, identify or purify these cells for important therapeutic or analytical purposes. Where the cells of interest are neurons or a particular subset of neurons, a need for DNA sequences conferring neuron-specific or subset-specific expression exists. Proteins expressed throughout an organism are often utilized for specific purposes by neurons. By expressing a particular subunit or component of these proteins solely in neuronal tissue, the neuron tailors the protein activity for its purposes. Finding the particular, neuron-specific subunits or components and unraveling why they are produced only in neuronal tissue holds the key to DNA elements conferring neuron-specific expression. The inventors' knowledge of the biology of acetylcholine receptors provided an important foundation for this invention (see Changeux, The New Biologist, vol. 3, no. 5, pp. 413-429), May 1991 Different types of acetylcholine receptors are found in different tissues and respond to different agonists. One type, the nicotinic acetylcholine receptor (nAChR), responds to nicotine. A subgroup of that type is found only in neurons and is called the neuronal nAChR. Generally, five subunits make up an acetylcholine receptor complex. The type of subunits in the receptor determines the specificity to agonists. It is the expression pattern of these subunits that controls the localization of particular acetylcholine receptor types to certain cell groups. The genetic mechanisms involved in the acquisition of these specific expression patterns could lead to an ability to control tissue-specific or even a more defined cell group-specific expression. The inventors' work indicates that defined elements in the promoter sequence confer neuron specific expression for the β2-subunit. The Pharmacological Effects of Nicotine. As noted above, nAChR responds to the agonist nicotine. Nicotine has been implicated in many aspects of behavior including learning and memory (1,2). The pharmacological and behavioral effects of nicotine involve the neuronal nAChRs. Studies using low doses of nicotine (23) or nicotinic agonists (16) suggest that high affinity nAChRs in the brain mediate the effects of nicotine on passive avoidance behavior. Model systems where neuronal nAChR has been altered can therefore provide useful information on the pharmacological effects of nicotine, the role of neuronal nAChR in cognitive processes, nicotine addiction, and dementias involving deficits in the nicotinic system. Functional neuronal nAChRs are pentameric protein complexes containing at least one type of α-subunit and one type of β-subunit (3-5) (although the α7-subunit can form functional homooligomers in vitro 6,7 ). The β2-subunit was selected for this study from among the 7 known α-subunits and 3 known β-subunits (3) because of its wide expression in the brain (8-10), and the absence of expression of other β-subunits in most brain regions (10). Mutation of this subunit should therefore result in significant deficits in the CNS nicotinic system. The inventors have examined the involvement of the P2-subunit in pharmacology and behavior. Gene targeting was used to mutate the β2-subunit in transgenic mice. The inventors found that high affinity binding sites for nicotine are absent from the brains of mice homozygous for the β2-subunit mutation, β2−/−. Further, electrophysiological recording from brain slices reveals that thalamic neurons from these mice do not respond to nicotine application. Finally, behavioral tests demonstrate that nicotine no longer augments the performance of β2−/− mice on the test of passive avoidance, a measure of associative learning. Paradoxically, mutant mice are able to perform better than their non-mutant siblings on this task. BRIEF SUMMARY OF THE INVENTION AND ITS UTILITY In an aspect of this invention, we describe a 15 kb fragment of DNA carrying regulatory and coding regions for the 2-subunit of the neuronal nAchR. We characterize the promoter of the β2-subunit gene in vitro and in transgenic mice. We describe several DNA elements, including an E-box and other consensus protein-binding sequences involved in the positive regulation of this gene. Moreover, we show that the cell-specific transcription of the β2-subunit promoter involves at least two negative regulatory elements including one located in the transcribed sequence. Preferred embodiments of these aspects relate to specific promoter sequences and their use in directing neuron-specific expression in various cells and organisms. An 1163 bp sequence and an 862 bp sequence both confer neuron-specific expression. Other embodiments include the −245 to −95 sequence of FIG. 1 , containing an essential activator element, and the −245 to −824 sequence of FIG. 1 containing a repressor. A repressor element composed of the NRSE/RE1 sequence is also present in the transcribed region. Certain plasmids comprising these genomic sequences are described as well. The promoter sequences are important for their ability to direct protein, polypeptide or peptide expression in certain defined cells. For example, in the transgenic mice as shown below, proteins encoding toxins or the like can be directed to neurons to mimic the degradation of those cells in disease states. Others will be evident from the data described below. Alternatively, the promoters can direct encoded growth factors or oncogenic, tumorigenic, or immortalizing proteins to certain neurons to mimic tumorigenesis. These cells can then be isolated and grown in culture. In another use, the promoter sequences can be operatively linked to reporter sequences in order to identify specific neurons in situ or isolate neurons through cell sorting techniques. The isolated, purified neurons can then be used for in vitro biochemical or genetic analysis. Reporter sequences such as LacZ and Luciferase are described below. In another aspect of this invention, the inventors provide the genomic clones for mouse β-2 subunit of the neuronal nAChR. These clones are useful in the analysis of the mammalian nicotinic system and the pharmacology of nicotine. The inventors describe assays using transgenic mice where the genomic clones of the β2-subunit have been used to knock out the high affinity binding of nicotine. In addition to the deletion mutants described, mutations incorporated into the exons or regulatory sequences for the β2-subunit will result in useful mutant transgenic animals. These mutations can be point mutations, deletions or insertions that result in non-efficient activity of the nAChR or even a non-active receptor. With such mutant animals, methods for determining the ability of a compound to restore or modulate the nAChR activity or function are possible and can be devised. Modulation of function can be provided by either up-regulating or down-regulating receptor number, activity, or other compensating mechanisms. Also, methods to determine the ability of a compound to restore or modulate wild type behavior in the behavioral assays described or known (see 17, 22, 18, 2, 19, 21, 23, 24) can be devised with the mutant animals. Behavioral assays comprise, but are not limited to, testing of memory, learning, anxiety, locomotor activity, and attention as compared to the untreated animal or patient. Pharmacological assays (see 12, 13, 14, 15, 20) to select compounds that restore or modulate nAChR-related activity or behavior can thus be performed with the mutant animals provided by this invention. Dose and quantity of possible therapeutic agents will be determined by well-established techniques. (See, for example, reference 16.) The present model systems comprising transgenic animals or cells derived from these animals can be used to analyze the role of nicotine on learning and behavior, the pharmacology of nicotine, nicotine addiction, and disease states involving deficits in the nicotinic system. In addition, potential therapies for nicotine addiction or deficits in the nicotinic system can be tested with the transgenic animals or the cells and cell lines derived from them or any cell line transfected with a DNA fragment or the complete DNA of phage β2 (CNCM accession number I-1503). These cell lines would include all those obtained directly from homozygous or heterozygous transgenic animals that carry or are mutated in the β2-subunit sequences. In addition, this would include cell lines created in culture using natural β2-subunit sequences or mutated β2-subunit sequences. Techniques used could be, for example, those cited in PCT WO 90/11354. Dementias, such as Alzheimer's disease, in which the high affinity nicotine binding site are diminished suggest that the present model can be used to screen drugs for compensation of this deficit. Accordingly, methods for screening compounds for the ability to restore or detectably affect activity of the neuronal nicotinic acetylcholine receptor comprising adding the compound to an appropriate cell line or introducing the compound into a transgenic animal can be devised. Transgenic animals and cell lines generated from this invention can be used in these methods. Such animal or cell line systems can also be used to select compounds that could be able to restore or to modulate the activity of the β2 gene. The transgenic animals obtained with the β2-subunit gene sequence (wildtype or mutated fragments thereof) can be used to generate double transgenic animals. For this purpose the β2-subunit transgenic animal can be mated with other transgenic animals of the same species or with naturally occurring mutant animals of the same species. The resulting double transgenic animal, or cells derived from it, can be used in the same applications as the parent β2-subunit transgenic animal. Both the promoter sequences and the genomic clones can be used to assay for the presence or absence of regulator proteins. The gel shift assays below exemplify such a use. The sequences or clones can also be used as probes by incorporating or linking markers such as radionuclides, fluorescent compounds, or cross-linking proteins or compounds such as avidin-biotin. These probes can be used to identify or assay proteins, nucleic acids or other compounds involved in neuron action or the acetylcholine receptor system. Known methods to mutate or modify nucleic acid sequences can be used in conjunction with this invention to generate useful β2 mutant animals, cell lines, or sequences. Such methods include, but are not limited to, point mutations, site-directed mutagenesis, deletion mutations, insertion mutations, mutations obtainable from homologous recombination, and mutations obtainable from chemical or radiation treatment of DNA or cells bearing the DNA. DNA sequencing is used to determine the mutation generated if desired or necessary. The mutant animals, cell lines or sequences are then used in the DNA sequences, systems, assays, methods or processes the inventors describe. The mutated DNA will, by definition, be different, or not identical to the genomic DNA. Mutant animals are also created by mating a first transgenic animal containing the sequences described here or made available by this invention, with a second animal. The second animal can contain DNA that differs from the DNA contained in the first animal. In such a way, various lines of mutant animals can be created. Furthermore, recombinant DNA techniques are available to mutate the DNA sequences described here, as above, link these DNA sequences to expression vectors, and express the β2-subunit protein or mutant derived from the β2-subunit sequences. The β2-subunit or mutant can thus be analyzed for biochemical or behavioral activity. In such a way, mutated DNA sequences can be generated that prevent the expression of an efficient nAchR. Alternatively, the promoter sequences described can be used in expression vectors or systems to drive expression of other proteins. Obtainable DNA sequence can thus be linked to the promoter or regulatory sequences the inventors describe in order to transcribe those DNA sequences or produce protein, polypeptide or peptides encoded by those DNA sequences. DESCRIPTION OF THE RELATED ART Previous studies by in situ hybridization (Wada et al., 1989; Hill et al., 1993; Zoli et al., 1994) and immunohistochemistry (Hill et al., 1993) demonstrate that all of the neuronal nAchR subunits cloned to date display a strict neuron-specific distribution. But different subunits exhibit an even tighter distribution to only small subsets of neurons in the brain. For example, the nAchR ∝2-subunit transcripts are only detected in the Spiriformis lateralis nucleus in the chick diencephalon (Daubas et al., 1990) or the Interpeduncularis nucleus in the rat (Wada et al., 1988). Also the β3, β4 and ∝3-subunit transcripts are only detected in a small set of structures in vertebrate brain (references in Zoli et al., 1994). The nAchR, ∝4, ∝5, ∝7, and β2-subunit gene transcripts, in comparison, show a much wider distribution. (Wada et al., 1989; references in Zoli et al., 1994). For example, the β2-subunit transcripts are found in the majority of neurons in the CNS and in all the peripheral neurons that express the nAchR (Role, 1992; Hill et al., 1993). As a consequence of the differential expression of these subunits, a wide diversity of nAchR species occurs in vertebrates. Each species has a defined pattern of expression involving diverse categories or groups of neurons. For example, the neurons from medial Habenula interconnect with those from the Interpedunculari nucleus and yet each express distinct sets of nAchR subunits (see Role, 1992 for review) exhibiting different physiological and pharmacological profiles (Mulle et al., 1991). Only limited information is available, to date, about the genetic mechanisms that account for regulation of nAchR gene transcription in neurons. Previous work on the promoter of the chick ∝7 subunit gene analyzed in vitro failed to characterize the DNA elements responsible for transcriptional regulation (Matter-Sadzinski et al., 1992). In another study, the promoter of the ∝2-subunit gene was partially characterized and a silence described and sequenced (Bessis et al., 1993, see also Daubas et al. 1993). Certain evidence leads to the study of the β2-subunit in particular. It is expressed in the majority of the neurons in the brain (Hill et al., 1993). Also, the timing of the appearance of the β2-transcripts closely parallels that of neuronal differentiation (Zoli et al., 1994). We thus decided to study the genetic mechanisms that regulate its transcription. BRIEF DESCRIPTION OF THE INVENTION Gene Structure We have cloned a genomic fragment containing the regulatory sequences and sequences encoding the mouse nAchR β2-subunit gene. The inventors have found that at least part of the regulatory region is conserved among different mammalian species. Particularly, the region between +16 to +38 bp corresponding to the NRSE/RE1 as described in FIG. 1 . Using RNase protection and amplification of primer extension products, we found one main and three minor transcription start sites ( FIG. 1 ). The primer extension experiments were performed using two different reverse transcriptases, with different batches of mRNA and with different primers. These PCR based techniques allowed us to amplify and subclone the same fragments corresponding to transcription start sites rather than reverse transcriptase stops. The transcription start sites that we have characterized are located downstream from the position of the longest rat (Deneris et al., 1988) and human (Anand and Lindstrom, 1990) β2 cDNA 5′ end (see FIG. 1 ). This implies that in human and rat, another transcription start site is used. Such a discrepancy between species has already been demonstrated for the e-subunit of the muscle nAchR (Dürr et al., 1994, see also Dong et al., 1993; Toussaint et al., 1994). In contrast with the α2 subunit gene (Bessis et al., 1993), no upstream exon could be detected. Structural analysis of a 1.2 kbp flanking region disclosed many consensus motifs for nuclear protein binding including an Sp1 site and an E-box. Approximately 90 bp of the undeleted 1.2 kb promoter are transcribed and this region contains a NRSE/RE1 sequence (Kraner et al., 1992; Mori et al., 1992). Regulatory elements have already been described downstream of the transcription start site in different systems such as the Polyomavirus (Bourachot et al., 1989) or the fos gene (Lamb et al., 1990). The promoter region is located between the Eco47III located in exon 1 (see FIG. 1 ) (SEQ ID NO: 22) and the BamHI site 4.5 kb upstream. One preferred embodiment is the 1163 bp sequence described in FIG. 1 between the EcoRI and Eco47III sites. Regulatory sequences may be located in the 2 kb downstream from the Eco47III site. The regulatory elements from the nAchR β2-subunit sequences can be used to direct the neuron specific expression of a nucleotide sequence encoding a protein, polypeptide or peptide linked to them. Said protein, polypeptide, or peptide can be toxins, trophic factors, neuropeptides, tumorigenic, oncogenic, or immortalizing proteins, or any other protein that can change the function of the neuron. A 1163 bp Promoter Achieves Cell-Specific Transcription. The 1163 bp promoter contains regulatory sequences for both tissue-specific and temporal specific transcription of the β2-subunit gene. Transient transfection experiments showed that the 1163 bp fragment contains sufficient information to confer cell-specific expression of the nAchR β2-subunit gene. We showed that the same promoter directs a strict cell-specific transcription of the β-galactosidase (β-gal) reporter gene. Moreover, the transgenic construct appears to be activated with the same timing as the endogenous β2-subunit gene during the development of the early embryonic nervous system (Zoli et al., 1994). At later stages of development, most of the peripheral β2 expressing neurons are still labelled ( FIG. 4C , D). The promoter sequence was tested in transgenic mice by generating two lines (13 and 26) expressing β-gal under the control of the β-subunit promoter. In CNS, the pattern of β3-galactosidase expression is different between the two lines. Only a subset of the cells that normally express β2 express the transgene. This type of discrepancy between the expression of the transgene and the endogenous gene has already been described for the dopamine β-hydroxylase gene promoter (Mercer et al., 1991; Hoyle et al., 1994) or for the GAP-43 gene (Vanselow et al., 1994). Unexpected expression has been observed in transgenic line 13 in the genital tubercule and in skin muscles. This expression is likely to be due to the integration site of the transgene as these tissues are not stained in line 26. To our knowledge, most of the neuronal promoters studied by transgenesis display ectopic expression in a certain small percentage of transgenic lines (Forss-Petter et al., 1990; Kaneda et al., 1991; Banerjee et al., 1992; Hoesche et al., 1993; Logan et al., 1993, Vanselow et al., 1994). However, techniques in the art afford the construction of lines where the expression pattern of the transgene closely mirrors or duplicates that of the original gene. See references for further details showing the success of the transgenesis procedure. By comparing the β-gal positive cell distribution with those of other known neuronal markers, it becomes apparent that a similarity exists with the distribution of choline acetyltransferase, TrkA (the high affinity nerve growth factor receptor) and p 75 (the low affinity nerve growth factor receptor) expressing cells (Yan and Johnson, 1988: Pioro and Cuello, 1990a, b; Ringstedt et al., 1993). In particular, in developing rats, p 75 is expressed in almost all the peripheral ganglia and central nuclei (with the exception of the zona incerta and hypothalamic nuclei), which express the transgene (Yan and Johnson, 1988). It is also interesting to note that p 75 expression (like the expression of the β2-promoter transgene) is transient in many peripheral ganglia and brain nuclei, decreasing to undetectable levels at perinatal or early postnatal ages. It is therefore possible that the β2-subunit promoter contains an element controlled by the activation of p 75 , or that both the β2 transgene and p 75 gene are controlled by a common regulator. In conclusion, although the promoter seems to lack some regulatory elements active in the brain, the existing regulatory elements are sufficient to allow a cell- and development-specific expression of β-galactosidase in the PNS, in the spinal cord, and in several brain structures. The promoter can also be used in assays to identify regulator proteins in neuronal tissue. DNA Regulatory Elements. To further characterize the DNA elements involved in the transcription of the β2 subunit gene, we deleted or mutated the 1163 bp promoter and analyzed the resulting constructs by transient transfection. A repressor element present in the distal 5′ end region is active in fibroblasts but not in neuroblastomas. This element thus accounts, at least in part, for the neuron-specific expression of the β2-subunit gene. Further analysis of the promoter shows that deleting 589 bp increases the activity in neuroblastomas, but not in fibroblasts ( FIG. 6 , compare 862E and 283E-Luci). An NRSE/RE1 element is located at the 3′ extremity of the promoter. This element has already been shown to restrict the activity of promoters in neuronal cells (Kraner et al., 1992; Mori et al., 1992; Li et al., 1993). In the 1163 bp promoter of the β2-subunit gene, point mutation of this sequence leads to a ˜100 fold increase of the transcriptional activity in fibroblasts implying that this sequence is involved in the neuron-specific expression of the β2-subunit gene. Moreover, sequence comparison shows that this sequence is highly conserved in rat and human β2-subunit cDNAs (Deneris et al., 1988; Anand and Lindstrom, 1990) as well as in several promoters of genes expressed in the nervous system, such as the middle-weight neurofilament gene, the CAM-L1 gene, the Calbinbin gene, or the cerebellar Ca-binding protein gene (see Table 1B). Deletion experiments described in FIG. 6 show that an essential activator element is present between nucleotides −245 and −95. An Sp1 binding site and an E-box could be detected in this region. Sp1 sites are ubiquitous factors, whereas E-boxes have been involved in several genetic regulatory mechanisms in muscle (see Bessereau et al., 1994 for the nAchR −∝1-subunit) as well as in neurons (Guillemot et al., 1993). Dyad elements have also been reported in some neuronal promoters, such as those of the Tyrosine hydroxylase gene (Yoon and Chikaraishi, 1994), the SCG1O gene (Mori et al., 1990), the GAP43 gene (Nedivi et al., 1992), or in the flanking region of the N-CAM gene (Chen et al., 1990). Results shown in Table 1A demonstrate that in neuroblastomas, the 1163 bp promoter mutated in the E-box/Dyad is significantly less active than the wild type promoter. Moreover, a gel shift assay ( FIG. 7 ) further demonstrates that the E-box/Dyad is able to bind specific complexes. This suggests that the E-Box/Dyad is responsible for at least part of the activation of β2-subunit gene transcription. However, transactivation experiments of heterologous promoters suggest that the E-box cooperates with the Sp1 site located 27 bp upstream to positively activate transcription. This type of cooperation between an E-Box and an Sp1 binding site has already been demonstrated for the regulation of the muscle nAchR ∝1-subunit transcription (Bessereau et al., 1993). In conclusion, we have shown that the β2-subunit gene is primarily regulated by negatively acting elements and by one positive element that comprises an E-box. This double regulation seems to be a general feature shared by several neuronal genes (Mandel and Mckinnon, 1993) and allows fine tuning of the transcription of neuronal genes. Moreover, our transgenic studies show that the 1163 bp promoter confers a tight neuron-specific expression, but lacks some developmental or CNS-specific regulatory elements. DESCRIPTION OF THE FIGURES FIG. 1 : Nucleotide sequence of the region surrounding the initiator ATG of the β2-subunit gene. The four vertical arrowheads show the four extremities found using RACE-PCR and SLIC, corresponding to the transcription start sites. The vertical arrows indicate the position corresponding to the 5′ end of the longest rat (r) and human (h) β2-subunit cDNA clones (Deneris et al., 1988). The endpoints of the deletions used in the experiments described in FIG. 3 are indicated above the sequence. Nucleotides located in the intron are typed in lower cases. FIG. 2 : Mapping of the 5′ end of the β2-subunit mRNA. A. RNase protection experiments. Total RNA from DBA2 mouse brain (5 and 15 μg, lane 2 and 3 respectively) and yeast tRNA (15 μg, lane 1) were hybridized to a 32 P-labeled RNA probe containing 158 nucleotides of intron 1, and 789 nucleotides of upstream sequences (−634/+155). The size of the protected bands were estimated according to the lower mobility in acrylamide of RNA as compared to DNA (Ausubel et al., 1994) and by comparison with the sequence of M13 mp18 primed with the universal primer. The arrow on the left part of the gel points to the major protected band. B. Identification of the transcription start site using SLIC. The lower part of the Figure shows the strategy and describes the oligonucleotides used for the SLIC or the RACE-PCR. In the SLIC experiment, a primer extension was performed using oligonucleotide pEx3. The first strand of the cDNA was subsequently ligated to oligonucleotides A5′, and the resulting fragment was amplified using oligonucleotides A5′-1/p0 then A5′-2/p1. The amplified fragment was then loaded onto a 1.2% agarose gel. The gel was blotted and hybridized to oligonucleotide p2. Lane 1:5 μg of total DBA2 mouse brain RNA. Lane 2-3: controls respectively without reverse transcriptase and without RNA. Minus: the T4 RNA Polymerase was omitted. Same result was obtained using RACE-PCR. FIG. 3 : Cell-specific expression of the β2-subunit promoter in vitro. The luciferase activity of the plasmids were normalized to the activity of the promoterless plasmid (KS-Luci, described in Materials and Methods). RACE-PCR on mRNA extracted from Sk—N—Be transfected with EE1.2-Luci, using luciferase oligonucleotides (described in Material and Methods) showed that the amplified fragment had the expected size for the correct transcription initiation site. FIG. 4 : Cell-specific expression of the β2-subunit promoter in transgenic mice. A. Whole mount coloration of E13 embryos. The arrowheads point to ectopic expression in skin muscles. B. Detection of the β-galactosidase activity in a parasagittal section of an E13 embryo at the lumbo-sacral level. Arrowheads indicate labelling in the ventral and dorsal horn of the spinal cord. C. Detection of the β2-subunit transcripts in an adjacent section of the same embryo. dr: dorsal root ganglion; t: tectum; og: orthosympathetic ganglionic chain; tr: trigeminal ganglion. FIG. 5 : Expression of β-galactosidase in transgenic mice. A. staining of the retina(re) and the trigeminal ganglia (tr) (E14.5). B. staining of cardiac parasympathetic ganglionic neurons (pg) (E14.5). C. transverse section of the spinal cord (P1). dr: dorsal root ganglion, og: orthosympathetic ganglion. D. Ventral view of the spinal cord (P1). The smaller arrows indicate neurons that have not been identified. FIG. 6 : Expression of the Luciferase fusion genes containing 5′ end deletions of the β-subunit promoter. Plasmids are called nnnE-Luci, where nnn is the size in nucleotides of the insertion, and E is the 5′ end restriction site (Eco47III). The arrow indicates the transcription start site. The activities of EE1.2-Luci are from FIG. 3 . FIG. 7 : Gel shift experiment. Autoradiogram of the mobility shift experiment. The probe used was a 32 P labelled double stranded E-D oligonucleotide. This oligonucleotide carries only the E-Box/Dyad element, whereas the oligonucleotide S-E carries the Sp1 binding site as well as the E-Box/Dyad element. The competitor oligonucleotides were used in 10- and 100-fold molar excess, except for S-E that was used only in 100-fold molar excess. FIG. 8 : Disruption of the gene encoding the P2-subunit of the neuronal nAChR. a-i, Normal genomic structure of the mouse β2-subunit gene. Portion of exon one removed by the recombination event is shaded in light grey. ATG—initiator methionine. Boxes represent exons I-IV. a-ii, Targeting replacement vector used to disrupt the endogenous β2-subunit gene. Initiator methionine and the rest of the first exon were replaced with the coding region of NLS-lacZ and the MCI neo R expression cassette 25 . The construct was able to direct lacZ expression after stable transfection of PC12 cells (not shown), but lacZ expression was never detected in recombinant animals, despite the lack of obvious recombination in the lacZ DNA. Diphtheria toxin-A gene (DTA) 26 was used to select against random integration. a-iii, Structure of the mutated β2-gene. Restriction sites: H, HindIII; R, EcoRI; E, Eco47III; P, PstI. Black arrows, primers used to detect recombination events in embryonic stem (ES) cells. Grey arrows, primers used to detect the wildtype or mutated β2 genes. b, PCR analysis of tail DNA from a +/+, +/− and a −/− mouse. c, Southern blot analysis of tail DNA restricted with HindIII from the same mice analyzed in panel b. d, Western blot analysis of total brain protein using a monoclonal antibody raised against the β2-subunit. METHODS: a, The β2-targeting vector was constructed by inserting a multiple cloning site (MCS) into the MCI neo cassette (GTC GAC GGT ACC GCC CGG GCA GGC CTG CTA GCT TAA TTA AGC GGC CGC CTC GAG GGG CCC ATG CAT GGA TCC). (SEQ ID NO: 30) A 4.1 kB EcoRI-Eco47III β2-genomic fragment 5′ to the ATG and a 1.5 kB PstI β2-genomic fragment starting within the first intron of the β2-gene were cloned into the MCS. HMI 27,28 embryonic stem cells (5×10 7 ) were transfected with the linearized targeting vector by electroporation as described 25 . Twenty-four surviving G418-resistant clones were screened by PCR (β2-primer—GCC CAG ACA TAG GTC ACA TGA TGG T (SEQ ID NO: 31); neo-primer—GTT TAT TGC AGC TTA TM TGG TTA CA)(SEQ ID NO: 32) Four were positive and were later confirmed by Southern blot analysis. Clones were injected into 3.5-day-old blastocysts from non-agouti, C57BL/6 mice and planted in receptive females. All resulting male chimaeric mice were mated to F1, C57BL/6xDBA/2 non-agouti females. Of 15 chimaeras, one showed germ-line transmission. β2+/− heterozygotes were mated and offspring were evaluated by PCR analysis (panel b). b, PCR was 35 cycles of 94°/1 min, 65°/2 min and 72°/1 min. c, Southern blotting was performed as described 29 . The 1.5 kB PstI genomic fragment used for the targeting construct was labelled by random priming. d, Western blotting was performed as described 29 using monoclonal antibody 270 11 . FIG. 9 : Mapping of the neuronal nAChR in mouse brain using in situ hybridization and tritiated nicotine binding. A, In situ hybridization using antisense oligonucleotide probes based on the sequence of the cDNAs encoding the β2-, α4- and β4-subunits of the nAChR to detect their respective mRNAs in serial sections from the brains of β2+/+, +/− and −/− mice. Midthalamic sections are shown. White arrows indicate the MHb labelled by the β4-antisense oligonucleotide. B, Receptor autoradiography using tritiated nicotine revealing high affinity binding sites in the brains of wildtype, heterozygous and β2-mutant mice. Representative sections at the level of the striatum, thalamus and tectum are shown. METHODS, A, In situ hybridization was performed as follows: In situ hybridization procedure. Frozen tissues were cut at the cryostat [14 μm thick sections), thaw mounted on poly-1-lysine coated slides and stored at −80 C. for 1-3 days. The procedure was carried out according to Young et al. (1986). Briefly, sections were fixed with 4% paraformaldehyde for 5 min. at room temperature, washed in phosphate buffered saline (PBS) and then acetylated and delipidated in ethanol and chloroform (5 min). They were prehybridized for 2-4 h at 37 C. under parafilm coverslips. The composition of the prehybridization and hybridization mixtures was 50% formamide, 0.6M NaCl, 0.1M dithiothreitol, 10% dextran sulfate, 1 mM ethylenediaminetetraacetic acid (EDTA), IXDenhardt's solution (50×=1% boyine serum albumin/1% Ficoll/1% polyvinylpyrrodlidone), 0.1 mg/ml polyA (Boehringer), 0.5 mg/mlyeast RNA (Sigma), 0.05 mg/ml herring sperm DNA (Promega) in 0.02M Tris-HCl, pH 7.5. Probes were applied at a concentration of 2000-3000 Bcq/30 μl section (corresponding to around 15 fmol/section). After removal of coverslips and initial rinse in 2× standard saline citrate (SSC) solution (3M NaCl/0.3M sodium citrate) at room temperature (two time for 5 min.), sections were washed four times for 15 mm in 2×SSC/50% formamide at 42° C. and, then, two times for 30 min in 1×SSC at room temperature. 1 mM dithiothreitol was added to all washing solutions. After rinsing in ice-cold distilled water and drying, they were exposed for 10-20 days to Hyperfilm βmax (Amersham) and then to a photographic emulsion (NTB2, Kodak) for 1-2 months. Analysis of histological preparations. The analysis of the labelling pattern for the different mRNAs was carried out both on film and emulsion autoradiograms. Identification of anatomical structures was carried out after counterstaining of the serial sections of the entire embryos with toluidine blue. Definition of anatomical areas in the brain and recognition of peripheral nervous system (PNS) structures was based on different atlases, including The Rat Brain in Stereotaxic Coordinates (Paxinos and Watson, 1986), the Atlas of Developing Rat Brain (Paxinos et al. 1991), the Atlas of Mouse Development (Kaufman, 1992), and the Atlas of the Prenatal Mouse Brain (Schambra et al., 1992). For cranial nerve ganglia development, the plates and descriptions from Altman and Bayer (1982) were consulted. In order to confirm the identification of some central and peripheral structures (e.g., cranial nerve motor nuclei, autonomic motor ganglia) in situ hybridization for choline acetyltransferase was performed on some sections. A score from 1+(low intensity) to 3+(high intensity) was assigned to the labelling of the anatomical structures based on the subjective evaluation of two experimenters. Background labelling was considered the density of grains in nonneural tissues high cellularity (such as the liver and muscles) or with high density of extracellular matrix (such as cartilage) or the density of labelling over neural structures after displacement with 20× cold probe. In the absence of grain counting at the cellular level, the scores must be regarded with caution. For instance, decreases in labelling intensity of a developing structure may be due to dispersion of positive cells in the structure caused by multiplication of negative cells or formation of neuronal processes. Though the oligonucleotides had the same length and they were labelled according to the same protocol, no attempt to compare the signal intensity or different transcripts was made. Unless specified otherwise, the labeling shown in the pictures has been obtained by using oligonucleotides no. 31 (∝3), 47 (∝4), 51 (†2), and 62 (∝4) (see Table 1 for oligonucleotide characteristics). Specificity controls. For each mRNA, two to four oligonucleotides were selected in unique parts of the sequence (e.g., the putative cytoplasmic loop between M3 and M4 for nAChR subunits). An initial assessment of the specificity was performed by searching for possible homology with other known sequences in Genbank/EMBL. As histological tests for specificity were considered the following: 1. Two or more oligonucleotide probes for each mRNA gave the same hybridization pattern ( FIG. 1 ). 2. The pattern of labelling in central structures in the adult rat was in agreement with that observed by other authors (Wada et al., 1989; Dineley-Miller and Patrick, 1992). 3. Given that most oligonucleotides used were 45-mers with similar GC content (Table 1), each oligonucleotide probe constituted a control for the specificity of the others. 4. The addition to the hybridization mixture of a 20-fold excess of cold probe produced a complete disappearance of the labelling ( FIG. 2 ). The oligonucleotide probes used fulfilled all these criteria, with the exception of the four probes against ∝3 mRNA, which did not satisfy criterion 2. Previous studies based on cRNA probes showed a relatively widespread distribution of this subunit mRNA in adult rats, notably high levels in the cerebral cortex layer IV, entorhinal cortex layer II, anterior and ventral thalamic nuclei, medial and lateral geniculate nuclei, medial habenula, posterior hypothalamus and supramammillary nuclei, pineal gland, motor nuclei of the V and VII nerves, locus coeruleus, nucleus ambiguus, and area postrema (Wada et al. 1989). At variance with these observations, in adult rats we could detect high levels of ∝3 mRNA signal only in the medial habenula, intermediate in the pineal gland, area postrema, motor nucleus of the V nerve and cerebellum, low in a few thalamic nuclei and locus coeruleus. Part of the discrepancy may be ascribed to a lower sensitivity of oligonucleotide probes versus riboprobes. However, considering the difficulty of carrying out specificity controls for cRNA probes, especially when hydrolysis of the probe is performed in the histological procedure (Wada et al., 1989), it is possible that some labelling previously attributed to ∝3 mRNA actually derives from hybridization to other (nAChR-related) RNA sequences. Oligonucleotides: β2 (SEQ ID NO: 1): 5′-TCG CAT GTG GTC CGC AAT GAA GCG TAC GCC ATC CAC TGC TTC CCG-3′; α4 (SEQ ID NO: 2): 5′-CCT TCT CAA CCT CTG ATG TCT TCA AGT CAG GGA CCT CAA GGG GGG-3′; β4 (SEQ ID NO 3): 5′-ACC AGG CTG ACT TCA AGA CCG GGA CGC TTC ATG G AGG AAG GTG-3′. B, 3 H-nicotine binding was performed as described by Clarke et al 30 . Fourteen μm coronal sections were incubated at room temperature for 30 min. in 50 mM Tris pH 7.4/8 mM CaCl 2 /4 nM 3 H-L-nicotine. was evaluated in the presence of 10 μM L-nicotine bitartrate. Following incubation, sections were rinsed 2×2 min. in ice cold PBS and briefly rinsed in ice cold water. Slides were exposed for 60 days to Hyperfilm 3 H. FIG. 10 : Patch clamp recording of nicotine evoked currents in the MHb and anterior thalamus of β2+/+ and −/− mice. A, Representative recordings from cells in the MHb and the anterior thalamus of wildtype and β2−/− mice. The off-rate of the agonist is significantly greater in the MHb than in the anterior thalamus, resulting in a different kinetics of response in the two structures. The response to nicotinic agonists of the MHb is maintained in β2−/− animals, while the response to nicotinic agonists of the anterior thalamus is completely abolished in β2−/− mice. B, table of responses to nicotinic agonists in various nuclei of β2+/+ and −/− mice. METHODS, Coronal slices were obtained from the thalamus of 8-12 day old mice using a Dosaka slicer in ice cold ACSF medium (125 mM NaCl/26 mM NaHCO 3 /25 mM Glucose/1.25 mM NaH 2 PO 4 /2.5 mM KCl 2.5/2 mM CaCl 2 /1 mM MgCl 2 pH 7.3). Slices were maintained in the same medium for 1-8 hours. Cells in slices were visualized through a Zeiss microscope. Whole cell recordings were obtained with 2-4 MOhm hard-glass pipettes containing 150 mM CsCl/10 mM EGTA/10 mM HEPES/4 mM di-sodium ATP/4 mM MgCl 2 pH adjusted to 7.3 with KOH. Five to ten sec. pulses of drug were applied rapidly to the cell through a 50 μM diameter pipette above the slice, fed by gravity with a solution containing 150 mM NaCl/10 mM Hepes/2.5 mM KCl/2 mM CaCl 2 /1 mM MgCl 2 . Recordings were made in the presence of CNQX (5 μM) and of the GABA A antagonist SR-95531 (10 μM). Currents were recorded with an Axopatch ID (Axon Instrument) patch amplifier, digitized on a Compaq PC and further analyzed with the PClamp program (Axon Instrument). FIG. 11 : Performance of β2−/− mice and their wildtype siblings on the passive avoidance test. A, response to various levels of footshock in retention test following a post-training injection of either vehicle or nicotine (10 μg/kg). Average step-through latency during the training trial was 17.0+/−3.6 sec for mutant mice and 15.0 +/−3.5 sec for their nonmutant siblings. B, bar graph showing the difference in retention latency between wildtype and homozygous β2 mutant mice injected with either vehicle or nicotine (10 μg/kg) at foot shock intensity of 2.00 mAmp. Data are represented as means+/−S.E.M. of the following groups: wildtype+vehicle (n=27); wildtype+nicotine (n=23); β2-mutant mice+vehicle (n=17); β2-mutant mice+nicotine (n=17). Statistical analysis was performed using a mixed factorial analysis of variance followed by a-posteriori testing of simple effects. #, p<0.05, wildtype vs mutant mice following vehicle injection; *, p<0.01, nicotine vs vehicle in wildtype mice. METHODS, Passive avoidance test was performed as described in the text, according to Nordberg and Bergh 20 and Faiman et al 20 . Nicotine (bitartrate, Sigma) was freshly dissolved in PBS. IP injection of the same volume of either nicotine or vehicle immediately followed footshock during the training trial. FIG. 12 : Phage and plasmids containing all or part of the β2-subunit gene and the promoter. In the names of the plasmids, the numerals indicate the size of the fragment and the letters indicate the restriction sites used to generate it. DETAILED DESCRIPTION The descriptions and examples below are exemplary of the embodiments and scope of this invention. The invention is not limited to the scope of this description. Furthermore, this description together with the accompanying sections of this specification and the material incorporated by reference enables the practice of all of the claims which follow. The examples and embodiments that follow of course can be modified by techniques known in the art. Variations in the nucleic acid sequences described or claimed can be produced by known methods without altering the effects or advantages the inventors have shown. Such variations are therefore included within the scope of this description and invention. Materials and Methods Isolation of Genomic Clones. The PCX49 plasmid (Deneris et al., 1988) containing the entire rat cDNA (kindly provided by Drs. J. Boulter and S. Heinemann, The Salk Institute, San Diego, Calif.) was cut with EcoRI, the ˜.2.2 kb fragment was isolated and used as a probe to screen an EMBL3 bacteriophage library of mouse DBA2 genomic DNA. One unique clone was obtained spanning ˜15 kb of DNA upstream and ˜5 kb downstream from the first exon. FIG. 1 shows the nucleotide sequence of 1.2 kb upstream from the initiator ATG. Hybridization conditions can be modified by known techniques 29 to determine stringent conditions for this probe. Changes in the hybridization conditions such as temperature (from about 45° C. to about 65° C.) and SSC buffer concentration (from about 0.1×SSC to about 6×SSC), as well as changes in the temperature of and the buffer for the washing condition can be made to develop sufficiently stringent conditions that allow hybridization to the β2-subunit sequences. Other related sequences can thus be isolated from other libraries based on this hybridization procedure. Human sequences will be isolated by using hybridization conditions such as 45° C. and 6×SSC. Three deposits were made on Dec. 13, 1994 at the Collection Nationale de Cultures de Microorganismes (CNCM), Institut Pasteur, 25 Rue du Docteur Roux, 75724 PARIS CEDEX 15, France. A phage, λβ2 nAchR, is deposited under the accession number I-1503. This phage contains 15-20 kb of genomic DNA including the promoter sequences and the coding sequences for all of the exons of the murine β2-subunit of neuronal nAchR. Two E. coli cultures bearing plasmids have also been deposited. Plasmid pSA9 in E. coli DH5α has accession number I-1501 and contains 9 kb of murine genomic DNA including the regulatory sequences and regions coding for exons 1, 2 and 3 of the β2-subunit. Plasmid pEA5 in E. coli DH5α has accession number I-1502 and contains 5 kb of murine genomic DNA including a region of about 1.2 kb upstream of the Eco47-III site and a region coding for exons 1 to 5 of the β2-subunit. The inventors intend to deposit the nucleotide sequence data reported here in the EMBL, GenBank and DDBJ Nucleotide Sequence Databases under the accession number: X82655. Mapping of the Transcription Initiation Site. For the mRNA mapping, we used different batches of total RNA extracted from DBA2 embryos at stage E13 or E15. The RNA samples were first digested with DNase I to avoid DNA contamination. RNase protection. An XbaI/PstI fragment containing part of intron 1 was inserted into Bluescript SK (Stratagene). The plasmid was then linearized by BglII, and an RNA probe was synthesized using the T7 promoter. The protection experiments were then performed as described in Ausubel et al. (1994). RACE-PCR (Frohman et al., 1988). The mRNA was hybridized 5 minutes at 80° C. with 10 pmol of primer. The synthesis of the cDNA was performed using 400 u MMLV (Gibco) for 45 minutes at 37° C. in the buffer recommended by the supplier. After a phenol/chloroform extraction, the cDNA was ethanol precipitated. The terminal transferase reaction was performed in 0.2 M potassium cacodylate; 25 mM Tris-HCl pH 6.6; 25 mg/ml BSA; 1.5 mMCoCl 2 ; 50 nM dATP and 50 u Terminal transferase (Boehringer) for 30 minutes at 37° C. After phenol/chloroform extraction and ethanol precipitation, one tenth of the terminal transferase reaction was amplified using Promega's Taq DNA polymerase (30 cycles, 1 minute at: 94° C.; 55° C.; 72° C.). The amplified fragment was then loaded on an agarose gel. The gel was blotted and hybridized to oligonucleotide p2. We used pEx2 as a primer for cDNA synthesis, and p0/BEpT for PCR to map mRNA from brain. OLUCI3 (synthesis of cDNA) and OLUCI2/BEpT (PCR) were used to map mRNA from transfected cells. SLIC (Dumas Milnes Edwards et al., 1991). The cDNA was first synthesized from 5 μg total RNA using pEx3 (6 pmol) as a primer in 50 mM Tris-HCl pH 8.3; 8 mM KCl; 1.6 mM MgCl 2 ; 5 mM spermidine; 0.5 mM dNTP; 1 u/μl RNasin; 0.1 mg/ml BSA; 70 mM β-mercaptoethanol; 80 u AMV reverse transcriptase (Promega) at 420 for 45 minutes. The RNA was subsequently degraded in NaOH. The first strand of the cDNA was then ligated with the oligonucleotide A5′. The resulting single stranded cDNA was then submitted to two rounds of PCR amplification with oligonucleotides A5′-1/p0 and A5′-2/pl (35 cycles 94° C. 1 minute; 60° C. 30 seconds; 72° C. 45 seconds) The sequence of the oligonucleotides were the following: (SEQ ID NO:4) A5′: 5′-CTGCATCTATCTAATGCTCCTCTCGCTACCTGCTCACTCTGCGTGA CATC (SEQ ID NO:5) A5′-1: 5′-GATGTCACGCAGAGTGAGCAGGTAG (SEQ ID NO:6) A5′-2 : 5′-AGAGTGAGCAGGTAGCGAGAGGAG (SEQ ID NO:7) p0: 5′-CCAAAGCTGAACAGCAGCGCCATAG (SEQ ID NO:8) p1: 5′-AGCAGCGCCATAGAGTTGGAGCACC (SEQ ID NO:9) p2: 5′-AGGCGGCTGCGCGGCTTCAGCACCACGGAC (SEQ ID NO:10) pEx2: 5′-GCCGCTCCTCTGTGTCAGTACGCAAAACCC (SEQ ID NO:11) pEx3: 5′-ACATTGGTGGTCATGATCTG (SEQ ID NO:12) BEpT: 5-GCGGGATCCGAATC(T) 21 A/C/G (SEQ ID NO:13) OLUCI3 : 5′-CGAAGTATTCCGCGTACGTGATG (SEQ ID NO:14) OLUCI2: 5′-ACCAGGGCGTATCTCTTCATAGC Construction of Plasmids. KS-Luci: The HindIII/KpnI restriction fragment of the pSVOAL plasmid (de Wet et al., 1987) was subcloned in the corresponding site of Bluescript KS. The most 5′ EcoRI/BsmI (45 bp) fragment of the Luciferase gene was then deleted according to (de Wet et al., 1987) and replaced by a Sal I site. The 342 bp PvuII/HindIII restriction fragment of SV40 containing the polyadenylation sites was subsequently subcloned into the EagI sites using adaptors. EE1.2-Luci: The 1.2 kbp EcoRI/Eco47II fragment of the λβ2 phage was inserted in the EagI/SalI sites of KS-Luci using adaptors. The 5′ end deletions of the promoter were obtained using BaI3.1 exonuclease as in Current Protocols in Molecular Biology (Ausubel, et al., 1994). The mutations were introduced using the Sculptor kit (Amersham). In the NRSE/RE1 sequence, the mutated sequence was: +24 (SEQ ID NO: 15) ACCACTTACA instead of (SEQ ID NO: 16) ACCACGGACA, as this mutation was shown to reduce the activity of the NRSE element (Mori et al., 1992). In the E-box sequence, the mutated sequence was: −120 (SEQ ID NO: 17) TCCTCAGG instead of TCCACTTG. FIG. 7 shows that a nuclear protein is able to bind to the wild type sequence, but not to the mutated sequence. Transfection of Cells. Neuroblastomas N1E115, human Sk—N—Be, HeLa and 3T6 fibroblasts, 293 Human kidney cells and SVLT striatal cells (Evrard et al., 1990) were grown in DMEM+10% FCS supplemented with 1% glutamine and 1% streptomycin. PC 2 cells were grown in DMEM+10% HS+5% FCS supplemented with 1% glutamine and 1% streptomycin. Cells were plated at 10 5 to 4×10 5 cells/60 mm 2 plates. The next day cells were transfected in 750 μl of DMEM+2% Penicillin/Streptomycin for 5 to 12 hours with 1 μg DNA mixed with 2.5 pl of Transfectam (IBF/Sepracor) in 150 mM NaCl. The Luciferase activity was measured 48 hours later. DNA was prepared using Qiagen or Wizard prep (Promega) kits. When plasmid activities were compared, all plasmids were prepared the same day. At least two different DNA preparations were tested for each plasmid. All transfections were done in duplicate and repeated at least three times. Production of Transgenic Mice. The luciferase gene from EE1.2-Luci was excised and replaced by the nlsLacZ gene (Kalderon et al., 1984). The β2-promoter/nlsLacZ fragment was electroeluted from a TAE agarose gel then further purified by ethanol precipitation, and finally resuspended in Tris-HCl 10 mM pH 7.5; EDTA 0.1 mM. The DNA solution (3 ng/ml) was injected into fertilized oocytes of C57BL6xSJL hybrids. Staining of tissues was performed as described in Mercer et al., 1991. See also the methods under FIG. 8 . Gel Shift Assay Oligonucleotides were labeled either with Y[ 32 P]ATP and T4 polynucleotide kinase, or with ∝[ 32 P]CTP and Klenow enzyme as in Current Protocols in Molecular Biology. Nuclear extracts were prepared from ˜10 7 cells as described (Bessis et al., 1993). For binding, 1 nmol of labeled oligonucleotide was mixed with 0.5 μg of protein extract in 10 mM Hepes pH 8, 10% glycerol], 0.1 mM EDTA, 0.1 M NaCl, 2 mM DTT, 0.1 mg/ml BSA, 4 mM MgCl 2 , 4 mM spermidine, 1 mM PMSF, 1 μg polydldC in 20 μl. The reaction was incubated for 10 minutes on ice. The DNA-protein complexes were then analyzed on a 7% polyacrylamide gel. The oligonucleotides used in this experiments were double stranded with the the following sequences (the highlighted nucleotides are changed between the mutated and the wild type oligonucleotides): (SEQ ID NO:19) E-D: 5′-TCCTCCCCTAGTAGTTCC A C TT GTGTTCCCTAG (SEQ ID NO:20) Mut-E: 5′-CCTCCCCTAGTAGTTCC T C AG GTGTTCCCTAGA (SEQ ID NO:21) S-E: 5′-CTAGCTCCGGGGCGGAGACTCCTCCCCTAGTAGTTCCAGTTG TGTTCCCTAG Results Characterization of the 5′ Flanking Sequences of the Gene Encoding the β2-Subunit A λ phage containing the gene encoding the β2-subunit was cloned and a region surrounding the initiator ATG was sequenced ( FIG. 1 ). The transcription initiation site was first mapped by RNase protection ( FIG. 2A ). This method allowed us to detect at least three initiation sites. However, minor additional start sites might not have been detected in these experiments. The size of the main protected band was estimated at about 150 nucleotides. To confirm and locate the initiation sites more precisely, we performed both RACE-PCR (Rapid Amplification of cDNA Ends; Frohman et al., 1988) and SLIC (Single Strand Ligation of cDNA; Dumas Milnes Edwards et al., 1991) which consist in the amplification of the primer extension product ( FIG. 2B ). Both techniques allowed us to subclone and sequence the same fragments corresponding to the four initiation sites described in FIG. 1 . It is probable that the −13 start site is very rare and was not detected by RNase mapping. Analysis of the sequence of the flanking region ( FIG. 1 ) revealed several consensus DNA binding elements: an Sp1 site (−146), a cAMP responsive element binding (CREB) site (−287; Sassone-Corsi, 1988), a nuclear receptor response element (−344 to −356; Parker, 1993), a GATA-3 site (−1073; Ko and Engel, 1993), and a weakly degenerate Octamer motif (−522). Moreover, an E-box (−118) contained in a dyad symmetrical element could be recognized. The proximal region (−245 to +82) also has an unusually high GC content (67%) and a high number of dinucleotide CpG that may have some regulatory significance (Antequera and Bird, 1993). Finally, a 20 bp sequence identical to the NRSE (Neural Restrictive Silencer Element; Mori et al., 1992) or RE1 (Restrictive Element; Kraner et al., 1992) sequence was found in the 3′ end of the 1.2 kbp fragment (+18 to +38). A 1.2 kbp Fragment of Flanking Sequence of the β2-Subunit Gene Promotes Neuron-Specific Expression in Vitro. A construct was generated containing the 1163 bp EcoRI/Eco47III fragment (from −1125 to +38) of the β2-subunit 5′ flanking region fused to the Luciferase gene (de Wet et al., 1987) (plasmid EE1.2-Luci). The polyadenylation sites of SV40 were inserted upstream from the β2-subunit sequences to avoid readthrough. The transcriptional activity of the plasmid EE1.2-Luci was then tested by transient transfection into pheochromocytoma (PC12) cells, neuroblastoma cell lines NIE 115 and Sk—N—Be, SVLT, a striatal cell line (Evrard et al., 1990), NIH3T6 or HeLa fibroblasts and human kidney cell line 293. Using RT-PCR, we verified that the neuroblastomas and the PC12 cells normally express the β2-subunit mRNA but not the striatal SVLT cell lines or the 3T6 fibroblasts. FIG. 3 shows that in PC12 cells and neuroblastomas, the 1.2 kbp fragment is 20 to 180-fold more active in mediating transcription of the reporter gene than in the other cell lines. In fibroblasts, 293 cells and SVLT cells, the transcriptional activity of the 1.2 kbp fragment is not significantly higher than that of the promoterless vector ( FIG. 3 ). Therefore, the β2-subunit promoter is not active in these cell lines. These in vitro transfection experiments demonstrate that the 1163 bp fragment mimics the expression pattern of the endogenous β2-subunit gene, and thus contains a cell-specific promoter. The 1163 bp Promoter in Transgenic Mice. To test the 1163 bp promoter in vivo, the EcoRI/Eco47III fragment was linked upstream from the nis-β-galactosidase reporter gene (Kalderon et al., 1984). The polyadenylation signals from SV40 were ligated downstream of the coding sequences. The resulting 4.7 kb fragment was subsequently microinjected into the male pronuclei of fertilized eggs from F1 hybrid mice (C57B16xSJL). DNA extracted from the tails of the offspring was analyzed for the presence of the β-galactosidase gene by the polymerase chain reaction (PCR). Three independent founders were obtained and analyzed for expression. Two lines (13 and 26) had expression in neurons and the third line did not express at all. This shows that the 1163 bp promoter contains regulatory elements sufficient to drive neuron-specific expression in vivo. In the peripheral nervous system PNS, both lines expressed in the same structure. In contrast, in the CNS the labelling pattern of line 26 is a subset of that of line 13. We will only describe line 13 in detail. As expected, most peripheral β2-expressing ganglia expressed β-galactosidase (β-gal), whereas in the CNS only a subset of β2-positive regions expressed the β-gal. For instance, FIG. 4C shows that the vast majority of the neurons of the lumbo-sacral spinal cord express the β2-subunit transcripts, whereas only a subset of neurons in the ventral and dorsal horns display β-gal activity. The expression of the transgene could be detected in the peripheral ganglia in E10.5 and E11 embryos. The labelling was examined in E13 total embryos ( FIG. 4A ) and in brains at later ages (E17, PO and adulthood). At E13, labelling was prominent in PNS: strong labelling was observed in the dorsal root ganglia (DRG, FIGS. 4 and 5C , D); some ganglia associated with the cranial nerves (the trigeminal see FIG. 5A , geniculate, glossopharyngeal and vagal ganglia); the ganglia of the sympathetic chain ( FIG. 5C , D); the ganglionic cells of the retina ( FIG. 5A ); and putative parasympathetic ganglia in the cardiac wall ( FIG. 5B ). At E13, clusters of positive cells were also present at several levels of the neuraxis, in both the brainstem and the proencephalon. Clusters of stained neurons were also observed in the ventral and lateral spinal cord. Later in development (E17), positive neurons were found clustered in several basal telencephalic nuclei whereas dispersed cells were stained in the caudate-putamen. At the diencephalic level, positive clusters were present in the zona incerta and reticular thalamic nucleus, and in many hypothalamic nuclei. In the brainstem, most motor nuclei of cranial nerves (with the exception of the dorsal motor nucleus of the vagus nerve) showed some to high labelling. In addition, the dispersed cells of the V mesencephalic nucleus appeared strongly stained, as well as the pontine nuclei, the prepositus hypoglossal nucleus and a few dispersed cells in the pontine tegmentum. At PO in line 13, the distribution of positive cells already appeared more restricted than at previous ages (for example labelling in basal telencephalon and oculomotor nuclei was clearly diminished). In the CNS of adult animals labelled cells were detected only in the hypothalamus. In line 13, some clusters of cells were stained in the mucosa of the gastrointestinal tract (stomach and duodenum) and in the pancreas. Ectopic labelling was detected in the genital tubercle and in several superficial muscles of line 13, but none of these tissues were stained in the line 26. Identification of a Minimal Cell Specific Promoter To investigate in more detail the regulatory elements involved in the promoter activity, we generated a series of plasmids containing 5′ deletions of the 1163 bp promoter. These plasmids were tested by transient transfection into fibroblasts and Sk—N—Be cells. These two cell lines were chosen as they were the most easily transfected cell lines. Moreover, the neuroblastoma line was initially isolated from peripheral structures (Biedler et al., 1978) and is a convenient tool to study the regulatory elements carried by the 1163 bp promoter. When 157 bp were deleted from the 5′ end of the 1163 bp promoter (plasmid 1006E-Luci, described in FIG. 1 ), the luciferase activity did not significantly change in neuroblastomas but increased in fibroblasts ( FIG. 6 ). When 301 bp were further deleted, the activity of the remaining promoter continued to increase in the fibroblasts but not in neuroblastomas (see plasmid 862E-Luci, FIG. 6 ). Thus, the 157 and 301 bp deleted plasmids carry repressor elements which are only active in fibroblasts. However, the truncated 862 bp promoter still displayed a neuron-specific activity ( FIG. 6 , compare activity of 862E-Luci in both cell lines), showing that additional regulatory elements are carried by the 1.2 kbp promoter. Moreover, a repressor could be present between −824 and −245 (compare the activities of 862E and 283E-Luci in the neuroblastomas). This putative regulatory element was not further analyzed. Indeed, a 283 bp promoter (plasmid 283E-Luci) is still ≅160 times more active in neuroblastomas than in fibroblasts, confirming the presence of another neuron-specific regulatory elements in this proximal portion of the promoter. When 150 bp were deleted from the 5′ end of the proximal 283 bp promoter, a very strong decrease of the transcriptional activity was detected in both fibroblasts and neuroblastomas (see activity of plasmid 133E-Luci). This shows that crucial positive regulatory elements have been deleted. These positive and negative elements were further investigated by deletion and mutation studies of the proximal portion of the promoter. Negative and Positive Regulatory Elements in the Proximal Region. The 3′ end of the β2-subunit promoter contains putative protein factor binding sites. To analyze the role of these elements in β2-subunit gene regulation, we generated plasmids containing mutations in these binding sites. Using deletion experiments, an activator was detected between −95 and −245 (see FIG. 3 , the difference between 283E and 133E-Luci). As the E-box located at nt-1l8 was a good candidate, we analyzed the effect of mutations in this element on transcriptional activity. Table 1A shows a 40% reduction of the transcriptional activity of the mutated promoter compared to that of the wild type promoter. The role of the E-box in non-neuronal tissues was more difficult to assess as the basal level of transcription was already low in fibroblasts. To further understand the role of the E-Box in the regulation of the promoter, we investigated the protein complexes able to interact with this sequence. Gel shift assays were performed using the 33 bp sequence (nt-135 to -103, oligonucleotide E-D) as a probe. When the 32 -P labelled oligonucleotide was mixed with nuclear extracts from neuroblastomas or fibroblasts, three complexes were observed ( FIG. 7 ). All of them were fully displaced by an excess of the unlabelled oligonucleotide E-D. In contrast, no competition was observed when the competitor oligonucleotide was mutated within the E-Box/Dyad (oligonucleotide Mut.E, see FIG. 7 lane “Mut-Eu”). This shows that the E-box/Dyad is the only element contained within the −135/103 sequence able to bind nuclear protein. This sequence is likely to be involved in the activity of the β-subunit promoter. An NRSE/RE1 sequence is also present in the proximal region and has been shown to act as a silencer in fibroblasts but not in PC12 cells or neuroblastomas (Kraner et al., 1992; Li et al., 1993; Mori et al., 1992). Point mutation of this sequence in the context of the 1163 bp promoter resulted in a 105-fold increase in the transcriptional activity in fibroblasts, and only a 3-fold increase in neuroblastomas (Table 1A). This sequence is thus responsible for at least part of the cell-specific expression of the β2 subunit gene. Table 1: Positive and Negative Regulatory Elements in the Proximal Region of the 1163 by Promoter Effect of mutations in the proximal part of the 1163 bp promoter. The activities of the wild type or mutated promoters are normalized to the luciferase activity of the promoterless KS-Luci plasmid. The activities of EE1.2-Luci are from FIG. 3 . TABLE 1 Positive and negative regulatory elements in the proximal region of the 1163 by promoter Effect of mutations in the proximal part of the 1163 bp promoter. The activities of the wild type or mutated promoters are nor- malized to the luciferase activity of the promoterless KS-Luci plasmid. The activities of EE1.2-Luci are from FIG. 3. Neuroblastomas Fibroblasts (3T6) (SK-N-Be) EE1.2-Luci wild type 1.1  (100%) 157 (100%) EE1.2-Luci/NRSE/ 115.5 ± 13.8 (1050%) 502 ± 204 (320%) RE1 EE1.2-Luci/E-Box ND 94 ± 14  (60%) Alignment of the proximal silencer of the β-subunit promoter with other neuronal promoters: Mouse β2 (SEQ ID NO:23) TGCGCGGC.TTCAGCACCACGGACAGCGC.TCCCGTCC Sodium Channel (nt 29) (SEQ ID NO:24) ATTGGGTT.TTCAG A ACCACGGACAGC A C.CAGAGTCT SCG10 (nt 621) (SEQ ID NO:25) AAAGCCAT.TTCAGCACCACGGA G AG T GC.CTCTGCTT Synapsin I (nt 2070) (SEQ ID NO:26) CTGCCAGC.TTCAGCACCGCGGACAG T GC.CTTCGCCC CAML1 (nt 1535) (SEQ ID NO:27) TACAGGCC.T C CAGCACCACGGACAGC AG .ACCGTGAA Calbindin (nt 1093) (SEQ ID NO:28) CCGAACGG. AG CAGCACC G CGGACAGCGC.CCCGCCGC Neurofilament (nt 383) (SEQ ID NO:29) ATCGGGGT.TTCAGCACCACGGACAGCTC.CCGCGGGG (SEQ ID NO:30)          TTCAGCACCACGGACAGCGC The sequences are taken from (Maue et al., 1990, Na channel, accession number M31433), (Mori et al., 1990; SCG10, M90489), (Sauerwald eta!., 1990; Synapsin I, M55301), (Kohl et al., 1992; CAML1 gene, X63509), (Gill and Christakos, 1993, Calbindin gene, L11891), (Zopf et al., 1990; Neurofilament gene, X17102, reverse orientation). The numbering refers to the sequences in the GenBankIEMBL library. Elimination of High Affinity Nicotine Receptor in Transgenic Mice Results in Alteration of Avoidance Learning The β2-subunit of the nAChR was disrupted in embryonic stem (ES) cells, and mice deficient in this subunit were subsequently generated ( FIG. 8 ). β2−/− mice were viable, mated normally and showed no obvious physical deficits. Overall brain size and organization were normal (see for example FIG. 9 , A and B). Western blot analysis of total brain homogenates using anti-β2 monoclonal 270 11 ( FIG. 8 d ) and immunocytochemistry throughout the brain using a polyclonal anti-β2 antibody 9 demonstrated that the immunoreactivity detected in control mice was absent in β2−/− mice and was diminished in β+/− mice. P2-encoding mRNA was undetectable in β2−/− mice by in situ hybridization using β2-antisense oligonucleotides ( FIG. 9A ). The distributions of the α4- and β2-subunits largely overlap in the brain, and these subunits are thought to combine to form the predominant nAChR isoform in the CNS 12 . Based on oocyte expression experiments 6 , β4-is the only subunit identified thus far that might also be able to form functional heteropentamers with the α4-subunit. The β4-subunit was expressed normally in the brains of β2+/− mice or β2−/− mice, with expression in the medial habenula (MHb) and the interpeduncular nucleus (IPN) 10 , and no upregulation elsewhere in the brain to replace the β2-subunit ( FIG. 9A ). Nor was the expression of the α4- ( FIG. 9A ), α5- or β3-subunit mRNAs significantly altered in mutant mice. Equilibrium binding experiments have shown that nicotine binds to a population of high affinity sites (KD near 10 nM 13,14 ), whose distribution tallies well with that of the α4- and β2-subunits 13-15 . Quantitative receptor autoradiography was performed using 3 H-nicotine (4 nM) to visualize high affinity nAChR in brain sections from β2+/+, +/− and −/− mice ( FIG. 9B ). Nicotine binding in situ was completely abolished in β2−/− animals, and was reduced by approximately 50% in all brain areas in β2+/− animals implicating the β2-subunit in mediating this high affinity binding. Electrophysiology of Transgenic Mice. Neurons of the anterior thalamus, which express very high levels of β2 (and α4) subunit mRNAs ( FIG. 9A ), were studied for an electrophysiological response to nicotine. This area, easily accessible in a slice preparation, responded consistently to 10 μM nicotine in wild type animals with an average inward current of 155+/−73 pA which was blocked by 1 μM dihydro-β-erythroidine. The agonist order of the response was compatible with that seen for α4/β2-containing nicotinic receptors in vitro 6 (nicotine>DMPP>cytisine) ( FIG. 10A ). Anterior thalamic neurons required several minutes to an hour for complete recovery of the agonist response, suggesting that receptor response is prone to desensitization. Moreover, a relatively high dose of 1 μM was required for a reproducible response, implying that nicotine does not bind to its high affinity site to activate. High affinity nicotine binding sites may therefore be nAChRs in a desensitized conformation. In β2−/− mice the response of anterior thalamic neurons to nicotine was completely abolished in 100% of neurons tested ( FIG. 10B ). As a control, neurons in the MHb, where both α3 and β4 are strongly expressed, were also tested. Nicotine caused an average inward current of 505+/−132 pA in wild type mice, and the agonist potency of this response followed the rank order for the α3/β4 containing receptor (cytisine=nicotine>DMPP) ( FIG. 10A ). As expected, the response of cells in the MHb to nicotine was maintained in mutant mice. The β2 subunit is expressed in the ganglia of wild type animals 8-10 , but there was no apparent difference in heart rate or basal body temperature. Spontaneous locomotor activity, which is sensitive to high doses of nicotine and is not modified by drugs selective for the β2/α4 isoform of the nAChR 16 , was not significantly different in β2−/−, B+/1 and β+/+ mice. Cognitive and Behavioral Results. Learning and memory were examined in mutant and wild type mice using two procedures. The Morris water maze 17,18 evaluates spatial orientation learning. The performance of mutant mice on this test did not differ from that of wild type mice when tested on the visible platform task, or on the hidden platform task (minimum swim-time reached after 5 days of training: mutants (n=8): 7.4+/−1.4 sec; wild type (n=8): 8.2+/−2.0 sec). In the transfer test both groups of animals spent approximately 35% of the time in the platform quadrant, with the same number of platform crossings (mutants: 4+/−0.4; wild type: 3.9+/−0.6). Retention of an inhibitory avoidance response was assessed using the passive avoidance test, which was also chosen for its pharmacological sensitivity to nicotine administration 19,20 . This test consisted of a training trial in which the mouse was placed in a well-lighted chamber of a shuttle box, and the latency to enter the adjacent dark chamber was measured. Upon entry to the dark chamber, a mild, inescapable foot shock was delivered, and vehicle or nicotine (10 μg/kg) was injected into the mouse. Twenty-four (24) hours later, retention was assessed by measuring the latency to enter the dark chamber. Time spent in the light chamber (retention latency) increased proportionally to the applied foot shock in both mutant and wild type mice. However, treatment with nicotine consistently facilitated retention (p<0.01) by shifting the curve upward by approximately 80 sec only in wild type mice ( FIG. 10A ). Nicotine administration was completely ineffective in mutant mice. Interestingly, retention latency was significantly higher for mutant mice than for their non-mutant, vehicle-injected siblings (p<0.05) ( FIG. 10B ). Increased retention in the passive avoidance test can be observed in animals with a decreased pain threshold or increased emotionality. Therefore, further behavioral testing was performed on all mice included in this experiment. Mutant mice did not differ from their non-mutant siblings for flinch, vocalization or jump response to foot shock. Emotionality was tested by measuring exploratory activity in a two compartment apparatus for 15 min 21,22 . The average time spent in the dark compartment, the locomotor activity in the dark compartment and the transitions between compartments did not differ between the mutant and wild type mice. Therefore, neither changes in pain sensitivity nor changes in emotionality can account for the difference in retention latency observed in passive avoidance testing. Studies using low doses of nicotine 23 or specific nicotinic agonists 16 suggest that high affinity nAChRs in the brain mediate the effects of nicotine on passive avoidance. Accordingly, nicotine cannot change the performance of β2−/− mice on this test, as they lack high affinity binding sites. The enhanced performance of mutant mice versus wild type mice is quite surprising, however. Several explanations for the paradoxical effect of the β2-subunit mutation can be proposed. One hypothesis is that nicotine injection improves performance of wild type mice on passive avoidance as a result of desensitization, and thus inactivation of aAChRs, leading to enhanced performance on the test. Therefore, the behavior of mice lacking the receptor might mimic that of mice whose receptors have been desensitized 24 . Another possibility is that nAChRs may be present in at least two pathways that interact with opposite effects to generate the behavior measured in passive avoidance. If one pathway is physiologically more active than the other, the inactive pathway will be preferentially stimulated by injection of nicotine in wild type animals, while the more active pathway will be preferentially influenced by β2-gene inactivation. 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Several genes encoding subunits of the neuronal nicotinic acetylcholine receptors have been cloned and regulatory elements involved in the transcription of the ∝:2 and ∝:7-subunit genes have been described. Yet, the detailed mechanisms governing the neuron-specific transcription and the spatio-temporal expression pattern of these genes remain largely uninvestigated. The β2-subunit is the most widely expressed neuronal nicotinic receptors subunit in the nervous system. We have studied the structural and regulatory properties of the 5′ sequence of this gene. A fragment of 1163 bp of upstream sequence is sufficient to drive the cell-specific transcription of a reporter gene in both transient transfection assays and in transgenic mice. Deletion analysis and site-directed mutagenesis of this promoter reveal two negative and one positive element. The positively acting sequence includes one functional E-box. One of the repressor elements is located in the transcribed region and is the NRSE/RE1 sequence already described in promoters of neuronal genes.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention The present invention relates to a Metal-Insulator-Semiconductor(hereinafter referred to as MIS) type semiconductor device, and specifically relates to a MIS transistor. More specifically the present invention relates to a thin-film state MIS type semiconductor device, a thin-film transistor (hereinafter referred to as TFT) formed on an insulating substrate, and above all relates to a MIS type semiconductor device having a so-called inverse stagger type structure, a channel forming region of which is positioned above a gate electrode. The application fields of the present invention are semiconductor integrated circuit formed on an insulating substrate, for example an active matrix type circuit used in a liquid crystal display, a driving circuit for an image sensor and the like. [0002] 2. Description of the Related Art [0003] In recent years, a thin-film state MIS type semiconductor device formed on an insulating substrate has been used. For example an active matrix type liquid crystal display etc. have been known. There are two kinds of active matrix type circuit which are on the present market, one is a TFT using type and the other is such diode as a MIM (Metal Insulator Metal) using type. Particularly, the former has been successfully manufactured recently because it has given a high quality image. [0004] As an active matrix circuit using TFT, two sorts of TFT, which employ such polycrystal semiconductor as polycrystal silicon and such amorphous semiconductor as amorphous silicon, have been known. The former has a difficulty in preparation for a large picture owing to its preparing process, and then the latter, which can be prepared at a temperature of 350° C. or below, has been mainly used for a large picture. [0005] [0005]FIG. 2 shows a preparing process of a conventional amorphous silicon TFT (an inverse stagger type). As the substrate 201 , such heat resistant and non-alkali glass as Corning 7059 is used. Since the maximum temperature of preparing process for the amorphous silicon TFT is around 350° C., it is required that the material therefor be resistant up to this temperature. Especially in case of a liquid crystal display panel, the material is in need of a heat resistant property and a high glass transition temperature not to be distorted by heat treatment. The Corning 7059 can meet for the need, as the glass transition temperature thereof is a little lower than 600° C. [0006] Also, in order to stabilize an operation of TFT, it is not desirable that such movable ion as Na is contained in a substrate. There is no problem with the Corning 7059 having quite low content of alkalies, but it is necessary to form such passivation film as a silicon nitride film or an aluminum oxide film so that the movable ions in a substrate do not invade into TFT, in case a lot of Na etc. is contained in the substrate. [0007] Next, a film is formed using materials such as aluminum or tantalum, a patterning is effected using the mask 1 and the gate electrode 202 is formed. In particular, in order to prevent a short circuit between the gate electrode wiring and the upper wiring thereof, it is recommended to form the oxide film 203 on this gate electrode surface. An anode oxidation method is chiefly employed in the forming way of the oxide film. [0008] Then, the gate insulating film 204 is formed. As the gate insulating film, a silicon nitride is generally used. But a silicon oxide can be also used, and a silicide mixed with nitrogen and oxygen in a free amount ratio can be used. Further both of the single layer and the polylayer films can be available. When a silicon nitride film is used as the gate insulating film and a plasma CVD method is applied, the process temperature becomes 350° C., the maximum temperature of the process, the situation of which is shown in FIG. 2(A). [0009] Next, an amorphous silicon film is formed. it is necessary to raise a temperature of the substrate up to 250 to 300° C., in case a plasma CVD method is used. The film thickness is desired as thin as possible, it is generally to be 10 to 100 nm, and preferably to be 10 to 30 nm. The amorphous silicon region 205 is formed by patterning with the mask 2 which later will become a channel forming region of TFT. The situation so far is shown in FIG. 2(B). [0010] Further, a silicon nitride film is formed all over the surface, which is patterned with the mask 3 to get the etching stopper 206 . This stopper is prepared so that the amorphous silicon region 205 for a channel forming region will not be etched by mistake in a later process, because the amorphous silicon region 205 is as thin as 10 to 100 nm as aforementioned. Also, since the amorphous silicon region under part of the etching stopper functions as a channel forming region, the etching stopper is designed to overlap with the gate electrode as fully as possible. A conventional mask alignment, however, gives a somewhat discrepancy, then the patterning is carried out so as to achieve an enough overlapping with the gate electrode. [0011] After that, N-type or P-type conductivity silicon film is formed. An ordinary amorphous silicon TFT is N-type one. This silicon film is prepared to be a microcrystal state, as an amorphous silicon is too low in a conductivity. N-type microcrystal silicon film can be prepared at a temperature of 350° C. or below by a plasma CVD method. But it is not low enough in resistance, and then the thickness of 200 nm or more was required. P-type microcrystal silicon film was too big in resistance to be used, it was, therefore, difficult to prepare a P-channel type TFT with an amorphous silicon. [0012] The silicon film prepared in this way is patterned using the mask 4 to form N-type microcrystal silicon region 207 . The situation so far is shown in FIG. 2(C), in which a function of TFT can not be realized, as (N-type) microcrystal silicon film is connected with itself on the etching stopper. It is, therefore, necessary to separate the connection, and the groove 208 is formed by separating the connection using the mask 5 . It is feared that even the amorphous silicon region 205 as a base is etched out making a mistake, if there is no etching stopper in this case. This is caused by the reason that the microcrystal silicon region 207 is from several to some ten times or more as thick as the amorphous silicon region thereunder. Afterward, the wiring 209 and the pixel electrode 210 are prepared, using the masks 6 and 7 by a known method, the situation of which is shown in FIG. 2(D). [0013] In the method stated above, so many seven sheets of mask are used, and it is worried that a yield will be lowered. Therefore, a decreasing way of the number of masks has been proposed as will be described in the following; Firstly, a gate electrode part is patterned on a substrate using the first mask. Then, a gate insulating film is formed, further, an amorphous silicon film and a silicon nitride film (later will be an etching stopper) are continuously formed. Next, an etching stopper is formed by etching only the silicon nitride film in a way of self-alignment, using a gate electrode as a mask and exposing from the back. Then, thereon a microcrystal silicon film is formed, and a TFT region including a groove over the channel(corresponds to the numeral 208 in FIG. 2) is formed using the second mask. Afterward, a wiring and an electrode are formed using the third and fourth masks. Finally, the equivalent one as shown in FIG. 2(D) can be obtained. In such way, the number of masks can be reduced by three utilizing a self-alignment process. [0014] Thus formed TFT is very uneven, as distinct from FIG. 2(D). This is mainly derived from the gate electrode part (contains gate electrode oxide 203 ), the etching stopper, and the microcrystal silicon region. A total 800 nm of unevenness will happen, supposing that each thickness of the gate electrode part, the etching stopper, and the microcrystal silicon region 206 is 300 nm, 200 nm, and 300 nm respectively. For example in case where TFT is used in an active matrix circuit of a liquid crystal display panel, the thickness of a cell is 5 to 6 μm and is controlled to an accuracy of 0.1 μm or less. Under such condition, even 1 μm of unevenness will cause a remarkable defect to a thickness uniformity of a cell. [0015] However, any of these factors to cause the unevenness of TFT can not be cut down easily. Namely, the thinner a gate electrode part is, the higher the resistance of gate electrode wiring will be. On the other hand, in order to keep the constant resistance, widening of a gate electrode (i.e. lengthening of a channel) will bring about not only lowering of TFT operation speed but also large area of TFT part, which will cause an aperture ratio to be lowered in case TFT is used in a liquid crystal display. [0016] Also, in case the etching stopper is thin, there is a possibility that even an amorphous silicon region underlying a microcrystal silicon region will be in error to be etched, during the etching of the microcrystal silicon region, and then a yield will be lowered. Further, in case the microcrystal silicon region is thin, the source/drain region resistance of TFT will be increased and ON/OFF ratio of TFT will be decreased. [0017] Still more, the etching stopper will remain as it is, at the time of completion of TFT. The silicon nitride film used for the etching stopper has a nature to trap electric charge. If electric charge is trapped therein for some reason, an unwilling channel will be formed in the amorphous silicon region 205 thereunder, which will cause a leak of drain current. To avoid this problem, it is necessary to cause the etching stopper to be two layer structures of silicon oxide and silicon nitride. In this case, it is needed that the silicon oxide film be also thick enough, and preferably be 100 nm thick or more. SUMMARY OF THE INVENTION [0018] The present invention seeks to solve such problems. Accordingly, it is an object of the present invention to simplify the process. For example, it is to improve a yield by decreasing the number of masks compared with that in a conventional method. It is also to improve a through-put and to reduce a cost, by decreasing the film-forming processes. It is another object of the present invention to make TFT flat. According to this flattening, the problem posed in case TFT is used in a liquid crystal display panel can be settled. Also the flattening is an important technical subject in other applications, and can be applicable to what a conventional TFT has not been put to a practical use. [0019] To overcome the above-mentioned problems, the present invention provides a new preparing method for TFT using no etching stopper, and also provides TFT prepared by the method thereof. Further, for purpose of making a microcrystal silicon region (source/drain) thin, the resistance thereof will be sufficiently rendered low. Still more, in accordance with the present invention, a sheet of silicon film will be formed by no way of conventional two-stage processes, which are the forming of an amorphous silicon region (film) to become a channel forming region, and the forming of a microcrystal silicon region (film) to become a source/drain region. And this one sheet of silicon film will be reformed partly for a source/drain region and partly for a channel forming region. [0020] In case of the through-put improvement, it is the most important subject to reduce the film formings. The film forming process takes much time and also requires an equal time for cleaning of a chamber innerside, thereby, the actual condition being that the film forming is carried out between the chamber cleanings, in the present semiconductor process where the purest environment is demanded. It is, therefore, necessary for the purpose of through-put improvement to form a thin-film than a thick-one, and to form a single layer film than a multilayer one. This means that the reduction of the film forming processes is most desirable. [0021] TFT in one mode of the present invention is claimed as follows; Firstly it is an insulated gate field effect transistor (TFT) of an inverted stagger type. A gate insulating film is formed covering a gate electrode provided on an insulating substrate, and a semiconductor film is formed on the gate insulating film to a thickness of 10 to 100 nm. But the upper part thereof provided on the gate electrode is substantially intrinsic so as to function as a channel forming region. Other parts are N-type or P-type, and fulfill function as source/drain. Also the part functioning as a channel forming region can be taken to be amorphous, semi-amorphous, microcrystal, polycrystal, or an intermediate state thereof. In case where an off-current is suppressed, an amorphous is preferable. On the other hand, the region functioning as source/drain is polycrystal, semiamorphous, or microcrystal, each of which is low enough in resistance. Moreover, the present invention is characterized in that this region is formed by applying a laser annealing. [0022] In the claimed invention, a mass production can be attained, as the film forming is all right by forming only one layer of a semiconductor film. Also, the unevenness of TFT can be reduced, if a conventional microcrystal silicon is not formed. Of course, it is needless to say that the present invention do not seek to form a channel forming region and such impurity region as source/drain with only one layer of a semiconductor film, but a multilayer of a semiconductor film may be formed, to improve the device properties taking cost and characteristics into account. [0023] TFT in another mode of the present invention is characterized in that an etching stopper is not provided on a channel forming region, and in that at least silicon nitride or such similar material as have a nature to trap an electric charge does not exist, adhering to a channel forming region or through a thin (100 nm or less) insulating film. [0024] The existence of an etching stopper is an important factor for the unevenness of TFT, and in case the stopper is composed of such material as silicon nitride, there will happen a leak of drain current. Such problems can be overcome by the above stated technological thoughts of the present invention. Of course, the technological thoughts of the present invention do not require that nobody exists on a channel forming region, and there poses no problem, even if somebody exists to such degree as not to reveal the above-mentioned problems. [0025] The preparation of TFT according to the present invention will be effected by the method as shown in FIG. 1. Of course, there may be some modifications to the process in FIG. 1, if necessary. As shown in FIG. 1, the gate electrode 102 will be patterned with the mask 1 , on the substrate 101 which is heat-resistant and non-alkali glass. If necessary, it may be possible that an insulating property is improved, by forming the oxide film 103 on the surface of gate electrode. Then, the gate insulating film 104 will be formed, thereby FIG. 1(A) being obtained. [0026] Next, an amorphous, semiamorphous, microcrystal, polycrystal, or the intermediate state thin silicon film will be formed, and patterned with the mask 2 to form the semiconductor region 105 . In many actual cases, an amorphous silicon film will be formed considering a film forming temperature and an off-current, but it may be possible that a polycrystal or a semiamorphous silicon is obtained, using such low temperature crystallization art as a laser annealing. In case a polycrystal or a semiamorphous silicon is used, a large electric field mobility can be obtained, however, it is not suitable for an active matrix circuit of liquid crystal display panel, because an off-current increases. [0027] After that, a film to be a masking material against the laser beams, e.g., silicon nitride film rich in silicon content (50 nm or more of thickness is favorable) will be formed, which will be patterned with the mask 3 . At this time, a photoresist can be made to remain on the silicon nitride film if necessary. Namely, in FIG. 1(C), the numeral 106 indicates a silicon nitride film and 107 indicates a photoresist. The thickness of photoresist is 100 nm or more and is favorably 500 nm or more, supposing a later ion implantation process. [0028] At this situation, firstly an impurity will be selectively implanted into the semiconductor region 105 , by an ion implantation or an ion doping method etc. thus being formed the impurity region 108 . The impurity implantation, however, brings about very big defects in a semiconductor film, which no longer functions as a semiconductor. Accordingly, a crystallization will be effected by radiating laser beams from upward. In this laser annealing process, various conditions of silicon ranging from polycrystal but very close to single crystal to amorphous can be formed, by properly controlling a pulse width and an energy density of the laser beams. [0029] If there is no silicon nitride film 106 , the laser beams will reach the region where functions as a channel forming region not doped with an impurity, and will enable its part to be crystallized. In case where a silicon nitride film exists, by which a lot of beams will be absorbed, then the crystallization will not occur and the initial situation will be maintained. It is considered favorable from the mobility increasing point of view that a channel region will be crystallized by laser beams. The present-day laser technologies, however, have a deviation in a laser shot-energy, which gives rise to a remarkable deviation in the crystallization degree. As a result, TFT with different mobilities will be formed. [0030] There is no problem when TFT with a constant mobility is only required. But the condition will be extremely strict, provided that the mobility is satisfied with a constant lower limit and further the off-current is satisfied with a constant upper limit. This comes from the reason that in general TFT with a big mobility will be also big in the off-current. For example, since not only the mobility but also the off-current is important factor, in an active matrix circuit of a liquid crystal display panel, uniformly good TFTs are required. Accordingly in such case, it is desired that TFT is formed using an amorphous silicon which has a low off-current, even if it has a low mobility, or using a material which is similar to the amorphous silicon. Consequently, in the present invention, the laser beams should be prohibited from being entered into a channel forming region by mistake, in the case of such purposes. [0031] This doping process may be done by a laser doping. The laser doping is a method that a sample (a semiconductor film) will be placed in an atmosphere containing an impurity, and by irradiating laser beams or equivalent strong beams to the sample (semiconductor film) in the atmosphere, the sample surface will be heated and activated and an impurity gas will be decomposed to diffuse the impurity over the sample surface. By the laser doping, the impurity is introduced into the semiconductor film and the semiconductor film is crystallized. As the impurity gas, in general PH 3 (phosphine) will be used in case where N-type is furnished, and B 2 H 6 (diborane) will be used in case where P-type is furnished. [0032] By the present inventors' knowledge, in case of the laser beams radiation, a heating of a sample (the semiconductor film) at around 250 to 500° C. enabled the impurity to diffuse into an inside of the sample, causing the impurity concentration thereof to be high enough. It is not desired to place the sample at a too high temperature, so as to keep an amorphous state in the channel forming region, and there is some restrictions added to a glass substrate. So that, it is preferable to put an end of heating to around 250 to 350° C. [0033] Also in case of the laser doping, the photoresist mask 107 is not always needed. In such doping method as an ion implantation, such mask as a photoresist, which is thick enough to enable an ion energy to be thoroughly slowed down, so that a high energy ion to be implanted will not enter into the channel forming region in mistake, is required. However, since the laser doping is a kind of heat-diffusion method, only such silicon nitride mask 106 as a material to have a full masking action to the heat-diffusion will do as a mask. The details about the laser doping technology are disclosed in the Japanese Patent Application No. Heisei 3-283981 filed by the present inventors et al. [0034] After such doping was executed as above, the silicon nitride film 106 and the photoresist (will be evaporated by laser beams radiation in most cases) 107 will be removed, and then, the wiring 110 and the pixel electrode of ITO (Indium Tin Oxide) 111 will be formed using the mask 4 and the mask 5 by a known method. In the above processes, there totally used five sheets of mask, but these can be reduced to four sheets of mask, by freely using a self-alignment method as usual. Namely, for the formings of gate electrode, semiconductor region, as well as pixel electrode and wiring, 1-, 1-, and 2-sheet of mask are respectively necessary. The patterning for the silicon nitride film 106 etc. will be effected by the back exposure (e.g. by irradiating a light from under the substrate to the mask material (the silicon nitride film) provided on the semiconductor region), using the gate electrode as a mask. [0035] As is evident in FIG. 1(D), TFT according to the present invention is smaller in an unevenness than that of a conventional one. This is due to the fact that the unevenness is chiefly caused by only an unevenness of the gate electrode. The semiconductor region 105 is very thin, and the thickness thereof is 10 to 100 nm, similar to the usual TFT, which will not contribute much. [0036] In this way, the semiconductor region, i.e., source/ drain can be available though it is thin. This is attributed to that the said region is high in an impurity concentration, and also is in a good crystalline state. In other words, the features of the present invention have been brought about by the laser annealing or the laser doping. Also, the masks used in the present invention are not needed to remain, after completion of TFT, then the unevenness of TFT can be exceedingly reduced. [0037] In accordance with the present invention, a practical P-channel TFT (hereinafter referred to as PTFT), which could not be prepared by a conventional technology in addition to N-channel TFT (hereinafter referred to as NTFT) prepared mainly with a usual amorphous silicon TFT, has come to be prepared. That is, PTFT has not been practical so far, because not only the hole mobility in an amorphous silicon of a channel region was small compared with the ion mobility, but also P-type silicon with low enough resistance of source/drain could not be obtained. In accordance with the present invention, however, the resistance of P-type silicon has been able to be as low as that of N-type silicon, and then, PTFT having a practical function of the device has been able to be prepared. [0038] Therefore, it has begun to be able to prepare a complementary type MOS circuit (hereinafter referred to as CMOS circuit), using the amorphous silicon TFT or TFT prepared at low temperatures. Up to the present time, the CMOS circuit has been limited to the high temperature prepared TFT formed on a quartz substrate at 1000° C. or higher, or the middle temperature prepared TFT formed on a non-alkali glass substrate at around 600° C. It has been so far considered that CMOS circuit can not be obtained, using TFT prepared at around 350° C. of the maximum process temperature. [0039] The instance is shown in FIG. 3. In the same way as indicated in FIG. 1, the gate electrode of NTFT 302 and the gate electrode of PTFT 303 will be formed on the substrate 301 , using the first mask. Then if necessary, the gate electrode surface will be oxidized by an anode oxidation method, and thereafter the gate insulating film 304 will be formed. Further, the semiconductor regions of NTFT 305 and PTFT 306 will be formed using the second mask. [0040] The better crystallized state of a semiconductor is, the bigger mobility of PTFT will be obtained. It is not preferable that the mobility between NTFT and PTFT is so different from each other, in order to function as CMOS. Though PTFT with a big mobility can be gotten by enabling a film forming temperature to be higher, it can not be excessively raised under such condition as substrate restrictions. But in case where a film is formed at around 350° C. of a substrate temperature using such polysilane as disilane or trisilane, PTFT, which is seemingly amorphous but its mobility is about one over several of that of NTFT, will be gotten. Also, it is possible that an annealing will be carried out in an atmosphere of hydrogen at 300 to 350° C. for 24 hr. or more, after the film forming by CVD plasma method. [0041] Then, the silicon nitride films 307 and 308 will be patterned using the third mask. Of course, as mentioned before, this silicon nitride mask may be formed in a self-alignment, by the back exposure using a gate electrode as a mask. In this case the third mask is not necessary. The cross-sectional view of thus obtained device is shown in FIG. 3(A). [0042] After that, the photoresist mask 309 will be formed in the region of PTFT using the fourth mask, and laser beams will be radiated in an atmosphere of phosphine PH 3 as illustrated in FIG. 3(B). Thereby the impurity region 310 of NTFT (left side) will be formed. Further, the photoresist mask 311 will be formed in NTFT region using the fifth mask, and laser beams will be radiated in an atmosphere of diborane B 2 H 6 as illustrated in FIG. 3(C), to form an impurity region 312 of PTFT (right side). In each laser doping process, laser beams will be absorbed into the silicon nitride mask, and then the channel forming regions 313 and 314 will not be crystallized. [0043] Then, as shown in FIG. 3(C), the metal wirings (aluminum etc.) 315 , 316 , 317 will be formed by a known metal wiring technology, thus being formed CMOS circuit consisting of NTFT 318 and PTFT 319 . In the above processes, six sheets of mask are used, but one sheet of mask will be reduced, if the back exposure technology is used in case of the preparation of silicon nitride masks 307 , 308 . The doping process will be also conducted by a known ion implantation or ion doping method. In case where an impurity region is formed by an ion implantation or an ion doping method, which is capable of a delicate controlling of an impurity concentration, it is possible to firstly form an impurity region of either conductivity type in all of TFT, and then to form an inverse conductivity type only in a specific TFT, not separately forming both impurity regions of NTFT and PTFT. In this case, one sheet of mask will be further reduced. This method, however, can not be applicable to the laser doping, on account of its difficulty in an impurity controlling. [0044] If such method is desired to be done by the laser doping, it will be performed as follows; Firstly a certain conductivity type impurity region will be formed toward all of TFT, setting a substrate temperature at a little low, and then an inverse conductivity type doping will be effected only to the specific TFT, raising the substrate temperature. This comes from the reason that the higher the substrate temperature is, the more concentration of an impurity will be doped. [0045] In the present invention, especially regarding the laser doping, such method as is shown in FIG. 4 can be also used. This method conducts the doping in a self-alignment, using the gate electrode as a mask and radiating laser beams from the back. First of all, in the same way as in the case of FIG. 1, the gate electrode 402 will be formed using the mask 1 on the substrate 401 which passes laser beams. If necessary, its oxide 403 will be formed, and also the gate insulating film 404 will be formed. Then, the semiconductor region 405 will be patterned using the mask 2 . [FIG. 4(A), (B)]. [0046] Next, laser beams will be radiated from the back of substrate. This time, the laser beams pass in parallel in the substrate as illustrated in FIG. 4(C), but are refracted in the gate electrode where is uneven, and diffracted in the gate electrode etc. thus resulting in that the parallel passing is injured. Additionally, in such uneven parts, laser beams are more absorbed in the parts (the oxide layer 403 or the gate insulating film 404 ), where the laser beams pass through, compared with the other parts. As a result, the intensity of laser beams will be extremely lowered on the protrusion part over the gate electrode part, not only by being masked with a gate electrode but also by the above stated complicated phenomena. Then, the laser doping will no longer be carried out, and the initial situation will be kept to become the channel forming region 406 . On the other hand, in the other parts, the laser doping will be performed and the impurity region 407 will be formed. Then, it will do well that the metal wiring 409 and the pixel electrode 410 etc. is formed using the masks 3 and 4 . [0047] This method is very simple in the process compared with the other methods. Namely, the number of masks is four sheets, similar to the case where the self-aligning process of the back exposure was adopted in the method of FIG. 1. Also the exposure processes for forming a mask (e.g., 106 of FIG. 1) will be reduced by one, different from the method of FIG. 1. As a matter of course, the forming process of silicon nitride film etc. used for a mask is not necessary. Also, the overlapping of source/drain and gate electrode is rare and the parasitic capacity can be suppressed. This is the most remarkable features of this method. [0048] This method, however, is in need of using a transparent substrate against the laser beams. The Corning 7059 glass substrate is an ideal non-alkali glass, but this is not good in the transparency of ultraviolet beams, so that it is not appropriate to conduct a laser doping using an excimer laser. If the Corning 7059 glass is to be used by all means, it is required to use a long wave of laser beams (e.g., argon ion laser or Nd: YAG laser etc.). Moreover, it is also possible to lengthen twice or more as long as the wave, by using a non-linear type optics effect of the excimer laser beams. BRIEF DESCRIPTION OF THE DRAWINGS [0049] The objects, features, and advantages of the present invention will become more apparent, from the following description of the preferred embodiments taken in conjunction with the accompanying drawings, in which: [0050] [0050]FIG. 1 shows a fragmentary cross-sectional view of a preparing method of TFT in accordance with the present invention. [0051] [0051]FIG. 2 shows a fragmentary cross-sectional view of a conventional preparing method of TFT. [0052] [0052]FIG. 3 shows a fragmentary cross-sectional view of a preparing method of TFT in accordance with the present invention. [0053] [0053]FIG. 4 shows a fragmentary cross-sectional view of a preparing method of TFT in accordance with the present invention. [0054] [0054]FIG. 5 shows a preparing process diagram of TFT in accordance with the present invention. [0055] [0055]FIG. 6 shows a preparing process diagram of TFT in accordance with the present invention. [0056] [0056]FIG. 7 shows a preparing process diagram of TFT in accordance with the present invention. [0057] [0057]FIG. 8 shows a preparing process diagram of TFT in accordance with the present invention. [0058] [0058]FIG. 9 shows a conventional preparing process diagram of TFT. [0059] [0059]FIG. 10 shows a conventional preparing process diagram of TFT. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0060] The present invention will be explained in more detail, by reference to the following Examples in connection with the drawings. The present invention is by no means limited to the Examples, without departing from the spirit and the scope thereof. EXAMPLE 1 [0061] This Example was carried out according to the preparing process shown in FIG. 5, and the cross-sectional view of process thereof corresponds to FIG. 1, but to as far as the forming process of the metal wiring/electrode 110 in FIG. 1. Then, the forming process of ITO pixel electrode 111 is not contained therein. The gate electrode is made of tantalum, on the surface of which about 200 nm thick anode oxide film was formed in the process 5 to improve the insulating properties. An ion doping method was employed as an impurity doping means. The number of the masks used in this process was four sheets, and all the processes consisted of 26 steps. [0062] In FIG. 5 to FIG. 10, SPUTTERING, PCVD, and RIE are meant by a sputtering film forming method, a plasma CVD method, and a reactive ion etching method respectively. The descriptions following these methods are meant by a film thickness, a used gas and the like. As for a conventional preparing process corresponding to the present Example, the cross-sectional view is shown in FIG. 2, and the process diagram is shown in FIG. 9. Here, six sheets of mask were used and all the processes were twenty-nine. [0063] According to the process diagram, the present Example will be explained in detail below. As a substrate, Corning 7059 glass ( 101 in FIG. 1) was used, which was washed (process 1), and 200 nm thick tantalum film was formed thereon by a sputtering method (process 2). Then, this was patterned using the mask 1 (process 3) and etched with a mixed acid (phosphoric acid containing nitric acid by 5%) (process 4) to form a single layer comprising tantalum as a gate electrode on the substrate. After that, the anode oxide film ( 103 in FIG. 1) was formed in thickness of 200 nm, by effecting an anode oxidation supplying the tantalum gate electrode ( 102 in FIG. 2) with current. The maximum voltage was 250 V (process 5). The way of anode oxidation was disclosed in Japanese Patent Application Nos. Heisei 3-237100 and Heisei 3-238713, then no explanation in detail is here. [0064] Next, the resist was removed (process 6), and the silicon nitride film ( 104 in FIG. 1) as a gate insulating film was formed, in thickness of 200 nm by a plasma CVD method (process 7). At this time, the substrate temperature was set at 300° C. After washing of the substrate (process 8), an amorphous silicon film was formed in thickness of 30 nm by a plasma CVD method (process 9). The substrate temperature at this time was controlled at 300° C. [0065] Then, a patterning in a semiconductor region was carried out using the mask 2 (process 10), and the amorphous silicon film was etched by a reactive ion etching method using CF 4 as a reactive gas (process 11), to form the semiconductor region ( 105 in FIG. 1). The remaining resist was removed (process 12), and the substrate was washed (process 13). [0066] After that, 200 nm thick silicon nitride film was formed on the semiconductor region by a plasma CVD (process 14). At this time, the temperature of substrate was set at 300° C. The patterning of silicon nitride mask was effected (process 15) using the mask 3 , and the silicon nitride film was etched with a buffer hydrofluoric acid (process 16), to form the silicon nitride mask pattern on the semiconductor region ( 106 in FIG. 1), on which about 500 nm thick resist ( 107 in FIG. 1) remained. [0067] Next, by an ion doping method, 1×10 14 cm −2 dose of phosphorus ion was implanted (introduced) into the semiconductor region with the silicon nitride mask pattern as a mask using 10 KeV of accelerated energy (process 17), to form the impurity region ( 108 in FIG. 1). Then, the substrate was washed (process 18), to remove the remaining resist (process 19). And then, a laser annealing was executed by irradiating XeCl excimer laser beam to the semiconductor region with the silicon nitride mask pattern as a mask (process 20) to crystallize the semiconductor region, and the silicon nitride mask pattern ( 106 in FIG. 1) was etched with a buffer hydrofluoric acid and removed (process 21). After that, the substrate was washed (process 22). [0068] Then, an aluminum film was formed in thickness of 400 nm by a sputtering method (process 23). The aluminum wiring was patterned with the mask 4 (process 24), and further the aluminum film was etched by a mixed acid (process 25) to form the aluminum wiring ( 110 in FIG. 1). The remaining resist was removed (process 26). NTFT was prepared through the above processes. EXAMPLE 2 [0069] The present Example was conducted in accordance with the preparing process shown in FIG. 6. The cross-sectional view of preparing process corresponds to FIG. 1, excepting the usage point of the back exposure technology. But FIG. 6 indicates as far as the forming process of the metal wiring/electrode 110 in FIG. 1, similar to Example 1. A gate electrode was made of aluminum, on the surface of which about 200 nm thick anode oxide film was formed in the process 5, to improve an insulating property thereof. A back exposure technology was adopted in the forming of silicon nitride mask, and an ion doping method was employed as the impurity doping means. The number of the mask sheets used in the present process was three, being reduced by one sheet according to the back exposure technology, and all the processes were made up of twenty-six. [0070] A conventional preparing process corresponding to the present Example is shown in FIG. 10, in which three sheets of masks were used and all the processes were twenty-three. The present Example will be explained in detail in accordance with the process diagram as follows. As a substrate, Corning 7059 glass ( 101 in FIG. 1) was used. This was washed (process 1), and thereon an aluminum film was formed in thickness of 400 nm by a sputtering method (process 2). Then, the film was patterned using the mask 1 (process 3), and etched with a mixed acid (phosphoric acid containing nitric acid by 5%) (process 4) to form a single layer comprising aluminum as a gate electrode. Next, an anode oxidation was effected supplying the aluminum gate electrode ( 102 in FIG. 1) with current, and the anodic oxidation film ( 103 in FIG. 1) was formed in thickness of 200 nm on an upper surface and a side surface of the gate electrode, increasing a voltage up to 250 V in maximum (process 5). [0071] After that, the resist was removed (process 6), and as a gate insulating film, the silicon nitride film ( 104 in FIG. 1) was formed in 200 nm thick over the anodic oxidation film by a plasma CVD method (process 7). At this time, the substrate temperature was set at 300° C. After washing of the substrate (process 8), 30 nm thick amorphous silicon film was formed by a plasma CVD method controlling the substrate temperature at 300° C. (process 9). [0072] Then, the semiconductor region was patterned using the mask 2 (process 10), and the amorphous silicon film was etched by a reactive ion etching method using CF 4 as a reaction gas (process 11), thereby forming the semiconductor region ( 105 in FIG. 1). The remaining resist was removed (process 12), and the substrate was washed (process 13). [0073] After that, 200 nm thick silicon nitride film was formed by a plasma CVD method (process 14). At this time, the substrate temperature was controlled at 300° C. Then, an exposure was effected from the back of substrate with a resist painted, and the silicon nitride mask was patterned in a self-alignment, using a gate electrode as a mask (process 15). And then, the silicon nitride film was etched with a buffer hydrofluoric acid (process 16), thereby forming the silicon nitride mask ( 106 in FIG. 1). Thereon about 500 nm thick resist ( 107 in FIG. 1) remained. [0074] Next, 1×10 14 cm −2 dose of phosphorus ion was implanted, by an ion doping method with 10 KeV of an accelerated energy (process 17), and the impurity region ( 108 in FIG. 1) was formed. A substantially intrinsic region 109 was then formed. And then, the substrate was washed (process 18), and the remaining resist was removed (process 19). Then, a laser annealing was executed using XeCl excimer laser (process 20), and the silicon nitride mask ( 106 in FIG. 1) was etched with a buffer hydrofluoric acid and removed (process 21). Subsequently, the substrate was washed (process 22). [0075] Finally, an aluminum film was formed in thickness of 400 nm by a sputtering method (process 23), an aluminum wiring was patterned using the mask 4 (process 24), and further an aluminum film was etched with a mixed acid (process 25), thereby forming the aluminum wiring ( 110 in FIG. 1). The remaining resist was removed (process 26). Thus, NTFT was prepared by way of the above processes. EXAMPLE 3 [0076] The present Example was conducted according to the preparing process shown in FIG. 7. The cross-sectional view of the preparing process corresponds to FIG. 4. However, FIG. 7 indicates only up to the forming process of the metal wiring/electrode 409 in FIG. 4. A gate electrode was made of aluminum, on the surface of which about 200 nm thick anode oxide film was formed to improve an insulating property in the process 5. As an impurity doping means, a laser doping technology with laser beams radiation from the back was employed. The number of the masks used in this process was three, and all the processes were nineteen. [0077] The following is a detail explanation of the present Example in accordance with the process diagram. As a substrate, Corning 7059 glass ( 401 in FIG. 4) was used. This was washed (process 1), and 400 nm thick aluminum film was formed thereon by a sputtering method (process 2). This was patterned with the mask 1 (process 3), and etched with a mixed acid (by 5% nitric acid contained phosphoric acid) (process 4). Then, an anode oxidation was effected supplying the aluminum gate electrode ( 402 in FIG. 4) with current, and the anode oxide film ( 403 in FIG. 4) was formed in thickness of 200 nm, raising the voltage up to 250 V in maximum (process 5). [0078] Afterward, the resist was removed (process 6), and the silicon nitride film ( 404 in FIG. 4) as a gate insulating film was formed in thickness of 200 nm by a plasma CVD method (process 7). At this time, the substrate temperature was set at 300° C. After washing of the substrate (process 8), 30 nm thick amorphous silicon film was formed by a plasma CVD method (process 9). The substrate temperature at this time was set at 300° C. [0079] Then, the semiconductor region was patterned with the mask 2 (process 10), and the amorphous silicon film was etched, by a reactive ion etching method using CF 4 of a reaction gas (process 11), to form the semiconductor region ( 405 in FIG. 4). The remaining resist was removed (process 12), and the substrate was washed (process 13). [0080] Next, the laser doping of the semiconductor region was performed in a self-alignment method, using the gate electrode as a mask, and irradiating XeCl excimer laser beams to the semiconductor region from the back of the substrate (from under the substrate) with the semiconductor film being placed in an atmosphere comprising the impurity (phosphine) (process 14). Since the XeCl excimer laser was 308 nm in a wave length, it was able to pass through Corning 7059. The substrate temperature during the laser doping was set at 300° C., and then the substrate was washed (process 15). The impurity is introduced into the semiconductor film and the semiconductor film is crystallized by the laser doping. [0081] After that, an aluminum film was formed in a thickness of 400 nm by a sputtering method (process 16), the aluminum wiring was patterned with the mask 4 (process 17). Further the aluminum film was etched with a mixed acid (process 18), and the aluminum wiring ( 409 in FIG. 4) was formed. The remaining resist was removed (process 19). Thus, NTFT was prepared by the above processes. EXAMPLE 4 [0082] The present Example is concerned with the forming of CMOS circuit, and carried out in accordance with the preparing process shown in FIG. 8. The cross-sectional view of the preparing process corresponds to FIG. 3. A gate electrode was made of aluminum, on the surface of which about 200 nm thick anode oxide film was formed in the process 5 to improve an insulating property. As an impurity doping means, a laser doping technology was adopted. In case of the doping, the regions of NTFT and PTFT were formed separately on the same substrate. The number of the masks used in the present processes was six, and all the processes were thirty-two. [0083] The present Example will be explained in detail according to the process diagram as follows. As a substrate, Corning 7059 glass ( 301 in FIG. 3) was used. This was washed (process 1), and an aluminum film was formed in a thickness of 400 nm thereon by a sputtering method (process 2). Then, this was patterned with the mask 1 (process 3), and etched with a mixed acid (by 5% nitric acid contained phosphoric acid) (process 4). After that, an anode oxidation was effected supplying the aluminum gate electrode ( 302 and 303 in FIG. 3) with current, and 200 nm thick anode oxide film was formed (process 5). The maximum voltage was 250V. A technical skill of the anode oxidation is not mentioned here in detail. [0084] Then, the resist was removed (process 6), and the silicon nitride film ( 304 in FIG. 3) as a gate insulating film was formed, in 200 nm thick by a plasma CVD method (process 7). At this time, the substrate temperature was controlled at 300° C. After washing of the substrate (process 8), 30 nm thick amorphous silicon film was formed by a plasma CVD method (process 9). At this time, the substrate temperature was set at 250° C. [0085] Next, the semiconductor region was patterned with the mask 2 (process 10), the amorphous silicon film was etched by a reactive ion etching method using CF 4 of a reaction gas (process 11), and the semiconductor regions ( 305 and 306 in FIG. 3) were formed. The remaining resist was removed (process 12), and the substrate was washed (process 13). [0086] Then, 200 nm thick silicon nitride film was formed by a plasma CVD method (process 14). At this time, the substrate temperature was set at 300° C. The silicon nitride mask was patterned using the mask 3 (process 15), the silicon nitride film was etched with a buffer hydrofluoric acid (process 16), and the silicon nitride masks ( 307 and 308 in FIG. 3) were formed. The resist on the silicon nitride mask was removed (process 17). [0087] After washing of the substrate (process 18), a pattern of NTFT was formed using the mask 4 (process 19). At this time, PTFT was covered with the resist ( 309 in FIG. 3). Under this state, the doping of phosphorus was effected by a laser doping in an atmosphere of phosphine (process 20) with the silicon nitride masks. In this way, the N-type impurity region ( 310 in FIG. 3) was formed. After the laser doping, the remaining resist ( 309 in FIG. 3) was removed (process 21), and the substrate was washed (process 22). [0088] In the same way, a pattern of PTFT was formed using the mask 5 (process 23), when NTFT was covered with the resist ( 311 in FIG. 3). Under this condition, the doping of boron was executed by a laser doping method in an atmosphere of diborane (process 24). The impurity (boron) is introduced into a portion of the semiconductor region 106 which is not covered with the silicon nitride mask 308 , and said portion is crystallized by the laser beam of the laser doping. Thus, the P-type impurity region ( 312 in FIG. 3) was formed. After the laser doping, the remaining resist ( 311 in FIG. 3) was removed (process 25), and the substrate was washed (process 26). Further, the silicon nitride masks ( 307 and 308 in FIG. 3) were etched with a buffer hydrofluoric acid and removed (process 27). Then, the substrate was washed (process 28). [0089] Finally, an aluminum film was formed in a thickness of 400 nm by a sputtering method (process 29), an aluminum wiring was patterned with the mask 6 (process 30), further, the aluminum film was etched with a mixed acid (process 31), and the aluminum wirings ( 315 , 316 , and 317 in FIG. 3) were formed. The remaining resist was removed (process 32). NTFT was prepared by the above-mentioned processes. [0090] In the foregoing description, the gate electrode is formed from a single layer made of aluminum or tantalum. However, the gate electrode may comprise a silicon layer and a metal layer provided on the silicon layer and comprising a material selected from the group consisting of aluminum and tantalum. [0091] As evident from the above description, the present invention is characterized in that not only the process can be simplified, but also such TFT as is excellent in qualities (e.g., prominent high speed operation or small threshold voltage etc.) can be provided, because a sheet resistance of source, drain region is small. In this way, the present invention is useful in industry.

In an inverted stagger type thin-film transistor, the preparing process thereof can be simplified, and the unevenness of the thin film transistor prepared thereby can be reduced. That is, disclosed is a preparing method which comprises selectively doping a semiconductor on a gate insulating film with an impurity to form source, drain, and channel forming regions, and conducting a laser annealing to them, or a preparing method which comprises selectively doping the semiconductor region with an impurity by a laser doping method.

FIELD OF THE INVENTION [0001] The present invention relates a method for operating a secondary station in a communication system like a mobile communication system as LTE. In such communication systems, the stations may be able to communicate by means of MIMO transmission streams. [0002] This invention is, for example, relevant for LTE or LTE-Advanced. BACKGROUND OF THE INVENTION [0003] In systems using MIMO such as LTE, the secondary station (or User Equipment or UE) can give the primary station (or base station or eNB) feedback on the downlink channel state. This can partly comprise an index to a preferred precoding matrix selected from a codebook of matrices. Alternatively, as proposed for LTE-A, the precoder is defined by a pair of indices, each for one of two codebooks, where the precoder is derived from the matrix multiplication of the two matrices. In this case there could be more that one particular type of “matrix multiplication” that could be applied. [0004] Typically a precoding matrix is defined such that the coefficients in column of the matrix represent the precoding coefficients applied the each transmit antenna for a given spatial channel. [0005] A constraint on the codebook design to ensure that CQI calculation can be consistent with equal power per transmit antenna, at least with a subset of codebook entries, was proposed. This is intended to support full power amplifier (PA) utilization, where the same total output power is required for each antenna: [0000] [ ww*] mm =κ, m =1 , . . . , N T [0006] Where W is the overall precoder, and N T is the number of transmit antennas. [0007] Moreover, it is possible that at least a subset of codebook entries should also have orthogonal columns with unit norm (i.e. corresponding to unitary precoding). [0008] In the RANI discussion of codebook design the desirability of a restricted alphabet (e.g. QPSK (Quadrature Phase Shift Keying), 8-PSK or 16-PSK) for precoding coefficients has been mentioned. One advantage of using an alphabet based on higher order M-PSK (e.g. M=8 or 16) is that it can better match the channel characteristics that low order M-PSK (e.g. M=4). Restricting strictly to M-PSK would ensure that requirements for both full PA utilization and unit norm are automatically met for all codebook entries. There may also be some reduction in computational complexity with restricted alphabets, but it is not clear how significant this consideration would be in practice. However, it is of interest to examine what other alphabets could be beneficial (e.g. whether different amplitude values should be allowed within a precoder). In principle, an ideal precoder, even with power balancing between antennas, would require an unconstrained alphabet, but we focus here on limited alphabets. [0009] We could consider the optimum allocation of power among the precoding coefficients as analogous to the “water filling” problem. It is well known that “constant power water filling” (i.e. allocating either zero or uniform power) is quite close to the optimal solution, assuming that unused power can be re-allocated elsewhere. This suggests that adding the possibility of “zero” to an M-PSK alphabet will achieve much of the potential benefit available from an alphabet with different amplitudes. [0010] The general principle of setting some elements of the precoder to zero is already known. SUMMARY OF THE INVENTION [0011] However, other amplitude scaling factors could also be considered (e.g. in the form of APSK (Amplitude and Phase Shift Keying), of which zero amplitude is a special case). More generally, a M-QAM alphabet could be considered (i.e. a limited set of amplitudes for I and Q components. [0012] It is an object of the invention to propose a method which alleviates the above mentioned problems. [0013] It is another object of the invention to propose a method for operating a secondary station which permits to maintain power balancing in the precoding matrix regardless of the selected alphabet. [0014] A method for operating a secondary station in a communication network including a primary station, the method comprising [0015] generating a precoding matrix defined as the Hadamard product of an alphabet modifying matrix and an original precoding matrix, wherein the original precoding matrix consist of complex coefficients of equal magnitude, [0016] transmitting a precoding report representative of the precoding matrix to the primary station. [0017] As a consequence, the alphabet modifying matrix is thus enabling a power balancing of the precoding matrix. [0018] The present invention also relates to a secondary station and primary station which comprise means for implementing the method of the first aspect of the invention. [0019] These and other aspects of the invention will be apparent from and will be elucidated with reference to the embodiments described hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS [0020] The present invention will now be described in more detail, by way of example, with reference to the accompanying drawing, wherein: [0021] FIG. 1 is a diagram representing schematically a network in which the invention is implemented. DETAILED DESCRIPTION OF THE INVENTION [0022] This invention relates to a mobile communication system like a 802.11, e.g. 802.11n, or a UMTS, e.g. UMTS LTE or LTE-Advanced system as illustrated on FIG. 1 . [0023] Referring to FIG. 1 , a radio communication system in accordance with the invention comprises a primary station (BS or eNodeB) 100 and a plurality of secondary stations (MS or UE) 110 . The primary station 100 comprises a microcontroller (μC) 102 , transceiver means (Tx/Rx) 104 connected to antenna means 106 , being here an antenna array including a plurality of antennas and an antenna array circuit for controlling the antenna weights, power control means (PC) 107 for altering the transmitted power level, and connection means 108 for connection to the PSTN or other suitable network. Each UE 110 comprises a microcontroller (μC) 112 , transceiver means (Tx/Rx) 114 connected to antenna means 116 , being here an antenna array including a plurality of antennas and an antenna array circuit for controlling the antenna weights, and power control means (PC) 118 for altering the transmitted power level. Communication from primary station 100 to mobile station 110 takes place on downlink channels, while communication from secondary station 110 to primary station 100 takes place on uplink channels. In this example, the downlink channels comprise control channels. The microcontroller 112 of the secondary stations is able to generate precoding matrix for the antenna array circuit in case of MIMO communication. [0024] As mentioned above, balanced power between the antennas is a desirable property for a transmission scheme, which allows full use of PA resources. This is probably easier to achieve with APSK than M-QAM, since a smaller number of additional amplitudes are involved. [0025] We first examine how to achieve power balancing between antennas for an alphabet of M-PSK plus zero, it is necessary that each transmit antenna is assigned the same number of zero values (i.e. each row in the precoding matrix contains the same number of zero values). This is not a difficult constraint to satisfy for the full rank case. [0026] For example, any number of up to N T pre-defined orthogonal patterns of zeros can be applied to the precoder. Suitable patterns could be generated by cyclic shifting of a base pattern with N T zeros. For lower transmission ranks, power balance between antennas may be achievable, but at the cost of power imbalance between layers. Note that in case the aim is moreover to achieve equal power per layer each precoding vector would need to contain the same number of zero values, but this is not necessarily an essential design requirement. [0027] Some sets of possible zero patterns (satisfying the power balance requirement) are proposed below. [0028] Since the same considerations for power balance apply, the same kind of patterns could be use if another amplitude factor (instead of zero) is applied (e.g. 0.5 or 1.5) [0029] The Hadamard product can be defined as follows: [0030] For two matrices of the same dimensions, we have the Hadamard product also known as the entrywise product and the Schur product. [0031] Formally, for two matrices of the same dimensions: [0000] A, B ∈ m×n [0000] the Hadamard product A·B is a matrix of the same dimensions [0000] A∘B ∈ m×n [0000] with elements given by [0000] ( A∘B ) i,j =A i,j ·B i,j [0032] The Hadamard product is commutative. [0033] In a first exemplary embodiment, codebook with zero value included in the alphabet (4×4 case) are considered. In the case of rank 4 transmission for 4Tx and 4 Rx antennas, where in general, the rank 4 precoder is a 4×4 matrix. [0034] We assume that the alphabet for the whole precoder is M-PSK plus zero, and that power balance is required between antennas. This means that each row and in the precoding vector will contain the same number of zero value coefficients. If we apply the further restriction that each precoding vector has the same number of zero value coefficients (power balancing among precoding vectors), each column will have the same number of zeros. [0035] To generate the precoding matrix, a secondary station may use an alphabet modifying matrix. An Hadamard product is applied between the original precoding matrix, for example the M-PSK precoding matrix, and the alphabet modifying matrix. [0036] The alphabet modifying matrix may be chosen in accordance to several criteria like one of the following: Power balance; Achievable data rate with the generated precoding matrix; Transmission rank to maximise the achievable data rate; [0040] For example, we can arbitrarily choose to keep the first elements as always non-zero. In this case, the alphabet modifying matrix may be one of the following examples, where zero patterns meet the above criteria for 1 zero per antenna. In these exemplary matrices, the blanks may be all equal to 1: [0000] [ 0 0 0 0 ] , [ 0 0 0 0 ] , [ 0 0 0 0 ] , [ 0 0 0 0 ] [0041] In total there are 3×3×2=18 such patterns [0042] If we choose to always keep the diagonal elements as non-zero, there are 9 such patterns: [0000] [ 0 0 0 0 ] , [ 0 0 0 0 ] , [ 0 0 0 0 ] , [ 0 0 0 0 ] ,    [ 0 0 0 0 ] , [ 0 0 0 0 ]  [ 0 0 0 0 ] , [ 0 0 0 0 ] , [ 0 0 0 0 ] [0043] An example set of three orthogonal patterns is: [0000] [ 0 0 0 0 ] , [ 0 0 0 0 ] , [ 0 0 0 0 ] [0044] From a linear combination of a set orthogonal matrices, other alphabet modifying matrices can be obtained and still maintaining the same power balancing effect. [0045] Example zero patterns meeting the above criteria for 2 zeros per antenna are: [0000] [ 0 0 0 0 0 0 0 0 ] , [ 0 0 0 0 0 0 0 0 ] , [ 0 0 0 0 0 0 0 0 ] , [ 0 0 0 0 0 0 0 0 ] [0046] If we choose to always keep the diagonal elements as non-zero, there are 5 such patterns [0000] [ 0 0 0 0 0 0 0 0 ] , [ 0 0 0 0 0 0 0 0 ] , [ 0 0 0 0 0 0 0 0 ] , [ 0 0 0 0 0 0 0 0 ] ,  [ 0 0 0 0 0 0 0 0 ] [0047] Note that the last matrix is block diagonal, which may be suitable for cross polar arrays. [0048] In the case that there is only one non-zero value per antenna, the actual coefficient values (and locations in the matrix) are not significant, then retaining only the diagonal elements would be sufficient. [0049] In the case of power balancing between antennas and precoding vectors, and retaining all the diagonal elements, signalling to the UE which patterns is applied would require the following numbers of bits: [0000] Number zeros Number per antenna bits required Up to 1 4 Up to 2 4 Up to 3 5 [0050] For rank 3 and lower, truncated versions of the patterns can be used, where the unused precoding vector is set to zero e.g for rank 3 [0000] [ 0 0 0 0 0 0 0 ] , [ 0 0 0 0 0 0 0 ] , [ 0 0 0 0 0 0 0 ] , [ 0 0 0 0 0 0 0 ] ,  [ 0 0 0 0 0 0 0 ] , [ 0 0 0 0 0 0 0 ]  [ 0 0 0 0 0 0 0 ] , [ 0 0 0 0 0 0 0 ] [0051] Or for rank 2, unfortunately if equal power per spatial channel is required, then the power is now unbalanced between antennas. [0000] [ 0 0 0 0 0 0 0 0 0 0 ] , [ 0 0 0 0 0 0 0 0 0 0 ] , [ 0 0 0 0 0 0 0 0 0 ] , [ 0 0 0 0 0 0 0 0 0 0 ] ,  [ 0 0 0 0 0 0 0 0 0 0 ] , [ 0 0 0 0 0 0 0 0 0 0 ]  [ 0 0 0 0 0 0 0 0 0 0 ] , [ 0 0 0 0 0 0 0 0 0 0 ] [0052] Power balance can be maintained for rank 2 transmission and 2 zero values per precoding vector. E.g [0000] [ 0 0 0 0 0 0 0 0 0 0 0 0 ] , [ 0 0 0 0 0 0 0 0 0 0 0 0 ] , [ 0 0 0 0 0 0 0 0 0 0 0 0 ] , [ 0 0 0 0 0 0 0 0 0 0 0 0 ] [0053] An embodiment is a system like LTE-A, where the UE indicates to the base station a preferred precoding matrix applicable for at least part of the downlink transmission band. This indication of preferred precoding vector comprises a first index to a first matrix of precoding coefficients selected from a first predetermined codebook. In the case of 4Tx antennas this could be the codebook used for MIMO in LTE Release 8. In addition the indication from the UE comprises a second index to a second matrix (selected from a second predetermined codebook) which defines a set of locations where the coefficients of the first matrix are to be modified by a specified scaling factor, the other locations being unmodified. According to different variations of the embodiment the specified scaling factor may be one of 0, 0.5 or 1.5. [0054] In a further variation of the embodiment the indication of preferred precoding matrix from the UE also comprises a preferred transmission rank. The indication may then be constructed as a third index to a list of possible combinations of transmission rank, first index and second index. [0055] In a further variation the contents of at least one the first and second codebooks depends on the transmission rank. As an alternative, the values in the alphabet modifying matrix may be varied in dependence on the preferred transmission rank. Similarly, the values in the alphabet modifying matrix can be changed in view of the size of the precoding matrix. [0056] a further variation the indication of preferred precoding matrix additionally comprises and indication of the value of the scaling factor. [0057] In another embodiment based on LTE-A the UE indicates to the base station a preferred precoding matrix applicable for at least part of the downlink transmission band. This indication of preferred precoding vector comprises First index to a first matrix of precoding coefficients selected from a first predetermined codebook. A second index to a second matrix (also selected from a second predetermined codebook). A third index to a third matrix which defines a set of locations where the coefficients of the first matrix are to be modified by a specified scaling factor, the other locations being unmodified [0061] One of the first or second codebooks is associated with long term/wideband channel characteristics and the other codebook is associated with short term/narrow band characteristics. [0062] In another embodiment based on LTE-A the UE indicates to the base station a preferred precoding matrix applicable for at least part of the downlink transmission band. This indication of preferred precoding vector comprises A first index to a first matrix of precoding coefficients selected from a first predetermined codebook. A second index to a second matrix which defines a set of locations where the coefficients of the first matrix are to be modified by a specified first scaling factor A third index to a third matrix which defines a set of locations where the coefficients of the first matrix are to be modified by a specified second scaling factor. The second scaling factor is different to the first scaling factor and the set of locations specified by the third index is orthogonal to the set of locations specified by the second index. Locations which are not modified by the first or second scaling factors are unmodified [0067] The examples of the invention are focussed on complex coefficients i.e. on M-PSK. In order to apply these examples to M-QAM, the I and Q components could be treated independently in a similar manner than in the above examples. [0068] In variations of the above embodiments the various indices may be jointly encoded together in the form of a single indication. [0069] In another embodiment of the invention, the precoding matrix generation is also done in the primary station, for example, in an E-NodeB or a base station. [0070] The invention has particular, but not exclusive, application to wireless communication systems such as UMTS, UMTS LTE, and UMTS LTE-Advanced, as well as wireless LANs (IEEE 802.11n) and broadband wireless (IEEE 802.16). [0071] In the present specification and claims the word “a” or “an” preceding an element does not exclude the presence of a plurality of such elements. Further, the word “comprising” does not exclude the presence of other elements or steps than those listed. [0072] The inclusion of reference signs in parentheses in the claims is intended to aid understanding and is not intended to be limiting. [0073] From reading the present disclosure, other modifications will be apparent to persons skilled in the art. Such modifications may involve other features which are already known in the art of radio communication.

The invention relates to a method for operating a secondary station in a communication network including a primary station, the method comprising generating a pre-coding matrix obtained from the Hadamard product of an alphabet modifying matrix and an original pre-coding matrix, wherein the original precoding matrix consist of complex coefficients of equal magnitude, transmitting a precoding report representative of the precoding matrix to the primary station.

CROSS-REFERENCE TO RELATED APPLICATIONS The present application is related to concurrently-filed U.S. patent application Ser. No. 12/347,354, entitled SYSTEM AND METHOD FOR MESSAGE-BASED CONVERSATIONS, which is incorporated herein by reference in its entirety. The present application is related to concurrently-filed U.S. patent application Ser. No. 12/347,223, entitled SYSTEM AND METHOD FOR MOBILE USER AUTHENTICATION, which is incorporated herein by reference in its entirety. BACKGROUND Field of the Invention The present invention relates generally to telecommunications services. More particularly, the present invention relates to capabilities that enhance substantially the value and usefulness of various messaging paradigms including, inter alia, Short Message Service (SMS), Multimedia Message Service (MMS), etc. BACKGROUND OF THE INVENTION As the ‘wireless revolution’ continues to march forward the importance to a Mobile Subscriber (MS)—for example a user of a Wireless Device (WD) such as a cellular telephone, a BlackBerry, a Palm Pilot, etc. that is serviced by a Wireless Carrier (WC)—of their WD grows substantially. One consequence of such a growing importance is the resulting ubiquitous nature of WDs—i.e., MSs carry them at almost all times and use them for an ever-increasing range of activities. Coincident with the expanding presence of WDs has been the explosive growth of messaging—a steady annual increase, year over year, in the number of (SMS, MMS, etc.) messages that have been exchanged by and between WDs. That steady increase shows no sign of abating. For example, as reported by the industry group CTIA (see ctia.org on the World Wide Web [WWW]) in the U.S. there were over 158 billion SMS messages sent during 2006 (representing a 95% increase over 2005) and there were over 2.7 billion MMS messages sent during 2006 (representing a 100% increase over 2005). Additionally, MSs would like to be able to use their WDs to engage in and complete increasingly more complicated activities (beyond, for example, exchanging simple messages with their friends, receiving one-way news/weather/financial/etc. notifications, etc.)—e.g., inquiring as to the current balance of an account at a financial institution, transferring funds between accounts within a financial institution, paying a bill, etc. Many of those activities require a coordinated exchange of multiple SMS, MMS, etc. messages supported by a robust back-end system. Given (1) the ubiquitous nature of WDs, (2) the popularity of (SMS, MMS, etc.) messaging, and (3) the need for MSs to use their WDs to engage in and complete increasingly more complicated activities, it would be desirable to have a flexible, extensile, and dynamically configurable back-end Application Server (AS) environment. Aspects of the present invention facilitate such an AS environment in new, creative, and unconventional ways and address various of the not insubstantial challenges that are associated with same. SUMMARY OF THE INVENTION In one embodiment of the present invention there is provided an application server system containing possibly inter alia a gateway at which an incoming message is received; an incoming queue on which at least aspects of the incoming message are deposited; workflow modules which may (a) retrieve the aspects of the incoming message from the incoming queue, (b) complete one or more processing steps, and (c) deposit an entry on an outgoing queue; a gateway from which at least aspects of the entry is transmitted after the entry is retrieved from the outgoing queue; a repository; and an administrator. These and other features of the embodiments of the present invention, along with their attendant advantages, will be more fully appreciated upon a reading of the following detailed description in conjunction with the associated drawings. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated herein and form part of the specification, depict embodiments of the present invention and, together with the summary that was presented above and the description that may be found below, further serve to illustrate inter alia the principles, structure, and operation of such embodiments. It will be readily apparent to one of ordinary skill in the relevant art that numerous variations, modifications, alternative forms, etc. of the depicted embodiments are easily possible and indeed are within the scope of the present invention. FIG. 1 is a diagrammatic presentation of an exemplary Messaging Inter-Carrier Vendor (MICV). FIG. 2 illustrates one particular arrangement that is possible through aspects of the present invention. FIG. 3 illustrates various of the exchanges or interactions that are possible during an optional registration portion of the present invention. FIG. 4 illustrates various of the exchanges or interactions that are supported by aspects of the present invention. FIG. 5 is a diagrammatic presentation of aspects of an exemplary AS as might be operated by a Service Provider (SP). FIG. 6 illustrates an aspect of an AS environment that might be possible under a particular implementation of aspects of the present invention. FIG. 7 depicts an example computer system through which embodiments of aspects of the present invention may be implemented. FIG. 8 presents a Java™ programming language code sample that may be possible under one particular embodiment of aspects of the present invention. Throughout the drawings (a) like reference numbers generally indicate identical or functionally similar elements and (b) the left-most digit(s) of a reference number generally identify the drawing in which the reference number first appears. For example, in FIG. 4 reference numeral 318 would direct the reader to FIG. 3 for the first appearance of that element. DETAILED DESCRIPTION It should be noted that the embodiments that are described below are merely exemplary of the invention, which may be embodied in various forms. Therefore the details that are disclosed below are not to be interpreted as limiting but merely as the basis for possibly inter alia (a) teaching one of ordinary skill in the relevant art how to make and/or use the invention and (b) the claims. The present invention may leverage the capabilities of a centrally-located, full-featured MICV facility. Reference is made to U.S. Pat. No. 7,154,901 entitled “Intermediary network system and method for facilitating message exchange between wireless networks,” and its associated continuations, for a description of a MICV, a summary of various of the services/functions/etc. that are performed by a MICV, and a discussion of the numerous advantages that arise from same. U.S. Pat. No. 7,154,901 and its associated continuations are hereby incorporated by reference in their entirety. As illustrated in FIG. 1 and reference numeral 100 a MICV 120 is disposed between, possibly inter alia: 1) Multiple WCs (WC 1 114 , WC 2 116 →WC Z 118 ) on one side, and 2) Multiple SPs (SP 1 122 →SP Z 124 ), entities that may possibly inter alia provide a range of services/products/etc. to MSs, on the other side and thus ‘bridges’ all of the connected entities. A MICV 120 thus, as one simple example, may offer various routing, formatting, delivery, value-add, etc. capabilities that provide, possibly inter alia: 1) A WC 114 → 118 (and, by extension, all of the MSs 102 → 104 , 106 → 108 , 110 → 112 that are serviced by the WC 114 → 118 ) with ubiquitous access to a broad universe of SPs 122 → 124 , and 2) A SP 122 → 124 with ubiquitous access to a broad universe of WCs 114 → 118 (and, by extension, to all of the MSs 102 → 104 , 106 → 108 , 110 → 112 that are serviced by the WCs 114 → 118 ). Generally speaking a MICV may have varying degrees of visibility (e.g., access, etc.) to the (MS⇄MS, MS⇄SP, etc.) messaging traffic: 1) A WC may elect to route just their out-of-network messaging traffic to a MICV. Under this approach the MICV would have visibility (e.g., access, etc.) to just the portion of the WC's messaging traffic that was directed to the MICV by the WC. 2) A WC may elect to route all of their messaging traffic to a MICV. The MICV may, possibly among other things, subsequently return to the WC that portion of the messaging traffic that belongs to (i.e., that is destined for a MS of) the WC. Under this approach the MICV would have visibility (e.g., access, etc.) to all of the WC's messaging traffic. While the discussion below will include a MICV, it will be readily apparent to one of ordinary skill in the relevant art that other arrangements are equally applicable and indeed are fully within the scope of the present invention. In the discussion below aspects of the present invention will be described and illustrated as being offered by a SP (i.e., as noted above an entity that may possibly inter alia provide a range of services/products/etc. to MSs). A SP may, for example, be realized as an independent service bureau, an element of or within some organization (such as possibly inter alia a financial institution, a retail establishment, an on-line retailer, etc.), an element of a WC or a landline carrier, an element of a MICV, multiple entities (such as for example those just listed) or aspects of same working together, etc. In the discussion below reference will be made to messages that are sent, for example, between a MS and a SP. As set forth below, a given ‘message’ sent between a MS and a SP may actually comprise a series of steps in which the message is received, forwarded, and routed between different entities, including possibly inter alia a MS, a WC, a MICV, and a SP. Thus, unless otherwise indicated, it will be understood that reference to a particular message generally includes that particular message as conveyed at any stage between an origination source, such as for example a MS, and an end receiver, such as for example a SP. As such, reference to a particular message generally includes a series of related communications between, for example, a MS and a WC; a WC and a MICV; a MICV and a SP; etc. The series of related communications may, in general, contain substantially the same information, or information may be added or subtracted in different communications that nevertheless may be generally referred to as a same message. To aid in clarity, a particular message, whether undergoing changes or not, is referred to by different reference numbers at different stages between a source and an endpoint of the message. To better understand the particulars of the present invention consider for a moment a simple hypothetical example—SP N offers a service that has been enhanced or augmented as provided through aspects of the instant invention and Mary, a MS, uses SP N 's service. FIG. 2 and reference numeral 200 depict one particular arrangement that may be possible under our hypothetical example. As indicated, all of the messaging traffic of numerous MSs (MS 1 102 →MS a 104 and MS 1 110 →MS c 112 , including Mary), serviced by various WCs (WC 1 114 →WC Z 118 ), is exchanged with a MICV 120 and the MICV 120 is connected with SP N 202 (a SP that offers, possibly inter alia, aspects of the present invention). FIG. 3 and reference numeral 300 illustrate various of the exchanges or interactions that might occur under an optional registration portion of our hypothetical example. Such a registration process may be tailored (e.g., the range of information gathered, the scope of services subsequently offered, etc.) to the class of user—e.g., possibly inter alia different types, categories, etc. of users may complete different registration processes. Additionally, a registration process may be supported or offered by any combination of one or more entities (e.g., a 3P such as a financial institution, a retail establishment, an on-line retailer, an employer, a utility company, etc.; a SP; etc.). As well, some or all of the information that is collected during a registration process may be shared or exchanged between any combination of one or more entities (e.g., a SP, a 3P, etc.). Thus a MS may complete a (required or optional) registration process with any number of entities and aspects of the information that is collected during a given registration process may be shared or exchanged between any number of entities. The registration process that is depicted through FIG. 3 is supported or offered by a SP (specifically by SP N 202 ). Of interest and note in FIG. 3 are the following entities: MS 302 WD 306 . For example, a mobile telephone, BlackBerry, PalmPilot, etc. belonging to Mary 302 . MS 302 Personal Computer (PC) 308 . For example, a home, work, etc. PC of Mary 302 . WC 310 . The provider of service for a WD 306 of Mary 302 . MICV 120 . As noted above the use of a MICV, although not required, provides significant advantages. SP N 202 Web Server (WS) 314 . A publicly-available WWW site that is optionally provided by SP N 202 . SP N 202 Billing Interface (BI) 316 . A single, consolidated interface that SP N 202 may use to easily reach, possibly inter alia, one or more internal and/or external entities such as a credit card or debit card clearinghouse, a carrier billing system, a service bureau that provides access to multiple carrier billing systems, invoicing or billing facilities, etc. SP N 202 AS 318 . Facilities that provide key elements of the instant invention (which will be described below). SP N 202 Gateway (GW) 320 . A facility through which SPN 202 may exchange possibly inter alia (SMS, MMS, etc.) messages with possibly inter alia a MICV 120 .SP N 202 Gateway (GW) 320 . It is important to note that while in FIG. 3 the MS 302 WD 306 and MS 302 PC 308 entities are illustrated as being adjacent or otherwise near each other, in actual practice the entities may, for example, be physically located anywhere. In FIG. 3 the exchanges that are collected under the designation Set 1 represent the activities that might take place as Mary 302 completes a registration process with SP N 202 : A) Mary 302 uses one of her PCs 308 to visit a WS 314 of SP N 202 to, possibly among other things, complete a service registration process (see 322 → 324 ). B) A WS 314 of SP N 202 interacts with an AS 318 of SP N 202 to, possibly among other things, commit some or all of the information that Mary 302 provided to one or more data repositories (e.g., a databases), optionally initiate a billing transaction, etc. (see 326 ). C) As appropriate and as required a BI 316 completes a billing transaction (see 328 → 330 ). D) After receiving a response from an AS 318 of SP N 202 ( 332 ) a WS 314 of SP N 202 responds appropriately (e.g., with the presentation of a confirmation message, etc.) (see 334 → 336 ). The specific exchanges that were described above (as residing under the designation Set 1 ) are illustrative only and it will be readily apparent to one of ordinary skill in the relevant art that numerous other exchanges are easily possible and indeed are fully within the scope of the present invention. For example, the collected information may be reviewed, confirmed, etc. through one or more manual and/or automatic mechanisms. For example, the registration process may be completed through any combination of one or more channels including, inter alia, the WWW, wireless messaging (SMS, MMS, etc.), Electronic Mail (E-Mail) messages, Instant Messaging (IM), conventional mail, telephone, an Interactive Voice Response (IVR) facility, etc. During the registration process described above a range of information may be captured from a MS including, possibly inter alia: A) Identifying Information. For example, possibly among other things, name, address, age, landline and wireless Telephone Numbers (TNs), E-Mail addresses, IM names/identifiers, a unique identifier and a password, etc. B) Account Information. For example, possibly among other things, various of the particulars for one or more of a MS' accounts (with organizations such as, possibly inter alia, utility companies, financial institutions, on-line retailers, etc.). The particulars may include, possibly inter alia, organization name and contact details, account number, account access credentials, etc. C) Security Service Information. For example, possibly among other things, the selection of one or more of the different security plans, programs, policies, etc. that a SP may optionally offer (each of which may carry, possibly inter alia, some type of fee or charge). Such plans, programs, etc. may provide, possibly inter alia, alerts to a MS (via, for example, SMS, MMS, E-Mail, IM, etc.) based on various events, criteria, thresholds, etc.; additional levels of notification, confirmation, etc. during a transaction; etc. D) Billing Information. For example, the particulars (such as, possibly inter alia, name, account/routing/etc. numbers, etc.) for financial institution (bank, brokerage, etc.) accounts, credit cards, debit cards, etc. As well, possibly the selection of one or more of the different service billing models may be offered by a SP (including, inter alia, a fixed one-time charge, a recurring [monthly, etc.] fixed charge, a recurring [monthly, etc.] variable charge, a per-transaction charge, etc.) and possibly the selection of one or more of the different payment mechanisms that may be offered by a SP (including, possibly among other things, credit or debit card information, authorization to place a charge on a MS's phone bill, authorization to deduct funds from a MS' [bank, brokerage, etc.] account, etc.). The specific pieces of information that were described above are illustrative only and it will be readily apparent to one of ordinary skill in the relevant art that numerous other pieces of information (e.g., additional Identifying Information, scheduled daily/weekly/etc. reporting desired and/or on-demand reporting desired, etc.) are easily possible and indeed are fully within the scope of the present invention. As noted above the information that Mary provided during the registration process may be preserved in a data repository (e.g., a database) and may optionally be organized as a MS Profile. The content of Mary's profile may be augmented by SP N 202 to include, as just a few examples of the many possibilities, internal and/or external demographic, psychographic, sociological, etc. data. As noted above, a SP's BI may optionally complete a billing transaction. The billing transaction may take any number of forms and may involve different external entities (e.g., a WC's billing system, a carrier billing system service bureau, a credit or debit card clearinghouse, a financial institution, etc.). The billing transaction may include, inter alia: 1) The appearance of a line item charge on the bill or statement that a MS receives from her WC. 2) The charging of a credit card or the debiting of a debit card. 3) The (electronic, etc.) transfer of funds. 4) The generation of an invoice, statement, etc. In FIG. 3 the exchanges that are collected under the designation Set 2 represent the activities that might take place as SP N 202 optionally coordinates, etc. with one or more external entities to, possibly among other things, secure access, exchange and/or confirm collected information, arrange to receive updates, etc. (see 338 → 340 ). During such exchanges SP N 202 may employ any combination of one or more of possibly inter alia an Application Programming Interface (API), an interface layer, an abstraction layer, communication protocols, Extensible Markup Language (XML) documents, etc. The specific exchanges that were described above (as residing under the designation Set 2 ) are illustrative only and it will be readily apparent to one of ordinary skill in the relevant art that numerous other exchanges (including, inter alia, updates to various of the information in a MS Profile in a SP's repository, etc.) are easily possible and indeed are fully within the scope of the present invention. In FIG. 3 the exchanges that are collected under the designation Set 3 represent the activities that might take place as an AS 318 of SP N 202 dispatches to Mary 302 one or more confirmation E-Mail messages (see 342 → 344 ). The specific exchanges that were described above (as residing under the designation Set 3 ) are illustrative only and it will be readily apparent to one of ordinary skill in the relevant art that numerous other exchanges (including, inter alia, the dispatch of multiple E-mail messages [i.e., multiple instances of the sequence 342 → 344 ], the reply by Mary 302 to a received E-mail message, etc.) are easily possible and indeed are fully within the scope of the present invention. In FIG. 3 the exchanges that are collected under the designation Set 4 represent the activities that might take place as an AS 318 of SP N 202 dispatches one or more confirmation SMS, MMS, etc. messages to a WD 306 of Mary 302 ( 346 → 352 ) and Mary 302 optionally replies or responds to the message(s) ( 354 → 360 ). Of interest and note are: 1) In the instant example the messages are shown traversing a MICV 120 . 2) SPN 202 may employ a Short Code (SC) or a regular TN as its source address (and to which it would ask users of its service to direct any reply messages). While the abbreviated length of a SC (e.g., five digits for a SC administered by Neustar under the Common Short Code [CSC] program) incrementally enhances the experience of a MS 302 (e.g., Mary 302 need remember and enter only a few digits as the destination address of a reply message) it also, by definition, constrains the universe of available SCs thereby causing each individual SC to be a limited or scarce resource and raising a number of SC/CSC management, etc. issues. A description of a common (i.e., universal) short code environment may be found in pending U.S. patent application Ser. No. 10/742,764 entitled “Universal Short Code administration facility.” The specific exchanges that were described above (as residing under the designation Set 4 ) are illustrative only and it will be readily apparent to one of ordinary skill in the relevant art that numerous other exchanges are easily possible and indeed are fully within the scope of the present invention. The Set 1 , Set 2 , Set 3 , and Set 4 exchanges that were described above are illustrative only and it will be readily apparent to one of ordinary skill in the relevant art that numerous other exchanges are easily possible and indeed are fully within the scope of the present invention. For example, possibly inter alia, aspects of the registration information that was described above may subsequently be managed (e.g., existing information may be edited or removed, new information may be added, etc.) through any combination of one or more channels including, inter alia, a WWW facility, wireless messaging (SMS, MMS, etc.), E-Mail messages, IM exchanges, conventional mail, telephone, IVR facilities, etc. Additionally, aspects of the registration information may be exchanged with one or more entities (such as possibly inter alia a 3P such as a financial institution, a retail establishment, an on-line retailer, an employer, a utility company, etc.; another SP; etc.). To continue with our hypothetical example . . . as Mary goes about her daily activities there may arise numerous instances where she would like to use her WD to perform some activity. For example: 1) Mary may wish to determine the balance of one of her (bank, brokerage, credit card, etc.) accounts. 2) Mary may wish to complete the payment portion of a purchase (from, for example, an on-line retailer, etc.). 3) Mary may wish to transfer money between various of her (bank, brokerage, credit card, etc.) accounts, transfer money from one of her (bank, brokerage, credit card, etc.) accounts to someone else, transfer money to someone else (perhaps another MS) with the amount of the transfer (along with, for example, charges, fees, etc.) appearing on her WC statement, etc. The specific examples that were cataloged above are illustrative only and it will be readily apparent to one of ordinary skill in the relevant art that numerous other examples are easily possible and indeed are fully within the scope of the present invention. FIG. 4 and reference numeral 400 provide a framework within which examples, such those cataloged above and others that would be readily apparent to one of ordinary skill in the relevant art, may be examined vis-à-vis aspects of the present invention. The entities that are depicted in FIG. 4 are the same as were depicted in, and described for, FIG. 3 with one exception: Third Party (3P) 402 . An organization such as, possibly inter alia, a financial institution, a retail establishment, an on-line retailer, an employer, a utility company, etc. As noted previously, while the discussion below presents aspects of the instant invention as being offered by a SP working together with a 3P it will be readily apparent to one of ordinary skill in the relevant art that numerous other arrangements (e.g., all of the activities that are described below being supported just by a SP, all of the activities that are described below being supported just by a 3P, various of the activities that are described below being supported by one or more SPs working together with one or more 3Ps, etc.) are equally applicable and indeed are fully within the scope of the present invention. In FIG. 4 the exchanges that are collected under the designation Set 1 represent the activities that might take place as Mary 302 employs her WD 306 to initiate, conduct, conclude, etc. an activity with a 3P 402 (see 404 → 412 )—e.g., perform an account balance inquiry, request a funds transfer operation, pay a bill, etc. During her activity Mary 302 may optionally include information such as access credentials (e.g., user identification and password). The specific exchanges that were described above (as residing under the designation Set 1 ) are illustrative only and it will be readily apparent to one of ordinary skill in the relevant art that numerous other exchanges are easily possible and indeed are fully within the scope of the present invention. For example, the sequence 404 → 412 may be repeated any number of times. In FIG. 4 the exchanges that are collected under the designation Set 2 represent the activities that might take place as 3P 402 completes a range of internal processing activities including possibly inter alia validating any supplied information (such as for example access credentials), determining the need for enhanced security, interacting with external entities, etc. During its processing activities 3P 402 may among other things possibly leverage: 1) One or more repositories containing information about Mary 302 (e.g., as previously collected during a registration process, as previously received from one or more external entities, etc.). 2) A body of dynamically updateable configuration information or data (for among other things the different types of supported transactions, available security policies, mappings for different levels of authentication, etc.). 3) Bodies of flexible, extensible, and dynamically configurable logic or rules (capturing among other things the particulars [when, how, etc.] governing the application of different levels of security). In instant example, 3P 402 may interact with an AS 318 of SP N 202 (see 414 ). Such an interaction may employ among other things any combination of one or more of possibly inter alia an API, an interface layer, an abstraction layer, communication protocols, XML documents, etc. and may include among other things information about Mary 302 (such as for example identifier, access credentials, the address [e.g., TN] of her WD 306 , etc.), etc. AS 318 of SP N 202 may complete a range of internal processing activities after which one or more message requests may be directed to a GW 320 of SP N 202 (see 416 ) where one or more (SMS, MMS, etc.) messages—containing possibly inter alia updates, information, etc.—may be dispatched to a WD 306 of Mary 302 (see 418 → 422 ). The specific exchanges that were described above (as residing under the designation Set 2 ) are illustrative only and it will be readily apparent to one of ordinary skill in the relevant art that numerous other exchanges are easily possible and indeed are fully within the scope of the present invention. For example, among other things: 1) SP N 202 may obtain the address (e.g., the TN) of the WD 306 of Mary 302 through any number of means including, for example, from 3P 402 (as described above), from one or more repositories within SP N 202 (possibly leveraging registration information that was provided by Mary 302 and which was supplied to SP N 202 either directly or indirectly), etc. 2) In any dispatched messages SP N 202 may employ any number of addresses (including, possibly inter alia, a SC, a TN, etc.) to which it would ask users to direct any reply messages. 3) SP N 202 may optionally confirm to 3P 402 (and/or one or more other entities) the dispatch of one or more (SMS, MMS, etc.) messages. 4) A dispatched message may optionally contain, possibly inter alia, descriptive or explanatory text, confirmation information, contact information, a request to call (e.g., a help center) at a particular TN, etc. 5) Mary 302 may optionally reply to one or more of the received (SMS, MMS, etc.) messages. Based on any received replies SP N 202 may optionally complete one or more additional processing steps. 6) The exchange 414 and/or the sequence 416 → 422 may be repeated any number of times The Set 1 and Set 2 exchanges that were described above are illustrative only and it will be readily apparent to one of ordinary skill in the relevant art that numerous other exchanges are easily possible and indeed are fully within the scope of the present invention. For example: 1) A MS may optionally need to acknowledge a received message (by, for example, replying to same). Such an acknowledgement may optionally need to occur within a defined period of time (after which an unacknowledged message may, possibly inter alia, go ‘stale’ and not be usable). 2) A SP may incorporate additional factors, criteria, tests, etc. during various of its processing activities (e.g., confirmation, authentication, etc.) including possibly inter alia MS Location-Based Service (LBS) and/or Global Positioning System (GPS) information, biometric information, etc. 3) During its different activities an SP may complete any number of billing, reporting, etc. transactions. 4) An SP may track a MS' usage, aggregate same, optionally offer (to the MS, to external entities such as a 3P, etc.) discounts, rebates, surcharges, etc. based on the tracked usage, etc. 5) During its processing steps an AS may employ any combination of a number of automated (e.g., through software solutions) and/or manual (e.g., through human intervention) actions, techniques, capabilities, etc. and each of the techniques, strategies, capabilities, etc. that were described above may have associated with it, possibly inter alia, an optional set of weighting, scoring, confidence, etc. factors that may be used, either individually or together, to develop results. The catalog of processing steps, activities, etc. that was described above is illustrative only and it will be readily apparent to one of ordinary skill in the relevant art that numerous other processing steps, activities, etc. are easily possible and indeed are fully within the scope of the present invention. The notification, confirmation, response, etc. message(s) that were described above may optionally contain an informational element—e.g., a relevant or applicable factoid, etc. The informational element may be selected statically (e.g., all generated messages are injected with the same informational text), randomly (e.g., a generated message is injected with informational text that is randomly selected from a pool of available informational text), or location-based (i.e., a generated message is injected with informational text that is selected from a pool of available informational text based on the current physical location of the recipient of the message as derived from, as one example, a LBS, GPS, etc. facility). The notification, confirmation, response, etc. message(s) that were identified above may optionally contain advertising—e.g., textual material if an SMS model is being utilized, or multimedia (images of brand logos, sound, video snippets, etc.) material if an MMS model is being utilized. The advertising material may be selected statically (e.g., all generated messages are injected with the same advertising material), randomly (e.g., a generated message is injected with advertising material that is randomly selected from a pool of available material), or location-based (i.e., a generated message is injected with advertising material that is selected from a pool of available material based on the current physical location of the recipient of the message as derived from, as one example, a LBS, GPS, etc. facility). The notification, confirmation, response, etc. message(s) that were identified above may optionally contain promotional materials (e.g., still images, video clips, etc.). FIG. 5 and reference numeral 500 provides a diagrammatic presentation of aspects of an exemplary SP AS 318 . The illustrated AS 318 contains several key components—Gateways (GW 1 508 →GW a 510 in the diagram), Incoming Queues (IQ 1 512 →IQ b 514 in the diagram), WorkFlows (WorkFlow 1 516 →WorkFlow d 518 in the diagram), Database 520 , Outgoing Queues (OQ 1 522 →OQ c 524 in the diagram), and an Administrator 526 . It will be readily apparent to one of ordinary skill in the relevant art that numerous other components are possible within an AS 318 . A dynamically updateable set of one or more Gateways (GW 1 508 →GW a 510 in the diagram) handle incoming (SMS/MMS/etc. messaging, management calls, administrative calls, programmatic calls, function or service invocations, etc.) traffic 504 → 506 and outgoing (SMS/MMS/etc. messaging, management calls, administrative calls, programmatic calls, function or service invocations, etc.) traffic 504 → 506 . Incoming traffic 504 → 506 and/or outgoing traffic 504 → 506 may encompass among other things any combination of one or more of possibly inter alia an APIs, interface layers, abstraction layers, communication protocols, XML documents, raw or unformatted data, etc. For example, a GW may support the receipt of incoming SMS/MMS/etc. messaging traffic 504 → 506 and the dispatch of outgoing SMS/MMS/etc. messaging traffic 504 → 506 via any combination of one or more of the available public and/or proprietary messaging paradigms including possibly inter alia Short Message Peer-to-Peer (SMPP), Computer Interface to Message Distribution (CIMD), External Machine Interface (EMI)/Universal Computer Protocol (UCP), Signaling System Seven (SS7) Mobile Application Part (MAP), MM4, MM7, etc. Incoming traffic 504 → 506 is accepted and deposited on an intermediate or temporary Incoming Queue (IQ 1 512 →IQ b 514 in the diagram) for subsequent processing. Processed artifacts are removed from an intermediate or temporary Outgoing Queue (OQ 1 522 →OQ c 524 in the diagram) and then dispatched 504 → 506 . A dynamically updateable set of one or more Incoming Queues (IQ 1 512 →IQ b 514 in the diagram) and a dynamically updateable set of one or more Outgoing Queues (OQ 1 522 →OQ c 524 in the diagram) operate as intermediate or temporary buffers for incoming 504 → 506 and outgoing traffic 504 → 506 . A dynamically updateable set of one or more WorkFlows (WorkFlow 1 516 →WorkFlow d 518 in the diagram) possibly inter alia remove incoming traffic 504 → 506 from an intermediate or temporary Incoming Queue (IQ 1 512 →IQ b 514 in the diagram), perform all of the required processing operations, and deposit processed artifacts on an intermediate or temporary Outgoing Queue (OQ 1 522 →OQ c 524 in the diagram). The WorkFlow component will be described more fully below. The Database 520 that is depicted in FIG. 5 is a logical representation of the possibly multiple physical repositories that may be implemented to support, inter alia, configuration, profile, monitoring, alerting, etc. information. The physical repositories may be implemented through any combination of conventional Relational Database Management Systems (RDBMSs) such as Oracle, through Object Database Management Systems (ODBMSs), through in-memory Database Management Systems (DBMSs), or through any other equivalent facilities. An Administrator 526 that is depicted in FIG. 5 provides management or administrative control over all of the different components of an AS 318 through, as one example, a WWW-based interface 528 . It will be readily apparent to one of ordinary skill in the relevant art that numerous other interfaces (e.g., a data feed, an API, etc.) are easily possible. Among other things an Administrator 526 may control (launch, start, quiesce, halt, etc.) various of an AS' components (e.g., IQ, OQ, WorkFlow, etc.). Through flexible, extensible, and dynamically updatable configuration information a WorkFlow component may be quickly and easily realized to support any number of activities. For example, WorkFlows might be configured to support a registration process; to support interactions with external entities; to support various internal processing steps; to support the generation and dispatch of confirmation, etc. messages; to support various billing transactions; to support the generation of scheduled and/or on-demand reports; to support the generation, validation, etc. of security credentials; etc. The specific WorkFlows that were just described are exemplary only; it will be readily apparent to one of ordinary skill in the relevant art that numerous other WorkFlow arrangements, alternatives, etc. are easily possible. Among other things: 1) A WorkFlow component may leverage one or more dynamically updateable XML repositories for possibly inter alia configuration (startup, operation, etc.) information. 2) A WorkFlow component may optionally automatically re-start itself whenever some portion of its configuration information is altered. 3) A WorkFlow component may for example be stateless, be thread safe, offer a range of (lifecycle, administrative, logging, performance, reporting, etc.) programmatic interfaces, etc. 4) A WorkFlow component may be derived from a base or underlying class (or set of classes) that provide, possibly inter alia, fundamental lifecycle (e.g., start, stop, initialization, termination, etc.), logging, administration and management, identification and location, performance monitoring, reporting, etc. capabilities. 5) A WorkFlow's base or underlying class may implement an Interceptor façade which possibly inter alia wraps or encapsulates a WorkFlow allowing for the selective ‘interception’ of information that flows in to and/or out of a WorkFlow (to for example allow for selective extensions, enhancements, etc.). For purposes of exposition, FIG. 6 and reference numeral 600 depict an illustrative AuditService class that might reside within a portion of an AS as realized under aspects of the present invention and FIG. 8 and reference numeral 800 present an illustrative Java language code snippet from a service factory through which an instance of for example an aspect of a WorkFlow might be secured (under a factory paradigm). A SP may maintain a repository (e.g., a database) into which selected details of all administrative, messaging, etc. activities may be recorded. Among other things, such a repository may be used to support: 1) Scheduled (e.g., daily, weekly, etc.) and/or on-demand reporting with report results delivered through SMS, MMS, etc. messages; through E-Mail; through a WWW-based facility; etc. 2) Scheduled and/or on-demand data mining initiatives (possibly leveraging or otherwise incorporating one or more external data sources) with the results of same presented through Geographic Information Systems (GISs), visualization, etc. facilities and delivered through SMS, MMS, etc. messages; through E-Mail; through a WWW-based facility; etc. Various aspects of the present invention can be implemented by software, firmware, hardware, or any combination thereof. FIG. 7 illustrates an example computer system 700 in which the present invention, or portions thereof, (such as described above under paragraphs 38→76, paragraphs 82→105, and paragraphs 110→127) can be implemented as computer-readable code. Various embodiments of the invention are described in terms of this example computer system 700 . After reading this description, it will become apparent to a person skilled in the relevant art how to implement the invention using other computer systems and/or computer architectures. Computer system 700 includes one or more processors, such as processor 704 . Processor 704 can be a special purpose processor or a general purpose processor. Processor 704 is connected to a communication infrastructure 702 (for example, a bus or a network). Computer system 700 also includes a main memory 706 , preferably Random Access Memory (RAM), containing possibly inter alia computer software and/or data 708 . Computer system 700 may also include a secondary memory 710 . Secondary memory 710 may include, for example, a hard disk drive 712 , a removable storage drive 714 , a memory stick, etc. A removable storage drive 714 may comprise a floppy disk drive, a magnetic tape drive, an optical disk drive, a flash memory, or the like. A removable storage drive 714 reads from and/or writes to a removable storage unit 716 in a well known manner. A removable storage unit 716 may comprise a floppy disk, magnetic tape, optical disk, etc. which is read by and written to by removable storage drive 714 . As will be appreciated by persons skilled in the relevant art(s) removable storage unit 716 includes a computer usable storage medium 718 having stored therein possibly inter alia computer software and/or data 720 . In alternative implementations, secondary memory 710 may include other similar means for allowing computer programs or other instructions to be loaded into computer system 700 . Such means may include, for example, a removable storage unit 724 and an interface 722 . Examples of such means may include a program cartridge and cartridge interface (such as that found in video game devices), a removable memory chip (such as an Erasable Programmable Read-Only Memory [EPROM], or Programmable Read-Only Memory [PROM]) and associated socket, and other removable storage units 724 and interfaces 722 which allow software and data to be transferred from the removable storage unit 724 to computer system 700 . Computer system 700 may also include an input interface 726 and a range of input devices 728 such as, possibly inter alia, a keyboard, a mouse, etc. Computer system 700 may also include an output interface 730 and a range of output devices 732 such as, possibly inter alia, a display, one or more speakers, etc. Computer system 700 may also include a communications interface 734 . Communications interface 734 allows software and/or data 738 to be transferred between computer system 700 and external devices. Communications interface 734 may include a modem, a network interface (such as an Ethernet card), a communications port, a Personal Computer Memory Card International Association (PCMCIA) slot and card, or the like. Software and/or data 738 transferred via communications interface 734 are in the form of signals 736 which may be electronic, electromagnetic, optical, or other signals capable of being received by communications interface 734 . These signals 736 are provided to communications interface 734 via a communications path 740 . Communications path 740 carries signals and may be implemented using wire or cable, fiber optics, a phone line, a cellular phone link, a Radio Frequency (RF) link or other communications channels. As used in this document, the terms “computer program medium,” “computer usable medium,” and “computer readable medium” generally refer to media such as removable storage unit 716 , removable storage unit 724 , and a hard disk installed in hard disk drive 712 . Signals carried over communications path 740 can also embody the logic described herein. Computer program medium and computer usable medium can also refer to memories, such as main memory 706 and secondary memory 710 , which can be memory semiconductors (e.g. Dynamic Random Access Memory [DRAM] elements, etc.). These computer program products are means for providing software to computer system 700 . Computer programs (also called computer control logic) are stored in main memory 706 and/or secondary memory 710 . Computer programs may also be received via communications interface 734 . Such computer programs, when executed, enable computer system 700 to implement the present invention as discussed herein. In particular, the computer programs, when executed, enable processor 704 to implement the processes of aspects of the present invention, such as the steps discussed above under paragraphs 38→76, paragraphs 82→105, and paragraphs 110→127. Accordingly, such computer programs represent controllers of the computer system 700 . Where the invention is implemented using software, the software may be stored in a computer program product and loaded into computer system 700 using removable storage drive 714 , interface 722 , hard drive 712 or communications interface 734 . The invention is also directed to computer program products comprising software stored on any computer useable medium. Such software, when executed in one or more data processing devices, causes data processing device(s) to operate as described herein. Embodiments of the invention employ any computer useable or readable medium, known now or in the future. Examples of computer useable mediums include, but are not limited to, primary storage devices (e.g., any type of random access memory), secondary storage devices (e.g., hard drives, floppy disks, Compact Disc Read-Only Memory [CD-ROM] disks, Zip disks, tapes, magnetic storage devices, optical storage devices, Microelectromechanical Systems [MEMS], nanotechnological storage device, etc.), and communication mediums (e.g., wired and wireless communications networks, local area networks, wide area networks, intranets, etc.). It is important to note that while aspects of the discussion that was presented above referenced the use of SCs and TNs it will be readily apparent to one of ordinary skill in the relevant art that other address identifiers (such as, for example, Session Initiation Protocol [SIP] Address, Uniform Resource Locator [URL], etc.) are equally applicable and, indeed, are fully within the scope of the present invention. The discussion that was just presented referenced two specific wireless messaging paradigms—SMS and MMS. Those paradigms potentially offer an incremental advantage over other paradigms in that native support for SMS and/or MMS is commonly found on a WD that a potential MS would be carrying. However, it is to be understood that it would be readily apparent to one of ordinary skill in the relevant art that numerous other paradigms (such as, for example, Internet Protocol [IP] Multimedia Subsystem [IMS], IM, E-Mail, WAP, etc.) are fully within the scope of the present invention. It is important to note that the hypothetical example that was presented above, which was described in the narrative and which was illustrated in the accompanying figures, is exemplary only. It is not intended to be exhaustive or to limit the invention to the specific forms disclosed. It will be readily apparent to one of ordinary skill in the relevant art that numerous alternatives to the presented example are easily possible and, indeed, are fully within the scope of the present invention. The following acronyms are employed in this disclosure: Acronym Meaning API Application Programming Interface AS Application Server BI Billing Interface CD-ROM Compact Disc Read-Only Memory CIMD Computer Interface to Message Distribution CIMIP Center for Identity Management and Information Protection CSC Common Short Code DBMS Database Management System DRAM Dynamic Random Access Memory E-Mail Electronic Mail EMI External Machine Interface EPROM Erasable Programmable Read-Only Memory GIS Geographic Information System GPS Global Positioning System GW Gateway IM Instant Messaging IMS IP Multimedia Subsystem IP Internet Protocol IQ Incoming Queue IVR Interactive Voice Response LBS Location-Based Service MAP Mobile Application Part MEMS Microelectromechanical Systems MICV Messaging Inter-Carrier Vendor MMS Multimedia Message Service MS Mobile Subscriber ODBMS Object Database Management System OQ Outgoing Queue PC Personal Computer PCMCIA Personal Computer Memory Card International Association PROM Programmable Read-Only Memory RAM Random Access Memory RDBMS Relational Database Management System RF Radio Frequency SC Short Code SFA Second Factor Authentication SIP Session Initiation Protocol SMPP Short Message Peer-to-Peer SMS Short Message Service SP Service Provider SS7 Signaling System Seven 3P Third Party TN Telephone Number UCP Universal Computer Protocol URL Uniform Resource Locator WAP Wireless Application Protocol WC Wireless Carrier WD Wireless Device WF WorkFlow WS Web Server WWW World-Wide Web XML Extensible Markup Language

A flexible, extensile, and dynamically configurable back-end Application Server environment that efficiently supports the ever-increasing range of activities for which mobile subscribers employ their wireless devices. The environment may operate within any number of entities within a messaging ecosystem including for example a service provider.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention concerns a coating material supply device for supplying a coating material at a predetermined flow rate to various types of coating machines such as an air atomizing spray gun, an airless atomizing spray gun or an electrostatic atomizing bell or disc type coating machine. More specifically, it relates to a coating material supply device suitable to a case of supplying, e.g., a two-component type coating material comprising a main agent and a curing agent therefor at a predetermined ratio to a coating machine or to a case of supplying coating material of different colors selectively to a coating machine, e.g., in multicolor coating. 2. Description of the Prior Art In the coating operation, if the flow rate of a coating material supplied from a coating material source to a coating machine is fluctuated, the amount and the area of spraying the coating material may vary to possibly cause unevenness in the coated layers. Accordingly, it is necessary to maintain the flow rate of the coating material supplied to the coating machine always constant. In view of the above, in the conventional coating material supplying devices, a rotary pump used for supplying the coating material under pressure from a coating material supply source is driven at a constant number of rotation so as to supply a constant amount of coating material to the coating machine. However, even if the rotary pump is driven at a constant number of rotation, the flow rate of the coating material may vary due to the change in the pressure loss at the suction port or discharge port of the rotary pump depending on the flowing state of the coating material, etc. and there has been a problem, e.g., in a two-component coating material that the main agent and the curing agent therefor can not be supplied at an accurate mixing ratio. In a two-component type coating material, the main agent and the curing agent supplied separately from their respective reservoirs have to be mixed in a precisely determined ratio upon or just prior to the spraying from the coating machine. If the flow rate for the main agent or the curing agent varies to cause a delicate change in the mixing ratio, no uniform curing can be obtained for the coated layer thus result in unsatisfactory coating such as defective drying or development of crackings in the coated layers. In view of the above, it has been attempted in the prior art to maintain an accurate flow rate for each of the main agent and the curing agent depending on the mixing ratio by measuring the flow rate for these agents supplied individually from their respective reservoirs by means of a rotary pump to the coating machine by flow meters disposed respectively to the flow channel for the main agent and that for the curing agent, thereby controlling the output from each of the rotary pumps based on the measured values. However, since most of two-component coating materials are highly viscous as compared with usual paints, it is extremely difficult to accurately measure the flow rate by the flowmeter disposed in the flow channel for the main agent or the curing agent. In addition, there has been a problem that the viscous coating material adheres to the flowmeter thereby causing erroneous operation or failure. Thus, it has been extremely difficult to maintain the flow rate constant upon supplying the coating material to the coating machine. In order to overcome such problems, use of a supersonic type flowmeter may be considered for contactless external measurement for the flow rate. However, the flowmeter of this kind is not practical for this purpose since it is extremely expensive and results in another problem of picking-up external noises to cause erroneous operation. Further, use of a gear pump may be considered for supplying a highly viscous paint under pressure. However, there has been a problem that the viscous coating material adheres and clogs at the bearing portion of the gear pump during long time operation to often interrupt the rotation of the pump. In addition, in the case of using a highly viscous paint, particularly, a metallic paint, the metal ingredient is ground by the gear pump failing to obtain uniform coating quality. Further, in a car coating line where coating materials of multiple colors, e.g., from 30 to 60 kinds of different colors are coated while conducting color-change, since the flow rate of the coating material of each color supplied under pressure from each of the coating material reservoirs by each of the pumps has to be controlled uniformly, it is necessary to dispose a flowmeter for the coating material of each color, which remarkably increases the installation cost. There have been proposed, for the related prior art, Japanese Patent Application Laying Open Nos. Sho 56-34988, Sho 60-48160, Sho 61-120660, Japanese Utility Model Publication No. Sho 60-17250, Japanese Utility Model Application Laying Open No. Sho 61-191146, etc. SUMMARY OF THE INVENTION Accordingly, it is the principal object of the present invention to provide a coating material supply device capable of accurately supplying even a highly viscous coating material such as a two-component coating material by a constant amount to a coating machine with no troubles, as well as with no requirement of individualy disposing flowmeters, e.g., for respective colors in the case of multicolor coating under color-change. It is another object of the present invention to provide a coating material supply device capable of supplying the coating material continuously, e.g., in line coating. It is a further object of the present invention to provide a coating material supply device capable of supplying the coating material always at a constant flow rate with no transient fluctuation. It is a still further object of the present invention to provide a coating material supply device of the aforementioned constitution capable of rapidly and surely detecting the failure in diaphragms, etc. It is a yet further object of the present invention to provide a coating material supply device suitable to the application use, for example, in multicolor coating apparatus. The foregoing principal object of the present invention can be attained by a coating material supply device in which coating material is pumped out at a predetermined flow rate and supplied at a constant flow rate to a coating machine, wherein the device comprises: hydraulically-powered reciprocal pumping means connected to the coating machine and having an inlet for coating material supplied from a coating material supply source and an exit for discharging the coating material by the pressure of hydraulic fluid supplied at a constant flow rate from a hydraulic fluid supply source and means for closing the flow channel on the side of the inlet for the coating material when the coating material is discharged from the exit for the coating material and means for closing the flow channel on the side of the exit when the coating material is supplied to the inlet. Another object of the present invention, i.e. continuous supply of the coating material can be attained by a coating material supply device of the afore-mentioned constitution wherein the device comprises: a plurality of hydraulically-powered reciprocal pumping means connected in parallel with each other to the coating machine and adapted to be operated successively and selectively in a predetermined sequence. The further object of the present invention, i.e. supply of the coating material with no fluctuations can be attained by a paint supply device in which coating material is pumped out at a predetermined flow rate and supplied at a constant flow rate to a coating machine, wherein the device comprises: a plurality of hydraulically-powered reciprocal pumping means connected in parallel with each other to the coating machine and adapted to operate successively and selectively in a predetermined sequence, each of the pumping means having an inlet for the coating material supplied from a coating material supply source and an exit for discharging the coating material by the pressure of hydraulic fluid supplied at a constant flow rate from a hydraulic fluid supply source and adapted such that the supply of the hydraulic fluid to a hydraulically-powered reciprocal pump to be operated next in the operation sequence is started at a predetermined time before interrupting the supply of the hydraulic fluid to other hydraulically-powered reciprocal pump currently supplying the hydraulic fluid at a constant flow rate to the coating machine. The afore-mentioned object can also be attained in another feature of the invention by a coating material supply device in which coating material is pumped out at a predetermined flow rate and supplied at a constant flow rate to a coating machine, wherein the device comprises: a plurality of hydraulically-powered reciprocal pumping means connected in parallel with each other to the coating machine and adapted to be operated successively and selectively in a predetermined sequence, each of the pumping means having an inlet for the coating material supplied from a coating material supply source and an exit for discharging the coating material by the pressure of hydraulic fluid supplied at a constant flow rate from a hydraulic fluid supply source, a pressure sensor for detecting the pressure of the coating material being supplied from each of the hydraulically-powered reciprocal pumps to the coating machine and a pressure control valve that controls the pressure of the coating material supplied to the hydraulically-powered reciprocal pump to be operated next in the operation sequence to the same level as that for the pressure of the coating material being supplied at a constant flow rate to the coating machine based on the pressure detection signal of the pressure sensor. The afore-mentioned object can also be attained in a further feature of the invention by a paint supply device of the constitution just mentioned above and further comprises: a pressure control device that controls the pressure of the hydraulic fluid supplied to a hydraulically-powered reciprocal pump currently supplying the coating material to the coating machine equal to the pressure of the hydraulic fluid discharged from a hydraulically-powered reciprocal pumps to be operated next in the operation sequence by the pressure of the coating material supplied thereto, in which the pressure control device comprises a diaphragm or piston actuated by the difference of pressures of the hydraulic fluids acted on both sides thereof and valves opened and closed by a needle interlocking with the diaphragm or piston, the valve causing to open the flow channel of the hydraulic fluid discharged from the hydraulically-powered reciprocal pump when the pressures of both of the hydraulic fluids acting on both sides of the diaphragm or piston are balanced to each other. The still further object of the present invention, i.e., failure detection for diaphragms, etc. can be attained by a coating material supply device of any of the aforementioned constitutions in which the hydraulically-powered reciprocal pumping means comprise diaphragm type pumping means, wherein a diaphragm comprises an electroconductive reinforcing member and an electrically insulation member coated over the entire surface thereof and is combined with an electrical circuit including a path consisting of the electroconductive reinforcing member, insulation member and an electroconductive coating material or electroconductive hydraulic fluid in the double-acting pumping means, the electrical circuit also including a detection section that detects the breakage caused to the diaphragm depending on the conduction state of the path. The just mentioned object of the invention can also be attained by a coating material supply device of any one of the afore-mentioned constitutions in which the hydraulically-powered reciprocal pumping means comprise diaphragm type pumping means, wherein the device further comprises a detection means that detects the breakage of the diaphragm depending on the optical change caused in the hydraulic fluid when the coating material supplied to the reciprocal pumping is mixed into the hydraulic fluid. The yet further object of the present invention in tended for application, e.g., to multicolor coating can be attained by the coating material supply device in which coating material is pumped out at a predetermined flow rate and supplied at a constant flow rate to a coating machine, wherein the device comprises: a plurality of hydraulically-powered reciprocal pumping means, each having an inlet for the coating material supplied from a coating material supply source and an exit for discharging the coating material by the pressure of hydraulic fluid supplied at a constant flow rate from a hydraulic fluid supply source, connected to coating material selection valves connected in parallel with each other to the coating machine, and connected to switching valves that selectively switch the flow channel for the hydraulic fluid supplied from the hydraulic fluid supply source in response to the switching operation of the coating material selection valves, in which a flow rate control mechanism for maintaining the flow rate of the hydraulic fluid constant is disposed to the flow channel for the hydraulic fluid between the hydraulic fluid supply source and the switching valves. DESCRIPTION OF THE ACCOMPANYING DRAWINGS These and other objects, as well as advantageous features of the present invention will become apparent by the description for the preferred embodiments thereof referring to the accompanying drawings, wherein FIG. 1 is a flow sheet showing a preferred embodiment of the coating material supply device according to the present invention; FIG. 2 is a time chart illustrating the operation of the device; FIG. 3 though FIG. 6 are, respectively, explanatory views illustrating means for detecting the occurrence of diaphragm failure in a hydraulically-powered reciprocal pump; FIG. 7 though FIG. 10 are, respectively, explanatory views illustrating means for controlling the pressure of a coating material supplied from a coating material supply source to a hydraulically-powered reciprocal pump; and FIG. 11 is a flow sheet illustrating a preferred embodiment of the present invention applied to a multicolor coating apparatus. DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a flow sheet illustrating one embodiment of the device for supplying coating material according to the present invention in which a coating material supplied from a coating material supply source 1 is discharged at a predetermined flow rate and supplied in a constant flow rate to a coating machine 2 by a pair of hydraulically-powered reciprocal pumps 3A and 3B, which are connected in parallel with each other to the coating machine 2 and actuated alternately one after the other. In each of the hydraulically-powered reciprocal pumps 3A, 3B, coating material supplied from the coating material supply source 1 and charged from an inlet 4 for coating material is pumped out from an exit 6 for coating material by the pressure of hydraulic fluid supplied at a constant flow rate from a hydraulic fluid supply source 5. Each of ON-OFF valves 7A, 7B disposed to the flow channel on the side of the inlet 4 is closed when the coating material is pumped out from the exit 6, whereas each of ON-OFF valves 8A, 8B disposed to the flow channel on the side of the exit 6 is closed when the coating material is charged from the inlet 4. In each of the hydraulically-powered reciprocal pumps 3A and 3B, a coating material chamber 9 having the inlet 4 and the exit 6 and a hydraulic fluid chamber 10 receiving the supply of the hydraulic fluid are formed in adjacent with each other by way of a diaphragm 11, so that the coating material in the coating material chamber 9 is pumped out at a constant low rate by the diaphragm 11 actuated by the pressure of the hydraulic fluid supplied at a predetermined flow rate from the hydraulic fluid supply source 5 to the hydraulic fluid chamber 10. The coating material supply source 1 comprises a reservoir 12 storing the coating material, a rotary pump 13 for supplying the coating material in the reservoir 12 under pressure to the coating material chamber 9 in each of the hydraulically-powered reciprocal pump 3A, 3B, and a back pressure valve 14 for controlling the pressure of the coating material supplied under pressure by the pump 13. The hydraulic fluid supply source 5 comprises a reservoir 15 for storing the hydraulic fluid, a rotary pump 16 such as a gear pump for supplying the hydraulic fluid under pressure in the reservoir 15 to the hydraulic fluid chamber 10 of each of the hydraulically-powered reciprocal pumps 3A, 3B, a flow sensor 17 for detecting the flow rate of the hydraulic fluid supplied under pressure by the pump 16, and a flow rate control device 20 that outputs a control signal to an inverter 19 for varying the number of the rotation of a driving motor 18 for the rotary pump 16 based on a detection signal from the flow sensor 17. The flow rate control device 20 is so adapted that it compares the flow rate of the hydraulic fluid detected by the flow sensor 17 with a predetermined flow rate of the hydraulic fluid depending on the flow rate of the coating material supplied to the coating machine 2 and, if there is any difference therebetween, outputs a control signal that variably controls the number of rotation of the driving motor 18 depending on the deviation. The hydraulic fluid supplied under pressure at a constant flow rate is supplied alternately to each of the hydraulic fluid chambers 10 of the hydraulically-powered type reciprocal pumps 3A, 3B by the switching of ON-OFF valves 22A, 22B disposed respectively in supply channels 21A, 21B branched two ways. The hydraulic fluid discharged from the hydraulic fluid chambers 10 is recycled by way of ON-OFF valves 23A, 23B through discharged channels 24A, 24B respectively to the inside of the tank 15. Further, a short-circuit channel 26 having a relief valve 25 disposed therein is connected between the supply flow channels 21A, 21B and the discharged flow channels 24A, 24B for recycling the hydraulic fluid supplied under pressure from the tank 15 by the rotary pump 16 directly to the reservoir 15. The circuit 26 is disposed for preventing an excess load from exerting on the rotary pump 16 when both of the ON-OFF valves 22A and 22B are closed. The relief valve 25 is adapted to be closed and opened interlocking with a trigger member attached to the coating machine 2 and closed only when the coating material is sprayed by triggering the coating machine 2. A back pressure valve 27 is disposed to the short circuit channel 26 for controlling the pressure of the hydraulic fluid supplied under pressure through the supply channels 21A, 21B. The hydraulic fluid is preferably composed of such material as causing less troubles even when the diaphragm 11 put between the coating material chamber 9 and the hydraulic fluid chamber 10 in each of the hydraulically-powered reciprocal pumps 3A, 3B is broken and the hydraulic fluid is mixed with the coating material. Further the hydraulic fluid should be selected so that the flow rate can reliably be measured with no troubles by the flow sensor. For instance, water is used in the case where aqueous coating material is employed, whereas hydraulic oil such as dioctyl phthalate (C 24 H 38 O 4 ), etc. is used when a resin type coating material is employed. The block 28 surrounded by a dotted line in FIG. 1 represents an air control device for controlling the ON-OFF operation of the ON-OFF valves 7A, 7B, 8A, 8B, the ON-OFF valves 22A, 22B and the ON-OFF valves 23A, 23B for alternately actuating the hydraulically-powered reciprocal pumps 3A, 3B thereby continuously supplying the coating material at a constant amount to the coating machine 2. Briefly speaking, the air control device 28 is so constituted that the ON-OFF valves 8A and 22A, or the ON-OFF valves 8B and 22B are opened by pressurized air supplied from air supply sources 29A and 29B by way of OFF-delay timers 30A and 30B respectively, while the ON-OFF valves 7A and 23A, or the ON-OFF valves 7B and 23B are opened respectively by the pressurized air supplied from air supply sources 31A and 31B by way of ON-delay timers 32A and 32B respectively. The OFF delay timer 30A or 30B normally allows the pressurized air supplied from the air supply source 29A, 29B to pass to the respective ON-OFF valves and, when an air signal is inputted from a signal air supply source 34 by the switching of a piston valve 33, interrupts the pressurized air supplied from the air supply source 29A or 29B to the respective ON-OFF valves after the elapse of a predetermined of time (for example 0.2 sec after). While on the other hand, ON-delay timer 32A or 32B normally interrupts the pressurized air supplied from the air supply source 31A, 31B to the respective On-OFF valves and, when an air signal is inputted from signal air supply source 31A or 31B described later, allows the pressurized air from the air supply source 31A or 31B to pass to the respective ON-OFF valves after the elapse of a predetermined of time (for example, 0.4 sec after). Signal air supply sources 35A and 35B are disposed for operating the ON-delay timers 32A, 32B, as well as for switching the piston valve 33, by supplying air signals to the ON-delay timers 32A, 32B and the piston valve 33 through piston valves 37A, 37B that are switched by reciprocally moving rods 36A, 36B attached respectively to diaphragms 11, 11 of the hydraulically-powered reciprocal pumps 3A, 3B and through AND gates 38A, 38B. Each of the AND gates 38A, 38B has such a logic function of generating an air signal only when air signals are inputted from both of the signal air supply sources 35A and 35B. When the air signal is outputted, the ON-delay timer 32A or 32B is operated after the elapse of a predetermined time to allow the pressurized air supplied from the air supply source 31A, 31B to pass therethrough to the ON-OFF valve, as well as the piston valve 33 is switched. The air supply source 29A or 29B is so adapted to be interlocked with the triggering action for the coating machine 2 and output the pressurized air only while the coating material is triggered for spraying. While on the other hand, pressurized air is always outputted from the air supply sources 31A, 31B, 34, 35A and 35B irrespective of the trigger for the coating machine 2. A pressure sensor 40 is disposed to the flow channel for the coating material supplied from each of the hydraulically-powered reciprocal pumps 3A, 3B to the coating machine for detecting the pressure thereof. A pressure control valve 41 is disposed so that it is actuated based on a pressure detection signal from the pressure sensor 40 that detects the pressure of the coating material supplied, for example, from the hydraulically-powered reciprocal pump 3A to the coating machine 2 and controls the pressure of the coating material supplied to the hydraulically-powered reciprocal pump 3B going to be actuated next in the operation sequence to the same level as that for the pressure of the coating material being currently supplied at a constant amount from the hydraulically-powered reciprocal pump 3A to the coating machine 2. The pressure control valve 41 is disposed to the flow channel 42 of the coating material supplied under pressure from the coating material supply source 1 to the hydraulically-powered acting reciprocal pumps 3A, 3B. The pressure control valve 41 may alternatively be disposed to the flow channel 24A, 24B for the hydraulic fluid which is discharged from the hydraulic fluid chamber 10 of each of the hydraulically-powered reciprocal pumps 3A, 3B by the pressure of the coating material supplied from the coating material supply source 1 to the coating material chamber 9 in each of the hydraulically-powered reciprocal pumps 3A, 3B. In this illustrated embodiment, the diaphragm 11 used for isolating the coating material in the chamber 9 and the hydraulic fluid in the chamber 10 in each of the hydraulically-powered reciprocal pumps 3A, 3B comprises electrically insulating members 43, 43 made of resilient rubber sheet, plastic sheet, etc. coated on both surfaces of an electroconductive reinforcing member 44 made of an electroconductive plastic sheet, metal net, carbon fibers, etc. As shown by an enlarged view in FIG. 1 for the portion of the diaphragm 11 indicated within a dotted chain circle, an electric circuit 45 having a power source 47 and a current or voltage detector 48 is formed including a path comprising an electrode 49 for the anode of the power source 47→electorconductive hydraulic fluid in the chamber 10→insulation member 43→the electroconductive reinforcing member 44. The output of the circuit 45 is taken out to a detection circuit 46 that detects the breakage, if any, in the diaphragm 11 depending on the change in the current or resulted when the diaphragm 11 is broken to render the normally insulated path conductive. The breakage detection circuit 46 comprises an amplifier 50 for amplifying the detection signal from the detector 48 and an alarm device 51 that generates an alarm sound and flickers an alarm lamp based on the detection signal inputted from the amplifier 50. The actual operation of one embodiment of the coating material supply device shown in FIG. 1 will be explained referring to the time chart shown in FIG. 2. In FIG. 2, (a) and (b) show the state of supplying the hydraulic fluid to the hydraulically-powered reciprocal pumps 3A, 3B, while (c) and (d) show the state of supplying the coating material to the hydraulically-powered reciprocal pumps 3A and 3B respectively. At first, the flow rate of the hydraulic fluid to be supplied from the hydraulic fluid supply source 5 to each of the hydraulically-powered reciprocal pumps 3A, 3B is previously set to the flow rate control device 20 in accordance with a required flow rate of the coating material to be supplied in a constant amount from the hydraulically-powered reciprocal pumps 3A, 3B to the coating machine. Then, the rotary pump 16 is started for supplying the hydraulic fluid stored in the reservoir 15 under pressure and, at the same time, the operation of the air control device 28 is started (at T 1 in FIG. 2). In this instance, both of the ON-OFF valves 22A and 22B are closed and, accordingly, the hydraulic fluid supplied under pressure by the rotary pump 16 is directly recycled to the inside of the reservoir 15 by way of the short-circuit channel 26 having the relief valve 25 and the back pressure valve 27. It is assumed here that the coating material supplied from the supply source 1 has been charged in the coating material chamber 9 of the hydraulically-powered reciprocal pump 3A, while the coating material has been completely discharged from the inside of the coating material chamber 9 of the hydraulically-powered reciprocal pump 3B. In this state, if the piston valves 37A and 37B are in the state as shown in FIG. 1, the pressurized air supplied from the signal air supply sources 35A and 35B are inputted as air signals to the AND gate 38B and then outputted from the AND gate 38B to the ON-delay timer 32B and the piston valve 33. The timer 32B allows the pressurized air supplied from the air supply source 31B to pass therethrough for opening the ON-OFF valves 7B and 23B, for example, after the elapse of 0.4 sec. Then, the coating material is supplied from the coating material supply source 1 by way of the valve 7B to the coating material chamber 9 of the hydraulically-powered reciprocal pump 3B and, at the same time, the hydraulic fluid is discharged from the inside of the hydraulic fluid chamber 10 by the pressure of the coating material by way of the valve 23B and then recycled through the discharge channel 24B to the inside of the reservoir 15 (T 2 in FIG. 2). In this state, the ON-OFF valve 8B disposed to the exit 6 for coating material of the hydraulically-powered reciprocal pump 3B is kept closed. Then, as the coating material is supplied to the coating material chamber 9 of the hydraulically-powered reciprocal pump 3B, the diaphragm 11 is expanded toward the hydraulic fluid chamber 10 and the piston valve 35B is switched by the rod 36B interlocking with the diaphragm 11. Since the air signal outputted so far from the signal air supply source 35B to the AND gate 38B is now switched to the AND gate 38A, the ON-delay timer 32B interrupts the supply of the pressurized air from the air supply source 31B to close the ON-OFF valves 7B and 23B to interrupt the supply of the coating material to the hydraulically-powered reciprocal pump 3B (T 3 in FIG. 2). Then, when the coating machine 2 is triggered, the pressurized air from the air supply sources 29A and 29B is outputted to open the ON-OFF valve 8A disposed to the flow channel on the exit 6 for coating material of the hydraulically-powered reciprocal pump 3A and, at the same time, open the ON-OFF valve 22A disposed in the supply channel 21A for supplying the hydraulic fluid from the hydraulic fluid supply source 5 to the hydraulic fluid chamber 10 of the hydraulically-powered reciprocal pump 3A. Thus, the coating material charged in the coating material chamber 9 of the hydraulically-powered reciprocal pump 3A is pumped out from the exit 6 by the pressure of the hydraulic fluid supplied at a constant flow rate into the hydraulic fluid chamber 10 and then supplied to the coating machine 2 at a constant flow rate depending on the flow rate of the hydraulic fluid (T 4 in FIG. 2). That is, the piston valve 33 sends the air signal outputted from the signal air supply source 34 to the OFF-delay timer 30B, to keep the OFF-delay timer 30B interrupted, while the other OFF-delay timer 30A is operated. Then, the ON-OFF valves 8A, 22A are opened by the pressurized air supplied from the air supply source 29A to the OFF-delay timer 30A, by which the hydraulic fluid is supplied from the hydraulic fluid supply source 5 to the hydraulic fluid chamber 10 of the hydraulically-powered reciprocal pump 3A, to displace the diaphragm 11 toward the coating material chamber 9, by which the coating material is pumped out from the coating material chamber 9 at the same flow rate as that of the hydraulic fluid and supplied by the constant amount to the coating machine 2. Since the flow rate of the hydraulic fluid supplied to the hydraulically-powered reciprocal pump 3A is maintained constant by the flow rate control device 20, the flow rate of the coating material supplied to the coating machine 2 is maintained at a predetermined desired flow rate. Then, just before the coating material in the coating material chamber 9 of the hydraulically-powered reciprocal pump 3A is completely pumped out by the diaphragm 11, the piston valve 37A is switched by the rod 36A interlocking with the diaphragm 11. Therefore, the air signals from both of the signal air supply sources 35A and 35B are inputted to the AND gate 38A and the gate 38A outputs the air signal to operate the ON-delay timer 32A. The air signal is also sent to the piston valve 33 to turn the valve and the air signal outputted so far from the signal air supply source 34 to the OFF-delay timer 30B is now outputted to the OFF-delay timer 30A (T 5 in FIG. 2). That is, by the switching of the piston valve 33, the OFF-delay timer 30A which was operated so far is shut, for example, after the elapse of 0.2 sec, to close the ON-OFF valves 8A and 22A thus stop the supply of the coating material from the hydraulically-powered reciprocal pump 3A to the coating machine 2 (T 6 in FIG. 2). Further, when the piston valve 33 is switched, since the output of the air signal from the signal air supply air source 34 to the OFF-delay timer 30B is interrupted to thereby operate the timer 30B, the ON-OFF valves 8B and 22B are opened to start the constant supply of the coating material also from the hydraulically-powered reciprocal pump 3B to the coating machine 2, 0.2 sec before the interruption of the OFF-delay timer 30A and thus the closure of the ON-OFF valves 8A and 22A (T 5 in FIG. 2). That is, the coating material is supplied from both of the hydraulically-powered reciprocal pumps 3A and 3B to the coating machine 2 while being overlapped for 0.2 sec. In this instance, the flow rate of the hydraulic fluid supplied from the hydraulic fluid supply source 5 is always maintained constant by the flow rate control device 20 and, accordingly, the total flow rate of the hydraulic fluid supplied simultaneously to the pair of the hydraulically-powered reciprocal pumps 3A and 3B is equal to the flow rate in a case where the hydraulic fluid is supplied only to one of the hydraulically-powered reciprocal pumps 3A and 3B. Therefore, the flow rate of the coating material supplied to the coating machine 2 does not fluctuate. Accordingly, upon switching of the alternately operating hydraulically-powered reciprocal pumps 3A, 3B, it is possible to avoid the momentary interruption of the coating material supply to the coating machine 2, which would otherwise cause transient pulsation to the coating material during supply to the coating machine 2. Therefore, undesired breathing phenomenon that the spray amount of the coating material from the coating machine 2 is instantaneously reduced is surely prevented and the coating material can always be sprayed continuously at a constant amount from the coating machine 2. Then, after the piston valve 37A has been switched as described above, the ON-delay timer 32A is conducted with a predetermined time delay of 0.4 sec (that is, after the elapse of 0.2 sec from the closure of the ON-OFF valves 8A and 22A) and the ON-OFF valves 7A and 23A are opened by the pressurized air supplied from the air supply source 31A. Accordingly, the coating material is supplied from the coating material supply source 1 to the coating material chamber 9 of the hydraulically-powered reciprocal pump 3A and, at the same time, the hydraulic fluid is discharged from the hydraulic fluid chamber 10 of the hydraulically-powered reciprocal 3A and returned by way of the discharge channel 24A to the inside of the reservoir 15 of the hydraulic fluid supply source 5 (T 7 in FIG. 2). Then, if the amount of the coating material supplied to the coating material chamber 9 of the hydraulically-powered reciprocal pump 3A reaches a predetermined amount, the piston valve 37A is switched by the rod 36A interlocking with the diaphragm 11, by which the output of the air signal from the AND gate 38A is stopped and the ON-OFF valves 7A and 23A are closed again (T 8 in FIG. 2). When the coating material is supplied from the coating material supply source 1 to the hydraulically-powered reciprocal pump 3A, the pressure of the coating material supplied is controlled to the same level as that for the pressure of the coating material currently supplied at a constant amount from the other hydraulically-powered reciprocal pump 3B to the coating machine 2. Such a pressure control is attained by detecting the pressure of the coating material supplied from the hydraulically-powered reciprocal pump 3B by the pressure sensor 40 and controlling the pressure of the coating material supplied to the pump 3A by the pressure control valve 41 based on the pressure detection signal from the pressure sensor 40. Then, just before the coating material in the coating material chamber 9 of the hydraulically-powered reciprocal pump 3B is completely discharged, the piston valve 37B interlocking with the diaphragm 11 of the hydraulically-powered reciprocal pump 3B is switched and the air signal is outputted from the AND gate 38B to start the ON-delay timer 32B. At the same time, the piston valve 33 is switched to stop the output of the air signal from the signal air supply source 34 to the OFF-delay timer 30A and the supply of the air signal is now switched to the OFF-delay timer 30B (T 9 in FIG. 2). Accordingly, the OFF-delay timer 30B kept operated so far is shut after the elapse of 0.2 sec from the switching of the piston valve 37B to close the ON-OFF valves 8B and 22B, by which the supply of the coating material from the hydraulically-powered reciprocal pump 3B to the coating machine 2 is completely stopped (T 10 in FIG. 2). While on the other hand, when the piston valve 37B is switched as described above, the output of the air signal to the OFF-delay timer 30A is interrupted and the OFF-delay timer 30A shut so far is now operated which opens the ON-OFF valves 8A and 22A 0.2 sec before the closure of the ON-OFF valves 8B and 22B. Thus, the supply of the coating material from the hydraulically-powered reciprocal pump 3A to the coating machine 2 is started just before the supply of the coating material from the hydraulically-powered reciprocal pump 3B to the coating machine 2 is stopped (T 9 in FIG. 2). Further, upon switching the piston valve 37B as described above, the ON-delay timer 32B is operated after the elapse of 0.4 sec to open the ON-OFF valves 7B and 28B by the pressurized air supplied from the air supply source 31B, by which the supply of the coating material from the coating material supply source 1 to the coating material chamber 9 of the hydraulically-powered reciprocal pump 3B is started at the same pressure as that for the coating material currently supplied from the hydraulically-powered reciprocal pump 3A to the coating machine 2 and, at the same time, the hydraulic fluid is discharged from the hydraulic fluid chamber 10 of the hydraulically-powered reciprocal pump 3B and returned to the hydraulic fluid supply source 5 (T 11 in FIG. 2). In this way, the foregoing operations of the coating material supply device are repeated hereinafter and the coating material is supplied continuously at a predetermined amount from the hydraulically-powered reciprocal pumps 3A and 3B to the coating machine 2. As has been described above according to the present invention, the coating material discharged alternately from each of the hydraulically-powered reciprocal pumps 3A, 3B can be supplied always at a constant flow rate to the coating machine by controlling the flow rate of the hydraulic fluid supplied to the hydraulically-powered reciprocal pumps 3A, 3B to a constant level. Accordingly, it is no more required in the present invention for the direct detection of the flow rate of the coating material supplied to the coating machine 2 but it is only necessary to detect the flow rate of the hydraulic fluid supplied from the hydraulic fluid supply source 5 to the hydraulically-powered reciprocal pumps 3A, 3B by the flow sensor 17. Therefore, there is no worry that misoperations or troubles are caused to the flow sensor even if highly viscous coating material is used. Further, since each of the hydraulically-powered reciprocal pumps 3A, 3B is so adapted that the flow channel on the side of the inlet 4 for coating material is closed during discharging of the coating material from the exit 6, while the flow channel on the side of the exit 6 is closed when the coating material is being charged to the coating inlet 4, the flow rate of the coating material supplied to the coating machine 2 does not suffer from the effect by the pressure of the coating material supplied under pressure from the coating material supply source 1. In addition, the coating material supplied under pressure from the coating material supply source 1 can surely be charged into the coating material chamber 9 with no undesired direct supply to the coating machine 2 (short-pass) while reliably discharging the hydraulic fluid in the hydraulic fluid chamber 10. Further, since the coating material is discharged from both of the hydraulically-powered reciprocal pumps 3A, 3B while being overlapped to each other for a predetermined of time just before their operations are switched with each other, supply of the coating material to the coating machine 2 does not interrupt even for a brief moment thereby enabling to prevent the pulsation in the coating material during supply to the coating machine 2, which would otherwise cause fluctuation in the spraying amount of the coating material from the coating machine 2. Furthermore, since the pressure sensor 40 and the pressure control valve 41 are disposed, the coating material can be supplied to the coating material chamber 9 of one of the hydraulically-powered reciprocal pumps 3A, 3B at the same pressure as that of the coating material being supplied from the other of the hydraulically-powered reciprocal pumps 3A, 3B to the coating machine 2 and, accordingly, there is no worry that pulsation is resulted due to the pressure difference between coating materials discharged from both of the hydraulically-powered reciprocal pumps 3A, 3B when the pumping operation is switched between them. Accordingly, the flow rate of the coating material continuously supplied to the coating machine 2 by alternately operating the hydraulically-powered reciprocal pumps 3A, 3B can always be maintained at an exact flow rate which is determined only by the flow rate of the hydraulic fluid maintained at a constant flow rate by the flow rate control device 20 with no worry of resulting in uneven coating or the like. In the coating material supply device according to the present invention, if a diaphragm used in the hydraulically-powered reciprocal pumps is worn out to lose it function for isolating the coating material and the hydraulic fluid, such a failure should rapidly and reliably be detected, becaue the failure such as breakage of the diaphragm may lead to undesirable mixing of the coating material and the hydraulic fluid. If crackings etc. are developed through the diaphragm 11 shown in FIG. 1, the electroconductive hydraulic fluid is in direct contact with the electroconductive reinforcing material 44 covered between the insulating members 43, 43, and the electrical circuit 45 is rendered conductive by way of the path including the electrode 49, the electroconductive hydraulic fluid present at the inside of the hydraulic fluid chamber 10 and the electroconductive reinforcing member 44. Then, an electrical current from the power source 47 flows through the detector 48 disposed in the electric circuit 45 and the voltage (current) change detected by the detector 48 is amplified by the amplifier 50 and then inputted to the alarm device 51 to generate an alarm sound and, at the same time, flickers an alarm lamp to inform the failure of the diaphragm 11. Thus, the development of cracking in the diaphragm 11 can rapidly be detected thereby enabling operators to take adequate countermeasures for defective coating due to the mixing of the hydraulic fluid into the coating material supplied to the coating machine 2. In a case where an electroconductive coating material such as an aqueous coating material or metallic coating material is used, the electrode 49 for the electrical circuit 45 may be disposed in the coating material chamber 9 instead of the hydraulic fluid chamber 10. The detection means for the breakage of the diaphragm 11 may be constituted in various modes, not restricted only to the electrical embodiment shown in FIG. 1. In FIG. 3 through FIG. 6, optical detection means is disposed to the discharge channel 24A, 24B for the hydraulic fluid and the optical change of the hydraulic fluid caused by the mixing of the coating material and the hydraulic fluid is detected to inform the breakage of the diaphragm 11. The optical detection means shown in FIG. 3 comprises a light emitting element 60 and a photoreceiving element 61 which are disposed on both sides of discharge channel 24A, 24B for hydraulic fluid so that the light emitted from the light emitting element 60 and transmitted along an optical path K through the hydraulic fluid is detected by the photoreceiving element 61, and a detection device 62 that checks the change of the transparency of the hydraulic fluid based on the detection output of the photoreceiving element 61. When the light outgoing from the light emitting element 60 and passed through an optical fiber 63 transmits through the hydraulic fluid in the discharge flow channel 24A, 24B and then inputted through the optical fiber 64 to the photoreceiving element 61, the intensity of the light detected by the element 61 is inputted to the detection device 62. The light emitting element 60 may be a light emitting diode or the like, while the photoreceiving element or device may be a photodiode or phototransistor. An alarm device 65 that generates an alarm sound or flickers an alarm lamp is connected to the detection device 62 and so adapted that it is actuated when the intensity of light inputted to the light receiving device 61 is decreased below a predetermined level. In view of the optical detection, the hydraulic fluid used is, desirably, a transparent fluid such as dioctyl phthalate or an aliphatic ester of neopentyl polyol. If the diaphragm 11 should happen to be broken, the hydraulic fluid passing through the discharge channel 24A, 24B becomes turbid by the mixing of the coating material, by which the intensity of the light transmitting through the hydraulic fluid is decreased and the breakage of the diaphragm 11 can be detected rapidly. Mixing of the coating material in the hydraulic fluid may, alternatively, be detected based on the wavelength of the light passing through the hydraulic fluid, that is, based on the change in the color of the hydraulic fluid when the coating material is mixed. In a case where a transparent coating material is used and no remarkable optical change is observed upon mixing into the hydraulic fluid, a color developer that can react with the coating material to develop a color may be contained in the hydraulic fluid. For instance, in a case where an aqueous alkaline coating material, for example, containing amines as the dispersant for paint material, phenolphthalein is dissolved as a color indicator in a neutral hydraulic fluid. In this case, if the diaphragm 11 is broken and the alkaline coating material is mixed into the hydraulic fluid, the indicator turns red to indicate the presence of the coating material in the hydraulic fluid. In the case of using a resinous coating material dissolved in an organic solvent, a colorant sealed in a solvent-soluble container may be used as a coating material detector. FIG. 4 shows one embodiment for such detection means, in which a container 67 having a colorant 66 sealed therein is connected at the midway of the discharge channel 24A, 24B to the upstream of the optical path K of the light emitting element 60 shown in FIG. 3 and the colorant 66 in the container 67 is normally isolated from the hydraulic fluid by means of a plastic film 68 which is easily soluble to the solvent of the coating material. As the colorant 66, ink, dye or toner not chemically attacking the plastic film 68 may be used. The plastic film 68 usable herein may be made, for example, of those materials that are not dissolved by the actuation fluid but easily be dissolved by the solvent of the coating material such as toluene, xylene, ketone, ethyl acetate and methyl ethyl ketone. Polystyrene film, for example, is preferably used. In this embodiment, if the coating material is mixed into the hydraulic fluid due to the cracking, etc. of the diaphragm 11, the plastic film in the container in contact with the stream of the fluid is dissolved by the solvent contained in the coating material to release the colorant 66 into the discharge channel 24A, 24B, whereby the intensity of the wavelength of light detected by the photoreceiving element 61 is changed and the breakage of the diaphragm 11 can reliably be detected. FIG. 5 shows another embodiment, in which detection means is disposed at the midway of the discharge channel 24A, 24B to the upstream of the optical path K of the light emitting element 60. Plastic capsules 71, 71, containing therein a colorant similar to that used in the embodiment shown in FIG. 4 are put between a pair of metal gages 70, 70 disposed at a predetermined distance to each other and in perpendicular to the flow direction of the hydraulic fluid in a container 69. The capsules 71 are also made of polystyrene or like other plastic that is easily soluble to the coating material solvent. Also in this case, if the coating material is mixed into the hydraulic fluid, the capsules 71 are dissolved by the solvent contained in the coating material to release the colorant contained therein, by which the intensity or the wavelength of the light detected by the photoreceiving element 61 is changed to reliably detect the breakage of the diaphragm 11. In a further embodiment of the optical detection means shown in FIG. 6, a porous transparent substrate 72 impregnated with a color developer that develops color upon reaction with the coating material is put between transprarent plates 73, 73 and secured in the discharge channel 24A, 24B. A light emitting element 60 and a photoreceiving device 61 are disposed opposing to each other on both sides of the substrate 72. In this embodiment, if the coating material is mixed into the hydraulic fluid, the color developer impregnated in the substrate 72 develops a color in reaction with the coating material, to change the intensity or the wavelength of the light emitted from the light emitting element 60 and passed through the substrate in the hydraulic fluid, by which the output from the photoreceiving element 61 is changed and the breakage of the diaphragm 11 can be detected. The photoreceiving device 61 may alternatively be adapted so as to detect the intensity or the wavelength of the light reflected at the surface of the substrate 72 in the hydraulic fluid. In the embodiment shown in FIG. 1, the pressure sensor 40 and the pressure control valve 41 are used for controlling the pressure of the coating material supplied to a hydraulically-powered reciprocal pump going to be operated next in the operation sequence such that it is equal to the pressure of the coating material currently supplied to the coating machine 2 from a hydraulically-powered reciprocal pump being operated at present. However, the pressure control for the coating material is not restricted only to such an embodiment but the same effect can be obtained also by using a pressure control device 74 as shown in FIG. 7 through FIG. 10, instead of the pressure sensor 40 and the pressure control valve 41. Each of the embodiments shown in FIG. 7 through FIG. 10 has a pressure control device 74 which equalizes the pressure of the hydraulic fluid supplied to the actuation fluid chamber 10 of the hydraulically-powered reciprocal pump 3A that currently supplies the coating material at a constant flow rate to the coating machine 2 with the pressure of the hydraulic fluid discharged from the actuation fluid chamber 10 in the other hydraulically-powered reciprocal pump 3B going to be operated next by the pressure of the coating material supplied to the coating material chamber 9 of the hydraulically-powered reciprocal pump 3B. The pressure control device 74 comprises a diaphragm (or piston) 75 actuated by the difference between the pressures of the hydraulic fluid acted on both sides thereof, and valves (79A and 79B) opened or closed by a needle 76 that moves interlocking with the diaphragm 75, in which the respective valves are so adapted that the discharge channel for the hydraulic fluid discharged from the hydraulically-powered reciprocal pump 3B is opened when the pressures of the hydraulic fluid acted on both sides of the diaphragm 75 are balanced. In the pressure control device 74 shown in FIG. 7, two static pressure chambers 77A and 77B formed in adjacent with each other by way of the diaphragm 75 are in communication with an hydraulic fluid supply source 5 by way of an hydraulic fluid supply channel 21A having an ON-OFF valve 22A disposed therein and an hydraulic fluid supply channel 21B having an ON-OFF valve 22B disposed therein respectively, and also connected to the hydraulic fluid chambers 10 of the hydraulically-powered reciprocal pumps 3A and 3B respectively. The valve 79A is disposed to the static pressure chamber 77A and opened or closed by a popett 78 formed at one end of the needle 76, while the valve 79B is disposed to the static pressure chamber 77B and opened or closed by a popett 78 formed at the other end of the needle 76. The length of the needle 76 is designed such that both of the valves 79A and 79B are opened when the diaphragm 75 situates at a neutral position, that is, when the pressures in the static chambers 77A and 77B are balanced, whereas one of the valves 79A and 79B is closed when the pressures in the static chambers 77A and 77B are not balanced. The valves 79A and 79B are connected to the hydraulic fluid supply source 5 by way of the hydraulic fluid discharge channel 24A having the ON-OFF valve 23A and the hydraulic fluid discharge channel 24B having the ON-OFF valve 23B respectively. Referring to the operation, the ON-OFF valve, e.g., 22A is opened to supply the hydraulic fluid at a constant flow rate from the hydraulic fluid supply source 5 by way of the static pressure chamber 77a of the pressure control device 74 to the hydraulic fluid chamber 10 of the hydraulically-powered reciprocal pump 3A to pump out the coating material charged in the coating material chamber 9 of the hydraulically-powered reciprocal pump 3A at a constant flow rate and supply the coating material by a constant amount to the coating machine 2, meanwhile supply of the coating material is initiated from the coating material supply source 1 to the coating material chamber 9 of the hydraulically-powered reciprocal pump 3A going to be operated next. At the initial stage, the pressure of the hydraulic fluid discharged from the hydraulic fluid chamber 10 of the hydraulically-powered reciprocal pump 3B by the pressure of the coating material supplied to the hydraulically-powered reciprocal pump 3B is lower than the pressure of the hydraulic fluid supplied to the hydraulic fluid chamber 10 of the double-acting reciprocal pump 3A. Therefore, the diaphragm 75 of the pressure control device 74 displaces toward the static pressure chamber 77B to close the valve 79B of the chamber 77B with the needle 76. Accordingly, if the ON-OFF valve 23B is opened, the discharge channel 24B having the ON-OFF valve 23B disposed therein is closed by the valve 79B. Then, the pressure of the coating material supplied from the coating material supply source 1 to the hydraulically-powered reciprocal pump 3B is gradually increased by the operation of the pump 13 (shown in FIG. 1) and, as the result thereof, the pressure of the hydraulic fluid discharged from the hydraulically-powered reciprocal pump 3B is increased. Then, a balance state is attained between the pressures of the hydraulic fluid in the static pressure chambers 77A and 77B by which the needle 78 uprises to open the valve 79B and the hydraulic fluid in the hydraulic fluid chamber 10 of the hydraulically-powered reciprocal pump 3B is recycled through the discharge channel 24B to the hydraulic fluid supply source 5. Thus, the coating material is supplied into the coating material chamber 9 of the hydraulically-powered reciprocal pump 3B at the same pressure as the pressure of the actuation fluid being supplied from the hydraulic fluid supply source 5 to the hydraulically-powered reciprocal pump 3A (that is, at the same pressure as that of the coating material currently supplied from the hydraulically-powered reciprocal pump 3A to the coating machine 2). Accordingly, upon switching the pump operation from one reciprocal pump 3A to the other hydraulically-powered reciprocal pump 3B, no pulsation is caused to the coating material being supplied to the coating machine 2. FIG. 8 shows another embodiment of the pressure control device 74 adapted so that the hydraulic fluid supplied under pressure from the hydraulic fluid supply source 5 through the supply channels 21A, 21B is directly supplied to the hydraulically-powered pump 3A, 3B not by way of the static pressure chamber 77A, 77B, while the pressure of the hydraulic fluid is exerted by way of branched channels 88A and 88B on both sides of the diaphragm 75 respectively. FIG. 9 shows a further embodiment of the pressure control device 74 adapted so that the hydraulic fluid discharged from each of the hydraulic fluid chambers 10 of the hydraulically-powered reciprocal pumps 3A, 3B is directly returned to the hydraulic fluid supply source 5 not by way of the static chamber 77A, 77B, while the pressure of the hydraulic fluid is exerted by way of branched channel 81A, 81B on both sides of the diaphragm 75 respectively. In the embodiment shown in FIG. 9, valves 79A and 79B are disposed separately from the static pressure chambers 77A and 77B respectively. FIG. 10 shows a still further embodiment of the pressure control device 74. A static pressure chamber 77B is disposed to the flow channel 21 in communicationb from the hydraulic fluid supply source 5 to the supply channel 21A, 21B so that the hydraulic fluid supplied to the hydraulically-powered reciprocal pump 3A, 3B is caused to flow through the static chamber 77B. A flow channel 82 branched from the flow channel 24, which is in communication from the discharge channel 24A, 24B to the hydraulic fluid supply source 5, is connected to the static pressure chamber 77A. Further, a valve 79 opened and closed by a needle 76 is disposed only to the flow channel 24, to which the hydraulic fluid is discharged alternately from the hydraulically-powered reciprocal pumps 3A, 3B. FIG. 11 is a flow sheet illustrating one embodiment of the present invention applied to a multicolor coating apparatus. Each one pair of the hydraulically-powered reciprocal pumps 3A, 3B as shown in FIG. 1 is connected to each of coating material selection valves CV W , CV B and CV R of a color-change device 83 connected in parallel with the coating machine 2, as well as connected to each of first switching valves PV W , PV B and PV R for selectively switching the first supply flow channel 21 that supplies the hydraulic fluid at a constant flow rate from the actuation fluid supply source 5 to each pair of the hydraulically-powered reciprocal pumps 3A, 3B in accordance with the switching operation of the coating material selection valves CV W , CV B and CV R . Further, a flow rate control mechanism comprising a flow sensor 17, a flow rate control device 20, etc. is disposed at the midway of the supply channel 21 of the hydraulic fluid between the hydraulic fluid supply source 5 and the switching valves PV W , PV B and PV R . Each pair of the hydraulically-powered reciprocal pumps 3A. 3B is so adapted that is always circulates the paint supplied from the coating material supply source 1 W for white paint, the coating material supply source 1 B for black paint and the coating material supply source 1 R for red paint in such a way that the paint is discharged to a forward recycling channel 84a, passed through each of the coating material selection valves CV W , CV R and CV R and then returned through a backward recycling channel 84b again to each of the coating material supply sources 1 W , 1 B and 1 R . In the color-change device 83, each of the coating material selection valves CV W , CV B and CV R , a solvent selection valve CV S supplied with a cleaning solvent for color-change from a solvent supply source 87 and an air selection valve CV A supplied with pressurized cleaning air for color change from an air supply source 88 are connected to the manifold 86 connected by way of a paint hose 85 to the coating machine 2, so that each of the valves are opened and closed selectively. The hydraulic fluid supply source 5 comprises a first supply channel 21 in which the flow rate of the hydraulic fluid supplied under pressure from the reservoir 15 by the pump 16 is always maintained constant in accordance with the flow rate of the coating material supplied to the coating machine 2 and a second supply channel 90 for supplying the hydraulic fluid under pressure in the reservoir 15 by the pump 89 irrespective of the flow rate of the coating material supplied to the coating machine 2. In the first supply channel 21, each of switching valves PV W , PV B and PV R connected to each of the hydraulically-powered double-acting reciprocal pumps 3A, 3B, and a switching valve PV O connected to the discharge channel 24 for recycling the hydraulic fluid discharged from each pair of the hydraulically-powered reciprocal pumps 3A, 3B into the reservoir 15 are connected in parallel with each other to the supply channel 21. Further, a back pressure valve 91 is disposed between the switching valve PV O and the discharge channel 24. In the second supply channel 90, second switching valves QV W , QV B and QV R are connected in parallel with each other to the hydraulic fluid supply channels 21 W , 21 B and 21 R that connect the respective pair of the hydraulically-powered reciprocal pumps 3A, 3B with the first switching valves PV W , PV B and PV R respectively, as well as a return channel 92 connected directly to the reservoir 15 is connected. A back pressure valve 93 is disposed to the return channel 92. Piston valves 94 are disposed between the hydraulic fluid discharge channel 24 and respective hydraulic fluid supply channels 21 W , 21 B and 21 R for alternately supplying the hydraulic fluid to each pair of the hydraulically-powered reciprocal pumps 3A and 3B. Each of the piston valves 94 is adapted to be switched for three states at a predetermined timing by a limit switch operated by rods 36A, 36B interlocking with the diaphragm 11 of each pair of the hydraulically-powered reciprocal pumps 3A, 3B. The operation of the coating material supply device having the constitution as shown in FIG. 11 will be explained. At first, the pumps 16 and 89 disposed to the hydraulic fluid supply source 5 are operated simultaneously to supply the hydraulic fluid in the reservoir 15 under pressure through both of the first supply channel 21 and the second supply channel 90. Since all of the coating material selection valves CV W , CV B and CV R of the color-change device 83 are closed before starting the coating, all of the first switching valves PV W , PV B and PV R corresponding to them are also closed, while only the switching valve PV O is opened. Accordingly, the hydraulic fluid supplied under pressure at the constant flow rate through the first supply channel 21 is directly recycled to the reservoir 15 of the hydraulic fluid supply source 5 from the switching valve PV O by way of the discharge channel 24. While on the other hand, all of the second switching valves QV W , QV B and QV R are kept open and the hydraulic fluid supplied under pressure at an optional flow rate through the second supply channel 90 is supplied from each of the switching valves QV W , QV B and QV R through each of the supply channels 21 W , 21 B and 21 R to each pair of the hydraulically-powered reciprocal pumps 3A, 3B. That is, each pair of the hydraulically-powered reciprocal pumps 3A, 3B continuously pumps out the paint of each color by the optional pressure of the hydraulic fluid supplied from the second supply channel 90 and supplies the paint recyclically to each of the coating material selection valves CV W , CV B and CV R . Accordingly, it is possible to prevent the paint supplied by the coating material supply sources 1 W , 1 B and 1 R from depositing to the inside of the forward recycling channel 84a or to the inside of the return recycling channel 84b, which can prevent clogging in the nozzle of the coating machine 2 or the defective coating due to generation of coarse grains. In the case of starting coating, for example, with white paint in this state, the coating material selection valve CV W is switched so that it connects the forward recycling channel 84a with the manifold 86 in communication with the paint hose 85, while the first switching valve PV W is opened in response to the operation of the switching valve CV W and the switching valve PV O is closed. Further, the second switching valve QV W is closed simultaneously therewith. Thus, the hydraulic fluid is supplied at a constant flow rate from the hydraulic fluid supply source 5 through the supply channels 21 and 21 W to the hydraulically-powered reciprocal pumps 3A, 3B already charged with the white paint from the coating material supply source 1 W , and the white paint is discharged at a predetermined flow rate from the pair of hydraulically-powered pumps 3A, 3B operated alternatively by the switching operation of the piston valve 94 and supplied at a constant amount to the coating machine 2 by way of the forward recycling channel 84a→manifold 86→paint hose 85. Then, when the color-change is conducted from the white to the black paint after the completion of the coating with the white paint, the forward recycling channel 84a for the white paint is again connected to the backward recycling channel 84b by the switching of the coating material selection valve CV W and, in response to the operation of the valve CV W , the first switching valve PV W is closed, while the switching valve PV O is opened. Further, the second switching valve QV W is again opened simultaneously therewith. Then, the solvent selection valve CV S and the air selection valve CV A are alternately opened and closed to wash and remove the white paint remaining in the paint hose 85 and the coating machine 2 with the solvent and the pressurized air supplied from the solvent supply source 87 and the air supply source 88 by way of the manifold 86. In this way, when the washing for color-change has been completed, the coating material selection valve CV B is switched so that it connects the forward recycling channel 84 for the black paint with the manifold 86 in communication to the paint hose 85 and, in response to the switching operation of the valve CV B , the first switching valve PV B is opened, while the switching valve PV O is closed. Further, the second switching valve QV S is closed simultaneously therewith. Thus, the hydraulic fluid is supplied at a constant flow rate from the hydraulic fluid supply source 5 through the supply channels 21 and 21 B to the hydraulically-powered reciprocating pumps 3A, 3B already supplied with the black paint from the coating material supply source 1 B , and the black paint is discharged at a predetermined flow rate from the alternately operating paired hydraulically-powered reciprocal pumps 3A, 3B by the switching of the piston valve 94 and is supplied at a constant amount to the coating machine by way of the forward recycling channel 84a→manifold 86→paint hose 85. In the constitution as has been described above, since only one set of the flow sensor 17 and the flow rate control device 20 is necessary for maintaining the flow rate of the paint of each color constant even in a case of multicolor coating apparatus that conducts color-change for more than 30 to 60 kinds of colors and it is no more necessary to dispose such a set to each color paint as usual, the installation cast can significantly be reduced. It is of course possible to adopt various kinds of mechanisms as described above referring to FIGS. 1 to 10 for the coating material supply device shown in FIG. 11. The hydraulically-powered reciprocal pump 3A, 3B are not restricted only to those using the diaphragm 11 but it may be a piston by the pump.

A coating material supply device capable of accurately supplying even a highly viscous coating material such as a two-component coating material by a constant amount to a coating machine with no trouble, as well as with no requirement of individually disposing flowmeters, e.g., for respective colors in the case of multicolor coating under color-change.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is Continuation of U.S. patent application Ser. No. 12/032,601, filed Feb. 15, 2008, which is Continuation of U.S. patent application Ser. No. 11/000,325, filed Nov. 29, 2004, now U.S. Pat. No. 7,343,201, issued Mar. 11, 2008, which claims priority benefit of U.S. Provisional Patent Application No. 60/525,138, filed Nov. 28, 2003. BACKGROUND OF THE INVENTION [0002] Gastrointestinal motility control is of interest to medical practitioners, including to treat disorders of the gastrointestinal tract and to treat conditions related to the function of the gastrointestinal tract such as obesity. Previous patents have described various stimulation techniques for entraining or stimulating gastrointestinal motility, but these methods enhance or manipulate the spontaneously existing gastrointestinal electrical activity, thus hoping to indirectly affect gastrointestinal motility, since spontaneously existing motility can be regarded as a result of the existing electrical slow waves. In our previous patents and in the published research that followed, we suggested a third method for stimulation using sequentially administered trains of high frequency (50-500 Hz) voltages. SUMMARY OF THE INVENTION [0003] In the present application we provide according to an aspect of the invention a method and apparatus for overriding the spontaneously existing gastrointestinal (GI) motility and produce artificial peristalsis completely asynchronously with the spontaneously existing mechanical phenomena in the GI tract, in a given GI organ, or in a portion thereof, using trains of external voltages with wide range of frequencies (5-50,000 Hz), wide range of duty cycles (10-100%) and wide range of amplitudes (3-30 V peak-to-peak). In a further aspect of the invention, we provide a method and apparatus for producing preliminary externally controlled contractions in the sphincter region or regions of the said GI organ or in a portion of it (for example, the pylorus in the stomach). The adjacent acetylcholine (ACh) patches in the vicinity of the said sphincter region are exhausted due to the prolonged invoked contractions, so that the sphincter inevitably relaxes as a result. In a still further aspect of the invention, we provide a method and apparatus that invokes externally controlled GI peristalsis after this sphincter relaxation is achieved, so that content is propelled through the said sphincter. And in a further aspect of the invention, we describe an implantable microsystem device which can achieve the described functionalities, which is either autonomously or transcutaneously powered. In addition, there is provided a way to disturb spontaneously existing peristalsis, or to completely or partially override it so that the process of spontaneous GI motility is asynchronously adversely affected as an avenue to treat morbid obesity, which can make use of the same device. [0004] Further description of the invention is contained in the detailed disclosure and claims that follow. BRIEF DESCRIPTION OF THE FIGURES [0005] There will now be described preferred embodiments of the invention, with reference to the drawings, by way of illustration only and not with the intention of limiting the scope of the invention, in which like numerals denote like elements and in which: [0006] FIGS. 1A-1D show placing of electrodes on portions of the gastrointestinal tract according to the invention; [0007] FIGS. 2A-2C show a configuration of synchronized patches of external signals: sequential (A), overlapping (B) and embedded (C); [0008] FIGS. 3A-3D and 4 A- 4 D are three dimensional views showing respectively the effect of the sequential and embedded excitation patterns on the stomach; [0009] FIGS. 5A-5C show exemplary external signal patterns for producing reversed peristalsis; [0010] FIGS. 6A-6D are three dimensional views showing effect of a sequential pattern of excitatory signals on the stomach; [0011] FIG. 7 illustrates a single session of a sample pattern to invoke asynchronous contractile desynchronization; [0012] FIGS. 8A-8B depict contractions resulting from the excitation pattern of FIG. 7 in a three-dimensional mathematical model of the stomach; [0013] FIG. 9A shows the cyclic nature of the smooth muscle response to external neural electrical control assessed with implanted force transducers in the vicinity of the electrodes; [0014] FIG. 9B is a detail of a cycle from FIG. 9A ; [0015] FIGS. 10A and 10B show electrode configurations for invoked peristalsis of a stomach; [0016] FIGS. 11A and 11B show excitation patterns for excitation of the corresponding electrode sets 1 , 2 , 3 in FIGS. 10A and 10B respectively; [0017] FIG. 12 is a perspective view, with an inset showing an internal detail, of apparatus for carrying for carrying out the invention; [0018] FIG. 13 shows schematically an arrangement for delivering excitation pulses without transcutaneous wires; and [0019] FIGS. 14A and 14B are block diagrams of apparatus for carrying out the invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS [0020] In this patent document, “comprising” means “including” and does not exclude other elements being present. In addition, a reference to an element by the indefinite article “a” does not exclude the possibility that more than one of the elements is present. A reference to an element is not restricted to the particular form of the element disclosed, but includes functional equivalents now know or hereafter developed. [0021] Electrodes for obtaining control of gastrointestinal tract motility are implanted either from the serosal or the mucosal side of the particular gastrointestinal organ (e.g. the stomach, the colon, the esophagus, etc.), and their axes could be either collinear or perpendicular to the organ axis. The electrodes are implanted in pairs. Each electrode pair consists of two electrodes, one being a ground (reference) and the other the active electrode. One or several electrode pairs (depending on the circumference of the organ in the area where the electrodes are implanted) form a local electrode set, which is implanted corresponding to an imaginary line perpendicular to the organ axis. One or several local electrode sets can be implanted along the axis of the gastrointestinal organ, either from the mucosal or from the serosal side. [0022] FIGS. 1A-1D show sample electrode configurations for the stomach (A, B and C) and for a segment of the colon (D). Electrodes 10 can be collinear with the organ axis (A, B, D), or perpendicular to it (C). The length of the electrodes is between 0.2 and 5 cm. The distance between electrode sets can be between 1.5 and 10 cm. Electrodes from a given pair and from adjacent sets should not touch, and the minimal distance between them should be 1 cm. The electrodes can be implanted subserosally (A, D, C) or from the mucosal side (B). Electrodes implanted on the posterior wall of the organ are lighter in color. The electrodes of a given set are arranged correspondingly to imaginary lines perpendicular to the organ axis (shown in lighter color as well). [0023] External signals are supplied to the electrodes 10 to achieve gastrointestinal motility control. The external signals supplied to the electrode sets, although synchronized between themselves, are completely asynchronous with the spontaneously existing slow waves in the particular GI organ, and override them, rather than stimulating or enhancing them in any way. The frequency of the synchronized signals ranges from 5 to 50,000 Hz, and their amplitudes range from 3 V peak-to-peak to 30 V peak-to-peak. The duty cycle can vary from 10 to 100%, for example 50% to 90%. The synchronized signals are delivered in patches with three basic configurations, sequential, overlapping, and embedded, and the pause between the patches or bursts ranges from 3 seconds to 3 minutes in a single session ( FIGS. 2A-2C ). Multiple sessions can be administered. The current delivery capability of the microsystem can be estimated considering the average total current consumption per unit muscular thickness of GI tissue per electrode pair, which is approximated as 3 mA/mm. With the assumption that the thickness of the muscle is in the range of 2.5 mm to 3.55 mm, the average total current drawn by the tissue will be in the range of 7.5 mA to 10.5 mA. [0024] FIGS. 2A-2C show a configuration of the synchronized patches of external signals: sequential (A), overlapping (B) and embedded (C). Each invoked motility session can last from 3 seconds to 3 minutes. The time T 3 represents the composite duration of the external signals from all channels. This time, combined with an appropriate relaxation time (post-motility pause), constitute the overall invoked motility session time. The relaxation time is at least 2 times longer that the composite duration of the external signals in all channels, so that a complete relaxation of the smooth muscles can be achieved. The pause between successive patches in the sequential pattern (A) can be from 0 seconds to the duration of the patch itself, Ts1. The time between the end of Ts1 in the proximal channel and the start of the signal patch in the next more distal channel is Ts2. The shift time To2 in the overlapping pattern can be in the range between To1 and To1−T, where T is the period of the high-frequency pulses (T=1/f, f=5 to 50,000 Hz) and To1 is the duration of the external signal in channel 1. The delay time Te2 in the embedded pattern can be from Te1−T to Te1/2, where Te1 is the duration of the external signal in channel 1 (which in this pattern coincides with the overall duration of the motility control session). The amplitude V of the stimuli can be in the range of 3-30 V (peak-to-peak). The sequential pattern of FIG. 2A is illustrated in FIGS. 3A-3D , and the embedded pattern of FIG. 2C is illustrated in FIGS. 4A-4D , using a three-dimensional model of the stomach. Extensive tests have been performed on 8 acute dogs and the anticipated contractile response resulting from the production of invoked peristalsis was verified both visually and with force transducers implanted in the vicinity of the implanted electrode sets. [0025] Invoked peristalsis using synchronized local contractions can be produced also in the opposite direction, a concept that could be labeled invoked reversed peristalsis. This opportunity could be very important for the treatment of morbid obesity, since reversed peristalsis can delay gastric emptying and affect in a controlled way the desire of a given patient to consume food. Similarly to the invoked distal peristalsis, three different patterns of the external synchronized patches can be employed. FIGS. 5A-5C represent various external signal patterns for producing reversed peristalsis. Since the microsystem producing the patterns is programmable, comfort levels specific to a given patient can be determined in order to produce the desired controlled peristalsis without inducing nausea and vomiting which are usual side effects of abnormal gastric motor function. FIGS. 5A-5C show sequential (A), overlapping (B) and embedded (C) synchronized patches of external signals aiming at producing reversed peristalsis. Each invoked motility session can last from 3 seconds to 3 minutes and the strength of the contractions is completely controllable by the microsystem, so that appropriate voltage thresholds can be selected in order to avoid invoked nausea and vomiting in the patient. The time T 3 represents the composite duration of the external signals from all channels. This time, combined with an appropriate relaxation time (post-motility pause), constitute the overall invoked motility session time aiming at producing reversed peristalsis. The relaxation time is at least 2 times longer that the composite duration of the external signals in all channels, so that a complete relaxation of the smooth muscles can be achieved. The pause between successive patches in the sequential pattern (A) can be from 0 seconds to the duration of the patch itself, Ts1. The time between the end of Ts1 in the distal channel and the start of the signal patch in the next more proximal channel is Ts2. The shift time To2 in the overlapping pattern can be in the range between To1 and To1−T, where T is the period of the high-frequency pulses (T=1/f, f=5 to 50,000 Hz) and To1 is the duration of the external signal in the most distal channel 4. The delay time Te2 in the embedded pattern can be from Te1−T to Te1/2, where Te1 is the duration of the external signal in the most distal channel 4 (which in this pattern coincides with the overall duration of the motility control session). The amplitude V of the stimuli can be in the range of 3-30 V (peak-to-peak). The patterns from FIG. 5A , the sequential pattern, is illustrated in FIGS. 6A-6D . It should also be mentioned that inducing controlled reversed peristalsis in the antrum affects the mechanoreceptors, which are abundant in the area. If appropriate voltage levels for the external signals are utilized. Thus, rather than inducing nausea and vomiting, a perception of early satiety could result. This, by itself, could be a substantial avenue for treating morbid obesity. [0026] Rather than producing reversed peristalsis, gastric content can be retained in the stomach simply by invoking controlled asynchronous contractile desynchronization. Similarly to the invoked peristalsis patterns described above, this technique also overrides the spontaneously existing contractile pattern in the stomach, but imposing a pattern which aims not to move content distally (normal forward persitalsis), nor to move it in a proximal direction (reversed peristalsis) in a synchronized fashion, but to keep the content in prolonged contact with the antral mechanoreceptors simply by “shaking it” back and forth, thus inducing in the patient a perception of early satiety. This can be achieved by the repetitive asynchronous administration of the external voltage signals controlling minimized number of implanted electrode sets (two sets could be sufficient, one proximal and one distal). FIG. 7 illustrates single session of a sample pattern to invoke asynchronous contractile desynchronization, and FIGS. 8A-8B depict the resulting contractions in a three-dimensional mathematical model of the stomach, which was verified experimentally in acute tests. The session can be repeated in random sequence to prolong the “shaking” effect. [0027] For sphincter control, a pair of electrodes is implanted on or in the vicinity of the sphincters of the organ (for example, on the pylorus of the stomach) so that the sphincters can be controlled (brought into a contracted stage to prevent content passing, or forced into relaxation to permit content passing) by utilizing or exhausting the available acetylcholine (ACh) patches in the vicinity of the said sphincters. These patches are released as a result of prolonged exposure to high frequency pulse trains, and the timing of this release, as well as the time it takes to exhaust these patches are known to us from extensive experimental work ( FIGS. 9A , 9 B). FIG. 9A shows the cyclic nature of the smooth muscle response to external neural electrical control assessed with implanted force transducers in the vicinity of the electrodes. Prolonged motility control session clearly reveals the cycles of sustained contractions followed by relaxations, although the continuous external electrical control was maintained ( FIG. 9A ). Within about 25-30 seconds the ACh patches in the vicinity of the muscle (e.g. the pylorus) get exhausted and the muscle relaxes even though the external electrical control continues. These timings are illustrated in details in FIG. 9B , which can be regarded as a zoomed-in averaged cycle extracted from FIG. 9A . [0028] Specifically, the timings for achieving forced pyloric relaxation have been measured in large dogs by implanting force transducer in the vicinity of the pylorus, and utilizing pyloric electrode configurations depicted in FIGS. 10A-10B with the excitation scheme shown in FIGS. 11A and 11B respectively. If, for example, a relaxation of the pylorus is required to propel content, continuous externally invoked and controlled contraction of this sphincter takes place until the ACh patches in its vicinity are exhausted, and the pylorus relaxes while the ACh patches recover. During this period of induced relaxation, the content is propelled using a synchronously produced invoked peristalsis under microprocessor control. Since the relaxation of the pylorus is also invoked under microprocessor control, the invoked peristalsis and the pyloric relaxation can be completely synchronized for maximally efficient gastric emptying. [0029] Alternatively, knowing for how long the pylorus can be kept contracted, and how often its cyclic contractions can be invoked, gastric emptying could be significantly slowed down in particular time intervals during or after food intake. In addition, pyloric control during fasting periods can be utilized to manipulate the feelings of hunger or satiety by interrupting the spontaneously-existing migrating myoelectrical complex in the stomach, again under microprocessor control and without synchronizing this activity with the spontaneously existing slow waves but by overriding them asynchronously. [0030] FIGS. 11A and 11B show an example of synchronizing preliminary pyloric contraction for the purpose of exhausting the ACh patches in the vicinity of the pylorus using electrode set 1 with the contractions produced using two other electrode sets (proximal, 2 and distal, 3). The region of the stomach subject to invoked peristalsis is shown darker. Electrode configurations can be perpendicular to the gastric axis ( FIG. 10A ), or collinear with it ( FIG. 10B ). The electrode set 1, implanted in the pyloric region, delivers external voltage trains for the time Tpr needed to exhaust the ACh patches in the vicinity of the pylorus (about 25-30 seconds), resulting in pyloric relaxation at the very end of this time period. About half way through Tpr (e.g. around the 10 th -15 th second), the delivery of external voltage pulses to the proximal electrode set starts, and after Tpr, the delivery of external voltage pulses to the distal electrode set takes place ( FIG. 11A ). Alternatively, the delivery of external voltage trains can continue with the pyloric electrode set 1 for the entire session, since the pylorus will relax after Tpr in a cyclic fashion anyway ( FIG. 11B ). The latter technique provides a prolonged, albeit cyclic, pyloric relaxation, but inevitably is related to higher power consumption. [0031] Apparatus for carrying out the invention is shown in FIGS. 12 , 13 , 14 A and 14 B. The power supply of the proposed implantable microsystem can be achieved either by (a) autonomous battery; (b) autonomous battery which is rechargeable through a transcutaneous inductive link facilitated by an abdominal belt periodically worn by the patient (preferably during sleep) ( FIG. 12 ); or (c) transcutaneous power transfer facilitated by an abdominal belt worn by the patient during the periods of the desired gastrointestinal organ control ( FIG. 13 ). [0032] FIG. 12 shows a distributed microsystem setup. The external control is administered via abdominal belt (left), in which the transmitting inductive coil for transcutaneous power transfer is positioned ( 1 ), along with the associated microcontroller-based electronics ( 2 , see also FIGS. 13 and 14B ). The belt is attached to the body in the abdominal area ( 3 ). The implanted microsystem (right) is sutured on the inner side of the abdominal wall right under the abdominal bell center. It contains receiving coil ( 4 ) which is aligned with the transmitting coil and microcontroller-based electronics ( 5 , see also FIG. 14A ). In case of autonomous non-rechargeable battery-based power supply for the implanted microsystem, transmitting and receiving coils are not necessary and the dimensions of both microsystems could be reduced. The implanted microsystem is shown with four channels, and the pyloric channel is connected to the schematic replica of the stomach of FIG. 1B . [0033] FIG. 13 depicts an external transmitter 20 located over the skin 22 in the abdominal belt worn by the patient can be utilized to power one or multiple implants 24 in various sections of the gut 26 (e.g. in the colon). The transcutaneous power supply link is inductor-based. [0034] The overall block diagrams of the entire system are presented in FIGS. 14A and 14B . Both the implantable device and the external controlling device are microsystems, each including a microcontroller. FIGS. 14A and 14B show block diagrams of the implantable device ( FIG. 14A ) and the controlling device located in the abdominal belt in a discrete electronic implementation. Very-Large-Scale-Integration (VLSI) of the same concept is also possible and could be preferred if further device miniaturization is desired. In this particular implementation the battery 32 of the implantable device can be autonomous or externally rechargeable. The communication between the controlling microsystem of FIG. 14B and the implant of FIG. 14A is provided with radio-frequency tranceivers. [0035] The system includes an external control circuitry and an implantable device. Once the implant is in place, the external control circuitry can be utilized to control the motility control parameters, the number of motility control sessions and the pause between successive sessions. The implantable microsystem of FIG. 14A includes five major blocks: (1) microcontroller 30 ; (2) DC-DC converters 34 ; (3) MOSFETs 36 ; (4) analog electronic switch 38 ; and (5) wireless transmitter 40 and receiver 42 (see FIG. 14A ). The microcontroller 30 may be for example model AT90S2313 (Atmel, San Jose, Calif.) programmed to generate the digital motility control pulses and to control the output of the DC-DC conversion stage. In addition, it determines the duration of each motility control session and the overlap between successive channels via the analog switch 38 . The motility control parameters (amplitude, frequency, overlap, and session length) can vary from one motility control session to another. The microcontroller 30 is pre-programmed with a set of different values for each motility control parameter. In addition, a default value is specified for each parameter. The operator can choose the desired value of each parameter from this pre-determined list using a transcutaneous control link. The clock frequency for the microcontroller 30 has been chosen to be 20 KHz. This low crystal frequency was chosen to minimize the switching power losses in the microcontroller 30 . The maximum frequency will be 500 Hz, resulting in a minimum pulse width of 2 ms. A 20 KHz crystal has an instruction cycle of 50 μs, which is sufficiently large for generating 2 ms or slower pulses. [0036] The RF receiver 40 , for example a MAX1473 (Maxim, Dallas, Tex.), is used to receive serial wireless data containing the choice of the motility control parameters from the external portable control unit of FIG. 14B . This data is transmitted serially and in an asynchronous mode to the microcontroller 30 using the UART input. The data transfer rate (baud rate) is set to 125 bit/s for operation with a crystal frequency of 20 KHz. The microcontroller 30 will sample the data at 16 times the baud rate. If the UART input does not detect a start bit for data transfer in the first 5 seconds after power-up, the microcontroller 30 will start a motility control session using its default parameters. The microcontroller 30 will send a ‘confirmation byte’ at the onset of the control pattern (5s after startup) to the external control circuit via the RF transmitter. A byte with all one bits represents the onset of motility control with new parameters, while a byte with all zeros represents the onset of motility control with default parameters. The DC-DC conversion block 34 includes two integrated circuits (ICs): LT1317 (Linear Technology, Milpitas, Calif.), a step-up voltage converter, and TC7662B (Microchip, Chandler, Ariz.), a charge-pump voltage inverter. These two ICs convert the supplied 3V to the desired amplitude (V stim ). V stim is in the range of ±5V to ±10V and can be adjusted by the microcontroller 30 . The MOSFET stage 36 utilizes for example two logic transistors FDV303N and FDV304P (Fairchild, South Portland, Me.) and two power transistors, which are included in one package IRF7105 (International Rectifier, El Segundo, Calif.). The logic FETs 36 have a low gate threshold voltage and can be switched by the 3V logic square wave produced by the microcontroller 30 . These logic transistors drive the gates of the power FETs, which convert the digital square wave to a bipolar analog output of the same frequency and an amplitude equal to V stim . The output of the transistors 36 is directed to the stimulating electrodes 10 through a four-channel analog switch 38 (for example ADG202, Analog Devices, Norwood, Mass.). Each of the four switch channels closes upon receiving an enable command from the microcontroller 30 . The analog switch 38 also isolates each electrode 10 from the successive electrode sets. The microcontroller 30 preferably receives both the necessary electrical power and the required stimulation pattern information transcutaneously through the receiver 40 , optionally also using an inductive coil as part of the receiver 40 . The microcontroller 30 then converts the obtained stimulation pattern information into real stimulation sequences delivered to the implanted electrodes by controlling operation of the logic FETs 36 . On conclusion of the sending of a stimulation sequence, the microcontroller 30 then reports back to an external controller the success or failure of the delivered stimulation sequences. Success or failure may be determined for example by sensors that detect whether a specified contraction has taken place and send a corresponding signal to the microcontroller 30 . [0037] A portable microcontroller-based controller circuit allows the user to select the appropriate parameters for producing artificially invoked peristalsis (frequency, amplitude, overlap between channels and session length). This battery-operated control circuit is external to the body, and is worn by the patient in an abdominal belt. A digital wireless transmitter 50 (MAX1472, Maxim, Dallas, Tex.) is used to transmit the chosen motility control parameters to the implanted motility control device ( FIG. 14A ). The external controller 52 can also be used to adjust the number of the successive motility control sessions (1-4) as well as the pause period between the successive sessions (30-120 s). The external circuit turns the implanted motility control device on or off for adjustable lengths of time by controlling a normally open magnetic reed switch 33 that is integrated in the implanted system. The reed switch 33 is placed in series with the implanted battery 32 . The controller 52 turns the magnetic reed switch 33 on by energizing a coil 54 to generate a static magnetic field. FIG. 14B shows the design of the external controller. [0038] The external controller has a toggle switch 56 that allows the user to implement either a default motility control session (using the implanted motility control device's default parameters) or a new motility control session. The parameters for the new motility control session are downloaded to the external unit's microcontroller 52 from a PC 58 via an RS232 link. These parameters are transferred from the microcontroller 52 to the wireless transmitter 50 using the UART line, at a baud rate equal to the implanted circuit's baud rate of 125 bit/s. The wireless transmitter 50 then sends this information to the implanted circuit ( FIG. 14A ). In the case of motility control session with default parameters, the RF transmitter 50 will be disabled and the microcontroller 52 will not send any data to it. The microcontroller 52 will simply turn the implanted circuit on via the reed switch 33 . The implanted circuit of FIG. 14A will interpret lack of incoming information from the transcutaneous link as a sign that default motility control session must be performed. The RF receiver 60 is used for receiving the ‘confirmation byte’ from the implanted stimulator. The microcontroller 52 will send a signal to de-energize the coil t+5 seconds after startup, where t represents the time length of each motility control session. [0039] The methods and apparatus disclosed here radically differ from previously proposed gastrointestinal stimulation techniques, at least since: (a) it does not stimulate or enhance the spontaneously existing gastrointestinal electrical or mechanical activity, but rather overrides the latter and imposes motility patterns that are entirely externally controlled by an implantable microprocessor; (b) calls for implantation of electrode sets (either from the serosal or from the mucosal side) around the circumference of the organ, but the electrode axes themselves could be collinear or perpendicular to the organ axis (see for example FIGS. 1A-1D ); (c) utilizes external signals with extended frequency and amplitude range, and with extended timing parameters depending on the desired application (see for example FIGS. 2A-2C , FIGS. 5A-5C and FIG. 7 ); (d) calls for synchronized sphincter control by exhausting the ACh patches in the vicinity of the organ with an appropriate timing (see for example FIGS. 9A , 9 b, 10 A, 10 B, 11 A and 11 B); (e) induces forward or reversed peristalsis, or asynchronous contractile desynchronization with appropriate and programmable intensity so that the patient would not experience discomfort, pain, nausea or vomiting; (f) suggests innovative and versatile power supply options using transcutaneous inductive link for battery recharging or for complete power transfer in the framework of an implantable microsystem (see for example FIGS. 12 , 13 ). [0046] A number of inventions have been disclosed in this patent disclosure and it will be appreciated that not all features disclosed here form part of all of the inventions. The embodiments disclosed are exemplary of the inventions.

A method and a multichannel implantable device are described for partial or complete restoration of impaired gastrointestinal motility, or for disturbing and/or partially or completely blocking normal gastrointestinal motility using one or multiple microsystem-controlled channels of circumferentially arranged sets of two or more electrodes which provide externally-invoked synchronized electrical signals to the smooth muscles via the neural pathways.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a Continuation Application of U.S. application Ser. No. 10/576,492 filed Feb. 6, 2007, which is a §371 of International Patent Application Serial No. PCT/EP2004/011619 filed Oct. 14, 2004, which claims priority from GB 0324159.3 filed Oct. 15, 2003 in the United Kingdom. [0002] The entire contents of each of the foregoing applications are incorporated herein by reference. This application contains no new matter. FIELD OF THE INVENTION [0003] The present invention relates to novel diazepanyl derivatives having pharmacological activity, processes for their preparation, to compositions containing them and to their use in the treatment of neurological and psychiatric disorders. BACKGROUND OF THE INVENTION [0004] WO 03/00480 (Novo Nordisk A/S and Boehringer Ingleheim International GMBH) describes a series of substituted piperazines and diazepanes as H3 antagonists. [0005] WO 02/08221 (Neurogen Corporation) describes a series of substituted piperazines and diazepanes as capsaicin receptor antagonists which are claimed to be useful in the treatment of neuropathic pain. WO 98/37077 and WO 99/42107 (Zymogenetics Inc) both describe a series of substituted heterocyclic derivatives which are claimed to act as calcitonin mimics to enhance bone formation. [0006] The histamine H3 receptor is predominantly expressed in the mammalian central nervous system (CNS), with minimal expression in peripheral tissues except on some sympathetic nerves (Leurs et al., (1998), Trends Pharmacol. Sci. 19, 177-183). Activation of H3 receptors by selective agonists or histamine results in the inhibition of neurotransmitter release from a variety of different nerve populations, including histaminergic and cholinergic neurons (Schlicker et al., (1994), Fundam. Clin. Pharmacol. 8, 128-137). Additionally, in vitro and in vivo studies have shown that H3 antagonists can facilitate neurotransmitter release in brain areas such as the cerebral cortex and hippocampus, relevant to cognition (Onodera et al., (1998), In: The Histamine H3 receptor, ed Leurs and Timmerman, pp 255-267, Elsevier Science B.V.). Moreover, a number of reports in the literature have demonstrated the cognitive enhancing properties of H3 antagonists (e.g. thioperamide, clobenpropit, ciproxifan and GT-2331) in rodent models including the five choice task, object recognition, elevated plus maze, acquisition of novel task and passive avoidance (Giovanni et al., (1999), Behav. Brain Res. 104, 147-155). These data suggest that novel H3 antagonists and/or inverse agonists such as the current series could be useful for the treatment of cognitive impairments in neurological diseases such as Alzheimer's disease and related neurodegenerative disorders. SUMMARY OF THE INVENTION [0007] The present invention provides, in a first aspect, a compound of formula (I) or a pharmaceutically acceptable salt thereof: [0000] [0000] wherein: R 1 represents branched C 3-6 alkyl, C 3-5 cycloalkyl or —C 1-4 alkylC 3-4 cycloalkyl; R 2 represents halogen, C 1-6 alkyl, C 1-6 alkoxy, cyano, amino or trifluoromethyl; n represents 0, 1 or 2; R 3 represents —X-aryl, —X-heteroaryl, —X-heterocyclyl, —X-aryl-aryl, —X-aryl-heteroaryl, —X-aryl-heterocyclyl, —X-heteroaryl-aryl, —X-heteroaryl-heteroaryl, —X-heteroaryl-heterocyclyl, —X-heterocyclyl-aryl, —X-heterocyclyl-heteroaryl or —X-heterocyclyl-heterocyclyl; such that when R 3 represents —X-piperidinyl, —X-piperidinyl-aryl, —X-piperidinyl-heteroaryl or —X-piperidinyl-heterocyclyl said piperidinyl group is attached to X via a nitrogen atom; wherein R 3 is attached to the phenyl group of formula (I) at the 3 or 4 position; X represents a bond, O, CO, SO 2 , CH 2 O, OCH 2 , NR 4 , NR 4 CO or C 1-6 alkyl; R 4 represents hydrogen or C 1-6 alkyl; wherein said aryl, heteroaryl or heterocyclyl groups of R 3 may be optionally substituted by one or more (e.g. 1, 2 or 3) halogen, hydroxy, cyano, nitro, oxo, haloC 1-6 alkyl, haloC 1-6 alkoxy, C 1-6 alkyl, C 1-6 alkoxy, arylC 1-6 alkoxy, C 1-6 alkylthio, C 1-6 alkoxyC 1-6 alkyl, C 3-7 cycloalkylC 1-6 alkoxy, C 3-7 cycloalkylcarbonyl, —COC 1-6 alkyl, C 1-6 alkoxycarbonyl, arylC 1-6 alkyl, heteroarylC 1-6 alkyl, heterocyclylC 1-6 alkyl, C 1-6 alkylsulfonyl, C 1-6 alkylsulfinyl, C 1-6 alkylsulfonyloxy, C 1-6 alkylsulfonylC 1-6 alkyl, arylsulfonyl, arylsulfonyloxy, arylsulfonylC 1-6 alkyl, aryloxy, —CO-aryl, —CO-heterocyclyl, —CO-heteroaryl, C 1-6 alkylsulfonamidoC 1-6 alkyl, C 1-6 alkylamidoC 1-6 alkyl, arylsulfonamido, arylaminosulfonyl, arylsulfonamidoC 1-6 alkyl, arylcarboxamidoC 1-6 alkyl, aroylC 1-6 alkyl, arylC 1-6 alkanoyl, or a group NR 15 R 16 , —NR 15 CO-aryl, —NR 15 CO-heterocyclyl, —NR 15 CO-heteroaryl, —CONR 15 R 16 , NR 15 COR 16 —NR 15 SO 2 R 16 or —SO 2 NR 15 R 16 groups, wherein R 15 and R 16 independently represent hydrogen or C 1-6 alkyl; or solvates thereof. [0008] In one particular aspect of the present invention, there is provided a compound of formula (I) as defined above wherein X represents a bond, O, CO, SO 2 , CH 2 O, OCH 2 or C 1-6 alkyl. DETAILED DESCRIPTION [0009] The term ‘C 1-6 alkyl’ as used herein as a group or a part of the group refers to a linear or branched saturated hydrocarbon group containing from 1 to 6 carbon atoms. Examples of such groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert butyl, n-pentyl, isopentyl, neopentyl or hexyl and the like. [0010] The term ‘C 1-6 alkoxy’ as used herein refers to an —O—C 1-6 alkyl group wherein C 1-6 alkyl is as defined herein. Examples of such groups include methoxy, ethoxy, propoxy, butoxy, pentoxy or hexoxy and the like. [0011] The term ‘C 3-8 cycloalkyl’ as used herein refers to a saturated monocyclic hydrocarbon ring of 3 to 8 carbon atoms. Examples of such groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl or cyclooctyl and the like. [0012] The term ‘halogen’ as used herein refers to a fluorine, chlorine, bromine or iodine atom. [0013] The term ‘haloC 1-6 alkyl’ as used herein refers to a C 1-6 alkyl group as defined herein wherein at least one hydrogen atom is replaced with halogen. Examples of such groups include fluoroethyl, trifluoromethyl or trifluoroethyl and the like. [0014] The term ‘halo C 1-6 alkoxy’ as used herein refers to a C 1-6 alkoxy group as herein defined wherein at least one hydrogen atom is replaced with halogen. Examples of such groups include difluoromethoxy or trifluoromethoxy and the like. [0015] The term ‘aryl’ as used herein refers to a C 6-12 monocyclic or bicyclic hydrocarbon ring wherein at least one ring is aromatic. Examples of such groups include phenyl, naphthyl or tetrahydronaphthalenyl and the like. [0016] The term ‘aryloxy’ as used herein refers to an —O-aryl group wherein aryl is as defined herein. Examples of such groups include phenoxy and the like. [0017] The term ‘heteroaryl’ as used herein refers to a 5-6 membered monocyclic aromatic or a fused 8-10 membered bicyclic aromatic ring containing 1 to 4 heteroatoms selected from oxygen, nitrogen and sulphur. Examples of such monocyclic aromatic rings include thienyl, furyl, furazanyl, pyrrolyl, triazolyl, tetrazolyl, imidazolyl, oxazolyl, thiazolyl, oxadiazolyl, isothiazolyl, isoxazolyl, thiadiazolyl, pyranyl, pyrazolyl, pyrimidyl, pyridazinyl, pyrazinyl, pyridyl, triazinyl, tetrazinyl and the like. Examples of such fused aromatic rings include quinolinyl, isoquinolinyl, quinazolinyl, quinoxalinyl, pteridinyl, cinnolinyl, phthalazinyl, naphthyridinyl, indolyl, isoindolyl, azaindolyl, indolizinyl, indazolyl, purinyl, pyrrolopyridinyl, furopyridinyl, benzofuranyl, isobenzofuranyl, benzothienyl, benzoimidazolyl, benzoxazolyl, benzoisoxazolyl, benzothiazolyl, benzoisothiazolyl, benzoxadiazolyl, benzothiadiazolyl and the like. [0018] The term ‘heterocyclyl’ refers to a 4-7 membered monocyclic ring or a fused 8-12 membered bicyclic ring which may be saturated or partially unsaturated containing 1 to 4 heteroatoms selected from oxygen, nitrogen or sulphur. Examples of such monocyclic rings include pyrrolidinyl, azetidinyl, pyrazolidinyl, oxazolidinyl, piperidinyl, piperazinyl, morpholinyl, thiomorpholinyl, thiazolidinyl, hydantoinyl, valerolactamyl, oxiranyl, oxetanyl, dioxolanyl, dioxanyl, oxathiolanyl, oxathianyl, dithianyl, dihydrofuranyl, tetrahydrofuranyl, dihydropyranyl, tetrahydropyranyl, tetrahydropyridinyl, tetrahydropyrimidinyl, tetrahydrothiophenyl, tetrahydrothiopyranyl, diazepanyl, azepanyl and the like. Examples of such bicyclic rings include indolinyl, isoindolinyl, benzopyranyl, quinuclidinyl, 2,3,4,5-tetrahydro-1H-3-benzazepine, tetrahydroisoquinolinyl and the like. [0019] Preferably, R 1 represents branched C 3-6 alkyl (e.g. isopropyl) or C 3-5 cycloalkyl (e.g. cyclopropyl or cyclobutyl), more preferably cyclobutyl. [0020] Preferably, n represents 0. [0021] Preferably, R 3 represents —X-aryl (e.g. -phenyl, —CO-phenyl, —O-phenyl, —OCH 2 -phenyl or —CH 2 O-phenyl) optionally substituted by one or more halogen (e.g. fluorine), cyano, —COC 1-6 alkyl (e.g. —COMe) or —CONR 15 R 16 (e.g. —CONH 2 ) groups; [0023] —X-heteroaryl (e.g. -tetrazolyl, -pyrazolyl, -pyrrolyl, -oxazolyl, -isoxazolyl, -oxadiazolyl, -pyridyl, —OCH 2 -pyridyl, —NHCO-pyridyl, -pyrimidinyl, —N(Me)-pyrimidinyl, -pyridazinyl or —OCH 2 -pyrazinyl) optionally substituted by one or more haloC 1-6 alkyl (e.g. —CF 3 ), cyano, oxo, C 1-6 alkyl (e.g. methyl or ethyl) or —CONR 15 R 16 (e.g. —CONHMe or —CON(Me) 2 ) groups; —X-heteroaryl-aryl (e.g. -thiazolyl-phenyl) optionally substituted by one or more halogen (e.g. fluorine) atoms; —X-aryl-heteroaryl (e.g. -phenyl-oxazolyl or -phenyl-oxadiazolyl) optionally substituted by one or more C 1-6 alkyl (e.g. methyl) groups; or —X-heterocyclyl (e.g. -thiomorpholinyl, -morpholinyl, -pyrrolidinyl or —O-tetrahydro-2H-pyran-4-yl) optionally substituted by one or more oxo groups. [0027] More preferably, R 3 represents —X-aryl (e.g. -phenyl or —CO-phenyl) optionally substituted by one or more halogen (e.g. fluorine), cyano or —COC 1-6 alkyl (e.g. —COMe) groups; —X-heteroaryl (e.g. -oxazolyl, -isoxazolyl, -oxadiazolyl, -pyridyl, -pyrimidinyl or -pyridazinyl) optionally substituted by one or more haloC 1-6 alkyl (e.g. —CF 3 ), cyano, C 1-6 alkyl (e.g. methyl) or —CONR 15 R 16 (e.g. —CONHMe) groups; —X-heteroaryl-aryl (e.g. -thiazolyl-phenyl) optionally substituted by one or more halogen (e.g. fluorine) atoms; or —X-heterocyclyl (e.g. -morpholinyl). [0032] Most preferably, R 3 represents —X-aryl (e.g. -phenyl) optionally substituted by one or more cyano or —COC 1-6 alkyl (e.g. —COMe) groups; or —X-heteroaryl (e.g. -pyridyl) optionally substituted by one or more haloC 1-6 alkyl (e.g. —CF 3 ) or cyano groups. [0035] Especially preferably, R 3 represents -pyridyl optionally substituted by one or more haloC 1-6 alkyl (e.g. —CF 3 ) or cyano groups. [0036] Preferably, R 3 is attached to the phenyl group of formula (I) at the 4 position. [0037] Preferably, X represents a bond, CO, O, NR 4 , NR 4 CO, CH 2 O or OCH 2 more preferably a bond. [0038] Preferably, R 4 represents hydrogen or methyl. [0039] Preferably, R 3 is attached to the phenyl group of formula (I) at the 4 position. [0040] Preferred compounds according to the invention include examples E1-E58 as shown below, or a pharmaceutically acceptable salt thereof. [0041] Compounds of formula (I) may form acid addition salts with acids, such as conventional pharmaceutically acceptable acids, for example maleic, hydrochloric, hydrobromic, phosphoric, acetic, fumaric, salicylic, sulphate, citric, lactic, mandelic, tartaric and methanesulphonic. Salts, solvates and hydrates of histamine H3 receptor antagonists or inverse agonists therefore form an aspect of the invention. [0042] Certain compounds of formula (I) are capable of existing in stereoisomeric forms. It will be understood that the invention encompasses all geometric and optical isomers of these compounds and the mixtures thereof including racemates. Tautomers also form an aspect of the invention. [0043] The present invention also provides a process for the preparation of a compound of formula (I) or a pharmaceutically acceptable salt thereof, which process comprises: [0000] (a) reacting a compound of formula (II) [0000] [0000] wherein R 2 , n and R 3 are as defined above and L 1 represents OH or a suitable leaving group, such as a halogen atom (e.g. chlorine), with a compound of formula (III) [0000] [0000] wherein R 1a is as defined above for R 1 or is a group convertible to R 1 ; or (b) reacting a compound of formula (IV) [0000] [0000] with a compound of formula R 3 -L 2 , wherein R 1a , R 2 , R 3 and n are as defined above, L 2 represents a suitable leaving group such as a halogen atom and Z represents a boronic acid ester group attached at the 3 or 4 position of the phenyl ring, such as a pinacol ester e.g. a group of formula Z a : [0000] [0000] (c) deprotecting a compound of formula (I) which is protected; and optionally thereafter (d) interconversion to other compounds of formula (I). [0044] Process (a) typically comprises activation of the compound of formula (II) wherein L 1 represents OH with a coupling reagent such as 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) in the presence of 1-hydroxybenzotriazole (HOBT) in a suitable solvent such as dichloromethane followed by reaction with the compound of formula (III). [0045] Process (a) may also involve halogenation of the compound of formula (II) wherein L 1 represents OH with a suitable halogenating agent (e.g. thionyl chloride or oxalyl chloride) followed by reaction with the compound of formula (III) in the presence of a suitable base such as triethylamine or a solid supported base such as diethylaminomethylpolystyrene in a suitable solvent such as dichloromethane. [0046] Process (b) typically comprises the use of a catalyst such as tetrakis(triphenylphosphine)palladium(0) in a solvent such as acetonitrile with a base e.g. sodium carbonate. [0047] In process (c), examples of protecting groups and the means for their removal can be found in T. W. Greene ‘Protective Groups in Organic Synthesis’ (J. Wiley and Sons, 1991). Suitable amine protecting groups include sulphonyl (e.g. tosyl), acyl (e.g. acetyl, 2′,2′,2′-trichloroethoxycarbonyl, benzyloxycarbonyl or t-butoxycarbonyl) and arylalkyl (e.g. benzyl), which may be removed by hydrolysis (e.g. using an acid such as hydrochloric acid) or reductively (e.g. hydrogenolysis of a benzyl group or reductive removal of a 2′,2′,2′-trichloroethoxycarbonyl group using zinc in acetic acid) as appropriate. Other suitable amine protecting groups include trifluoroacetyl (—COCF 3 ) which may be removed by base catalysed hydrolysis or a solid phase resin bound benzyl group, such as a Merrifield resin bound 2,6-dimethoxybenzyl group (Ellman linker), which may be removed by acid catalysed hydrolysis, for example with trifluoroacetic acid. [0048] Process (d) may be performed using conventional interconversion procedures such as epimerisation, oxidation, reduction, alkylation, nucleophilic or electrophilic aromatic substitution, ester hydrolysis or amide bond formation. [0049] Compounds of formula (II) and (III) are either known in the literature or can be prepared by analogous methods. [0050] Compounds of formula (IV) may be prepared by reacting a compound of formula (V) [0000] [0000] wherein R 2 , n and Z are as defined above, with a compound of formula (III) as defined above. This process typically comprises activation of the compound of formula (V) with a coupling reagent such as 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) in the presence of 1-hydroxybenzotriazole (HOBT) in a suitable solvent such as DMF. [0051] Compounds of formula (V) are either known in the literature or can be prepared by analogous methods. [0052] Compounds of formula (I) and their pharmaceutically acceptable salts have affinity for and are antagonists and/or inverse agonists of the histamine H3 receptor and are believed to be of potential use in the treatment of neurological diseases including Alzheimer's disease, dementia (including Lewy body dementia and vascular dementia), age-related memory dysfunction, mild cognitive impairment, cognitive deficit, epilepsy, neuropathic pain, inflammatory pain, migraine, Parkinson's disease, multiple sclerosis, stroke and sleep disorders (including narcolepsy and sleep deficits associated with Parkinson's disease); psychiatric disorders including schizophrenia (particularly cognitive deficit of schizophrenia), attention deficit hypereactivity disorder, depression, anxiety and addiction; and other diseases including obesity and gastro-intestinal disorders. [0053] It will be appreciated that certain compounds of formula (I) believed to be of potential use in the treatment of Alzheimer's disease and cognitive deficit of schizophrenia will advantageously be CNS penetrant, e.g. have the potential to cross the blood-brain barrier. [0054] It will also be appreciated that compounds of formula (I) are expected to be selective for the histamine H3 receptor over other histamine receptor subtypes, such as the histamine H1 receptor. Generally, compounds of the invention may be at least 10 fold selective for H3 over H1, such as at least 100 fold selective. [0055] Thus the invention also provides a compound of formula (I) or a pharmaceutically acceptable salt thereof, for use as a therapeutic substance in the treatment or prophylaxis of the above disorders, in particular cognitive impairments in diseases such as Alzheimer's disease and related neurodegenerative disorders. [0056] The invention further provides a method of treatment or prophylaxis of the above disorders, in mammals including humans, which comprises administering to the sufferer a therapeutically effective amount of a compound of formula (I) or a pharmaceutically acceptable salt thereof. [0057] In another aspect, the invention provides the use of a compound of formula (I) or a pharmaceutically acceptable salt thereof in the manufacture of a medicament for use in the treatment of the above disorders. [0058] When used in therapy, the compounds of formula (I) are usually formulated in a standard pharmaceutical composition. Such compositions can be prepared using standard procedures. [0059] Thus, the present invention further provides a pharmaceutical composition for use in the treatment of the above disorders which comprises the compound of formula (I) or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable carrier. [0060] The present invention further provides a pharmaceutical composition which comprises the compound of formula (I) or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable carrier. [0061] Compounds of formula (I) may be used in combination with other therapeutic agents, for example medicaments claimed to be useful as either disease modifying or symptomatic treatments of Alzheimer's disease. Suitable examples of such other therapeutic agents may be agents known to modify cholinergic transmission such as 5-HT 6 antagonists, M1 muscarinic agonists, M2 muscarinic antagonists or acetylcholinesterase inhibitors. When the compounds are used in combination with other therapeutic agents, the compounds may be administered either sequentially or simultaneously by any convenient route. [0062] The invention thus provides, in a further aspect, a combination comprising a compound of formula (I) or a pharmaceutically acceptable derivative thereof together with a further therapeutic agent or agents. [0063] The combinations referred to above may conveniently be presented for use in the form of a pharmaceutical formulation and thus pharmaceutical formulations comprising a combination as defined above together with a pharmaceutically acceptable carrier or excipient comprise a further aspect of the invention. The individual components of such combinations may be administered either sequentially or simultaneously in separate or combined pharmaceutical formulations. [0064] When a compound of formula (I) or a pharmaceutically acceptable derivative thereof is used in combination with a second therapeutic agent active against the same disease state the dose of each compound may differ from that when the compound is used alone. Appropriate doses will be readily appreciated by those skilled in the art. [0065] A pharmaceutical composition of the invention, which may be prepared by admixture, suitably at ambient temperature and atmospheric pressure, is usually adapted for oral, parenteral or rectal administration and, as such, may be in the form of tablets, capsules, oral liquid preparations, powders, granules, lozenges, reconstitutable powders, injectable or infusible solutions or suspensions or suppositories. Orally administrable compositions are generally preferred. [0066] Tablets and capsules for oral administration may be in unit dose form, and may contain conventional excipients, such as binding agents, fillers, tabletting lubricants, disintegrants and acceptable wetting agents. The tablets may be coated according to methods well known in normal pharmaceutical practice. [0067] Oral liquid preparations may be in the form of, for example, aqueous or oily suspension, solutions, emulsions, syrups or elixirs, or may be in the form of a dry product for reconstitution with water or other suitable vehicle before use. Such liquid preparations may contain conventional additives such as suspending agents, emulsifying agents, non-aqueous vehicles (which may include edible oils), preservatives, and, if desired, conventional flavourings or colorants. [0068] For parenteral administration, fluid unit dosage forms are prepared utilising a compound of the invention or pharmaceutically acceptable salt thereof and a sterile vehicle. The compound, depending on the vehicle and concentration used, can be either suspended or dissolved in the vehicle. In preparing solutions, the compound can be dissolved for injection and filter sterilised before filling into a suitable vial or ampoule and sealing. Advantageously, adjuvants such as a local anaesthetic, preservatives and buffering agents are dissolved in the vehicle. To enhance the stability, the composition can be frozen after filling into the vial and the water removed under vacuum. Parenteral suspensions are prepared in substantially the same manner, except that the compound is suspended in the vehicle instead of being dissolved, and sterilisation cannot be accomplished by filtration. The compound can be sterilised by exposure to ethylene oxide before suspension in a sterile vehicle. Advantageously, a surfactant or wetting agent is included in the composition to facilitate uniform distribution of the compound. [0069] The composition may contain from 0.1% to 99% by weight, preferably from 10 to 60% by weight, of the active material, depending on the method of administration. The dose of the compound used in the treatment of the aforementioned disorders will vary in the usual way with the seriousness of the disorders, the weight of the sufferer, and other similar factors. However, as a general guide suitable unit doses may be 0.05 to 1000 mg, more suitably 1.0 to 200 mg, and such unit doses may be administered more than once a day, for example two or three a day. Such therapy may extend for a number of weeks or months. [0070] The following Descriptions and Examples illustrate the preparation of compounds of the invention. [0071] It will be appreciated that hydrochloride salt compounds may be converted into the corresponding free base compounds by treatment with saturated aqueous potassium carbonate solution followed by extraction into a suitable solvent such as diethyl ether or DCM. Description 1 (Method A) 1-tert-Butyl-4-(isopropyl)-hexahydro-1H-1,4-diazepine-1-carboxylate (D1) [0072] tert-Butyl-hexahydro-1H-1,4-diazepine-1-carboxylate (10.0 g) was dissolved in DCM (200 ml). Acetone (7.33 ml) was added and the reaction was left to stir for 5 min. Sodium triacetoxyborohydride (21.0 g) was then added and the reaction was stirred at rt for 16 h. The reaction mixture was washed with saturated potassium carbonate solution (2×200 ml). The organic layer was dried (magnesium sulphate) and evaporated to give the title compound (D1) as a clear oil (11.0 g). Description 1 (Method B) 1-tert-Butyl-4-(isopropyl)-hexahydro-1H-1,4-diazepine-1-carboxylate (D1) [0073] tert-Butyl-hexahydro-1H-1,4-diazepine-1-carboxylate (25.06 g) was dissolved in acetonitrile (250 ml). Anhydrous potassium carbonate (34.5 g) and 2-iodopropane (63 g, 37 ml) were added and the mixture was heated at reflux for 18 h. The cooled mixture was filtered and the solids were washed with acetonitrile. The combined filtrates were evaporated and the residual oil was dissolved in diethyl ether, washed with water, sodium thiosulphate solution and brine, dried (Na 2 SO 4 ) and evaporated to give the title compound (D1) as a light brown oil (29.8 g). Description 2 1-(Isopropyl)-hexahydro-1H-1,4-diazepine dihydrochloride (D2) [0074] 1-tert-Butyl-4-(isopropyl)-hexahydro-1H-1,4-diazepine-1-carboxylate (D1) (11.0 g) was dissolved in methanol (200 ml) and 4N HCl in dioxan (100 ml) was added. The reaction was stirred at rt for 2 h and then evaporated to give the title compound (D2) as a white solid (9.6 g). 1 H NMR δ (CDCl 3 ): 11.35 (1H, s), 10.22 (1H, s), 9.72 (1H, s), 4.15-3.52 (9H, m), 2.83-2.40 (2H, m), 1.47 (6H, d, J=6.24 Hz). Description 3 1-tert-Butyl-4-(cyclobutyl)-hexahydro-1H-1,4-diazepine-1-carboxylate (D3) [0075] tert-Butyl-hexahydro-1H-1,4-diazepine-1-carboxylate (10.0 g) was dissolved in DCM (300 ml). Cyclobutanone (7.5 ml) was added and the reaction was left to stir for 5 min. Sodium triacetoxyborohydride (21.1 g) was then added and the reaction was stirred at rt for 16 h. The reaction mixture was washed with saturated potassium carbonate solution (2×200 ml). The organic layer was dried (magnesium sulphate) and evaporated to give the title compound (D3) as a clear oil (11.3 g). Description 4 1-(Cyclobutyl)hexahydro-1H-1,4-diazepine dihydrochloride (D4) [0076] 1-tert-Butyl-4-(cyclobutyl)-hexahydro-1H-1,4-diazepine-1-carboxylate (D3) (11.3 g) was dissolved in methanol (200 ml) and 4N HCl in dioxan (100 ml) was added. The reaction was stirred at rt for 3 h and then co-evaporated from toluene (3×50 ml) to give the title compound (D4) as a white solid (9.8 g). 1 H NMR δ (DMSO-d6): 11.95 (1H, s), 9.55 (1H, s), 9.64 (1H, s), 3.78-3.08 (9H, m), 2.51-2.07 (6H, m), 1.80-1.51 (2H, m). Description 5 Ethyl 4-(tetrahydro-2H-pyran-4-yloxy)benzoate (D5) [0077] An ice-cold solution of ethyl 4-hydroxybenzoate (0.82 g), 4-hydroxy-tetrahydro-2H-pyran (0.5 g) and triphenylphosphine in THF (50 ml) was treated dropwise with diisopropyl azodicarboxylate (1.69 ml). After 15 min the cooling bath was removed and the reaction stood overnight at rt. The mixture was evaporated, redissolved in toluene and successively washed with 2N sodium hydroxide (2×20 ml), water (2×20 ml) and brine (20 ml). After drying (magnesium sulfate) the solution was loaded directly on to a silica flash column (step gradient 10-30% EtOAc in light petroleum 40-60) to give the title compound (D5) (0.75 g). 1 H NMR δ (CDCl 3 ): 7.98 (2H, d, J=8.5 Hz), 6.91 (2H, d, J=8.5 Hz), 4.60 (1H, m), 4.35 (2H, q, J=9.8 Hz), 3.98 (2H, m), 3.57 (2H, m), 2.05 (2H, m), 1.80 (2H, m), 1.38 (3H, t, J=9.8 Hz). Description 6 4-(Tetrahydro-2H-pyran-4-yloxy)benzoic acid (D6) [0078] A solution of ethyl 4-(tetrahydro-2H-pyran-4-yloxy)benzoate (D5) (0.73 g) in EtOH (10 ml) was treated with 1M NaOH (5.84 ml) and the mixture stirred at 60° C. for 5 h. The solution was cooled to rt and the EtOH was evaporated. The aqueous was washed with DCM (2×10 ml) and acidified. The solid was filtered off, washed with water and dried to give the title compound (D6) (0.55 g). MS electrospray (−ion) 221 (M-H). 1 H NMR δ (DMSO-d6): 7.87 (2H, d, J=8.5 Hz), 7.05 (2H, d, J=8.5 Hz), 4.69 (1H, m), 3.85 (2H, m), 3.50 (2H, m), 1.98 (2H, m), 1.59 (2H, m). Description 7 1-Cyclobutyl-4-{[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]carbonyl}hexahydro-1H-1,4-diazepine (D7) [0079] 4-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)benzoic acid (1.24 g) in dry DMF (30 ml) was treated with EDC (1.48 g) and HOBT (0.67 g). The reaction mixture was stirred at rt for 5 min, followed by the addition of 1-(cyclobutyl)hexahydro-1H-1,4-diazepine dihydrochloride (D4) (1.13 g) and triethylamine (2.7 ml). The mixture was stirred at rt overnight. The reaction mixture was then poured into water (250 ml) and extracted with EtOAc (2×35 ml). The combined organic layers were washed with saturated aqueous sodium hydrogen carbonate (2×30 ml) followed by water (5×30 ml). After drying (magnesium sulphate) the solution was evaporated to give the title compound (D7) as an oil (0.84 g). MS electrospray (+ve ion) 385 (MH + ). Description 8 Methyl 4-(6-cyano-3-pyridinyl)benzoate (D8) [0080] 4-Methoxycarbonylphenyl boronic acid (0.5 g) and 5-bromo-2-pyridinecarbonitrile (0.5 g) in a mixture of THF (5 ml) and water (5 ml) were treated with tetrakis(triphenyl phosphine)palladium(0) (0.32 g) and potassium carbonate (1 g). A further amount of THF (5 ml) was added and the reaction was heated at 80° C. for 1 h. After cooling the reaction mixture was diluted with EtOAc (30 ml) and washed with saturated aqueous sodium hydrogen carbonate solution. The organic layer was dried (magnesium sulfate) and concentrated to give a crude residue that was purified by column chromatography (silica-gel, gradient 0-100% EtOAc in hexane) to give the title compound (D8) as a white solid (0.5 g). LCMS electrospray (+ve) 239 (MH + ). Description 9 4-(6-Cyano-3-pyridinyl)benzoic acid (D9) [0081] Methyl 4-(6-cyano-3-pyridinyl)benzoate (D8) (0.5 g) in dioxane (30 ml) was treated with 1.1 eq aqueous LiOH solution (2.3 ml, 1N) and stirred at rt for 2 days. Solvent was removed by evaporation to give a white solid which was dissolved in water (10 ml) and acidified with 2N HCl to give a white solid which was filtered and dried to give the title compound (D9) (0.35 g). LCMS electrospray (+ve) 224 (MH + ). Description 10 5-Bromo-2-pyridinecarboxylic acid (D10) [0082] 4-Bromobenzonitrile (4.45 g) was heated at reflux in concentrated hydrochloric acid (60 ml) for 3 h. After cooling, white crystals were filtered off and dried in a vacuum oven to give the title compound (D10) (3.46 g). LCMS electrospray (+ve) 203 (MH + ). Description 11 5-Bromo-N-methyl-2-pyridinecarboxamide (D11) [0083] 5-Bromo-2-pyridinecarboxylic acid (D10) (1 g) was dissolved in dry DMF (50 ml) and treated with methylamine hydrochloride (0.42 g), EDC (1.2 g), HOBT (0.56 g) and Et 3 N (2.4 ml). The reaction was stirred at rt overnight then poured into water (200 ml) and extracted with DCM (50 ml). The organic extract was washed with brine (5×50 ml), dried (magnesium sulfate) and evaporated to give the title compound (D11) as a yellow crystalline solid (0.45 g). LCMS electrospray (+ve) 349 (MH + ). Description 12 1-(Isopropyl)-4-{[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]carbonyl}hexahydro-1H-1,4-diazepine (D12) [0084] The tile compound (D12) was prepared in a similar manner to Description 7 from 1-(isopropyl)-hexahydro-1H-1,4-diazepine (free base of D2) and 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzoic acid and isolated as a brown oil. LCMS electrospray (+ve) 373 (MH + ). Description 13 5-Bromo-2-trifluoromethylpyrimidine (D13) [0085] A mixture of potassium fluoride (1.77 g) and cuprous iodide (5.79 g) was stirred and heated together using a heat gun under vacuum (˜1 mm) for 20 min. After cooling, dimethyl formamide (20 ml) and N-methylpyrrolidinone (20 ml) were added followed by (trifluoromethyl)trimethylsilane (4.1 ml) and 5-bromo-2-iodopyrimidine (6.5 g). The mixture was stirred at rt for 5 h and then the brown solution was poured into 6N ammonia solution. The product was extracted into ethyl acetate and the extracts were washed with sodium bicarbonate solution and brine and then dried (Na 2 SO 4 ) and evaporated. Chromatography on silica gel (elution with 20-50% dichloromethane in pentane) gave the title compound (D13) as a white solid (2.4 g). 1 H NMR (CDCl 3 ): 8.97 (2H, s). Description 14 4-(4-Bromophenyl)-2-methyl-oxazole (D14) [0086] 4-Bromophenacyl bromide (21.3 g) and acetamide (11.3 g) were heated together at 130° C. under argon. After 2.5 h the reaction mixture was allowed to cool, and partitioned between water (150 ml) and Et 2 O (150 ml). The organic phase was washed with aqueous NaOH (0.5N), aqueous HCl (0.5M) and saturated aqueous NaCl solution (100 ml of each), dried (MgSO 4 ) and evaporated to give a brown solid which was recrystallised from hexanes to give the title compound (D14) as an orange solid (4.1 g). LCMS electrospray (+ve) 239 (MH + ). Description 15 5-(4-Bromophenyl)-2-methyl-oxazole (D15) [0087] Trifluoromethanesulfonic acid (6.6 ml) was added to a flask containing iodobenzene diacetate (12.2 g) and MeCN (200 ml) at rt. After 25 min. a solution of 4′-bromoacetophenone (5 g) in MeCN (50 ml) was added and the resultant mixture heated at reflux for 6 h. The reaction was allowed to cool to rt before the solvent was evaporated and the residue partitioned between saturated aqueous Na 2 CO 3 (150 ml) and EtOAc (150 ml). The organic phase was washed with saturated brine (150 ml), dried (MgSO 4 ) and evaporated to give an orange solid. The crude product was purified by column chromatography (silica gel, 50% EtOAc in hexane) to give the title compound (D15) as a pale yellow solid (3.5 g). LCMS electrospray (+ve) 239 (MH + ). Description 16 3-(4-Bromophenyl)-5-methyl-1,2,4-oxadiazole (D16) Step 1: 4-Bromo-N-hydroxy-benzenecarboximidamide [0088] 4-Bromophenylcarbonitrile (10.2 g), hydroxylamine hydrochloride (7.8 g) and Et 3 N (11.3 g) were dissolved in EtOH (250 ml) and the reaction mixture was heated at reflux for 3 h, after which it was evaporated to form a white precipitate of the desired amidoxime, which was filtered off and washed with water (25 ml). The filtrate was extracted into EtOAc (2×25 ml), and the combined organic extracts were dried (Na 2 SO 4 ) and evaporated to give a second crop of the subtitle compound (combined yield=11.1 g). LCMS electrospray (+ve) 216 (MH + ). Step 2: 3-(4-Bromophenyl)-5-methyl-1,2,4-oxadiazole [0089] The product from D16, step 1 was suspended in acetic anhydride and heated to 100° C. for 4 h, then 120° C. for 3 h. After cooling the reaction mixture was evaporated to give a brown solid. This was partitioned between saturated aqueous NaHCO 3 and EtOAc. The organic phase was washed with saturated aqueous NaCl, dried (Na 2 SO 4 ) and evaporated to give a yellow solid. The crude product was purified by column chromatography (silica gel, 10-100% gradient of EtOAc in hexane) to give the title compound (D16) as a white solid (6.2 g). LCMS electrospray (+ve) 240 (MH + ). Description 17 2-(4-Bromophenyl)-oxazole (D17) Step 1: 4-Bromo-N-(2,2-dimethoxyethyl)-benzamide [0090] Potassium carbonate (8.0 g) was added to a solution of 2,2-dimethoxyethylamine in water (90 ml) and acetone (40 ml) at rt. The reaction mixture was cooled in an ice-water bath and 4-bromobenzoyl chloride (16.4 g) dissolved in acetone (70 ml) was added drop-wise over 90 min. The stirred reaction mixture was allowed to warm to rt. After a further 2 h the reaction mixture was extracted into EtOAc (3×75 ml), the combined organics were washed with saturated aqueous sodium hydrogen carbonate, dried (MgSO 4 ) and evaporated to give the amide as an off white solid (18.5 g). LCMS electrospray (+ve) 289 (MH + ). Step 2: 2-(4-Bromophenyl)-oxazole [0091] The product of D17, step 1 was suspended in Eaton's reagent (200 ml), the reaction mixture was purged with argon and heated to 240° C. for 9 h. The reaction mixture was then allowed to cool and stirred for 65 h at rt. The crude mixture was poured over ice (1 L) and stirred for 1 h. The aqueous mixture was extracted into EtOAc (2×250 ml), dried (MgSO 4 ) and evaporated to give a grey powder. This crude solid was dissolved in THF (300 ml) and EtOH (300 ml), and Hunig's base (21.1 ml) was added. MP-carbonate resin (40.1 g) and PS-thiophenol resin (69.7 g) were suspended in the reaction mixture, which was stirred for 24 h. The suspension was filtered and the solid phase resins washed with 1:1 THF:EtOH (3×600 ml), and the combined organics evaporated to give the title compound (D17) as a white solid (9.0 g). LCMS electrospray (+ve) 225 (MH + ). Description 18 4-(3-Methyl-1,2,4-oxadiazol-5-yl)benzoic acid (D18) [0092] Methyl 4-(3-methyl-1,2,4-oxadiazol-5-yl)benzoate (J. R. Young and R. J. DeVita, Tetrahedron Lett., 1998, 39, 3931) was dissolved in a mixture of dioxan (110 ml), water (70 ml) and isopropanol (30 ml), and lithium hydroxide (1.38 g) was added. The mixture was stirred at room temperature for ca 5 h and then the mixture was acidified to ca pH 4 by addition of Amberlyst 15 H + resin. The resin was removed by filtration and the filtrate was concentrated in vacuo. The solid white precipitate which was obtained was collected by filtration, washed with water on the filter and dried in vacuo at 40° C. for 48 h to give the title compound (D18) (4.23 g). Example 1 4′-[(4-Cyclobutylhexahydro-1H-1,4-diazepin-1-yl)carbonyl]-4-biphenylcarbonitrile hydrochloride (E1) [0093] [0094] 1-(Cyclobutyl)-hexahydro-1H-1,4-diazepine dihydrochloride (D4) (0.15 g) was stirred with diethylaminomethyl polystyrene (1.0 g), HOBT (0.045 g), 4′-cyano-4-biphenylcarboxylic acid (0.16 g) in DCM (5 ml). EDC (0.16 g) was then added and the reaction was stirred at rt for 16 h. The polymer supported base was filtered off and the filtrate was diluted with DCM (10 ml) and washed with saturated sodium hydrogen carbonate (2×15 ml). The organic layer was then loaded directly onto a silica column eluting with 0-10% MeOH (containing 10% 0.880 ammonia solution)/DCM. The isolated free base product was dissolved in DCM (5 ml) and treated with excess 1N HCl/diethyl ether solution (1 ml) and stirred for 10 min. [0095] The mixture was evaporated (co-evaporated with acetone 2×10 ml), triturated with acetone, then dried at 50° C. under high vacuum for 16 h to yield the title compound (E1) as a pale solid (0.119 g). MS electrospray (+ion) 360 (MH + ). 1 H NMR δ (DMSO-d6): 10.60 (1H, s), 7.97 (4H, m), 7.86 (2H, d, J=8.4 Hz), 7.60 (2H, d, J=7.6 Hz), 4.18 (1H, m), 3.89-3.37 (6H, m), 3.10 (2H, m), 2.40-1.59 (8H, m). Example 2 1-{4′-[(4-Cyclobutylhexahydro-1H-1,4-diazepin-1-yl)carbonyl]-4-biphenylyl}ethanone hydrochloride (E2) [0096] [0097] 1-(Cyclobutyl)-hexahydro-1H-1,4-diazepine dihydrochloride (D4) (0.15 g) was stirred with diethylaminomethyl polystyrene (1.0 g), HOBT (0.045 g) and 4′-acetyl-4-biphenylcarboxylic acid (0.13 g) in DCM (5 ml). EDC (0.16 g) was then added and the reaction stirred at rt for 16 h. The polymer supported base was filtered off and the filtrate was diluted with DCM (10 ml) and washed with saturated sodium hydrogen carbonate (2×15 ml). The organic layer was loaded directly onto a silica column eluting with 0-10% MeOH (containing 10% 0.880 ammonia solution)/DCM. The isolated free base product was dissolved in DCM (5 ml) and treated with excess 1N HCl/diethyl ether solution (1 ml) and stirred for 10 min. The mixture was evaporated (co-evaporated with acetone 2×10 ml), triturated with acetone, then dried at 50° C. under high vacuum for 16 h to yield the title compound (E2) as a pale solid (0.055 g). MS electrospray (+ion) 377 (MH + ). 1 H NMR δ (DMSO-d6): 10.57 (1H, s), 9.07 (2H, d, J=6.4 Hz), 7.88 (4H, m), 7.60 (2H, d, J=7.6 Hz), 4.15 (1H, m), 3.82-3.33 (6H, m), 3.02 (2H, m), 2.62 (3H, s), 2.41-1.62 (8H, m). Examples 3-6 (E3-E6) [0098] Examples 3-6 were prepared from 1-(cyclobutyl)-hexahydro-1H-1,4-diazepine dihydrochloride (D4) and the appropriate carboxylic acid, using the procedure described in Example 1 and displayed 1 H NMR and mass spectral data that were consistent with structure. [0000] Mass Example Spectrum No R (ES + ) E3 [MH] + 335 E4 [MH] + 363 E5 [MH] + 351 E6 [MH] + 365 Example 7 1-Cyclobutyl-4-{[4-tetrazol-1-yl)phenyl]carbonyl}hexahydro-1H-1,4-diazepine hydrochloride (E7) [0099] [0100] 1-(Cyclobutyl)-hexahydro-1H-1,4-diazepine dihydrochloride (D4) (0.15 g) was stirred with diethylaminomethyl polystyrene (1.0 g), HOBT (0.045 g) and 4-(tetrazol-1-yl)-benzoic acid (0.14 g) in DCM (5 ml). EDC (0.165 g) was then added and the reaction was stirred at rt for 16 h. The polymer supported base was filtered off and the filtrate was diluted with DCM (10 ml) and washed with saturated sodium hydrogen carbonate (2×15 ml). The organic layer was then loaded directly onto a silica column eluting with 0-10% MeOH (containing 10% 0.880 ammonia solution)/DCM. The isolated free base product was dissolved in DCM (5 ml) and treated with excess 1N HCl/diethyl ether solution (1 ml) and stirred for 10 min. The mixture was evaporated (co-evaporated with acetone 2×10 ml), triturated with acetone, then dried at 50° C. under high vacuum for 16 h to yield the title compound (E7) as a pale solid (0.096 g). MS electrospray (+ion) 327 (MH + ). 1 H NMR δ (DMSO-d6): 11.11 (1H, s), 10.18 (1H, s), 8.02 (2H, d, J=8.4 Hz), 7.76 (2H, d, J=8.0 Hz), 4.17 (1H, m), 3.81-3.27 (6H, m), 3.11 (2H, m), 2.47-1.95 (6H, m), 1.80-1.59 (2H, m). Example 8 1-Cyclobutyl-4-({4-[4-(4-fluorophenyl)-1,3-thiazol-2-yl]phenyl}carbonyl) hexahydro-1H-1,4-diazepine hydrochloride (E8) [0101] [0102] The title compound (E8) was prepared from 1-(cyclobutyl)-hexahydro-1H-1,4-diazepine dihydrochloride (D4) and 4-[4-(4-fluorophenyl)-1,3-thiazol-2-yl]benzoic acid using the procedure described in Example 7. MS APCI-436 (MH + ). Example 9 1-Cyclobutyl-4-{[4-(1,1-dioxido-4-thiomorpholinyl)phenyl]carbonyl}hexahydro-1H-1,4-diazepine hydrochloride (E9) [0103] [0104] 1-(Cyclobutyl)-hexahydro-1H-1,4-diazepine dihydrochloride (D4) (0.15 g) was stirred with diethylaminomethyl polystyrene (1.0 g), HOBT (0.045 g), 4-(1,1-dioxido-4-thiomorpholinyl)benzoic acid (0.186 g) in DCM (5 ml). EDC (0.165 g) was then added and the reaction was stirred at rt for 16 h. The polymer supported base was filtered off and the filtrate was diluted with DCM (10 ml) and washed with saturated sodium hydrogen carbonate (2×15 ml). The organic layer was then loaded directly onto a silica column and eluted with 0-10% MeOH (containing 10% 0.880 ammonia solution)/DCM. The isolated free base product was dissolved in DCM (5 ml) and treated with excess 1N HCl/diethyl ether solution (1 ml) and stirred for 10 min. The mixture was evaporated (co-evaporated with acetone 2×10 ml), triturated with acetone, then dried at 50° C. under high vacuum for 16 h to yield the title compound (E9) as a pale solid (0.086 g). MS electrospray (+ion) 392 (MH + ). 1 H NMR δ (DMSO-d6): 10.5 (1H, s), 7.37 (2H, d, J=8.4 Hz), 7.07 (2H, d, J=8.8 Hz), 4.18-3.24 (10H, m), 3.11 (4H, m), 3.10-2.85 (2H, m), 2.45-1.98 (7H, m), 1.80-2.54 (2H, m). Example 10 1-(Isopropyl)-4-{[4-(tetrahydro-2H-pyran-4-yloxy)phenyl]carbonyl}hexahydro-1H-1,4-diazepine hydrochloride (E10) [0105] [0106] A stirred suspension of 4-(tetrahydro-2H-pyran-4-yloxy)benzoic acid (D6) (222 mg) in DCM (5 ml) at rt was treated with oxalyl chloride (0.28 ml) and 10% DMF in DCM (1 drop). After 1 h the solution was evaporated and then re-evaporated from DCM (2×5 ml). The acid chloride was redissolved in DCM (10 ml) and treated with 1-(isopropyl)-hexahydro-1H-1,4-diazepine dihydrochloride (D2) (178 mg) and diethylaminomethyl polystyrene (3.2 mmol/g, 938 mg). After stirring overnight the mixture was loaded directly on to a silica gel flash column [step gradient 6-10% MeOH (containing 10% 0.880 ammonia solution) in DCM]. Fractions containing the required product were evaporated, then redissolved in DCM and treated with excess 4M HCl in dioxan. Crystallisation from acetone afforded the title compound (E10) (225 mg). MS electrospray (+ion) 347 (MH + ). 1 H NMR δ (DMSO-d6): 10.45 (1H, m), 7.41 (2H, d, J=8.5 Hz), 7.02 (2H, d, J=8.5 Hz), 4.63 (2H, m), 4.02 (1H, m), 3.02-3.93 (13H, m), 2.32 (1H, m), 1.96 (2H, m), 1.61 (2H, m), 1.27 (6H, d, J=6.5 Hz). Example 11 1-Cyclobutyl-4-({4-[6-(trifluoromethyl)-3-pyridinyl]phenyl}carbonyl)hexahydro-1H-1,4-diazepine hydrochloride (E11) [0107] [0108] A mixture of 1-cyclobutyl-4-{[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]carbonyl}hexahydro-1H-1,4-diazepine (D7) (0.28 g) and 5-bromo-2-(trifluoromethyl)pyridine (F. Cottet and M. Schlosser, Eur. J. Org. Chem., 2002, 327) in dry and degassed acetonitrile (3.5 ml) was treated with tetrakis(triphenyl phosphine)palladium(0) (0.050 g), and 2M aqueous Na 2 CO 3 solution (0.6 ml). The reaction mixture was heated at 140° C. for 5 min in an Emrys Optimiser microwave reactor. The crude reaction mixture was then diluted with MeOH (10 ml) and the solution was poured directly onto an SCX column (10 g) and washed first with MeOH (60 ml) and then eluted with 2M ammonia in MeOH solution (60 ml). The ammonia/methanol fractions were concentrated and further purified on a Waters mass directed preparative HPLC. The required fractions were concentrated and the residual gum was redissolved in MeOH (1 ml) and treated with ethereal HCl (1 ml, 1N). After evaporation of solvent the residue was triturated with diethyl ether to give the title hydrochloride salt (E11) as a white solid (0.088 g). 1 H NMR δ (methanol-d4): 1.76-1.89 (2H, m), 2.18-2.38 (6H, m), 3.09-3.18 (2H, m), 3.47-3.9 (6H, m), 4.31-4.35 (1H, m), 7.64 (2H, d, J=8 Hz), 7.88 (1H, d, J=8 Hz), 7.92 (2H, d, J=8 Hz), 8.33 (1H, d, J=8 Hz), 9.02 (1H, s). LCMS electrospray (+ve) 404 (MH + ). Example 12 6-{4-[(4-Cyclobutylhexahydro-1H-1,4-diazepin-1-yl)carbonyl]phenyl}-3-cyanopyridine hydrochloride (E12) [0109] [0110] The title compound (E12) was prepared in a similar manner to Example 11 from 1-cyclobutyl-4-{[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]carbonyl}hexahydro-1H-1,4-diazepine (D7) (0.15 g) and 6-chloronicotinonitrile (0.054 g). The crude reaction mixture was purified by flash chromatography [silica gel, step gradient 0-15% MeOH (containing 10% 0.88 ammonia solution) in DOM]. The free base compound was converted into the HCl salt in dry DCM (2 ml) with ethereal HCl (1 ml, 1N). Evaporation of solvent afforded the title compound (E12) as a white solid (0.046 g). 1 H NMR δ (methanol-d4): 1.78-1.90 (2H, m), 2.1-2.4 (6H, m), 3.03-3.2 (2H, m), 3.5-3.9 (6H, m), 4.28-4.35 (1H, m), 7.65 (2H, d, J=8 Hz), 8.13 (1H, d, J=8 Hz), 8.23-8.26 (3H, m), 8.99 (1H, d, J=2.4 Hz). LCMS electrospray (+ve) 361 (MH + ). Example 13 5-{4-[(4-Cyclobutylhexahydro-1H-1,4-diazepin-1-yl)carbonyl]phenyl}-N-methyl-2-pyridinecarboxamide hydrochloride (E13) [0111] [0112] The title compound (E13) was prepared in a similar manner to Example 11 from 1-cyclobutyl-4-{[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]carbonyl}hexahydro-1H-1,4-diazepine (D7) (0.22 g) and 5-bromo-N-methyl-2-pyridinecarboxamide (D11) (0.11 g). The crude mixture after SCX work-up was purified on a Waters mass directed preparative HPLC. Pure fractions were concentrated, redissolved in dry DCM (2 ml) and treated with 1N ethereal HCl. After evaporation of solvents the title compound (E13) was obtained as a white solid (0.062 g). 1 H NMR δ (methanol-d4): 1.77-2.00 (2H, m), 2.15-2.45 (6H, m), 3.0 (3H, s), 3.07-3.25 (2H, m), 3.45-3.85 (6H, m), 4.28-4.39 (1H, m), 7.67-7.69 (2H, d, J=8 Hz), 7.90-7.88 (2H, d, J=8 Hz), 8.25 (1H, d, J=8 Hz), 8.42 (1H, d, J=8 Hz), 8.99 (1H, d, J=1.2 Hz). LCMS electrospray (+ve) 393 (MH + ). Example 14 5-{4-[(4-Cyclobutylhexahydro-1H-1,4-diazepin-1-yl)carbonyl]phenyl}-2-cyanopyridine hydrochloride (E14) [0113] [0114] The title compound (E14) was prepared in a similar manner to Example 11 from 5-bromo-2-cyanopyridine (0.043 g) and 1-cyclobutyl-4-{[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]carbonyl}hexahydro-1H-1,4-diazepine (D7) (0.1 g). 1 H NMR δ (methanol-d4): 1.8-1.9 (2H, m), 2.18-2.38 (6H, m), 3.05-3.20 (2H, m), 3.48-3.90 (6H, m), 4.28-4.38 (1H, m), 7.64 (2H, d, J=8.4 Hz), 7.83 (2H, d, J=8.4 Hz), 7.92 (1H, d, J=8 Hz), 8.24 (1H, dd, J=8 Hz), 9.04 (1H, d, J=1.6 Hz). [0115] LCMS electrospray (+ve) 361 (MH + ). Example 15 5-(4-{[4-(1-Isopropyl)hexahydro-1H-1,4-diazepin-1-yl]carbonyl}phenyl)-2-cyanopyridine hydrochloride (E15) [0116] [0117] 4-(6-Cyano-3-pyridinyl)benzoic acid (D9) (0.35 g) was dissolved in dry DMF and treated with EDC (0.51 g) and a catalytic quantity of HOAT. The reaction mixture was stirred at rt for 5 min, followed by the addition of 1-(isopropyl)-hexahydro-1H-1,4-diazepine dihydrochloride (D2) (0.28 g) and N,N-diisopropylethylamine (1 ml), and allowed to stir at rt overnight. After evaporation of solvent the residue was partitioned between DCM (15 ml) and water (15 ml). The DCM layer was dried (magnesium sulfate) and concentrated to leave a crude residue which was purified by flash chromatography [silica gel, step gradient 0-15% MeOH (containing 10% 0.88 ammonia solution) in DCM]. Pure fractions were combined and concentrated to give the free base which was converted into the HCl salt in DCM (2 ml) with 1N ethereal HCl (1 ml). Evaporation of the solvents afforded the title compound (E15) (8 mg). 1 H NMR δ (methanol-d4): 1.4 (6H, d, J=6.4 Hz), 2.16 (2H, bs), 3.47-4.2 (8H, m), 4.2-4.4 (1H, m), 7.68 (2H, d, J=8 Hz), 7.85 (2H, d, J=8 Hz), 7.98 (1H, d, J=8 Hz), 8.29 (1H, dd, J=8 Hz), 9.04 (1H, d, J=1.6 Hz). LCMS electrospray (+ve) 349 (MH + ). Example 16 N-Methyl-5-(4-{[4-(1-isopropyl)hexahydro-1H-1,4-diazepin-1-yl]carbonyl}phenyl)-2-pyridinecarboxamide hydrochloride (E16) [0118] [0119] The title compound (E16) was prepared in a similar manner to Example 11 from 1-(isopropyl)-4-{[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]carbonyl}hexahydro-1H-1,4-diazepine (D12) (0.15 g) and 5-bromo-N-methyl-2-pyridine carboxamide (D11) (0.086 g). After SCX work-up the product was purified using flash chromatography [silica gel, step gradient 0-15% MeOH (containing 10% 0.88 ammonia solution) in DCM]. The free base product was dissolved in dry DCM (2 ml) and treated with 1N ethereal HCl (1 ml). Evaporation of solvents afforded the title compound (E16) as a white solid (0.1 g). 1 H NMR δ (DMSO-d6): 1.25-1.30 (6H, m), 1.99-2.2 (1H, m), 2.27-2.45 (1H, m), 2.84-2.85 (3H, d, J=4.8 Hz), 3.2-4.18 (9H, m), 7.65 (2H, d, J=8 Hz), 7.90 (2H, d, J=8 Hz), 8.12 (1H, d, J=8 Hz), 8.32 (1H, dd, J=8 Hz), 8.82 (1H, q, J=4.8 Hz), 8.98 (1H, d, J=1.6 Hz). LCMS electrospray (+ve) 381 (MH + ). Examples 17-21 (E17-E21) [0120] Examples 17-21 were prepared in a similar manner to Example 11 from 1-(isopropyl)-4-{[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]carbonyl}hexahydro-1H-1,4-diazepine (D12) and the appropriate heteroaryl bromide or chloride. All compounds displayed 1 H NMR and mass spectral data that were consistent with structure. [0000] Example Mass No R Spectrum (ES + ) 17 (MH+) 393 18 (MH+) 393 19 (MH+) 392 20 (MH+) 395 21 (MH+) 349 Example 22 1-Cyclobutyl-4-({4-[6-(trifluoromethyl)-3-pyridazinyl]phenyl}carbonyl)hexahydro-1H-1,4-diazepine hydrochloride (E22) [0121] [0122] The title compound (E22) was prepared in a similar manner to Example 11 from 1-cyclobutyl-4-{[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]carbonyl}hexahydro-1H-1,4-diazepine (D7) and 3-chloro-6-(trifluoromethyl)pyridazine (Goodman, Stanforth and Tarbit, Tetrahedron, 1999, 55, 15067). The crude product after work-up was by purified by flash chromatography [silica gel, gradient 0-100% EtOAc-MeOH) and the free base was converted into the title hydrochloride salt (E22). 1 H NMR δ (methanol-d4): 1.8-1.95 (2H, m), 2.15-2.48 (6H, m), 3.07-3.25 (2H, m), 3.48-3.95 (6H, m), 4.3-4.5 (1H, m), 7.72 (2H, d, J=8 Hz), 8.21 (1H, d, J=8 Hz), 8.32 (2H, d, J=8 Hz), 8.45 (1H, d, J=8 Hz). Example 23 1-Cyclobutyl-4-({4-[2-(trifluoromethyl)-5-pyrimidinyl]phenyl}carbonyl)hexahydro-1H-1,4-diazepine hydrochloride (E23) [0123] [0124] The title compound (E23) was prepared in a similar manner to Example 11 from 1-cyclobutyl-4-{[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]carbonyl}hexahydro-1H-1,4-diazepine (D7) and 5-bromo-2-trifluoronnethylpyrimidine (D13). The crude product after work-up was by purified by flash chromatography [silica gel, gradient 0-100% EtOAc-MeOH] and the free base was converted into the title hydrochloride salt (E23). 1 H NMR δ (DMSO-d6): 1.6-1.75 (2H, m), 2.0-2.4 (6H, m), 2.97-3.05 (2H, m), 3.35-3.70 (6H, m), 4.14-4.19 (1H, m), 7.67 (2H, d, J=8 Hz), 8.0 (2H, d, J=8 Hz), 9.45 (2H, s), 10.8-11.0 (1H, bs). LCMS electrospray (+ye) 405 (MH + ). Example 24-28 (E24-E28) [0125] Examples 24-28 were prepared in a similar manner to Example 15 from either 1-(cyclobutyl)hexahydro-1H-1,4-diazepine dihydrochloride (D4) or 1-(isopropyl)hexahydro-1H-1,4-diazepine dihydrochloride (D2) and the appropriate benzoic acid. The free base products were converted into the corresponding hydrochloride salts with ethereal HCl. [0000] Ex- ample Mass No R R 1 Spectrum 24 [MH] + 378 (ES + ) 25 [MH] + 418 (ES + ) 26 [MH] + 434 (ES + ) 27 [MH] + 348 (APCI) 28 [MH] + 394 (ES + ) Example 29-43 (E29-E43) [0126] Examples 29-43 were prepared from either 1-(cyclobutyl)hexahydro-1H-1,4-diazepine dihydrochloride (D4) (0.1 g) or 1-(isopropyl)hexahydro-1H-1,4-diazepine dihydrochloride (D2) (0.1 g) in a 1:1 mixture of DCM/DMF (5 ml). To this solution diethylaminomethyl-polystyrene (3.2 mmole/g) (0.4 g, 3 eq) was added and stirred at rt for 10 min, followed by the addition of N-cyclohexylcarbodiimide-N-methylpolystyrene (200-400 mesh, 2.3 mmole/g) (0.2 g), catalytic HOBT and 1 equivalent of the appropriate benzoic acid. The reaction mixture was shaken at rt for 48 h. Tris-(2-aminoethyl)aminomethyl polystyrene (PS-Trisamine) (0.050 g) was added and the reaction mixture was shaken at rt for further 4 h. The resins were filtered off and the filtrate was evaporated to dryness. The crude residue was purified by flash chromatography [silica gel, step gradient 0-15% MeOH (containing 10% 0.88 ammonia solution) in DCM]. The free base compounds were converted into the HCl salts in dry DCM (2 ml) with ethereal HCl (1 ml, 1N). Compounds showed 1 H NMR and mass spectra that were consistent with structure. [0000] Example Mass No R R 1 Spectrum E29 [MH] + 353 (APCI) E30 [MH] + 353 (APCI) E31 [MH] + 336 (ES + ) E32 [MH] + 336 (ES + ) E33 [MH] + 376 (ES + ) E34 [MH] + 365 (APCI) E35 [MH] + 354 (APCI) E36 [MH] + 342 (APCI) E37 [MH] + 326 (ES + ) E38 [MH] + 355 (APCI) E39 [MH] + 324 (ES + ) E40 [MH] + 353 (APCI) E41 [MH] + 367 (APCI) E42 [MH] + 344 (ES + ) E43 [MH] + 332 (ES + ) Examples 44-51 (E44-E51) [0127] Examples 44-51 were prepared in a similar manner to Examples 29-43 from 1-(cyclobutyl)hexahydro-1H-1,4-diazepine dihydrochloride (D4) and the appropriate benzoic acid. [0000] Example Mass No R Spectrum E44 [MH] + 365 (APCI) E45 [MH] + 366 (APCI) E46 [MH] + 367 (APCI) E47 [MH] + 341 (APCI) E48 [MH] + 342 (APCI) E49 [MH] + 379 (ES + ) E50 [MH] + 379 (ES + ) E51 [MH] + 336 (ES + ) Examples 52-55 (E52-E55) [0128] Examples 52-55 were prepared in a similar manner to Example 11 from 1-cyclobutyl-4-{[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]carbonyl}hexahydro-1H-1,4-diazepine (D7) and the appropriate aryl bromides (e.g. D14-D16 for E53-E55, respectively), except that THF/H 2 O was used as solvent and potassium carbonate as base, and the reaction was heated at 80-85° C. for 1 h. Compounds showed 1 H NMR and mass spectra that were consistent with structure. [0000] Example Mass No R Spectrum E52 [MH] + 402 (ES + ) E53 [MH] + 416 (ES + ) E54 [MH] + 416 (ES + ) E55 [MH] + 417 (ES + ) Example 56 1-Cyclobutyl-4-{[4-(1,3-oxazol-2-yl)phenyl]carbonyl}hexahydro-1H-1,4-diazepine hydrochloride (E56) [0129] Step 1: 1,1-Dimethylethyl 4-{[4-(1,3-oxazol-2-yl)phenyl]carbonyl}hexahydro-1H-1,4-diazepine carboxylate [0130] A microwave vial was charged with 2-(4-bromophenyl)-oxazole (D17) (0.224 g), molybdenum hexacarbonyl (0.111 g), trans-Di-μ-acetatobis[2-(di-o-tolylphosphino)benzyl]palladium(II) (0.04 g), (±)-2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (0.08 g) and purged with argon. Diglyme (4 ml), toluene (2 ml) and 4M aqueous potassium carbonate (0.74 ml) were added, and the reaction mixture was degassed by argon saturation. tert-Butyl-hexahydro-1H-1,4-diazepine carboxylate (0.22 g) was added and the reaction vial was heated at 150° C. for 20 min in the microwave reactor. The reaction mixture was filtered, dried (Na 2 SO 4 ) and evaporated. Chromatography of the crude product (silica gel, eluting with EtOAc/hexanes, 50-100%) afforded the subtitle compound (0.141 g). Step 2: 4-{[4-(1,3-Oxazol-2-yl)phenyl]carbonyl}hexahydro-1H-1,4-diazepine [0131] The product from E56, Step 1 was dissolved in DCM (5 ml) and TFA (0.5 ml) was added. After 7 h saturated aqueous potassium carbonate (5 ml) was added and the aqueous phase extracted into DCM (3×10 ml). The combined organics were washed with brine (20 ml), dried (MgSO 4 ) and evaporated to give the subtitle compound as a yellow oil (0.064 g). Step 3: 1-Cyclobutyl-4-{[4-(1,3-oxazol-2-yl)phenyl]carbonyl}hexahydro-1H-1,4-diazepine hydrochloride [0132] Cyclobutanone (0.04 ml) was added to a solution of the product of E56 Step 2 (0.064 g) and triethylamine (0.12 ml) in DCM (2.5 ml). After 5 min sodium triacetoxyborohydride (0.111 g) was added and the reaction mixture was stirred for 16 h. Saturated aqueous sodium hydrogen carbonate (5 ml) was added and the aqueous phase extracted into DCM (10 ml). The organic phase was filtered through a PhaseSep® cartridge and evaporated. Chromatography of the crude mixture [silica gel, eluting with 2N NH 3 in MeOH/DCM, 0-15%] afforded the required amine free base, which was dissolved in DCM (2 ml) and treated with HCl (1 ml, 1M in diethyl ether). The precipitate was filtered and dried to give the title compound (E56) (0.07 g). MS electrospray (+ion) 326 (MH + ). Example 57 1-(1-Methylethyl)-4-{[4-(3-methyl-1,2,4-oxadiazol-5-yl)phenyl]carbonyl}hexahydro-1H-1,4-diazepine hydrochloride [0133] [0134] 4-(3-Methyl-1,2,4-oxadiazol-5-yl)benzoic acid (D18) (0.415 g), 1-(isopropyl)hexahydro-1H-1,4-diazepine (free base of D2) (0.294 g), EDC (0.425 g) and HOBT (0.282 g) were dissolved in DMF (10 ml) and stirred under argon. Hunig's base (1.43 ml) was added and the reaction mixture stirred for 15 h. The solvent was evaporated and the yellow residue partitioned between DCM (10 ml) and saturated sodium hydrogen carbonate (10 ml). The aqueous phase was extracted into DCM (2×10 ml), dried (MgSO 4 ) and evaporated to give the crude amide as a brown solid. Chromatography of the crude mixture [silica gel, eluting with MeOH/DCM, 0-20%] afforded the desired amine free base, which was dissolved in DCM (2 ml) and treated with HCl (1 ml, 1M in diethyl ether). The precipitate was filtered and dried to give the title compound (E57) (0.07 g). MS electrospray (+ion) 329 (MH + ). 1 H NMR δ (CDCl 3 , free base): 8.16 (2H, d, J=8.4 Hz), 7.56 (2H, d, J=8.4 Hz), 3.79-3.77 (2H, m), 3.44-3.40 (2H, m), 2.93 (1H, app pent, J=6.8 Hz), 2.82 (1H, app tr, J=5.2 Hz), 2.70 (1H, app tr, J=5.8 Hz), 2.65-2.59 (2H, m), 2.48 (3H, s), 1.96-1.90 (1H, m), 1.77-1.71 (1H, m), 1.04 (3H, d, J=6.4 Hz) and 0.99 (3H, d, J=6.4 Hz). Example 58 1-Cyclobutyl-4-{[4-(3-methyl-1,2,4-oxadiazol-5-yl)phenyl]carbonyl}hexahydro-4H-1,4-diazepine hydrochloride (E58) [0135] [0136] 4-(3-Methyl-1,2,4-oxadiazol-5-yl)benzoic acid (D18) (0.365 g), 1-(cyclobutyl)hexahydro-1H-1,4-diazepine (free base compound from D4) (0.28 g), EDC (0.374 g) and HOBT (0.248 g) were dissolved in DMF (10 ml) and stirred under argon. Hunig's base (1.26 ml) was added and the reaction mixture stirred for 15 h. The solvent was evaporated and the yellow residue partitioned between DCM (10 ml) and saturated sodium hydrogen carbonate (10 ml). The aqueous phase was extracted into DCM (2×10 ml), dried (MgSO 4 ) and evaporated to give the crude amide as a brown solid. Chromatography of the crude mixture [silica gel, eluting with MeOH/DCM, 0-20%] afforded the desired amine free base, which was dissolved in DCM (2 ml) and treated with HCl (1 ml, 1M in diethyl ether). The precipitate was filtered and dried to give the title compound (E58) (0.07 g). MS electrospray (+ion) 341 (MH + ). 1 H NMR δ (CDCl 3 , free base): 8.16 (2H, d, J=8.4 Hz), 7.55 (2H, d, J=8.4 Hz), 3.81-3.78 (2H, m), 3.48-3.42 (2H, m), 2.97-2.85 (1H, m), 2.65-2.63 (1H, m), 2.54-2.42 (3H, m), 2.50 (3H, s), 2.11-1.95 (3H, m), 1.90-1.75 (3H, m) and 1.71-1.58 (2H, m). Abbreviations [0137] Boc tert-butoxycarbonyl EtOAc ethyl acetate h hour min minutes DCM dichloromethane MeOH methanol rt room temperature DMF dimethylformamide TFA trifluoroacetic acid HOBT 1-hydroxybenzotriazole EDC 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride [0138] All publications, including but not limited to patents and patent applications, cited in this specification are herein incorporated by reference as if each individual publication were specifically and individually indicated to be incorporated by reference herein as though fully set forth. Biological Data [0139] A membrane preparation containing histamine H3 receptors may be prepared in accordance with the following procedures: (i) Generation of Histamine H3 Cell Line [0140] DNA encoding the human histamine H3 gene (Huvar, A. et al. (1999) Mol. Pharmacol. 55(6), 1101-1107) was cloned into a holding vector, pcDNA3.1 TOPO (InVitrogen) and its cDNA was isolated from this vector by restriction digestion of plasmid DNA with the enzymes BamH1 and Not-1 and ligated into the inducible expression vector pGene (InVitrogen) digested with the same enzymes. The GeneSwitch™ system (a system where in transgene expression is switched off in the absence of an inducer and switched on in the presence of an inducer) was performed as described in U.S. Pat. Nos. 5,364,791; 5,874,534; and 5,935,934. Ligated DNA was transformed into competent DH5α E. coli host bacterial cells and plated onto Luria Broth (LB) agar containing Zeocin™ (an antibiotic which allows the selection of cells expressing the sh ble gene which is present on pGene and pSwitch) at 50 μg ml −1 . Colonies containing the re-ligated plasmid were identified by restriction analysis. DNA for transfection into mammalian cells was prepared from 250 ml cultures of the host bacterium containing the pGeneH3 plasmid and isolated using a DNA preparation kit (Qiagen Midi-Prep) as per manufacturers guidelines (Qiagen). [0141] CHO K1 cells previously transfected with the pSwitch regulatory plasmid (InVitrogen) were seeded at 2×10e6 cells per T75 flask in Complete Medium, containing Hams F12 (GIBCOBRL, Life Technologies) medium supplemented with 10% v/v dialysed foetal bovine serum, L-glutamine, and hygromycin (100 μg ml −1 ), 24 hours prior to use. Plasmid DNA was transfected into the cells using Lipofectamine plus according to the manufacturers guidelines (InVitrogen). 48 hours post transfection cells were placed into complete medium supplemented with 500 μg ml −1 Zeocin™ [0142] 10-14 days post selection 10 nM Mifepristone (InVitrogen), was added to the culture medium to induce the expression of the receptor. 18 hours post induction cells were detached from the flask using ethylenediamine tetra-acetic acid (EDTA; 1:5000; InVitrogen), following several washes with phosphate buffered saline pH 7.4 and resuspended in Sorting Medium containing Minimum Essential Medium (MEM), without phenol red, and supplemented with Earles salts and 3% Foetal Clone II (Hyclone). Approximately 1×10e7 cells were examined for receptor expression by staining with a rabbit polyclonal antibody, 4a, raised against the N-terminal domain of the histamine H3 receptor, incubated on ice for 60 minutes, followed by two washes in sorting medium. Receptor bound antibody was detected by incubation of the cells for 60 minutes on ice with a goat anti rabbit antibody, conjugated with Alexa 488 fluorescence marker (Molecular Probes). Following two further washes with Sorting Medium, cells were filtered through a 50 μm Filcon™ (BD Biosciences) and then analysed on a FACS Vantage SE Flow Cytometer fitted with an Automatic Cell Deposition Unit. Control cells were non-induced cells treated in a similar manner. Positively stained cells were sorted as single cells into 96-well plates, containing Complete Medium containing 500 μg ml −1 Zeocin™ and allowed to expand before reanalysis for receptor expression via antibody and ligand binding studies. One clone, 3H3, was selected for membrane preparation. [0000] (ii) Membrane Preparation from Cultured Cells [0143] All steps of the protocol are carried out at 4° C. and with pre-cooled reagents. The cell pellet is resuspended in 10 volumes of buffer A2 containing 50 mM N-2-hydroxyethylpiperazine-N′-2-ethanesulfonic acid (HEPES) (pH 7.40) supplemented with 10e-4M leupeptin (acetyl-leucyl-leucyl-arginal; Sigma L2884), 25 μg/ml bacitracin (Sigma B0125), 1 mM ethylenediamine tetra-acetic acid (EDTA), 1 mM phenylmethylsulfonyl fluoride (PMSF) and 2×10e-6M pepstain A (Sigma). The cells are then homogenised by 2×15 second bursts in a 1 litre glass Waring blender, followed by centrifugation at 500 g for 20 minutes. The supernatant is then spun at 48,000 g for 30 minutes. The pellet is resuspended in 4 volumes of buffer A2 by vortexing for 5 seconds, followed by homogenisation in a Dounce homogeniser (10-15 strokes). At this point the preparation is aliquoted into polypropylene tubes and stored at −70° C. [0000] (iii) Generation of Histamine H1 Cell Line [0144] The human H1 receptor was cloned using known procedures described in the literature [Biochem. Biophys. Res. Commun. 1994, 201(2), 894]. Chinese hamster ovary cells stably expressing the human H1 receptor were generated according to known procedures described in the literature [Br. J. Pharmacol. 1996, 117(6), 1071]. [0145] Compounds of the invention may be tested for in vitro biological activity in accordance with the following assays: (I) Histamine H3 Binding Assay [0146] For each compound being assayed, in a white walled clear bottom 96 well plate, is added:— [0000] (a) 10 μl of test compound (or 10 μl of iodophenpropit (a known histamine H3 antagonist) at a final concentration of 10 mM) diluted to the required concentration in 10% DMSO; (b) 10 μl 125 I 4-[3-(4-iodophenylmethoxy)propyl]-1H-imidazolium (iodoproxyfan) (Amersham; 1.85 MBq/μl or 50 μCi/ml; Specific Activity ˜2000 Ci/mmol) diluted to 200 pM in assay buffer (50 mM Tris(hydroxymethyl)aminomethane buffer (TRIS) pH 7.4, 0.5 mM ethylenediamine tetra-acetic acid (EDTA)) to give 20 pM final concentration; and (c) 80 μl bead/membrane mix prepared by suspending Scintillation Proximity Assay (SPA) bead type WGA-PVT at 100 mg/ml in assay buffer followed by mixing with membrane (prepared in accordance with the methodology described above) and diluting in assay buffer to give a final volume of 800 which contains 7.5 μg protein and 0.25 mg bead per well—mixture was pre-mixed at room temperature for 60 minutes on a roller. [0147] The plate is shaken for 5 minutes and then allowed to stand at room temperature for 3-4 hours prior to reading in a Wallac Microbeta counter on a 1 minute normalised tritium count protocol. Data was analysed using a 4-parameter logistic equation. (II) Histamine H3 Functional Antagonist Assay [0148] For each compound being assayed, in a white walled clear bottom 96 well plate, is added:— [0000] (a) 10 μl of test compound (or 10 μl of guanosine 5′-triphosphate (GTP) (Sigma) as non-specific binding control) diluted to required concentration in assay buffer (20 mM N-2-Hydroxyethylpiperazine-N′-2-ethanesulfonic acid (HEPES)+100 mM NaCl+10 mM MgCl 2 , pH7.4 NaOH); (b) 60 μl bead/membrane/GDP mix prepared by suspending wheat germ agglutinin-polyvinyltoluene (WGA-PVT) scintillation proximity assay (SPA) beads at 100 mg/ml in assay buffer followed by mixing with membrane (prepared in accordance with the methodology described above) and diluting in assay buffer to give a final volume of 60 μl which contains 10 μg protein and 0.5 mg bead per well—mixture is pre-mixed at 4° C. for 30 minutes on a roller and just prior to addition to the plate, 10 μM final concentration of guanosine 5′ diphosphate (GDP) (Sigma; diluted in assay buffer) is added; The plate is incubated at room temperature to equilibrate antagonist with receptor/beads by shaking for 30 minutes followed by addition of: (c) 10 μl histamine (Tocris) at a final concentration of 0.3 μM; and (d) 20 μl guanosine 5′ [γ35-S] thiotriphosphate, triethylamine salt (Amersham; radioactivity concentration=37 kBq/μl or 1 mCi/ml; Specific Activity 1160 Ci/mmol) diluted to 1.9 nM in assay buffer to give 0.38 nM final. [0149] The plate is then incubated on a shaker at room temperature for 30 minutes followed by centrifugation for 5 minutes at 1500 rpm. The plate is read between 3 and 6 hours after completion of centrifuge run in a Wallac Microbeta counter on a 1 minute normalised tritium count protocol. Data is analysed using a 4-parameter logistic equation. Basal activity used as minimum i.e. histamine not added to well. (III) Histamine H1 Functional Antagonist Assay [0150] Compounds are assayed in a black walled clear bottom 384-well plate with cells seeded at 10000 cells/well. Tyrodes buffer is used throughout (NaCl 145 mM, KCl 2.5 mM, HEPES 10 mM, glucose 10 mM, MgCl 2 1.2 mM, CaCl 2 1.5 mM, probenecid 2.5 mM, pH adjusted to 7.40 with NaOH 1.0 M). Each well is treated with 10 μl of a solution of FLUO4AM (10 μM in Tyrodes buffer at pH 7.40) and plates are then incubated for 60 minutes at 37° C. Wells are then washed with Tyrodes buffer using a EMBLA cell washer system, leaving 400 buffer in each well, and then treated with 100 of test compound in Tyrodes buffer. Each plate is incubated for 30 min to allow equilibration of the test compound with the receptor. Each well is then treated with 100 of histamine solution in Tyrodes buffer. [0151] Functional antagonism is indicated by a suppression of histamine induced increase in fluorescence, as measured by the FLIPR system (Molecular Devices). By means of concentration effect curves, functional potencies are determined using standard pharmacological mathematical analysis. Results [0152] The compounds of Examples E1-E58 were tested in the histamine H3 functional antagonist assay and exhibited pK b values >8.0. More particularly, the compounds of Examples 1-9, 11-14, 16, 22-28, 30-42, 44, 47, 52-56 and 58 exhibited pK b values ≧9.0. Most particularly, the compounds of Examples 1, 2, 11, 12 and 58 exhibited pK b values >9.5. [0153] The compounds of Examples E1-42, 44, 46-48 and 51-55 were tested in the histamine H1 functional antagonist assay and exhibited antagonism <7.0 pK b . More particularly, the compounds of Examples E1-25, 27-42, 44, 46-48 and 51-55 exhibited antagonism <6.0 pK b .

The present invention relates to novel diazepanyl derivatives having pharmacological activity, processes for their preparation, to compositions containing them and to their use in the treatment of neurological and psychiatric disorders.

[0001] This application claims priority to U.S. Provisional Patent Application No. 61/372,507 filed on Aug. 11, 2010 and now pending, which is incorporated herein by reference in its entirety. BACKGROUND OF THE INVENTION [0002] A. Field of Invention [0003] This invention generally relates to devices systems and methods for retrieving a baby bottle. [0004] B. Description of the Related Art [0005] It is well know that infants tend to throw objects such as baby bottles, which can cause a parent or caregiver to repeatedly fetch the bottle. Thus it would be desirable to have an automatic bottle retrieval system for returning the bottle to the infant if it were to fall or be thrown by the infant. [0006] Some embodiments of the present invention may provide a system for retrieving a baby item such as a baby bottle. SUMMARY OF THE INVENTION [0007] Some embodiments of the present invention relate to an infant item retrieval system, comprising: a housing adapted to at least partially enclose a retraction means; a central anchor post disposed on an inner surface of the housing, and defining a centrally oriented slit; a spiral spring having an inner end and an outer end, the inner end being received by the centrally oriented slit in an anchored relation; a spool comprising a central hub having an inner annular surface defining a central aperture, the spool further comprising a slit disposed on the inner annular surface adapted to receive the outer end of the spiral spring in an anchored relation, wherein the spool receives the central anchor post in the central aperture with the spiral spring therebetween; a first flange dispose on a first side of the central hub; a second flange disposed on a second side of the central hub and defining a plurality of indexing notches about a circumference of the second flange; a tethering member attached to the spool at one end of the tethering member and stowable about the spool in a coiled configuration, wherein the other end of the tethering member is threaded through an aperture in the housing to an exterior of the housing, and wherein the tethering member terminates in a linking member selected from one or more of a hook, a buckle, a clip, or a clasp; and a retaining member adapted to hold a baby item in a retained relation, the retaining member being linked to the tethering member through the linking member. [0008] According to some embodiments, the housing comprises a portion of a clamping member adapted to join to a support structure in a clamping relation. [0009] According to some embodiments, the clamping member comprises one or more of a spring-loaded clamp, a C-clamp, or a screw-driven clamp. [0010] According to some embodiments, the housing comprise a portion of a support structure selected from one or more of an infant car seat, an infant high chair, an infant walker, an infant playpen, an infant stroller, an infant carrying device, or an infant cradle. [0011] Some embodiments further comprise a means for mechanically linking the system to a support structure. [0012] According to some embodiments, the means for mechanically linking comprise one or more of a hook, a clasp, a loop, a carabineer, a buckle, or a hook-and-loop fastener. [0013] According to some embodiments, the tethering member comprise one or more of a fabric web, a strap, a cord, a string, a rope, or a cable. [0014] According to some embodiments, the retaining member comprises one or more of a strap, a harness, a hook-and-loop fastener, a buckle, a clip, or a clamp. [0015] Some embodiments relate to an infant item retrieval system, comprising: a housing adapted to at least partially enclose a retraction means, wherein the housing comprises a portion of a clamping member adapted to join to a support structure in a clamping relation, wherein the clamping member comprises one or more of a spring-loaded clamp, a C-clamp, or a screw-driven clamp; a central anchor post disposed on an inner surface of the housing, and defining a centrally oriented slit; a spiral spring having an inner end and an outer end, the inner end being received by the centrally oriented slit in an anchored relation; a spool comprising a central hub having an inner annular surface defining a central aperture, the spool further comprising a slit disposed on the inner annular surface adapted to receive the outer end of the spiral spring in an anchored relation, wherein the spool receives the central anchor post in the central aperture with the spiral spring therebetween; a first flange dispose on a first side of the central hub; a second flange disposed on a second side of the central hub and defining a plurality of indexing notches about a circumference of the second flange; a tethering member attached to the spool at one end of the tethering member and stowable about the spool in a coiled configuration, wherein the other end of the tethering member is threaded through an aperture in the housing to an exterior of the housing, and wherein the tethering member terminates in a linking member selected from one or more of a hook, a buckle, a clip, or a clasp; and a retaining member adapted to hold a baby item in a retained relation, the retaining member being linked to the tethering member through the linking member. [0016] Some embodiments further comprise a means for mechanically linking the system to a support structure. [0017] According to some embodiments, the means for mechanically linking comprise one or more of a hook, a clasp, a loop, a carabineer, a buckle, or a hook-and-loop fastener. [0018] According to some embodiments, the tethering member comprise one or more of a fabric web, a strap, a cord, a string, a rope, or a cable. [0019] According to some embodiments, the retaining member comprises one or more of a strap, a harness, a hook-and-loop fastener, a buckle, a clip, or a clamp. [0020] Some embodiments relate to an infant item retrieval system, comprising: a housing adapted to at least partially enclose a retraction means, wherein the housing comprise a portion of a support structure selected from one or more of an infant car seat, an infant high chair, an infant walker, an infant playpen, an infant stroller, an infant carrying device, or an infant cradle; a central anchor post disposed on an inner surface of the housing, and defining a centrally oriented slit; a spiral spring having an inner end and an outer end, the inner end being received by the centrally oriented slit in an anchored relation; a spool comprising a central hub having an inner annular surface defining a central aperture, the spool further comprising a slit disposed on the inner annular surface adapted to receive the outer end of the spiral spring in an anchored relation, wherein the spool receives the central anchor post in the central aperture with the spiral spring therebetween; a first flange dispose on a first side of the central hub; a second flange disposed on a second side of the central hub and defining a plurality of indexing notches about a circumference of the second flange; a tethering member attached to the spool at one end of the tethering member and stowable about the spool in a coiled configuration, wherein the other end of the tethering member is threaded through an aperture in the housing to an exterior of the housing, and wherein the tethering member terminates in a linking member selected from one or more of a hook, a buckle, a clip, or a clasp; and a retaining member adapted to hold a baby item in a retained relation, the retaining member being linked to the tethering member through the linking member. [0021] Some embodiments further comprise a means for mechanically linking the system to a support structure. [0022] According to some embodiments, the means for mechanically linking comprise one or more of a hook, a clasp, a loop, a carabineer, a buckle, or a hook-and-loop fastener. [0023] According to some embodiments, the tethering member comprise one or more of a fabric web, a strap, a cord, a string, a rope, or a cable. [0024] According to some embodiments, the retaining member comprises one or more of a strap, a harness, a hook-and-loop fastener, a buckle, a clip, or a clamp. [0025] Other benefits and advantages will become apparent to those skilled in the art to which it pertains upon reading and understanding of the following detailed specification. BRIEF DESCRIPTION OF THE DRAWINGS [0026] The invention may take physical form in certain parts and arrangement of parts, embodiments of which will be described in detail in this specification and illustrated in the accompanying drawings which form a part hereof and wherein: [0027] FIG. 1 is a plan view of an embodiment including a clamp member; and [0028] FIG. 2 is an exploded view of a portion of FIG. 1 . DETAILED DESCRIPTION OF THE INVENTION [0029] According to one embodiment, an infant item retrieval system can comprise a clamping member for anchoring the system to a support structure. In such embodiments the clamping member may define a housing for a retrieval means. The retrieval system can further comprise a stowable/extendable tethering member retractably linked to the retrieval system. Still further, the system can comprise a bottle retaining member for reversibly linking an item such as, without limitation, a baby bottle or other baby-related item to the tethering member. Alternatively, some embodiments do not include a clamping member, but rather link a tethering member directly to a support structure through a built-in retraction means. According to such embodiments, the support structure may define a housing for a retrieval means. [0030] In some embodiments, a clamping member fixedly engages, in a clamping relation, a support structure such as a frame of an infant car seat or a tabletop of an infant highchair. According to such embodiments, a tethering member can terminate in a bottle retaining member which engages a baby bottle, sip cup, or other infant-related item in a retained relation. Thus, when the bottle is drawn away from the clamping member, the tethering member can extend continuously from a stowed configuration, and a means for retracting the tethering member responds with increasing retractive spring force. Accordingly, when the bottle is released, the retractive force causes the tethering member to return to the stowed configuration thereby retrieving the attached baby bottle. [0031] According to some embodiments a clamping member can comprise any of a wide variety of structures suitable for developing a clamping force. For example, suitable clamps can comprise one or more of a spring-loaded clamp, a C-clamp, or a screw-driven clamp. One of skill in the art will appreciate that embodiments can also replace a clamping means with any of a wide variety of known structures for reversibly linking an embodiment to a support structure. Such structures can include, without limitation, hooks, clasps, loops, carabineers, buckles, hook-and-loop fasteners, and the like. [0032] In some embodiments a tethering member can comprise a structure selected from one or more of a fabric web, a strap, a cord, a string, a rope, a cable, or other similar structures. A tethering member generally has a first end and a second end spaced apart from the first end. One end of a tethering means may be linked to a means for retracting the tethering members into a stowed configuration, wherein a stowed configuration can comprise, for example, a spiral and/or coil. The other end of a tethering means may be linked to, form, or comprise a means for retaining an item, such as a baby bottle. [0033] According to some embodiments a means for retracting the tethering member can comprise a spool. More specifically, a suitable spool may include a means for generating a retractive force. In some embodiments, structures that may be used to generate such a retractive force can include, without limitation a spring, a spiral spring, a torsion spring, a compression spring, or an extension spring. For example, a tethering member can be joined at one end to a hub or inner annular surface of the spool. A spool may include a central aperture defining an inner annular surface which may include a means for receiving an outer end of a spiral spring in a retained relation, while the inner end of the spiral spring may be retained by a central anchor post fixed, for instance, to a housing. According to such embodiments, when the spiral spring is compressed the tethering means is in an extended configuration. Thus, releasing the tethering means allows the spiral spring to relax thereby retracting the tethering means and coiling the tethering means into a stowed configuration on the spool. [0034] In some embodiments, a spool may include a central hub having a flange on one side and an indexed flange on an opposing side. An indexed flange can include one or more indexing notches adapted to receive, for instance, a spring-loaded mechanical stop. According to such embodiments, rotation of the spool can be stopped by engaging the mechanical stop with one of the indexing notches. [0035] According to some embodiments a retaining means can comprise a structure selected from one or more of a strap, a harness, a hook-and-loop fastener, a buckle, a clip, or a clamp. For example, in some embodiments, a retaining means can include a strap having an adjustable length which is adapted to fit tightly around an item such as, without limitation a baby bottle. [0036] In an alternative embodiment, a tethering means may be slidably affixed to a support structure such that the tethering means is retained by the support structure at one end of the tethering means. The other end of the tethering means may be attached to a baby item such as a baby bottle. Thus, the item can be retrieved manually by pulling the end of the tethering means opposing the baby item. [0037] Referring now to the drawings wherein the showings are for purposes of illustrating embodiments of the invention only and not for purposes of limiting the same, FIG. 1 is a plan view of an embodiment comprising a clamp 100 . The embodiment includes a first arm 120 terminating in a rubber pad 124 A, and a second opposing arm 122 terminating in a rubber pad 124 B. The arms 120 and 122 are joined in a pivotable relation about a spring-loaded joint 130 . The spring-loaded joint 130 generates a clamping force between rubber pads 124 A and 124 B. The clamping force can be overcome by applying an opposing force to lever arms 140 and 142 , thereby opening the clamp 100 . Furthermore, a portion 150 of clamp 100 defines a housing and is shown as transparent thus revealing an inner retraction means. The retraction means includes a central anchor post 154 upon which is a spool 153 having an indexed flange with indexing notches 152 , which are adapted to receive a mechanical stop 151 . [0038] FIG. 2 is an exploded view drawing showing the detail of portion 150 in FIG. 1 . According to the embodiment shown in FIG. 2 , the retraction means includes a two-part housing having a first part 200 A and a second part 200 B which are adapted to join, for instance, in a snap fit relation. Each of the two parts of the housing 200 A, 200 B include an aperture 280 A, 280 B through which a tethering means may be threaded. The second part 200 B of the housing includes a central anchor post 154 defining a centrally oriented slit 250 adapted to receive the inner end 230 of a spiral spring 210 in an anchoring relation. The outer end 220 of the spiral spring 210 is received in a retaining relation by a retaining slit 240 defined by an inner annular surface 242 of a central aperture 244 of the spool 153 . According to this embodiment, the inner annular surface 242 and central aperture 244 are defined by a hub 246 of the spool 153 . [0039] Further according to FIG. 2 , the spool 153 includes a flange 260 and an indexed flange 270 . The indexed flange 270 includes evenly spaced indexing notches 152 disposed about a perimeter of the indexed flange 270 . Between the flanges 260 , 270 a tethering member 290 can be wound about the spool 153 defining a stowed configuration. Furthermore, according to the embodiment shown in FIG. 2 , the tethering member 290 can be threaded through apertures 280 A and 280 B and may terminate in a linking member such as a hook, buckle, clip, clasp, or the like for connecting the tethering member to a retaining means. [0040] Embodiments having been described, hereinabove, it will be apparent to those skilled in the art that the above methods and apparatuses may incorporate changes and modifications without departing from the general scope and spirit of the invention. The present invention is intended to include all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof. [0041] Having thus described the invention, it is now claimed:

Embodiments may relate to a means for retrieving one or more infant items when thrown by an infant. According to some embodiments, a retrieval means can include a manual or spring-loaded means. Furthermore, embodiments can comprise a means for attaching the system to a support structure, or the embodiment may be built into the support structure instead. Suitable support structures may include, without limitation, one or more of an infant car seat, an infant high chair, an infant walker, an infant playpen, an infant stroller, an infant carrying device, or an infant cradle.

RELATED APPLICATIONS [0001] This application is a continuation of U.S. application Ser. No. 12/497,474, titled SUSPENSION PACKAGING SYSTEM, filed Jul. 2, 2009, which claims priority to U.S. Provisional Patent Application No. 61/077,765, titled SUSPENSION PACKAGING ASSEMBLY, filed Jul. 2, 2008, the entire contents of both of which is hereby expressly incorporated by reference. BACKGROUND OF THE INVENTIONS [0002] 1. Field of the Inventions [0003] The present inventions are directed to packaging systems, for example, suspension packaging systems that includes a plurality of foldable members. [0004] 2. Description of the Related Art [0005] Protective packaging devices are often used to protect goods from shocks and impacts during shipping or transportation. For example, when transporting articles that are relatively fragile, it is often desirable to cushion the article inside a box to protect the article from a physical impact with the inner walls of the box that might be caused by shocks imparted to the box during loading, transit, and unloading. [0006] In most cases, some additional structure is used to keep the article from moving uncontrollably within the box. Such additional structures include paper or plastic packing material, structured plastic foams, foam-filled cushions, and the like. Ideally, the article to be packaged is suspended within the box so as to be spaced from at least some of the walls of the box, thus protecting the article from other foreign objects which may impact or compromise the outer walls of the box. [0007] U.S. Pat. No. 6,675,973 discloses a number of inventions directed to suspension packaging assemblies which incorporate frame members and one or more retention members. For example, at least one of the embodiments of the U.S. Pat. No. 6,675,973 includes the use of a foldable member of a substantially rigid board, for example, a cardboard. The foldable member includes foldable portions configured to form a frame member. Additionally, a retention member formed of a resilient material is used. Some of the retention members include pockets at opposite ends thereof. SUMMARY OF THE INVENTIONS [0008] One aspect of at least one of the inventions disclosed herein includes the realization of suspension packaging assemblies can be constructed in a manner so as to provide sufficient cushioning without any plastic or plastic-like materials yet provide sufficient cushioning for delicate items and provide convenient and easy un-packing and/or re-packaging. Additionally, another aspect includes the realization that such suspension packaging assemblies can also be constructed such that additional resilient plastic materials can optionally be used with the packing structure to provide additional cushioning if desired, thereby providing two modes of use. Such packaging systems can be particularly advantageous, for example, to a rental business of electronic devices or a business providing repair services requiring shipping of delicate components back and forth between the owner and service provider [0009] In accordance with an embodiment, a packaging assembly for packaging an article and maintaining the article therein, the assembly can comprise: a container comprising a top, a bottom and a plurality of sidewalls; a first frame contained within the container, the first frame comprising a first support panel comprising a first surface configured to face an article and a second surface opposite to the first surface, and a first leg portion pivotably connected to the first support panel and located between the first support panel and the bottom, wherein the first leg portion is rotatable relative to the first support panel between a first rotational position and a second rotational position so as to allow movement of the first support panel relative to the bottom, wherein the first leg portion is configured to cause a resilient force to bias the first support panel away from the bottom when the first leg portion is located at a third rotational position between the first rotational position and the second rotational position; and a second frame comprising a second support panel, the second frame being configured to nest with the first frame within the container so as to retain an article between the first and second support panels. [0010] In the foregoing embodiment, the first frame can further comprise a first anchor panel extending between the top and bottom of the container; and a first connecting portion interconnecting the first support panel and the first anchor panel and comprising at least one fold line configured to allow movement of the first support panel relative to the bottom of the container. The first connecting portion can comprise at least two panels pivotably connected to each other along the at least one fold line. [0011] Still in the foregoing embodiment, the first connecting portion can comprise a first side panel pivotally connected to the first support panel, and a ridge panel pivotably connected to each of the first anchor panel and the first side panel, wherein the first anchor panel and the first side panel are substantially parallel to each other. The first frame further can comprise: a second anchor panel extending between the top and the bottom of the container; and a second connecting portion interconnecting the first support panel and the second anchor panel and comprising at least one fold line configured to allow movement of the first support panel relative to the bottom of the container. The first frame can further comprise a second connecting portion interconnecting the first support panel and one of the plurality of sidewalls of the container and comprising at least one fold line configured to allow movement of the first support panel relative to the bottom of the container. [0012] Yet in the foregoing embodiment, the first leg portion can comprise a distal end contacting the bottom and configured to slide with respect to the bottom when the first leg portion moves between the first and second rotational positions. The first frame can further comprise a second leg portion pivotably connected to the first support panel such that the first support panel is interposed between the first and second leg portions. [0013] Further in the foregoing embodiment, the second support panel of the second frame can comprise at least one foldable flap configured to resiliently support an article retained between the first and second frames. The second frame can be sized such that the second frame substantially fits into a space defined by the container and first frame. The assembly can further comprise a retention member which comprises a resilient body and an end portion configured to engage with the at least one folded portion such that the resilient body disposed over the second support panel, wherein the resilient body is configured to resiliently support an article retained between the first and second frames. The assembly may have no resilient retention sheet member configured to engage with one of the first and second frames. The assembly can be configured to provide substantial cushioning without a resilient retention sheet member configured to engage with one of the first and second frames. [0014] The second frame can comprise a third leg portion pivotably connected to the second support panel and located between the second support panel and the top, wherein the third leg portion is rotatable relative to the second support panel between a first rotational position and a second rotational position so as to allow movement of the second support panel relative to the top, wherein the third leg portion is configured to cause a resilient force to bias the second support panel away from the top when the third leg portion is located at a third rotational position between the first rotational position and the second rotational position. The container and the first frame can be pivotably connected to each other and are formed of a single cardboard. [0015] In another embodiment, a packaging kit for packaging an article and maintaining the article can comprise: a container forming member comprising a plurality of foldable portions configured to form a container which comprises a top, a bottom and a plurality of sidewalls; a first frame forming member comprising a plurality of foldable portions configured to form a first frame to be contained within the container, wherein the first frame comprises a first support panel comprising a first surface configured to face an article and a second surface opposite to the first surface, and a first leg portion pivotably connected to the first support panel and configured to be located between the first support panel and the bottom, wherein the first leg portion is rotatable relative to the first support panel between a first rotational position and a second rotational position so as to allow movement of the first support panel relative to the bottom, wherein the first leg portion is configured to cause a resilient force to bias the first support panel away from the bottom when the first leg portion is located at a third rotational position between the first rotational position and the second rotational position; and a second frame forming member comprising a plurality of foldable portions and configured to form a second frame which comprises a second support panel and at least one side panel connected to the second support panel, the second frame being configured to nest with the first frame within the container so as to retain an article between the first and second support panels. [0016] In the foregoing embodiment, the first frame can further comprise: a first anchor panel extending between the top and bottom of the container when the first frame is contained in the container; and a first connecting portion interconnecting the first support panel and the first anchor panel and comprising at least one fold line configured to allow movement of the first support panel relative to the bottom of the container. The first connecting portion can comprise a first side panel pivotally connected to the first support panel and a ridge panel pivotably connected to each of the first anchor panel and the first side panel, wherein the first anchor panel and the first side panel are substantially parallel to each other. [0017] Still in the foregoing embodiment, the first frame can further comprise: a second anchor panel extending between the top and the bottom of the container when the first frame is contained in the container; and a second connecting portion interconnecting the first support panel and the second anchor panel and comprising at least one fold line configured to allow movement of the first support panel relative to the bottom of the container. [0018] Still in another embodiment, a packaging kit for packaging an article and maintaining the article can comprise: a first foldable member comprising a plurality of foldable portions, the first foldable member being configured to form a container which comprises a top, a bottom and a plurality of sidewalls, and further configured to form a first frame to be contained within the container and pivotably connected to the container, wherein the first frame comprises a first support panel comprising a first surface configured to face an article and a second surface opposite to the first surface, and a first leg portion pivotably connected to the first support panel and configured to be located between the first support panel and the bottom, wherein the first leg portion is rotatable relative to the first support panel between a first rotational position and a second rotational position so as to allow movement of the first support panel relative to the bottom, wherein the first leg portion is configured to cause a resilient force to bias the first support panel away from the bottom when the first leg portion is located at a third rotational position between the first rotational position and the second rotational position; and a second foldable member comprising a plurality of foldable portions and configured to form a second frame which comprises a second support panel and at least one side panel connected to the second support panel, the second frame being configured to nest with the first frame within the container so as to retain an article between the first and second support panels. BRIEF DESCRIPTION OF THE DRAWINGS [0019] These and other features of the inventions are described below with reference to the drawings of several embodiments of the present packaging assemblies and kits which are intended to illustrate, but not to limit, the inventions. The drawings contain the following figures: [0020] FIG. 1 is an exploded, perspective view of a packaging assembly in accordance with one embodiment along with an article to be packaged; [0021] FIG. 2 is a plan view of a first foldable member configured to form a container and a first suspension support shown in FIG. 1 , illustrating an unfolded and unassembled state thereof, the first foldable member having folding lines and foldable portions; [0022] FIG. 3 is a plan view of the first foldable member of FIG. 2 in a first partially folded state; [0023] FIG. 4 is a plan view of the first foldable member of FIG. 2 in a second partially folded state; [0024] FIG. 5 is a sectional view of the first foldable member taken along line 5 - 5 of FIG. 4 ; [0025] FIG. 6 is a sectional view of the first foldable member taken along line 6 - 6 of FIG. 4 ; [0026] FIG. 7 is a plan view of the first foldable member of FIG. 2 in a third folded state; [0027] FIG. 8 is a sectional view of the first foldable member taken along line 8 - 8 of FIG. 7 ; [0028] FIG. 9 is a plan view of a second foldable member configured to form a second suspension support shown in FIG. 1 , illustrating an unfolded and unassembled state thereof; [0029] FIG. 10 is a plan view of the second suspension support of FIG. 9 in a folded state; [0030] FIG. 11 is a plan view of the packaging assembly shown in FIG. 1 , the first and second suspension supports being assembled and an article being located therebetween; [0031] FIG. 12 is a cut-away side elevation view of the packaging assembly with a lid closed, an article being packaged between the first and second suspension supports; [0032] FIG. 13 is a cut-away front elevation view of the packaging assembly with a lid closed, an article being packaged between the first and second suspension supports; [0033] FIG. 14 is a plan view of a retention member having pockets in accordance with one embodiment; [0034] FIG. 15 is a plan view of a sub-assembly of a foldable member and the retention member configured to form a second suspension support in accordance with an embodiment; [0035] FIG. 16 is a cut-away front elevation view of a packaging assembly in accordance with one embodiment, the second suspension support being formed of the sub-assembly shown in FIG. 15 ; [0036] FIG. 17 is a perspective view of a packaging assembly in accordance with one embodiment, an article being located between first and second suspension supports; [0037] FIG. 18 is a perspective view of the second suspension support shown in FIG. 17 ; [0038] FIG. 19 is a plan view of a foldable member configured to form the second suspension support shown in FIG. 17 ; [0039] FIG. 20 is a cut-away side elevation view of the packaging assembly shown in FIG. 17 with a lid closed, an article being located between the first and second suspension supports; [0040] FIG. 21 is a perspective view of a sub-assembly of a packaging assembly in accordance with one embodiment, illustrating that a first suspension support is being folded and inserted into a container; [0041] FIG. 22 is a plan view of a foldable member configured to form the container member of the sub-assembly shown in FIG. 20 ; [0042] FIG. 23 is a plan view of a foldable member configured to form the first suspension support of the sub-assembly shown in FIG. 20 , showing the unfolded state thereof; [0043] FIG. 24 is a cut-away side elevation view of the packaging assembly including the container and the suspension supports shown in FIG. 21 with a lid closed, an article being located between first and second suspension supports. DETAILED DESCRIPTION OF EMBODIMENTS [0044] An improved packaging system is disclosed herein. The packaging system includes an improved structure which provides new alternatives to known suspension packaging systems. [0045] In the following detailed description, terms of orientation such as “top,” “bottom,” “front,” “upper,” “lower,” “longitudinal,” “horizontal,” “vertical,” “lateral,” “midpoint,” and “end” may be used here to simplify the description in the context of the illustrated embodiments. Because other orientations are possible, however, the present inventions should not be limited to the illustrated orientations. Additionally, the term “suspension” is not intended to require that anything, such as an article to be packaged, is suspended above anything. Rather, the terms “suspended” as used herein, is only intended to reflect that such an article is held in a position spaced from another member, such as at least some of the walls of a container or box. Those skilled in the art will appreciate that other orientations of various components described herein are possible. [0046] With reference to FIG. 1 , a packaging assembly 100 is constructed in accordance with one embodiment. The packaging assembly 100 includes a container 102 , a first suspension support 104 and a second suspension support 106 . The container 102 has a cavity or a recess. The suspension supports 104 , 106 can nest with each other within the container 102 , and support an article 108 to be packaged in a position spaced from at least some of the walls of the container portion 102 . In FIG. 1 , the first suspension support 104 is contained within the cavity of the container 102 . The article 108 is shown to be positioned over the first suspension support 104 , and the second suspension support 106 is inserted in the container to nest with the first suspension support 104 . [0047] Referring to FIG. 2 , a first foldable packaging member 110 is illustrated therein in an unfolded state and is constructed in accordance with one embodiment. The foldable member 110 includes a plurality of foldable portions configured to form the container 102 and a first suspension support 104 . [0048] A further advantage is provided where, as illustrated in FIGS. 1 and 2 , the container portion 102 is connected to the first support portion 104 . As such, when manipulated into a folded state, the support portion 104 can be conveniently folded into the cavity of the container portion 102 . Additionally, in this embodiment, both the container portion 102 and the suspension portion 104 can be formed from a single piece of material. [0049] In one embodiment, the member 110 can be constructed from various materials, including but without limitation, paper, cardboard, corrugated cardboard, plastic, and other appropriate materials. The chosen material for constructing the member 110 can be any substantially rigid but foldable material. It will be appreciated that, although denominated as rigid or substantially rigid, the chosen material would preferably have an amount of flexibility in the cases of extreme physical impact. In some embodiments, the material used to form the member 110 is a single wall corrugated C-flute cardboard. [0050] Referring to FIGS. 1 and 2 , in one embodiment, the member 110 includes two portions foldably connected to each other and configured to form the container 102 and the first suspension support 104 , respectively. The container 102 includes a bottom panel 120 . The size of the panel 120 can be chosen by one of ordinary skilled in the art to provide the desired amount of surface area of the bottom of the container 102 formed by the member 110 . In an example but non-limiting embodiment, where the member 110 is intended to package a handheld communication device, modem or a hard drive, the panel 120 can be about 10 inches square. However, this is merely an embodiment, and the panel member 120 can have other dimensions for use in packaging modems or hard drives, or any other article that is to be packaged. [0051] Still referring to FIGS. 1 and 2 , the container 102 can also include lateral walls 122 , 124 and end walls 126 , 128 . For brevity, the construction of the lateral wall portion 122 will be described. However, it is to be understood that the lateral wall portion 124 also can include the same features. The lateral wall 122 has a double wall structure when folded. For this end, the member 110 includes an inner panel 130 and an outer panel 132 configured to form a double wall structure 122 . Additionally, the lateral wall 122 can include at least one fold line 134 defined between the outer panel 130 and the outer panel 132 . In the illustrated embodiment, the lateral wall portion 122 includes two fold lines 134 . [0052] The fold lines 134 can be formed as perforations in the member 110 , i.e., broken cut lines passing partially or completely through the material forming the member 110 . In the alternative, or in addition, the fold lines can be crushed portions of the material forming the member 110 . Of course, depending on the material used to construct the member 110 , the fold lines can be formed as mechanical hinges, thinned portions, adhesive tape, or any other appropriate mechanical connection which would allow various portions of the tray member to be folded or rotated with respect to each other. These concepts apply to all the fold lines described herein, although this description will not be repeated with respect to the other fold lines described below. For brevity, the construction of the fold lines 134 has been described above. However, it is to be understood that the other fold lines in the member 110 or other members described in the description also can include the same features. [0053] In the illustrated embodiment, when the lateral wall 122 is folded upwardly and inwardly towards the panel member 120 , the inner panel 130 forms an outer wall of the container 102 and the outer panel 132 forms an inner wall. The area between the fold lines 134 , identified generally by the reference numeral 138 , will form an upper edge of the lateral wall 122 . [0054] The lateral wall 122 can also include means for securing the walls in place when folded. For example, in the illustrated embodiment, the outer panel 132 includes a projection 140 on its outermost edge 142 . When the lateral wall 122 is completely folded, the projection 140 will rest against the panel member 120 adjacent a fold line 144 defined at the boundary between the bottom portion 120 and the lateral wall 122 . The projection 140 is merely one type of configuration that can be provided for securing the lateral wall portion 122 in place. Further, in one embodiment, the panel member 120 can include an aperture for receiving the projection 140 . [0055] Still referring to FIGS. 1 and 2 , each of the end walls 126 , 128 can include a single wall panel 150 connected to the main panel 120 along a fold line 152 . For brevity, the construction of the end wall 126 will be described. However, it is to be understood that the end wall portion 128 also can include the same features. The end wall 126 can also include corner flaps 154 , 156 , connected to the wall panel 150 along fold lines 158 , 160 . [0056] The end wall 126 is configured such that the panel 150 can be folded towards the bottom portion 120 along the fold line 152 . Additionally, the corner flaps 154 , 156 can be folded inwardly towards the panel 150 , at about a right angle, for example, such that when the panel 150 is folded into an orientation being approximately perpendicular to the bottom portion 120 , each of the corner flaps 154 , 156 lie along or adjacent to the fold lines 144 between the bottom portion 120 and one of the lateral walls 122 , 124 . With the corner flaps 154 , 156 in this orientation, each of the lateral walls 122 , 124 can be folded over the corner flaps 154 , 156 . As such, for example, each of the corner flaps 154 , 156 can be sandwiched between the inner panel 130 and the outer panel 132 . [0057] In one embodiment, the container 102 can include a lid portion 166 connected to the end wall 126 . The lid 166 can include a top panel 170 connected to the wall panel 150 along the fold line 168 . The top panel 170 can be approximately the same size as the bottom panel 120 . [0058] Additionally, the lid portion 166 can include a front panel 172 and corner flaps 174 , 176 . The front panel 172 is connected to the top panel 170 along a fold line 178 . Additionally, the corner flaps 174 , 176 are attached to the front panel 172 along fold lines 180 , 182 . Each of the corner flaps 174 , 176 are configured to be inserted into a space between the panels 130 , 132 of one of the lateral walls 122 , 124 . [0059] In one embodiment, the lid 166 can include side flaps 184 , 186 connected to the top panel 170 along fold lines 188 , 190 . For brevity, the construction of the side flap 184 will be described. However, it is to be understood that the side flap 186 also can include the same features. [0060] The side flap 184 can be folded inwardly towards the top panel 170 , at about a right angle, for example, such that when the panel 170 is folded into an orientation being approximately perpendicular to the end wall 126 , the side flap 184 lies along and adjacent the lateral wall portion 122 . In one embodiment, a width of the top panel 170 that is a distance between the fold lines 188 , 190 is sized such that the side flaps 184 , 186 are positioned inside and contact the inner walls of the lateral wall portions 122 , 124 . Additionally, the side flap 184 is sized such that a distance between the fold line 188 or 190 and a distal end of the side flap 184 or 186 is generally same with or slightly smaller than the height of the lateral wall 122 , 124 , but not limited thereto. [0061] With continued reference to FIGS. 1 and 2 , in one embodiment, the first suspension support 104 is connected to the end wall 128 along a fold line 192 . The first suspension support portion 104 can include a support panel 212 and at least one foldable leg portion pivotally connected to the first article support panel 212 . The panel 212 can include a first surface 208 and a second surface 210 opposing the first surface. (See FIGS. 5 and 13 ) The first surface 208 faces an article 108 , when the article is packaged. [0062] In some embodiments, the first suspension support portion 104 can include two foldable leg portions 214 , 216 such that the support panel 212 is interposed between the leg portions 214 , 216 . Each of the foldable leg portions 214 , 216 is pivotably connected to the support panel 212 along a fold line 218 . Each of the leg portions 214 , 216 can be folded towards the second surface 210 to form an angle with respect to the second surface 210 smaller than about 90° such that each of the leg portions 214 , 216 provides a spring effect. (See FIGS. 8 and 13 ). [0063] In one embodiment, the first suspension support 104 can include side panels 222 , 224 . Each of the side panels 222 , 224 is pivotably connected to the support panel 212 along a fold line 226 such that the base panel 212 is interposed between the side panels 222 , 224 . Each of the side panels 222 , 224 can be folded towards the first surface 208 into a generally perpendicular orientation relative to the base panel 212 . [0064] Referring to FIG. 2 , in some embodiments, the first suspension support portion 104 can include corner panels 230 , 232 , 234 , 236 . For brevity, the construction related to the corner panel 230 will be described. However, it is to be understood that the packaging assembly can include the same features for the corner panels 232 , 234 , 236 . The corner panel 230 is connected to both the leg portion 214 and the side panel 222 along fold lines 238 , 240 , respectively. In one embodiment, the side panels 222 include a hole 242 located near the corner panel 230 . As shown in FIG. 2 , a cut line 244 extends from a side edge 245 of the side panel 222 to the hole 242 . A further fold line 246 can be formed from a corner 248 of the base panel 212 to the hole 242 . [0065] The corner panel 230 can be folded along the fold line 238 towards the side panel 222 , to form a first folded state of the corner panel 230 when the leg panel 214 is folded towards the second surface 210 of the base panel 212 . In this configuration, the corner panel 230 can form an angle smaller than about 90° with respect to the side panel 222 . In one embodiment, the corner panel 230 can be further folded along the fold line 240 to form a second folded state of the corner panel 230 when the side panel 222 is folded towards the first surface of the base panel 212 . Additionally, in this folded configuration, a delta-shaped portion 250 of the side panel 222 is configured to be folded along the fold lines 246 with respect to a main portion of the side panel 222 . This configuration can allow an edge of the corner panel 230 to be spaced from the side panel 222 , and provide a spring effect. [0066] In one embodiment, the first suspension support 104 can include ridge portions 260 , 262 that are pivotally connected to the side panels 222 , 224 along fold lines 264 , 266 , respectively. The ridge portion 222 is pivotally connected to the end wall 128 of the container 102 along the fold line 192 . Additionally, the first suspension support 104 can further include a foldable anchor panel 270 that is connected to the ridge 262 along a fold line 274 . [0067] In some embodiments, the ridge portion 260 and the side panel 222 can be folded towards the end wall 128 such that the side 128 and the side panel 222 are generally parallel to each other. Similarly, the ridge portion 262 and the anchor panel 270 can be folded towards the side panel 224 such that the anchor 270 and the side panel 224 are generally parallel to each other. [0068] With reference to FIGS. 2 and 3 , when folding the container 102 so as to define a cavity, the corner panels 154 , 156 can first be folded upwardly into a generally perpendicular orientation relative to the end walls 126 , 128 . Then, the walls 126 , 128 , along with the corner panels 154 , 156 attached thereto and folded relative thereto, can be folded upwardly into a generally perpendicular orientation relative to the panel 120 . The panels 130 , 132 of the lateral wall portions 122 , 124 can then be folded so as to enclose the corner panels 154 , 156 therein. As shown in FIG. 3 , the lateral wall sections 122 , 124 , now form walls of a cavity 280 . Similarly, the end walls 126 , 128 form walls of the cavity 280 , with the bottom portion 120 forming the bottom thereof. After the formation of the cavity 280 as such, the folded structure of the first suspension support 104 can be inserted in the cavity 280 . [0069] FIG. 3 illustrates the ridge portion 262 folded with respect to the end wall 124 into an orientation being approximately perpendicular to the end wall 124 such that the support panel 212 is approximately parallel to the panel 120 of the container 102 . However, in another embodiment, the ridge portion 262 is not folded during the formation of the folded structure of the first suspension support 104 , which will be described further. [0070] Referring to FIGS. 3 to 6 , in one embodiment, the foldable leg portions 214 , 216 can be folded until leaving a clearance between the foldable portions 214 , 216 and the panel 212 with an angle α smaller than about 90°. This can provide cushioning for an article 108 when an article 108 is packaged. When folding the leg panels 214 , 216 , the corner panels 230 , 232 , 234 , 236 can be folded with respect to the side panels 222 , 224 , too. [0071] Subsequently, the side panels 222 , 224 can be folded towards the first surface of the support panel 212 to be approximately perpendicular to the support panel. When folding the side panels 222 , 224 , the corner panels 230 , 232 , 234 , 236 can be folded with respect to the leg panels 214 , 216 . Further, the portion 250 can be folded along the fold line 246 and provides a clearance between each of the corner panels 230 , 232 and the side panel 222 and between each of the corner panels 234 , 236 and the side panel 224 . [0072] Additionally, the side panel 222 can be folded with respect to the ridge portion 260 into an orientation being approximately perpendicular orientation to the ridge portion 260 . Similarly, the side panel 224 can be folded with respect to the ridge portion 262 into an orientation being approximately perpendicular orientation to the ridge portion 262 . The anchor panel 270 can be folded towards the side panel 224 with respect to the ridge portion 262 into an orientation being approximately perpendicular orientation to the ridge portion 262 . In this folded configuration, the side panel 224 is approximately parallel to the anchor panel 270 . [0073] With reference to FIGS. 6 and 7 , once the folded formation of the first suspension support 104 is completed, the ridge portion 262 can be folded with respect to the end wall 128 of the container such that the first suspension support 104 is contained in the container 102 . As shown in FIG. 8 , the legs 214 , 216 are positioned between the support panel 212 and the bottom panel 120 of the container. In one embodiment, edges of the leg portions 214 , 216 contact the bottom of the container 102 so that the legs 214 resiliently support the support panel 212 and an article 108 that will be disposed over the support panel 212 and suspended within the container. As shown in FIG. 12 , in some embodiments, at least a portion of each of the corner panels 130 , 132 can be interposed between one of the side panel 222 and the end wall 128 . Edges of the corner panels 130 , 132 contact the end wall 128 . Similarly, in some embodiments, at least a portion of each of the corner panels 134 , 136 can be interposed between one of the side panel 222 and the end wall 126 . In the illustrated embodiment, edges of the corner panels 130 , 132 contact the anchor panel 270 . [0074] Referring to FIGS. 1 , 9 and 10 , in one embodiment, the second suspension support 106 can be formed by folding a second foldable member 112 . As shown in FIG. 10 , the member 112 can include a plurality of foldable portions configured to form walls of the second suspension support 106 . In one embodiment, similarly to the member 110 , the member 112 can be constructed from various materials, including but without limitation, paper, cardboard, corrugated cardboard, plastic, and other appropriate materials. The chosen material for constructing the member 112 can be any substantially rigid but foldable material. It will be appreciated that, although denominated as rigid or substantially rigid, the chosen material would preferably have an amount of flexibility in the cases of extreme physical impact. In some embodiments, the material used to form the member 112 is a single wall corrugated C-flute cardboard. [0075] The second suspension support 106 can include a support panel 302 . In one embodiment the size of the support panel 302 can be chosen by one of ordinary skilled in the art to allow the second suspension support 106 to nest with the first suspension support 104 shown in FIG. 7 . In one embodiment, the size of the support panel 302 can be determined to allow the second suspension support 106 to fit within a space formed between the side panels 222 , 224 and further between the side flaps 184 , 186 . (See FIGS. 11-13 .) [0076] Still referring to FIGS. 1 , 9 and 10 , the second suspension support 106 can also include lateral walls 322 , 324 and end walls 326 , 328 . For brevity, the construction of the lateral wall portion 322 will be described. However, it is to be understood that the lateral wall portion 324 also can include the same features. The lateral wall 322 has a double wall structure when folded. For this end, the member 112 can include an inner panel 330 and an outer panel 332 configured to form a double wall structure 322 . Additionally, the lateral wall 322 can include at least one fold line 334 defined between the outer panel 330 and the outer panel 332 . [0077] In the illustrated embodiment, when the lateral wall 222 is folded upwardly and inwardly towards the support panel 302 , the inner panel 330 forms an outer wall of the second support 106 and the outer panel 332 forms an inner wall. The lateral wall 322 can also include means for securing the walls in place when folded. For example, in the illustrated embodiment, the outer panel 332 can include a projection 340 on its outermost edge 342 . When the lateral wall 322 is completely folded, the projection 340 will rest against the support panel 302 adjacent a fold line 344 defined at the boundary between the support panel 302 and the lateral wall 322 . Further, in the illustrated embodiment, the support member 302 can include an aperture 346 for receiving the projection 340 . [0078] Still referring to FIGS. 1 , 9 and 10 , each of the end walls 326 , 328 can include a single wall panel 350 connected to the main panel 302 along a fold line 352 . For brevity, the construction of the end wall 326 will be described. However, it is to be understood that the end wall portion 328 also can include the same features. The end wall 326 can also include corner flaps 354 , 356 , connected to the wall panel 350 along fold lines 358 , 360 . [0079] The end wall 326 is configured such that the panel 350 can be folded towards the support panel 302 along the fold line 352 . Additionally, the corner flaps 354 , 356 can be folded inwardly towards the panel 350 , at about a right angle, for example, such that when the panel 350 is folded into an orientation being approximately perpendicular to the support panel 302 , each of the corner flaps 354 , 356 lie along or adjacent to the fold lines 344 between the support panel 302 and one of the lateral walls 322 , 324 . With the corner flaps 354 , 356 in this orientation, each of the lateral walls 322 , 324 can be folded over the corner flaps 354 , 356 . As such, for example, each of the corner flaps 354 , 356 can be sandwiched between the inner panel 330 and the outer panel 332 . [0080] With reference to FIGS. 9 and 10 , in one embodiment, the support panel 302 can include at least one foldable flap 364 . In particular, the support panel 302 can include four pivotable flaps 364 in the illustrated embodiment. To construct the pivotable flaps 364 , the support panel 302 can include a rectangular hole 362 at the center portion thereof and cut lines 365 . Each of the cut lines 365 extends from a corner of the hole 362 in an approximately diagonal direction. Each of the foldable flaps 364 is formed between two neighboring cut lines 365 and is foldable along a fold line 368 . In one embodiment, each of the foldable flaps 364 can be resiliently folded and be restored to the unfolded state. This configuration of the pivotable flaps 364 provides resilient support to an article to be packaged. [0081] Now referring to FIGS. 1 and 11 - 13 , in one embodiment, when packaging an article 108 , the article 108 can be placed over the support panel 212 of the first suspension support 104 , and subsequently, the second suspension support 106 can be inserted into the container 102 and placed over the article 108 . As can be seen in FIG. 12 , the pivotable flaps 364 can be folded to provide resilient support for the article 108 . Additionally, the lid 166 can be closed to cover the suspension supports 104 , 106 and the article 108 . FIGS. 12 and 13 illustrate sectional views of the packaging assembly with the lid 166 closed. [0082] Referring to FIG. 13 , in one embodiment, when an impact may be applied to the packaging assembly 100 to urge the article 108 to move in a downward direction, the leg portions 214 , 216 can be further folded to decrease the angle α. The movement causes the generation of resilient force to support the article 108 , and provides cushioning to absorb of such impact. When the article 108 moves down along with the support panel 212 , the side panels 222 , 224 move down so that the ridge portions 260 , 262 are further folded with respect to the end wall 128 and/or the anchor panel 274 . The movement further provides cushioning to absorb of such impact. [0083] As can be seen in FIGS. 12 and 13 , in one embodiment, when an impact is applied to the packaging assembly 100 to urge the article 108 to move in an upward direction, at least one of the pivotable flaps 364 can be further folded. The movement of the flaps 364 causes the generation of resilient force to support the article 108 , and provides cushioning to absorb of such impact. [0084] In one embodiment, when an impact is applied to the packaging assembly 100 to urge the article 108 to move in a horizontal direction, at least one of the pivotable flaps 364 can be further folded. The movement of the flaps 364 causes the generation of resilient force to support the article 108 , and provides cushioning to absorb of such impact. Further, as shown in FIG. 13 , at least one of the corner panels 230 , 232 , 234 , 236 can be further folded to decrease the clearance between the at least one of the corner panels and one of the side panels 222 , 224 . The movement causes the generation of resilient force to support the article 108 , and provides cushioning to absorb of such impact. [0085] With reference to FIGS. 1 , 2 and 7 , in one embodiment, the first support panel 212 can include at least one support tab 282 . In the illustrated embodiment, each of four support tabs 282 can be formed with a cut line 284 and a fold line 286 . Each tab 282 can be folded to an upright position to provide additional support to the article 108 in a horizontal direction. [0086] In some embodiments illustrated in, for example, FIGS. 1 and 13 , the assembly can have no resilient retention sheet member formed of, for example, a pliable plastic film, and configured to engage with one of the first and second frames and formed of a pliable plastic film. The assembly can be configured to provide sufficient cushioning without such resilient retention sheet member. [0087] The amount of such cushioning can vary according to the articles maintained in the packaging assembly. In one embodiment, the sufficient cushioning of the packaging assembly that does not use such resilient retention sheet member can be accomplished by determining design parameters of the first frame and second frame. The design parameters can be, for example, size of the leg portions 214 , 216 , the angle α of the leg portions 214 , 216 , thickness and characteristics of the board material for forming the first and second frames, size of flaps 364 and the like. These design parameters for sufficient cushioning can be determined by one of ordinary skill in the art through modification of the above-noted design parameters or other design parameters and drop or impact tests. The drop or impact tests can be designed to apply impacts to the packaging assembly maintaining an article in various directions. The magnitude of the impacts can be, for example, 2-5 G (gravities) or more and is determined based on the durability of the article to be packaged in the assembly. [0088] FIGS. 14-16 illustrate another embodiment, in which a second suspension support 406 can include a foldable member 412 and optionally a resilient member. It can be understood that a packaging assembly can be maintain an article therein with sufficient cushioning without using an optional resilient member. However, as shown in FIGS. 14-16 , a resilient member can be used for providing further cushioning. The assembly 406 of the foldable member 412 and the resilient member can replace the second suspension support 106 used in the embodiments discussed in the above. It can be appreciated by one of the ordinary skilled in the art that a container 402 and a first suspension support 404 having structures same with those of the container 102 and the first suspension support 104 in the foregoing embodiments can be also used in the embodiment. [0089] Referring to FIG. 14 , the resilient member in the illustrated embodiment is identified as a retention member 470 . The retention member 470 preferably is formed of a resilient body 472 . The resilient body 472 also can include pockets 474 , 476 at opposite ends thereof. In the illustrated embodiment, the retention member 470 is formed of a single piece of resilient material, and is sized to engage with the foldable member 412 having lateral walls 422 , 424 . The configuration of the foldable member 412 is same with that of the foldable member 112 discussed above. The retention member 470 can be made of a polyethylene film. However, virtually any polymer, elastomer, or plastic film can be used to form the retention member 470 . The density of the film can be varied to provide the desired retention characteristics such as overall strength, resiliency, and vibrational response. Preferably, the density of the retention member 470 is determined such that the retention member 470 is substantially resilient when used to package a desired article. [0090] Referring to FIGS. 14 and 15 , in one embodiment, the lateral walls 422 , 424 are received in the pockets 474 , 476 in an unfolded state of the foldable member 412 . Subsequently, the foldable portions of the foldable member 412 are folded in the same manner with that of the foldable member 112 of the embodiment discussed above. When folding the foldable portions of the foldable member 412 , the retention member 470 is folded such that the body 472 is placed over an article support panel 402 . As shown in FIG. 16 , the second suspension support 406 is retained in a container and assembled with a first suspension support 404 to package an article between the first and second suspension supports 404 and 406 . When packaged, the body 472 provides additional resilient support in addition to the resilient support of foldable flaps 466 . [0091] In some embodiments, a second suspension support can include structures similar to the structures that the first suspension support 104 include as discussed above. For example, a second suspension support can include a base panel and leg panels configured to provide spring effect for resiliently supporting the base panel when folded. FIGS. 17-20 illustrate one embodiment, in which a second suspension support 506 includes a foldable member 508 having a plurality of foldable portions to form a base panel and foldable leg panels. This suspension support can replace the second suspension support 106 , 506 used in the foregoing embodiments. [0092] Referring to FIGS. 18 and 19 , the second suspension support 506 is formed from a foldable member 508 by folding foldable portions. In one embodiment, the member 508 can be constructed from various materials, including but without limitation, paper, cardboard, corrugated cardboard, plastic, and other appropriate materials. The chosen material for constructing the member 508 can be any substantially rigid but foldable material. It will be appreciated that, although denominated as rigid or substantially rigid, the chosen material would preferably have an amount of flexibility in the cases of extreme physical impact. In some embodiments, the material used to form the member 508 is a single wall corrugated C-flute cardboard. [0093] With continued reference to FIGS. 18 and 19 , in one embodiment, the second first suspension support 506 can include a support panel 512 and at least one foldable leg portion pivotally connected to the first article support panel 512 . The panel 512 includes a first surface 508 and a second surface 510 opposing the first on which an article to be packaged is disposed. In one embodiment, the first surface 508 faces an article 508 when the article is packaged. [0094] In some embodiments, the second suspension support portion 506 can include two foldable leg portions 514 , 516 such that the support base panel 512 is interposed between the leg portions 514 , 516 . Each of the foldable leg portions 514 , 516 is pivotably connected to the support panel 512 along a fold line 518 . Each of the leg portions 514 , 516 can be folded towards the second surface 510 to form an angle with respect to the second surface 510 smaller than about 90° such that each of the leg portions 514 , 516 provides a spring effect. [0095] In one embodiment, the second suspension support 506 can include side panels 522 , 524 . Each of the side panels 522 , 524 is pivotably connected to the support base panel 512 along a fold line 526 such that the base panel 512 is interposed between the side panels 522 , 524 . Each of the side panels 522 , 524 can be folded towards the first surface 508 into a generally perpendicular orientation relative to the base panel 512 . [0096] Referring to FIG. 19 , in some embodiments, the second suspension support 506 includes corner panels 530 , 532 , 534 , 536 . For brevity, the construction related to the corner panel 530 will be described. However, it is to be understood that the packaging assembly includes same features for the corner panels 532 , 534 , 536 . The corner panel 530 is connected to both the leg portion 514 and the side panel 522 along fold lines 538 , 540 , respectively. In one embodiment, the side panels 522 include a hole 542 located near the corner panel 530 . As shown in FIG. 19 , a cut line 544 extends from a side edge 545 of the side panel 522 to the hole 542 . A further fold line 546 can be formed from a corner 548 of the base panel 512 to the hole 542 . [0097] The corner panel 530 can be folded along the fold line 538 towards the side panel 522 , to form a first folded state of the corner panel 530 when the leg panel 514 is folded towards the second surface 510 of the base panel 512 . In this configuration, the corner panel 530 can form an angle smaller than about 90° with respect to the side panel 522 . In one embodiment, the corner panel 530 can be further folded along the fold line 540 to form a second folded state of the corner panel 530 when the side panel 522 is folded towards the first surface of the base panel 512 . Additionally, in this folded configuration, a delta-shaped portion 550 of the side panel 522 is configured to be folded along the fold lines 546 with respect to a main portion of the side panel 522 . This configuration can allow an edge of the corner panel 530 to be spaced from the side panel 522 , and provide a spring effect. [0098] In one embodiment, the foldable leg portions 514 , 516 can be folded until leaving a clearance between the foldable portions 514 , 516 and the panel 512 with an angle smaller than about 90°. This can provide cushioning for an article 508 when the article 508 is packaged. When folding the leg panels 514 , 516 , the corner panels 530 , 532 , 534 , 536 can be folded with respect to the side panels 522 , 524 , too. [0099] Subsequently, the side panels 522 , 524 can be folded towards the first surface of the support panel 512 to be approximately perpendicular to the support panel. When folding the side panels 522 , 524 , the corner panels 530 , 532 , 534 , 536 can be folded with respect to the leg panels 514 , 516 . Further, the portion 550 can be folded along the fold line 524 and provides a clearance between each of the corner panels 530 , 532 and the side panel 522 and between each of the corner panels 534 , 536 and the side panel 524 . [0100] As shown in FIG. 20 , in one embodiment, an article 508 is retained between the first and second suspension supports 504 , 506 . When assembled, the legs 514 , 516 can be positioned between the support panel 512 and the lid 520 of the container 502 . In some embodiments, edges of the leg portions 514 , 516 contact the top of the container 502 so that the legs 514 resiliently urge the support panel 512 to support an article that will be disposed between the support panel 511 of the first suspension support 502 and the support panel 512 of the second suspension support 502 . In some embodiments, at least a portion of each of the corner panels 530 , 532 can be interposed between one of the side panel 522 and the lateral wall 552 . Edges of the corner panels 530 , 532 contact the lateral wall 554 . Similarly, in some embodiments, at least a portion of each of the corner panels 534 , 536 can be interposed between one of the side panel 522 and the lateral wall 556 . In the illustrated embodiment, edges of the corner panels 530 , 532 contact the lateral wall 556 . [0101] Referring to FIG. 20 , in one embodiment, when an impact may be applied to the packaging assembly 500 to urge the article 508 to move in an upward direction, the leg portions 514 , 516 can be further folded to decrease the angle 13 . The movement causes the generation of resilient force to support the article 508 , and provides cushioning to absorb of such impact. In one embodiment, when an impact is applied to the packaging assembly 500 to urge the article 508 to move in a horizontal direction, at least one of the corner panels 530 , 532 , 534 , 536 can be further folded to decrease the clearance between the at least one of the corner panels and one of the lateral walls 552 , 554 . The movement causes the generation of resilient force to support the article 508 , and provides cushioning to absorb of such impact. [0102] With reference to FIGS. 21-24 , a modification of the embodiment shown in FIGS. 1-13 will be described. As shown in FIGS. 21-24 , a foldable member 610 can include foldable portions configured to form a container 102 a . A foldable member 611 includes foldable portions configured to form a first suspension support 104 a . The container 102 a receives the first suspension support 104 a to form a subassembly 601 . As shown in FIGS. 21-24 , the container 102 a is constructed substantially identical to the container 102 shown in FIGS. 1-7 and 10 - 13 except that the container 102 is foldable connected to the first suspension support 104 as shown in FIGS. 1-7 and 10 - 13 while the container 102 a is not integrated with the first suspension support 104 a as shown in FIGS. 21-22 . Thus, the reference numerals used to designate the various components of the container 102 a are identical to those used for identifying the corresponding components of the container 102 in FIGS. 1-7 and 10 - 13 , except that an “a” has been added to the reference numerals. The above description applies equally to the common elements unless otherwise indicated. Therefore, a further description of the container 102 a is not necessary for one of ordinary skilled in the art to practice the invention. [0103] As shown in FIGS. 21-24 , the first suspension support 104 a is constructed similarly to the first suspension support 104 shown in FIGS. 1-7 and 10 - 13 except as noted below. Thus, the reference numerals used to designate the various components of the first suspension support 104 a are identical to those used for identifying the corresponding components of the first suspension support 104 in FIGS. 1-7 and 10 - 13 , except that an “a” has been added to the reference numerals. The above description applies equally to the common elements unless otherwise indicated. Therefore, a further description of the common elements is not necessary for one of ordinary skilled in the art to practice the invention. However, anchor panels will further be described below. [0104] With reference to FIGS. 21 , 23 and 24 , in one embodiment, the first suspension support 104 a can further include foldable anchor panels 270 a , 272 a that are connected to the ridge panels 262 a , 260 a along a fold line 274 a , 276 a , respectively. In some embodiments, the ridge portions 262 a and the anchor panel 270 a can be folded towards the side panel 224 a such that the anchor 270 a and the side panel 224 a are generally parallel to each other. Similarly, the ridge portions 260 a and the anchor panel 272 a can be folded towards the side panel 222 a such that the anchor 272 a and the side panel 222 a are generally parallel to each other. As shown in FIG. 21 , in one embodiment, the anchor panel 272 a can be folded while the first frame 104 a is being received in the container 102 a . In some embodiments, the frame 104 a can be received in the container 102 a once the folding of the foldable portions of the support 104 a is completed. [0105] With reference to FIG. 24 , once the folded formation of the first suspension support 104 a is completed and received in the container 102 a , the anchor panel 272 a is located between the end wall 128 a and the side panel 222 a , while the anchor panel 270 a is located between the end wall 126 a and the side panel 224 a . The anchor panels 270 a , 272 a aid in anchoring the position of the first support 104 a in the container. [0106] FIG. 24 illustrates an embodiment, in which a second suspension support 106 a constructed substantially identically to the second suspension support 106 shown in FIG. 1 can be used, but not limited thereto. It can be easily understood by one of the ordinary skilled in the art that other second suspension supports shown in FIGS. 14-20 can be used. [0107] Although the present inventions have been described in terms of certain embodiments, other embodiments apparent to those of ordinary skilled in the art also are within the scope of these inventions. Thus, various changes and modifications may be made without departing from the spirit and scope of the inventions. For instance, various components may be repositioned as desired. Moreover, not all of the features, aspects and advantages are necessarily required to practice the present inventions.

A packaging assembly can include a container comprising a top, a bottom and a plurality of sidewalls, a first frame and a second frame. The first frame can include a first support panel including a first surface configured to face an article and a second surface opposite to the first surface, and a first leg portion pivotably connected to the first support panel and located between the first support panel and the bottom. The first leg portion can cause a resilient force to bias the first support panel away from the bottom when the first leg portion is located at a third rotational position between the first rotational position and the second rotational position. The second frame can include a second support panel. The second frame can nest with the first frame within the container so as to retain an article between the first and second support panels.